Release 1.0.210

Merge pull request #2818 from dtolnay/coreerror
Stabilize no-std Error trait
2026-04-22 21:48:02 +00:00 · 2024-09-06 11:17:20 -07:00 · 2024-09-06 11:16:43 -07:00 · 2024-09-06 11:12:13 -07:00 · 2024-09-06 11:05:54 -07:00 · 2024-09-06 11:05:54 -07:00
158 changed files with 13872 additions and 16301 deletions
@@ -3,22 +3,36 @@ name: CI
 on:
  push:
  pull_request:
+  workflow_dispatch:
  schedule: [cron: "40 1 * * *"]

+permissions:
+  contents: read
+
+env:
+  RUSTFLAGS: -Dwarnings
+
 jobs:
  test:
    name: Test suite
    runs-on: ubuntu-latest
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@nightly
      - run: cd test_suite && cargo test --features unstable
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: Cargo.lock
+          path: Cargo.lock

  windows:
    name: Test suite (windows)
    runs-on: windows-latest
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@nightly
      - run: cd test_suite && cargo test --features unstable -- --skip ui --exact

@@ -29,15 +43,14 @@ jobs:
      fail-fast: false
      matrix:
        rust: [stable, beta]
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@master
        with:
          toolchain: ${{matrix.rust}}
      - run: cd serde && cargo build --features rc
      - run: cd serde && cargo build --no-default-features
-      - run: cd serde_test && cargo build
-      - run: cd serde_test && cargo test --features serde/derive,serde/rc

  nightly:
    name: Rust nightly ${{matrix.os == 'windows' && '(windows)' || ''}}
@@ -46,33 +59,22 @@ jobs:
      fail-fast: false
      matrix:
        os: [ubuntu, windows]
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@nightly
      - run: cd serde && cargo build
      - run: cd serde && cargo build --no-default-features
      - run: cd serde && cargo build --no-default-features --features alloc
      - run: cd serde && cargo build --no-default-features --features rc,alloc
+      - run: cd serde && cargo build --no-default-features --features unstable
      - run: cd serde && cargo test --features derive,rc,unstable
      - run: cd test_suite/no_std && cargo build
        if: matrix.os != 'windows'
-
-  msrv:
-    name: Rust 1.13.0
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@1.13.0
-      - name: Get timestamp for cache
-        id: date
-        run: echo ::set-output name=yearmo::$(date +%Y%m)
-      - uses: actions/cache@v1
-        with:
-          path: ~/.cargo/registry/index
-          key: cargo-registry-index-${{steps.date.outputs.yearmo}}
-      - run: cd serde && cargo build --features rc
-      - run: cd serde && cargo build --no-default-features
-      - run: cd serde_test && cargo build
+      - run: cd serde_derive && cargo check --tests
+        env:
+          RUSTFLAGS: --cfg exhaustive ${{env.RUSTFLAGS}}
+        if: matrix.os != 'windows'

  build:
    name: Rust ${{matrix.rust}}
@@ -80,38 +82,26 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        rust: [1.19.0, 1.20.0, 1.21.0, 1.25.0, 1.26.0, 1.34.0]
+        rust: [1.31.0, 1.34.0]
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@master
        with:
          toolchain: ${{matrix.rust}}
-      - run: cd serde && cargo build --no-default-features
-      - run: cd serde && cargo build
-
-  more:
-    name: Rust ${{matrix.rust}}
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        rust: [1.27.0, 1.28.0]
-    steps:
-      - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{matrix.rust}}
-        # Work around failing to parse manifest because editions are unstable.
-      - run: sed -i /test_suite/d Cargo.toml
+      - run: sed -i '/"test_suite"/d' Cargo.toml
+      - run: cd serde && cargo build --features rc
      - run: cd serde && cargo build --no-default-features
      - run: cd serde && cargo build

  derive:
-    name: Rust 1.31.0
+    name: Rust 1.56.0
    runs-on: ubuntu-latest
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@1.31.0
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@1.56.0
+      - run: sed -i '/"test_suite"/d' Cargo.toml
      - run: cd serde && cargo check --no-default-features
      - run: cd serde && cargo check
      - run: cd serde_derive && cargo check
@@ -119,43 +109,73 @@ jobs:
  alloc:
    name: Rust 1.36.0
    runs-on: ubuntu-latest
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@1.36.0
+      - run: sed -i '/"test_suite"/d' Cargo.toml
      - run: cd serde && cargo build --no-default-features --features alloc

-  emscripten:
-    name: Emscripten
+  minimal:
+    name: Minimal versions
    runs-on: ubuntu-latest
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@nightly
-      - uses: actions/setup-node@v1
-        with:
-          node-version: 9
-      - name: Install cargo-web
-        run: |
-          CARGO_WEB_RELEASE=$(curl -L -s -H Accept:application/json https://github.com/koute/cargo-web/releases/latest)
-          CARGO_WEB_VERSION=$(echo "${CARGO_WEB_RELEASE}" | jq -r .tag_name)
-          CARGO_WEB_URL="https://github.com/koute/cargo-web/releases/download/${CARGO_WEB_VERSION}/cargo-web-x86_64-unknown-linux-gnu.gz"
-          mkdir -p ~/.cargo/bin
-          curl -L "${CARGO_WEB_URL}" | gzip -d > ~/.cargo/bin/cargo-web
-          chmod +x ~/.cargo/bin/cargo-web
-      - run: cd test_suite && cargo web test --target=asmjs-unknown-emscripten --nodejs
-        continue-on-error: true
-      - run: cd test_suite && cargo web test --target=wasm32-unknown-emscripten --nodejs
-        continue-on-error: true
+      - run: cargo generate-lockfile -Z minimal-versions
+      - run: cargo check --locked --workspace
+
+  doc:
+    name: Documentation
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    env:
+      RUSTDOCFLAGS: -Dwarnings
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: dtolnay/install@cargo-docs-rs
+      - run: cargo docs-rs -p serde
+      - run: cargo docs-rs -p serde_derive
+      - run: cargo docs-rs -p serde_derive_internals

  clippy:
    name: Clippy
    runs-on: ubuntu-latest
    if: github.event_name != 'pull_request'
+    timeout-minutes: 45
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@clippy
      - run: cd serde && cargo clippy --features rc,unstable -- -Dclippy::all -Dclippy::pedantic
      - run: cd serde_derive && cargo clippy -- -Dclippy::all -Dclippy::pedantic
      - run: cd serde_derive_internals && cargo clippy -- -Dclippy::all -Dclippy::pedantic
-      - run: cd serde_test && cargo clippy -- -Dclippy::all -Dclippy::pedantic
      - run: cd test_suite && cargo clippy --tests --features unstable -- -Dclippy::all -Dclippy::pedantic
      - run: cd test_suite/no_std && cargo clippy -- -Dclippy::all -Dclippy::pedantic
+
+  miri:
+    name: Miri
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@miri
+      - run: cargo miri setup
+      - run: cd serde && cargo miri test --features derive,rc,unstable
+        env:
+          MIRIFLAGS: -Zmiri-strict-provenance
+      - run: cd test_suite && cargo miri test --features unstable
+        env:
+          MIRIFLAGS: -Zmiri-strict-provenance
+
+  outdated:
+    name: Outdated
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request'
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/install@cargo-outdated
+      - run: cargo outdated --workspace --exit-code 1
@@ -3,6 +3,13 @@ members = [
    "serde",
    "serde_derive",
    "serde_derive_internals",
-    "serde_test",
    "test_suite",
 ]
+
+[patch.crates-io]
+serde = { path = "serde" }
+
+[workspace.dependencies]
+proc-macro2 = { version = "1.0.74", default-features = false }
+quote = { version = "1.0.35", default-features = false }
+syn = { version = "2.0.46", default-features = false }
@@ -174,28 +174,3 @@ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
   of your accepting any such warranty or additional liability.

 END OF TERMS AND CONDITIONS
-
-APPENDIX: How to apply the Apache License to your work.
-
-   To apply the Apache License to your work, attach the following
-   boilerplate notice, with the fields enclosed by brackets "[]"
-   replaced with your own identifying information. (Don't include
-   the brackets!)  The text should be enclosed in the appropriate
-   comment syntax for the file format. We also recommend that a
-   file or class name and description of purpose be included on the
-   same "printed page" as the copyright notice for easier
-   identification within third-party archives.
-
-Copyright [yyyy] [name of copyright owner]
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-	http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
@@ -1,13 +1,13 @@
-# Serde &emsp; [![Build Status]][actions] [![Latest Version]][crates.io] [![serde: rustc 1.13+]][Rust 1.13] [![serde_derive: rustc 1.31+]][Rust 1.31]
+# Serde &emsp; [![Build Status]][actions] [![Latest Version]][crates.io] [![serde msrv]][Rust 1.31] [![serde_derive msrv]][Rust 1.56]

-[Build Status]: https://img.shields.io/github/workflow/status/serde-rs/serde/CI/master
+[Build Status]: https://img.shields.io/github/actions/workflow/status/serde-rs/serde/ci.yml?branch=master
 [actions]: https://github.com/serde-rs/serde/actions?query=branch%3Amaster
 [Latest Version]: https://img.shields.io/crates/v/serde.svg
 [crates.io]: https://crates.io/crates/serde
-[serde: rustc 1.13+]: https://img.shields.io/badge/serde-rustc_1.13+-lightgray.svg
-[serde_derive: rustc 1.31+]: https://img.shields.io/badge/serde_derive-rustc_1.31+-lightgray.svg
-[Rust 1.13]: https://blog.rust-lang.org/2016/11/10/Rust-1.13.html
+[serde msrv]: https://img.shields.io/crates/msrv/serde.svg?label=serde%20msrv&color=lightgray
+[serde_derive msrv]: https://img.shields.io/crates/msrv/serde_derive.svg?label=serde_derive%20msrv&color=lightgray
 [Rust 1.31]: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html
+[Rust 1.56]: https://blog.rust-lang.org/2021/10/21/Rust-1.56.0.html

 **Serde is a framework for *ser*ializing and *de*serializing Rust data structures efficiently and generically.**

@@ -19,7 +19,7 @@ You may be looking for:
 - [Data formats supported by Serde](https://serde.rs/#data-formats)
 - [Setting up `#[derive(Serialize, Deserialize)]`](https://serde.rs/derive.html)
 - [Examples](https://serde.rs/examples.html)
- [API documentation](https://docs.serde.rs/serde/)
+- [API documentation](https://docs.rs/serde)
 - [Release notes](https://github.com/serde-rs/serde/releases)

 ## Serde in action
@@ -48,7 +48,7 @@ serde_json = "1.0"
 <p></p>

 ```rust
-use serde::{Serialize, Deserialize};
+use serde::{Deserialize, Serialize};

 #[derive(Serialize, Deserialize, Debug)]
 struct Point {
@@ -77,17 +77,20 @@ fn main() {

 Serde is one of the most widely used Rust libraries so any place that Rustaceans
 congregate will be able to help you out. For chat, consider trying the
-[#general] or [#beginners] channels of the unofficial community Discord, the
-[#rust-usage] channel of the official Rust Project Discord, or the
-[#general][zulip] stream in Zulip. For asynchronous, consider the [\[rust\] tag
-on StackOverflow][stackoverflow], the [/r/rust] subreddit which has a pinned
-weekly easy questions post, or the Rust [Discourse forum][discourse]. It's
-acceptable to file a support issue in this repo but they tend not to get as many
-eyes as any of the above and may get closed without a response after some time.
+[#rust-questions] or [#rust-beginners] channels of the unofficial community
+Discord (invite: <https://discord.gg/rust-lang-community>), the [#rust-usage] or
+[#beginners] channels of the official Rust Project Discord (invite:
+<https://discord.gg/rust-lang>), or the [#general][zulip] stream in Zulip. For
+asynchronous, consider the [\[rust\] tag on StackOverflow][stackoverflow], the
+[/r/rust] subreddit which has a pinned weekly easy questions post, or the Rust
+[Discourse forum][discourse]. It's acceptable to file a support issue in this
+repo but they tend not to get as many eyes as any of the above and may get
+closed without a response after some time.

-[#general]: https://discord.com/channels/273534239310479360/274215136414400513
-[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-questions]: https://discord.com/channels/273534239310479360/274215136414400513
+[#rust-beginners]: https://discord.com/channels/273534239310479360/273541522815713281
 [#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[#beginners]: https://discord.com/channels/442252698964721669/448238009733742612
 [zulip]: https://rust-lang.zulipchat.com/#narrow/stream/122651-general
 [stackoverflow]: https://stackoverflow.com/questions/tagged/rust
 [/r/rust]: https://www.reddit.com/r/rust
@@ -10,13 +10,13 @@ You may be looking for:
 - [Data formats supported by Serde](https://serde.rs/#data-formats)
 - [Setting up `#[derive(Serialize, Deserialize)]`](https://serde.rs/derive.html)
 - [Examples](https://serde.rs/examples.html)
- [API documentation](https://docs.serde.rs/serde/)
+- [API documentation](https://docs.rs/serde)
 - [Release notes](https://github.com/serde-rs/serde/releases)

 ## Serde in action

 ```rust
-use serde::{Serialize, Deserialize};
+use serde::{Deserialize, Serialize};

 #[derive(Serialize, Deserialize, Debug)]
 struct Point {
@@ -45,17 +45,20 @@ fn main() {

 Serde is one of the most widely used Rust libraries so any place that Rustaceans
 congregate will be able to help you out. For chat, consider trying the
-[#general] or [#beginners] channels of the unofficial community Discord, the
-[#rust-usage] channel of the official Rust Project Discord, or the
-[#general][zulip] stream in Zulip. For asynchronous, consider the [\[rust\] tag
-on StackOverflow][stackoverflow], the [/r/rust] subreddit which has a pinned
-weekly easy questions post, or the Rust [Discourse forum][discourse]. It's
-acceptable to file a support issue in this repo but they tend not to get as many
-eyes as any of the above and may get closed without a response after some time.
+[#rust-questions] or [#rust-beginners] channels of the unofficial community
+Discord (invite: <https://discord.gg/rust-lang-community>), the [#rust-usage]
+or [#beginners] channels of the official Rust Project Discord (invite:
+<https://discord.gg/rust-lang>), or the [#general][zulip] stream in Zulip. For
+asynchronous, consider the [\[rust\] tag on StackOverflow][stackoverflow], the
+[/r/rust] subreddit which has a pinned weekly easy questions post, or the Rust
+[Discourse forum][discourse]. It's acceptable to file a support issue in this
+repo but they tend not to get as many eyes as any of the above and may get
+closed without a response after some time.

-[#general]: https://discord.com/channels/273534239310479360/274215136414400513
-[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-questions]: https://discord.com/channels/273534239310479360/274215136414400513
+[#rust-beginners]: https://discord.com/channels/273534239310479360/273541522815713281
 [#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[#beginners]: https://discord.com/channels/442252698964721669/448238009733742612
 [zulip]: https://rust-lang.zulipchat.com/#narrow/stream/122651-general
 [stackoverflow]: https://stackoverflow.com/questions/tagged/rust
 [/r/rust]: https://www.reddit.com/r/rust
@@ -1,30 +1,43 @@
 [package]
 name = "serde"
-version = "1.0.131" # remember to update html_root_url and serde_derive dependency
+version = "1.0.210"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-rust-version = "1.15"
-license = "MIT OR Apache-2.0"
-description = "A generic serialization/deserialization framework"
-homepage = "https://serde.rs"
-repository = "https://github.com/serde-rs/serde"
-documentation = "https://docs.serde.rs/serde/"
-keywords = ["serde", "serialization", "no_std"]
-categories = ["encoding"]
-readme = "crates-io.md"
-include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 build = "build.rs"
+categories = ["encoding", "no-std", "no-std::no-alloc"]
+description = "A generic serialization/deserialization framework"
+documentation = "https://docs.rs/serde"
+edition = "2018"
+homepage = "https://serde.rs"
+keywords = ["serde", "serialization", "no_std"]
+license = "MIT OR Apache-2.0"
+readme = "crates-io.md"
+repository = "https://github.com/serde-rs/serde"
+rust-version = "1.31"

 [dependencies]
-serde_derive = { version = "=1.0.131", optional = true, path = "../serde_derive" }
+serde_derive = { version = "1", optional = true, path = "../serde_derive" }

 [dev-dependencies]
-serde_derive = { version = "1.0", path = "../serde_derive" }
+serde_derive = { version = "1", path = "../serde_derive" }
+
+[lib]
+doc-scrape-examples = false

 [package.metadata.playground]
 features = ["derive", "rc"]

 [package.metadata.docs.rs]
+features = ["derive", "rc", "unstable"]
 targets = ["x86_64-unknown-linux-gnu"]
+rustdoc-args = ["--generate-link-to-definition"]
+
+# This cfg cannot be enabled, but it still forces Cargo to keep serde_derive's
+# version in lockstep with serde's, even if someone depends on the two crates
+# separately with serde's "derive" feature disabled. Every serde_derive release
+# is compatible with exactly one serde release because the generated code
+# involves nonpublic APIs which are not bound by semver.
+[target.'cfg(any())'.dependencies]
+serde_derive = { version = "=1.0.210", path = "../serde_derive" }


 ### FEATURES #################################################################
@@ -6,106 +6,105 @@ use std::str::{self, FromStr};
 // opening a GitHub issue if your build environment requires some way to enable
 // these cfgs other than by executing our build script.
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
    let minor = match rustc_minor_version() {
        Some(minor) => minor,
        None => return,
    };

+    if minor >= 77 {
+        println!("cargo:rustc-check-cfg=cfg(no_core_cstr)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_error)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_net)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_num_saturating)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_try_from)");
+        println!("cargo:rustc-check-cfg=cfg(no_diagnostic_namespace)");
+        println!("cargo:rustc-check-cfg=cfg(no_float_copysign)");
+        println!("cargo:rustc-check-cfg=cfg(no_num_nonzero_signed)");
+        println!("cargo:rustc-check-cfg=cfg(no_relaxed_trait_bounds)");
+        println!("cargo:rustc-check-cfg=cfg(no_serde_derive)");
+        println!("cargo:rustc-check-cfg=cfg(no_std_atomic)");
+        println!("cargo:rustc-check-cfg=cfg(no_std_atomic64)");
+        println!("cargo:rustc-check-cfg=cfg(no_systemtime_checked_add)");
+        println!("cargo:rustc-check-cfg=cfg(no_target_has_atomic)");
+    }
+
    let target = env::var("TARGET").unwrap();
    let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";

-    // std::collections::Bound was stabilized in Rust 1.17
-    // but it was moved to core::ops later in Rust 1.26:
-    // https://doc.rust-lang.org/core/ops/enum.Bound.html
-    if minor >= 26 {
-        println!("cargo:rustc-cfg=ops_bound");
-    } else if minor >= 17 && cfg!(feature = "std") {
-        println!("cargo:rustc-cfg=collections_bound");
-    }
-
-    // core::cmp::Reverse stabilized in Rust 1.19:
-    // https://doc.rust-lang.org/stable/core/cmp/struct.Reverse.html
-    if minor >= 19 {
-        println!("cargo:rustc-cfg=core_reverse");
-    }
-
-    // CString::into_boxed_c_str and PathBuf::into_boxed_path stabilized in Rust 1.20:
-    // https://doc.rust-lang.org/std/ffi/struct.CString.html#method.into_boxed_c_str
-    // https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.into_boxed_path
-    if minor >= 20 {
-        println!("cargo:rustc-cfg=de_boxed_c_str");
-        println!("cargo:rustc-cfg=de_boxed_path");
-    }
-
-    // From<Box<T>> for Rc<T> / Arc<T> stabilized in Rust 1.21:
-    // https://doc.rust-lang.org/std/rc/struct.Rc.html#impl-From<Box<T>>
-    // https://doc.rust-lang.org/std/sync/struct.Arc.html#impl-From<Box<T>>
-    if minor >= 21 {
-        println!("cargo:rustc-cfg=de_rc_dst");
-    }
-
-    // Duration available in core since Rust 1.25:
-    // https://blog.rust-lang.org/2018/03/29/Rust-1.25.html#library-stabilizations
-    if minor >= 25 {
-        println!("cargo:rustc-cfg=core_duration");
-    }
-
-    // 128-bit integers stabilized in Rust 1.26:
-    // https://blog.rust-lang.org/2018/05/10/Rust-1.26.html
-    //
-    // Disabled on Emscripten targets before Rust 1.40 since
-    // Emscripten did not support 128-bit integers until Rust 1.40
-    // (https://github.com/rust-lang/rust/pull/65251)
-    if minor >= 26 && (!emscripten || minor >= 40) {
-        println!("cargo:rustc-cfg=integer128");
-    }
-
-    // Inclusive ranges methods stabilized in Rust 1.27:
-    // https://github.com/rust-lang/rust/pull/50758
-    // Also Iterator::try_for_each:
-    // https://blog.rust-lang.org/2018/06/21/Rust-1.27.html#library-stabilizations
-    if minor >= 27 {
-        println!("cargo:rustc-cfg=range_inclusive");
-        println!("cargo:rustc-cfg=iterator_try_fold");
-    }
-
-    // Non-zero integers stabilized in Rust 1.28:
-    // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
-    if minor >= 28 {
-        println!("cargo:rustc-cfg=num_nonzero");
-    }
-
-    // Current minimum supported version of serde_derive crate is Rust 1.31.
-    if minor >= 31 {
-        println!("cargo:rustc-cfg=serde_derive");
-    }
-
    // TryFrom, Atomic types, non-zero signed integers, and SystemTime::checked_add
    // stabilized in Rust 1.34:
    // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#tryfrom-and-tryinto
    // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#library-stabilizations
-    if minor >= 34 {
-        println!("cargo:rustc-cfg=core_try_from");
-        println!("cargo:rustc-cfg=num_nonzero_signed");
-        println!("cargo:rustc-cfg=systemtime_checked_add");
+    if minor < 34 {
+        println!("cargo:rustc-cfg=no_core_try_from");
+        println!("cargo:rustc-cfg=no_num_nonzero_signed");
+        println!("cargo:rustc-cfg=no_systemtime_checked_add");
+        println!("cargo:rustc-cfg=no_relaxed_trait_bounds");
+    }

-        // Whitelist of archs that support std::sync::atomic module. Ideally we
-        // would use #[cfg(target_has_atomic = "...")] but it is not stable yet.
-        // Instead this is based on rustc's src/librustc_target/spec/*.rs.
+    // f32::copysign and f64::copysign stabilized in Rust 1.35.
+    // https://blog.rust-lang.org/2019/05/23/Rust-1.35.0.html#copy-the-sign-of-a-floating-point-number-onto-another
+    if minor < 35 {
+        println!("cargo:rustc-cfg=no_float_copysign");
+    }
+
+    // Current minimum supported version of serde_derive crate is Rust 1.56.
+    if minor < 56 {
+        println!("cargo:rustc-cfg=no_serde_derive");
+    }
+
+    // Support for #[cfg(target_has_atomic = "...")] stabilized in Rust 1.60.
+    if minor < 60 {
+        println!("cargo:rustc-cfg=no_target_has_atomic");
+        // Allowlist of archs that support std::sync::atomic module. This is
+        // based on rustc's compiler/rustc_target/src/spec/*.rs.
        let has_atomic64 = target.starts_with("x86_64")
            || target.starts_with("i686")
            || target.starts_with("aarch64")
            || target.starts_with("powerpc64")
            || target.starts_with("sparc64")
-            || target.starts_with("mips64el");
+            || target.starts_with("mips64el")
+            || target.starts_with("riscv64");
        let has_atomic32 = has_atomic64 || emscripten;
-        if has_atomic64 {
-            println!("cargo:rustc-cfg=std_atomic64");
+        if minor < 34 || !has_atomic64 {
+            println!("cargo:rustc-cfg=no_std_atomic64");
        }
-        if has_atomic32 {
-            println!("cargo:rustc-cfg=std_atomic");
+        if minor < 34 || !has_atomic32 {
+            println!("cargo:rustc-cfg=no_std_atomic");
        }
    }
+
+    // Support for core::ffi::CStr and alloc::ffi::CString stabilized in Rust 1.64.
+    // https://blog.rust-lang.org/2022/09/22/Rust-1.64.0.html#c-compatible-ffi-types-in-core-and-alloc
+    if minor < 64 {
+        println!("cargo:rustc-cfg=no_core_cstr");
+    }
+
+    // Support for core::num::Saturating and std::num::Saturating stabilized in Rust 1.74
+    // https://blog.rust-lang.org/2023/11/16/Rust-1.74.0.html#stabilized-apis
+    if minor < 74 {
+        println!("cargo:rustc-cfg=no_core_num_saturating");
+    }
+
+    // Support for core::net stabilized in Rust 1.77.
+    // https://blog.rust-lang.org/2024/03/21/Rust-1.77.0.html
+    if minor < 77 {
+        println!("cargo:rustc-cfg=no_core_net");
+    }
+
+    // Support for the `#[diagnostic]` tool attribute namespace
+    // https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#diagnostic-attributes
+    if minor < 78 {
+        println!("cargo:rustc-cfg=no_diagnostic_namespace");
+    }
+
+    // The Error trait became available in core in 1.81.
+    // https://blog.rust-lang.org/2024/09/05/Rust-1.81.0.html#coreerrorerror
+    if minor < 81 {
+        println!("cargo:rustc-cfg=no_core_error");
+    }
 }

 fn rustc_minor_version() -> Option<u32> {
@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;

-use de::{
+use crate::de::{
    Deserialize, Deserializer, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor,
 };

@@ -10,13 +10,12 @@ use de::{
 /// any type, except that it does not store any information about the data that
 /// gets deserialized.
 ///
-/// ```edition2018
-/// use std::fmt;
-/// use std::marker::PhantomData;
-///
+/// ```edition2021
 /// use serde::de::{
 ///     self, Deserialize, DeserializeSeed, Deserializer, IgnoredAny, SeqAccess, Visitor,
 /// };
+/// use std::fmt;
+/// use std::marker::PhantomData;
 ///
 /// /// A seed that can be used to deserialize only the `n`th element of a sequence
 /// /// while efficiently discarding elements of any type before or after index `n`.
@@ -108,7 +107,7 @@ use de::{
 /// #     Ok(())
 /// # }
 /// ```
-#[derive(Copy, Clone, Debug, Default)]
+#[derive(Copy, Clone, Debug, Default, PartialEq)]
 pub struct IgnoredAny;

 impl<'de> Visitor<'de> for IgnoredAny {
@@ -130,12 +129,10 @@ impl<'de> Visitor<'de> for IgnoredAny {
        Ok(IgnoredAny)
    }

-    serde_if_integer128! {
-        #[inline]
-        fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
-            let _ = x;
-            Ok(IgnoredAny)
-        }
+    #[inline]
+    fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
    }

    #[inline]
@@ -144,12 +141,10 @@ impl<'de> Visitor<'de> for IgnoredAny {
        Ok(IgnoredAny)
    }

-    serde_if_integer128! {
-        #[inline]
-        fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
-            let _ = x;
-            Ok(IgnoredAny)
-        }
+    #[inline]
+    fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
    }

    #[inline]
@@ -198,7 +193,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
    where
        A: SeqAccess<'de>,
    {
-        while let Some(IgnoredAny) = try!(seq.next_element()) {
+        while let Some(IgnoredAny) = tri!(seq.next_element()) {
            // Gobble
        }
        Ok(IgnoredAny)
@@ -209,7 +204,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
    where
        A: MapAccess<'de>,
    {
-        while let Some((IgnoredAny, IgnoredAny)) = try!(map.next_entry()) {
+        while let Some((IgnoredAny, IgnoredAny)) = tri!(map.next_entry()) {
            // Gobble
        }
        Ok(IgnoredAny)
@@ -228,7 +223,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
    where
        A: EnumAccess<'de>,
    {
-        data.variant::<IgnoredAny>()?.1.newtype_variant()
+        tri!(data.variant::<IgnoredAny>()).1.newtype_variant()
    }
 }

@@ -30,7 +30,7 @@
 //! # The Deserializer trait
 //!
 //! [`Deserializer`] implementations are provided by third-party crates, for
-//! example [`serde_json`], [`serde_yaml`] and [`bincode`].
+//! example [`serde_json`], [`serde_yaml`] and [`postcard`].
 //!
 //! A partial list of well-maintained formats is given on the [Serde
 //! website][data formats].
@@ -64,8 +64,8 @@
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
-//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
-//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Rc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -104,7 +104,7 @@
 //! [`Deserialize`]: ../trait.Deserialize.html
 //! [`Deserializer`]: ../trait.Deserializer.html
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
-//! [`bincode`]: https://github.com/servo/bincode
+//! [`postcard`]: https://github.com/jamesmunns/postcard
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 //! [`serde_derive`]: https://crates.io/crates/serde_derive
 //! [`serde_json`]: https://github.com/serde-rs/json
@@ -112,7 +112,7 @@
 //! [derive section of the manual]: https://serde.rs/derive.html
 //! [data formats]: https://serde.rs/#data-formats

-use lib::*;
+use crate::lib::*;

 ////////////////////////////////////////////////////////////////////////////////

@@ -120,16 +120,19 @@ pub mod value;

 mod ignored_any;
 mod impls;
-mod utf8;
+pub(crate) mod size_hint;

 pub use self::ignored_any::IgnoredAny;

+#[cfg(all(not(feature = "std"), no_core_error))]
+#[doc(no_inline)]
+pub use crate::std_error::Error as StdError;
+#[cfg(not(any(feature = "std", no_core_error)))]
+#[doc(no_inline)]
+pub use core::error::Error as StdError;
 #[cfg(feature = "std")]
 #[doc(no_inline)]
 pub use std::error::Error as StdError;
-#[cfg(not(feature = "std"))]
-#[doc(no_inline)]
-pub use std_error::Error as StdError;

 ////////////////////////////////////////////////////////////////////////////////

@@ -160,7 +163,7 @@ macro_rules! declare_error_trait {
            ///
            /// The message should not be capitalized and should not end with a period.
            ///
-            /// ```edition2018
+            /// ```edition2021
            /// # use std::str::FromStr;
            /// #
            /// # struct IpAddr;
@@ -305,7 +308,7 @@ declare_error_trait!(Error: Sized + Debug + Display);
 /// This is used as an argument to the `invalid_type`, `invalid_value`, and
 /// `invalid_length` methods of the `Error` trait to build error messages.
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use std::fmt;
 /// #
 /// # use serde::de::{self, Unexpected, Visitor};
@@ -398,20 +401,20 @@ impl<'a> fmt::Display for Unexpected<'a> {
            Bool(b) => write!(formatter, "boolean `{}`", b),
            Unsigned(i) => write!(formatter, "integer `{}`", i),
            Signed(i) => write!(formatter, "integer `{}`", i),
-            Float(f) => write!(formatter, "floating point `{}`", f),
+            Float(f) => write!(formatter, "floating point `{}`", WithDecimalPoint(f)),
            Char(c) => write!(formatter, "character `{}`", c),
            Str(s) => write!(formatter, "string {:?}", s),
-            Bytes(_) => write!(formatter, "byte array"),
-            Unit => write!(formatter, "unit value"),
-            Option => write!(formatter, "Option value"),
-            NewtypeStruct => write!(formatter, "newtype struct"),
-            Seq => write!(formatter, "sequence"),
-            Map => write!(formatter, "map"),
-            Enum => write!(formatter, "enum"),
-            UnitVariant => write!(formatter, "unit variant"),
-            NewtypeVariant => write!(formatter, "newtype variant"),
-            TupleVariant => write!(formatter, "tuple variant"),
-            StructVariant => write!(formatter, "struct variant"),
+            Bytes(_) => formatter.write_str("byte array"),
+            Unit => formatter.write_str("unit value"),
+            Option => formatter.write_str("Option value"),
+            NewtypeStruct => formatter.write_str("newtype struct"),
+            Seq => formatter.write_str("sequence"),
+            Map => formatter.write_str("map"),
+            Enum => formatter.write_str("enum"),
+            UnitVariant => formatter.write_str("unit variant"),
+            NewtypeVariant => formatter.write_str("newtype variant"),
+            TupleVariant => formatter.write_str("tuple variant"),
+            StructVariant => formatter.write_str("struct variant"),
            Other(other) => formatter.write_str(other),
        }
    }
@@ -430,10 +433,9 @@ impl<'a> fmt::Display for Unexpected<'a> {
 /// Within the context of a `Visitor` implementation, the `Visitor` itself
 /// (`&self`) is an implementation of this trait.
 ///
-/// ```edition2018
-/// # use std::fmt;
-/// #
+/// ```edition2021
 /// # use serde::de::{self, Unexpected, Visitor};
+/// # use std::fmt;
 /// #
 /// # struct Example;
 /// #
@@ -455,7 +457,7 @@ impl<'a> fmt::Display for Unexpected<'a> {
 ///
 /// Outside of a `Visitor`, `&"..."` can be used.
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::de::{self, Unexpected};
 /// #
 /// # fn example<E>() -> Result<(), E>
@@ -463,7 +465,10 @@ impl<'a> fmt::Display for Unexpected<'a> {
 /// #     E: de::Error,
 /// # {
 /// #     let v = true;
-/// return Err(de::Error::invalid_type(Unexpected::Bool(v), &"a negative integer"));
+/// return Err(de::Error::invalid_type(
+///     Unexpected::Bool(v),
+///     &"a negative integer",
+/// ));
 /// # }
 /// ```
 pub trait Expected {
@@ -499,8 +504,8 @@ impl<'a> Display for Expected + 'a {
 /// by Serde.
 ///
 /// Serde provides `Deserialize` implementations for many Rust primitive and
-/// standard library types. The complete list is [here][de]. All of these can
-/// be deserialized using Serde out of the box.
+/// standard library types. The complete list is [here][crate::de]. All of these
+/// can be deserialized using Serde out of the box.
 ///
 /// Additionally, Serde provides a procedural macro called `serde_derive` to
 /// automatically generate `Deserialize` implementations for structs and enums
@@ -516,7 +521,6 @@ impl<'a> Display for Expected + 'a {
 /// `LinkedHashMap<K, V>` type that is deserializable by Serde because the crate
 /// provides an implementation of `Deserialize` for it.
 ///
-/// [de]: https://docs.serde.rs/serde/de/index.html
 /// [derive]: https://serde.rs/derive.html
 /// [impl-deserialize]: https://serde.rs/impl-deserialize.html
 ///
@@ -527,6 +531,13 @@ impl<'a> Display for Expected + 'a {
 /// deserializer lifetimes] for a more detailed explanation of these lifetimes.
 ///
 /// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        note = "for local types consider adding `#[derive(serde::Deserialize)]` to your `{Self}` type",
+        note = "for types from other crates check whether the crate offers a `serde` feature flag",
+    )
+)]
 pub trait Deserialize<'de>: Sized {
    /// Deserialize this value from the given Serde deserializer.
    ///
@@ -563,7 +574,7 @@ pub trait Deserialize<'de>: Sized {
        D: Deserializer<'de>,
    {
        // Default implementation just delegates to `deserialize` impl.
-        *place = Deserialize::deserialize(deserializer)?;
+        *place = tri!(Deserialize::deserialize(deserializer));
        Ok(())
    }
 }
@@ -576,7 +587,7 @@ pub trait Deserialize<'de>: Sized {
 /// from the input string, but a `from_reader` function may only deserialize
 /// owned data.
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::de::{Deserialize, DeserializeOwned};
 /// # use std::io::{Read, Result};
 /// #
@@ -615,7 +626,7 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 ///
 /// The canonical API for stateless deserialization looks like this:
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::Deserialize;
 /// #
 /// # enum Error {}
@@ -629,7 +640,7 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 /// Adjusting an API like this to support stateful deserialization is a matter
 /// of accepting a seed as input:
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::de::DeserializeSeed;
 /// #
 /// # enum Error {}
@@ -662,12 +673,11 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 /// into it. This requires stateful deserialization using the `DeserializeSeed`
 /// trait.
 ///
-/// ```edition2018
+/// ```edition2021
+/// use serde::de::{Deserialize, DeserializeSeed, Deserializer, SeqAccess, Visitor};
 /// use std::fmt;
 /// use std::marker::PhantomData;
 ///
-/// use serde::de::{Deserialize, DeserializeSeed, Deserializer, SeqAccess, Visitor};
-///
 /// // A DeserializeSeed implementation that uses stateful deserialization to
 /// // append array elements onto the end of an existing vector. The preexisting
 /// // state ("seed") in this case is the Vec<T>. The `deserialize` method of
@@ -706,6 +716,11 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 ///             where
 ///                 A: SeqAccess<'de>,
 ///             {
+///                 // Decrease the number of reallocations if there are many elements
+///                 if let Some(size_hint) = seq.size_hint() {
+///                     self.0.reserve(size_hint);
+///                 }
+///
 ///                 // Visit each element in the inner array and push it onto
 ///                 // the existing vector.
 ///                 while let Some(elem) = seq.next_element()? {
@@ -855,10 +870,10 @@ where
 /// The `Deserializer` trait supports two entry point styles which enables
 /// different kinds of deserialization.
 ///
-/// 1. The `deserialize` method. Self-describing data formats like JSON are able
-///    to look at the serialized data and tell what it represents. For example
-///    the JSON deserializer may see an opening curly brace (`{`) and know that
-///    it is seeing a map. If the data format supports
+/// 1. The `deserialize_any` method. Self-describing data formats like JSON are
+///    able to look at the serialized data and tell what it represents. For
+///    example the JSON deserializer may see an opening curly brace (`{`) and
+///    know that it is seeing a map. If the data format supports
 ///    `Deserializer::deserialize_any`, it will drive the Visitor using whatever
 ///    type it sees in the input. JSON uses this approach when deserializing
 ///    `serde_json::Value` which is an enum that can represent any JSON
@@ -867,7 +882,7 @@ where
 ///    `Deserializer::deserialize_any`.
 ///
 /// 2. The various `deserialize_*` methods. Non-self-describing formats like
-///    Bincode need to be told what is in the input in order to deserialize it.
+///    Postcard need to be told what is in the input in order to deserialize it.
 ///    The `deserialize_*` methods are hints to the deserializer for how to
 ///    interpret the next piece of input. Non-self-describing formats are not
 ///    able to deserialize something like `serde_json::Value` which relies on
@@ -877,7 +892,7 @@ where
 /// `Deserializer::deserialize_any` unless you need to be told by the
 /// Deserializer what type is in the input. Know that relying on
 /// `Deserializer::deserialize_any` means your data type will be able to
-/// deserialize from self-describing formats only, ruling out Bincode and many
+/// deserialize from self-describing formats only, ruling out Postcard and many
 /// others.
 ///
 /// [Serde data model]: https://serde.rs/data-model.html
@@ -908,7 +923,7 @@ pub trait Deserializer<'de>: Sized {
    /// `Deserializer::deserialize_any` unless you need to be told by the
    /// Deserializer what type is in the input. Know that relying on
    /// `Deserializer::deserialize_any` means your data type will be able to
-    /// deserialize from self-describing formats only, ruling out Bincode and
+    /// deserialize from self-describing formats only, ruling out Postcard and
    /// many others.
    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
@@ -939,18 +954,15 @@ pub trait Deserializer<'de>: Sized {
    where
        V: Visitor<'de>;

-    serde_if_integer128! {
-        /// Hint that the `Deserialize` type is expecting an `i128` value.
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default behavior unconditionally returns an error.
-        fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-        where
-            V: Visitor<'de>
-        {
-            let _ = visitor;
-            Err(Error::custom("i128 is not supported"))
-        }
+    /// Hint that the `Deserialize` type is expecting an `i128` value.
+    ///
+    /// The default behavior unconditionally returns an error.
+    fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        let _ = visitor;
+        Err(Error::custom("i128 is not supported"))
    }

    /// Hint that the `Deserialize` type is expecting a `u8` value.
@@ -973,18 +985,15 @@ pub trait Deserializer<'de>: Sized {
    where
        V: Visitor<'de>;

-    serde_if_integer128! {
-        /// Hint that the `Deserialize` type is expecting an `u128` value.
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default behavior unconditionally returns an error.
-        fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-        where
-            V: Visitor<'de>
-        {
-            let _ = visitor;
-            Err(Error::custom("u128 is not supported"))
-        }
+    /// Hint that the `Deserialize` type is expecting an `u128` value.
+    ///
+    /// The default behavior unconditionally returns an error.
+    fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        let _ = visitor;
+        Err(Error::custom("u128 is not supported"))
    }

    /// Hint that the `Deserialize` type is expecting a `f32` value.
@@ -1149,10 +1158,10 @@ pub trait Deserializer<'de>: Sized {
    /// Some types have a human-readable form that may be somewhat expensive to
    /// construct, as well as a binary form that is compact and efficient.
    /// Generally text-based formats like JSON and YAML will prefer to use the
-    /// human-readable one and binary formats like Bincode will prefer the
+    /// human-readable one and binary formats like Postcard will prefer the
    /// compact one.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use std::ops::Add;
    /// # use std::str::FromStr;
    /// #
@@ -1213,6 +1222,20 @@ pub trait Deserializer<'de>: Sized {
    fn is_human_readable(&self) -> bool {
        true
    }
+
+    // Not public API.
+    #[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+    #[doc(hidden)]
+    fn __deserialize_content<V>(
+        self,
+        _: crate::actually_private::T,
+        visitor: V,
+    ) -> Result<crate::__private::de::Content<'de>, Self::Error>
+    where
+        V: Visitor<'de, Value = crate::__private::de::Content<'de>>,
+    {
+        self.deserialize_any(visitor)
+    }
 }

 ////////////////////////////////////////////////////////////////////////////////
@@ -1229,10 +1252,9 @@ pub trait Deserializer<'de>: Sized {
 ///
 /// # Example
 ///
-/// ```edition2018
-/// # use std::fmt;
-/// #
+/// ```edition2021
 /// # use serde::de::{self, Unexpected, Visitor};
+/// # use std::fmt;
 /// #
 /// /// A visitor that deserializes a long string - a string containing at least
 /// /// some minimum number of bytes.
@@ -1270,7 +1292,7 @@ pub trait Visitor<'de>: Sized {
    /// "an integer between 0 and 64". The message should not be capitalized and
    /// should not end with a period.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use std::fmt;
    /// #
    /// # struct S {
@@ -1343,18 +1365,20 @@ pub trait Visitor<'de>: Sized {
        Err(Error::invalid_type(Unexpected::Signed(v), &self))
    }

-    serde_if_integer128! {
-        /// The input contains a `i128`.
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default implementation fails with a type error.
-        fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
-        where
-            E: Error,
-        {
-            let _ = v;
-            Err(Error::invalid_type(Unexpected::Other("i128"), &self))
-        }
+    /// The input contains a `i128`.
+    ///
+    /// The default implementation fails with a type error.
+    fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        let mut buf = [0u8; 58];
+        let mut writer = crate::format::Buf::new(&mut buf);
+        fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as i128", v)).unwrap();
+        Err(Error::invalid_type(
+            Unexpected::Other(writer.as_str()),
+            &self,
+        ))
    }

    /// The input contains a `u8`.
@@ -1403,18 +1427,20 @@ pub trait Visitor<'de>: Sized {
        Err(Error::invalid_type(Unexpected::Unsigned(v), &self))
    }

-    serde_if_integer128! {
-        /// The input contains a `u128`.
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default implementation fails with a type error.
-        fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
-        where
-            E: Error,
-        {
-            let _ = v;
-            Err(Error::invalid_type(Unexpected::Other("u128"), &self))
-        }
+    /// The input contains a `u128`.
+    ///
+    /// The default implementation fails with a type error.
+    fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        let mut buf = [0u8; 57];
+        let mut writer = crate::format::Buf::new(&mut buf);
+        fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as u128", v)).unwrap();
+        Err(Error::invalid_type(
+            Unexpected::Other(writer.as_str()),
+            &self,
+        ))
    }

    /// The input contains an `f32`.
@@ -1450,7 +1476,7 @@ pub trait Visitor<'de>: Sized {
    where
        E: Error,
    {
-        self.visit_str(utf8::encode(v).as_str())
+        self.visit_str(v.encode_utf8(&mut [0u8; 4]))
    }

    /// The input contains a string. The lifetime of the string is ephemeral and
@@ -1505,6 +1531,7 @@ pub trait Visitor<'de>: Sized {
    /// `String`.
    #[inline]
    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
    where
        E: Error,
@@ -1527,7 +1554,6 @@ pub trait Visitor<'de>: Sized {
    where
        E: Error,
    {
-        let _ = v;
        Err(Error::invalid_type(Unexpected::Bytes(v), &self))
    }

@@ -1535,7 +1561,7 @@ pub trait Visitor<'de>: Sized {
    /// `Deserializer`.
    ///
    /// This enables zero-copy deserialization of bytes in some formats. For
-    /// example Bincode data containing bytes can be deserialized with zero
+    /// example Postcard data containing bytes can be deserialized with zero
    /// copying into a `&'a [u8]` as long as the input data outlives `'a`.
    ///
    /// The default implementation forwards to `visit_bytes`.
@@ -1564,6 +1590,7 @@ pub trait Visitor<'de>: Sized {
    /// The default implementation forwards to `visit_bytes` and then drops the
    /// `Vec<u8>`.
    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
    where
        E: Error,
@@ -1714,9 +1741,9 @@ pub trait SeqAccess<'de> {
    }
 }

-impl<'de, 'a, A: ?Sized> SeqAccess<'de> for &'a mut A
+impl<'de, 'a, A> SeqAccess<'de> for &'a mut A
 where
-    A: SeqAccess<'de>,
+    A: ?Sized + SeqAccess<'de>,
 {
    type Error = A::Error;

@@ -1807,9 +1834,9 @@ pub trait MapAccess<'de> {
        K: DeserializeSeed<'de>,
        V: DeserializeSeed<'de>,
    {
-        match try!(self.next_key_seed(kseed)) {
+        match tri!(self.next_key_seed(kseed)) {
            Some(key) => {
-                let value = try!(self.next_value_seed(vseed));
+                let value = tri!(self.next_value_seed(vseed));
                Ok(Some((key, value)))
            }
            None => Ok(None),
@@ -1867,9 +1894,9 @@ pub trait MapAccess<'de> {
    }
 }

-impl<'de, 'a, A: ?Sized> MapAccess<'de> for &'a mut A
+impl<'de, 'a, A> MapAccess<'de> for &'a mut A
 where
-    A: MapAccess<'de>,
+    A: ?Sized + MapAccess<'de>,
 {
    type Error = A::Error;

@@ -2011,7 +2038,7 @@ pub trait VariantAccess<'de>: Sized {
    /// If the data contains a different type of variant, the following
    /// `invalid_type` error should be constructed:
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
    /// #
    /// # struct X;
@@ -2051,7 +2078,7 @@ pub trait VariantAccess<'de>: Sized {
    /// If the data contains a different type of variant, the following
    /// `invalid_type` error should be constructed:
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
    /// #
    /// # struct X;
@@ -2107,7 +2134,7 @@ pub trait VariantAccess<'de>: Sized {
    /// If the data contains a different type of variant, the following
    /// `invalid_type` error should be constructed:
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
    /// #
    /// # struct X;
@@ -2124,11 +2151,7 @@ pub trait VariantAccess<'de>: Sized {
    /// #         T: DeserializeSeed<'de>,
    /// #     { unimplemented!() }
    /// #
-    /// fn tuple_variant<V>(
-    ///     self,
-    ///     _len: usize,
-    ///     _visitor: V,
-    /// ) -> Result<V::Value, Self::Error>
+    /// fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error>
    /// where
    ///     V: Visitor<'de>,
    /// {
@@ -2154,7 +2177,7 @@ pub trait VariantAccess<'de>: Sized {
    /// If the data contains a different type of variant, the following
    /// `invalid_type` error should be constructed:
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
    /// #
    /// # struct X;
@@ -2214,10 +2237,10 @@ pub trait VariantAccess<'de>: Sized {
 ///
 /// # Example
 ///
-/// ```edition2018
+/// ```edition2021
+/// use serde::de::{value, Deserialize, IntoDeserializer};
+/// use serde_derive::Deserialize;
 /// use std::str::FromStr;
-/// use serde::Deserialize;
-/// use serde::de::{value, IntoDeserializer};
 ///
 /// #[derive(Deserialize)]
 /// enum Setting {
@@ -2261,15 +2284,52 @@ impl Display for OneOf {
            1 => write!(formatter, "`{}`", self.names[0]),
            2 => write!(formatter, "`{}` or `{}`", self.names[0], self.names[1]),
            _ => {
-                try!(write!(formatter, "one of "));
+                tri!(formatter.write_str("one of "));
                for (i, alt) in self.names.iter().enumerate() {
                    if i > 0 {
-                        try!(write!(formatter, ", "));
+                        tri!(formatter.write_str(", "));
                    }
-                    try!(write!(formatter, "`{}`", alt));
+                    tri!(write!(formatter, "`{}`", alt));
                }
                Ok(())
            }
        }
    }
 }
+
+struct WithDecimalPoint(f64);
+
+impl Display for WithDecimalPoint {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        struct LookForDecimalPoint<'f, 'a> {
+            formatter: &'f mut fmt::Formatter<'a>,
+            has_decimal_point: bool,
+        }
+
+        impl<'f, 'a> fmt::Write for LookForDecimalPoint<'f, 'a> {
+            fn write_str(&mut self, fragment: &str) -> fmt::Result {
+                self.has_decimal_point |= fragment.contains('.');
+                self.formatter.write_str(fragment)
+            }
+
+            fn write_char(&mut self, ch: char) -> fmt::Result {
+                self.has_decimal_point |= ch == '.';
+                self.formatter.write_char(ch)
+            }
+        }
+
+        if self.0.is_finite() {
+            let mut writer = LookForDecimalPoint {
+                formatter,
+                has_decimal_point: false,
+            };
+            tri!(write!(writer, "{}", self.0));
+            if !writer.has_decimal_point {
+                tri!(formatter.write_str(".0"));
+            }
+        } else {
+            tri!(write!(formatter, "{}", self.0));
+        }
+        Ok(())
+    }
+}
@@ -1,4 +1,4 @@
-use de::{Deserialize, DeserializeSeed, Deserializer};
+use crate::de::{Deserialize, DeserializeSeed, Deserializer};

 /// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
 ///
@@ -1,4 +1,4 @@
-use lib::*;
+use crate::lib::*;

 pub fn from_bounds<I>(iter: &I) -> Option<usize>
 where
@@ -8,9 +8,17 @@ where
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
-#[inline]
-pub fn cautious(hint: Option<usize>) -> usize {
-    cmp::min(hint.unwrap_or(0), 4096)
+pub fn cautious<Element>(hint: Option<usize>) -> usize {
+    const MAX_PREALLOC_BYTES: usize = 1024 * 1024;
+
+    if mem::size_of::<Element>() == 0 {
+        0
+    } else {
+        cmp::min(
+            hint.unwrap_or(0),
+            MAX_PREALLOC_BYTES / mem::size_of::<Element>(),
+        )
+    }
 }

 fn helper(bounds: (usize, Option<usize>)) -> Option<usize> {
@@ -1,46 +0,0 @@
-use lib::*;
-
-const TAG_CONT: u8 = 0b1000_0000;
-const TAG_TWO_B: u8 = 0b1100_0000;
-const TAG_THREE_B: u8 = 0b1110_0000;
-const TAG_FOUR_B: u8 = 0b1111_0000;
-const MAX_ONE_B: u32 = 0x80;
-const MAX_TWO_B: u32 = 0x800;
-const MAX_THREE_B: u32 = 0x10000;
-
-#[inline]
-pub fn encode(c: char) -> Encode {
-    let code = c as u32;
-    let mut buf = [0; 4];
-    let pos = if code < MAX_ONE_B {
-        buf[3] = code as u8;
-        3
-    } else if code < MAX_TWO_B {
-        buf[2] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        2
-    } else if code < MAX_THREE_B {
-        buf[1] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        1
-    } else {
-        buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
-        buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        0
-    };
-    Encode { buf: buf, pos: pos }
-}
-
-pub struct Encode {
-    buf: [u8; 4],
-    pos: usize,
-}
-
-impl Encode {
-    pub fn as_str(&self) -> &str {
-        str::from_utf8(&self.buf[self.pos..]).unwrap()
-    }
-}
@@ -1,10 +1,10 @@
 //! Building blocks for deserializing basic values using the `IntoDeserializer`
 //! trait.
 //!
-//! ```edition2018
+//! ```edition2021
+//! use serde::de::{value, Deserialize, IntoDeserializer};
+//! use serde_derive::Deserialize;
 //! use std::str::FromStr;
-//! use serde::Deserialize;
-//! use serde::de::{value, IntoDeserializer};
 //!
 //! #[derive(Deserialize)]
 //! enum Setting {
@@ -21,12 +21,11 @@
 //! }
 //! ```

-use lib::*;
+use crate::lib::*;

 use self::private::{First, Second};
-use __private::size_hint;
-use de::{self, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor};
-use ser;
+use crate::de::{self, size_hint, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor};
+use crate::ser;

 ////////////////////////////////////////////////////////////////////////////////

@@ -113,6 +112,7 @@ impl Debug for Error {
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl error::Error for Error {
    fn description(&self) -> &str {
        &self.err
@@ -128,9 +128,7 @@ where
    type Deserializer = UnitDeserializer<E>;

    fn into_deserializer(self) -> UnitDeserializer<E> {
-        UnitDeserializer {
-            marker: PhantomData,
-        }
+        UnitDeserializer::new()
    }
 }

@@ -141,6 +139,15 @@ pub struct UnitDeserializer<E> {

 impl_copy_clone!(UnitDeserializer);

+impl<E> UnitDeserializer<E> {
+    #[allow(missing_docs)]
+    pub fn new() -> Self {
+        UnitDeserializer {
+            marker: PhantomData,
+        }
+    }
+}
+
 impl<'de, E> de::Deserializer<'de> for UnitDeserializer<E>
 where
    E: de::Error,
@@ -178,12 +185,14 @@ impl<E> Debug for UnitDeserializer<E> {

 /// A deserializer that cannot be instantiated.
 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 pub struct NeverDeserializer<E> {
    never: !,
    marker: PhantomData<E>,
 }

 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl<'de, E> IntoDeserializer<'de, E> for !
 where
    E: de::Error,
@@ -236,8 +245,15 @@ macro_rules! primitive_deserializer {
            type Deserializer = $name<E>;

            fn into_deserializer(self) -> $name<E> {
+                $name::new(self)
+            }
+        }
+
+        impl<E> $name<E> {
+            #[allow(missing_docs)]
+            pub fn new(value: $ty) -> Self {
                $name {
-                    value: self,
+                    value,
                    marker: PhantomData,
                }
            }
@@ -279,20 +295,17 @@ primitive_deserializer!(i8, "an `i8`.", I8Deserializer, visit_i8);
 primitive_deserializer!(i16, "an `i16`.", I16Deserializer, visit_i16);
 primitive_deserializer!(i32, "an `i32`.", I32Deserializer, visit_i32);
 primitive_deserializer!(i64, "an `i64`.", I64Deserializer, visit_i64);
+primitive_deserializer!(i128, "an `i128`.", I128Deserializer, visit_i128);
 primitive_deserializer!(isize, "an `isize`.", IsizeDeserializer, visit_i64 as i64);
 primitive_deserializer!(u8, "a `u8`.", U8Deserializer, visit_u8);
 primitive_deserializer!(u16, "a `u16`.", U16Deserializer, visit_u16);
 primitive_deserializer!(u64, "a `u64`.", U64Deserializer, visit_u64);
+primitive_deserializer!(u128, "a `u128`.", U128Deserializer, visit_u128);
 primitive_deserializer!(usize, "a `usize`.", UsizeDeserializer, visit_u64 as u64);
 primitive_deserializer!(f32, "an `f32`.", F32Deserializer, visit_f32);
 primitive_deserializer!(f64, "an `f64`.", F64Deserializer, visit_f64);
 primitive_deserializer!(char, "a `char`.", CharDeserializer, visit_char);

-serde_if_integer128! {
-    primitive_deserializer!(i128, "an `i128`.", I128Deserializer, visit_i128);
-    primitive_deserializer!(u128, "a `u128`.", U128Deserializer, visit_u128);
-}
-
 /// A deserializer holding a `u32`.
 pub struct U32Deserializer<E> {
    value: u32,
@@ -308,8 +321,15 @@ where
    type Deserializer = U32Deserializer<E>;

    fn into_deserializer(self) -> U32Deserializer<E> {
+        U32Deserializer::new(self)
+    }
+}
+
+impl<E> U32Deserializer<E> {
+    #[allow(missing_docs)]
+    pub fn new(value: u32) -> Self {
        U32Deserializer {
-            value: self,
+            value,
            marker: PhantomData,
        }
    }
@@ -390,8 +410,15 @@ where
    type Deserializer = StrDeserializer<'a, E>;

    fn into_deserializer(self) -> StrDeserializer<'a, E> {
+        StrDeserializer::new(self)
+    }
+}
+
+impl<'a, E> StrDeserializer<'a, E> {
+    #[allow(missing_docs)]
+    pub fn new(value: &'a str) -> Self {
        StrDeserializer {
-            value: self,
+            value,
            marker: PhantomData,
        }
    }
@@ -470,7 +497,7 @@ impl<'de, E> BorrowedStrDeserializer<'de, E> {
    /// Create a new borrowed deserializer from the given string.
    pub fn new(value: &'de str) -> BorrowedStrDeserializer<'de, E> {
        BorrowedStrDeserializer {
-            value: value,
+            value,
            marker: PhantomData,
        }
    }
@@ -538,6 +565,7 @@ impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> {

 /// A deserializer holding a `String`.
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct StringDeserializer<E> {
    value: String,
    marker: PhantomData<E>,
@@ -554,6 +582,7 @@ impl<E> Clone for StringDeserializer<E> {
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, E> IntoDeserializer<'de, E> for String
 where
    E: de::Error,
@@ -561,8 +590,16 @@ where
    type Deserializer = StringDeserializer<E>;

    fn into_deserializer(self) -> StringDeserializer<E> {
+        StringDeserializer::new(self)
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<E> StringDeserializer<E> {
+    #[allow(missing_docs)]
+    pub fn new(value: String) -> Self {
        StringDeserializer {
-            value: self,
+            value,
            marker: PhantomData,
        }
    }
@@ -604,7 +641,7 @@ where
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
-impl<'de, 'a, E> de::EnumAccess<'de> for StringDeserializer<E>
+impl<'de, E> de::EnumAccess<'de> for StringDeserializer<E>
 where
    E: de::Error,
 {
@@ -633,6 +670,7 @@ impl<E> Debug for StringDeserializer<E> {

 /// A deserializer holding a `Cow<str>`.
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct CowStrDeserializer<'a, E> {
    value: Cow<'a, str>,
    marker: PhantomData<E>,
@@ -649,6 +687,7 @@ impl<'a, E> Clone for CowStrDeserializer<'a, E> {
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, 'a, E> IntoDeserializer<'de, E> for Cow<'a, str>
 where
    E: de::Error,
@@ -656,8 +695,16 @@ where
    type Deserializer = CowStrDeserializer<'a, E>;

    fn into_deserializer(self) -> CowStrDeserializer<'a, E> {
+        CowStrDeserializer::new(self)
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, E> CowStrDeserializer<'a, E> {
+    #[allow(missing_docs)]
+    pub fn new(value: Cow<'a, str>) -> Self {
        CowStrDeserializer {
-            value: self,
+            value,
            marker: PhantomData,
        }
    }
@@ -739,7 +786,7 @@ impl<'a, E> BytesDeserializer<'a, E> {
    /// Create a new deserializer from the given bytes.
    pub fn new(value: &'a [u8]) -> Self {
        BytesDeserializer {
-            value: value,
+            value,
            marker: PhantomData,
        }
    }
@@ -798,7 +845,7 @@ impl<'de, E> BorrowedBytesDeserializer<'de, E> {
    /// Create a new borrowed deserializer from the given borrowed bytes.
    pub fn new(value: &'de [u8]) -> Self {
        BorrowedBytesDeserializer {
-            value: value,
+            value,
            marker: PhantomData,
        }
    }
@@ -893,8 +940,8 @@ where
    where
        V: de::Visitor<'de>,
    {
-        let v = try!(visitor.visit_seq(&mut self));
-        try!(self.end());
+        let v = tri!(visitor.visit_seq(&mut self));
+        tri!(self.end());
        Ok(v)
    }

@@ -936,7 +983,7 @@ struct ExpectedInSeq(usize);
 impl Expected for ExpectedInSeq {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        if self.0 == 1 {
-            write!(formatter, "1 element in sequence")
+            formatter.write_str("1 element in sequence")
        } else {
            write!(formatter, "{} elements in sequence", self.0)
        }
@@ -959,6 +1006,7 @@ where
 ////////////////////////////////////////////////////////////////////////////////

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for Vec<T>
 where
    T: IntoDeserializer<'de, E>,
@@ -972,6 +1020,7 @@ where
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for BTreeSet<T>
 where
    T: IntoDeserializer<'de, E> + Eq + Ord,
@@ -985,6 +1034,7 @@ where
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, T, S, E> IntoDeserializer<'de, E> for HashSet<T, S>
 where
    T: IntoDeserializer<'de, E> + Eq + Hash,
@@ -1009,7 +1059,7 @@ pub struct SeqAccessDeserializer<A> {
 impl<A> SeqAccessDeserializer<A> {
    /// Construct a new `SeqAccessDeserializer<A>`.
    pub fn new(seq: A) -> Self {
-        SeqAccessDeserializer { seq: seq }
+        SeqAccessDeserializer { seq }
    }
 }

@@ -1118,8 +1168,8 @@ where
    where
        V: de::Visitor<'de>,
    {
-        let value = try!(visitor.visit_map(&mut self));
-        try!(self.end());
+        let value = tri!(visitor.visit_map(&mut self));
+        tri!(self.end());
        Ok(value)
    }

@@ -1127,8 +1177,8 @@ where
    where
        V: de::Visitor<'de>,
    {
-        let value = try!(visitor.visit_seq(&mut self));
-        try!(self.end());
+        let value = tri!(visitor.visit_seq(&mut self));
+        tri!(self.end());
        Ok(value)
    }

@@ -1192,8 +1242,8 @@ where
    {
        match self.next_pair() {
            Some((key, value)) => {
-                let key = try!(kseed.deserialize(key.into_deserializer()));
-                let value = try!(vseed.deserialize(value.into_deserializer()));
+                let key = tri!(kseed.deserialize(key.into_deserializer()));
+                let value = tri!(vseed.deserialize(value.into_deserializer()));
                Ok(Some((key, value)))
            }
            None => Ok(None),
@@ -1297,7 +1347,7 @@ where
        V: de::Visitor<'de>,
    {
        let mut pair_visitor = PairVisitor(Some(self.0), Some(self.1), PhantomData);
-        let pair = try!(visitor.visit_seq(&mut pair_visitor));
+        let pair = tri!(visitor.visit_seq(&mut pair_visitor));
        if pair_visitor.1.is_none() {
            Ok(pair)
        } else {
@@ -1361,7 +1411,7 @@ struct ExpectedInMap(usize);
 impl Expected for ExpectedInMap {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        if self.0 == 1 {
-            write!(formatter, "1 element in map")
+            formatter.write_str("1 element in map")
        } else {
            write!(formatter, "{} elements in map", self.0)
        }
@@ -1371,6 +1421,7 @@ impl Expected for ExpectedInMap {
 ////////////////////////////////////////////////////////////////////////////////

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V>
 where
    K: IntoDeserializer<'de, E> + Eq + Ord,
@@ -1385,6 +1436,7 @@ where
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, K, V, S, E> IntoDeserializer<'de, E> for HashMap<K, V, S>
 where
    K: IntoDeserializer<'de, E> + Eq + Hash,
@@ -1410,7 +1462,7 @@ pub struct MapAccessDeserializer<A> {
 impl<A> MapAccessDeserializer<A> {
    /// Construct a new `MapAccessDeserializer<A>`.
    pub fn new(map: A) -> Self {
-        MapAccessDeserializer { map: map }
+        MapAccessDeserializer { map }
    }
 }

@@ -1457,7 +1509,7 @@ where
    where
        T: de::DeserializeSeed<'de>,
    {
-        match self.map.next_key_seed(seed)? {
+        match tri!(self.map.next_key_seed(seed)) {
            Some(key) => Ok((key, private::map_as_enum(self.map))),
            None => Err(de::Error::invalid_type(de::Unexpected::Map, &"enum")),
        }
@@ -1466,10 +1518,47 @@ where

 ////////////////////////////////////////////////////////////////////////////////

-mod private {
-    use lib::*;
+/// A deserializer holding an `EnumAccess`.
+#[derive(Clone, Debug)]
+pub struct EnumAccessDeserializer<A> {
+    access: A,
+}

-    use de::{self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor};
+impl<A> EnumAccessDeserializer<A> {
+    /// Construct a new `EnumAccessDeserializer<A>`.
+    pub fn new(access: A) -> Self {
+        EnumAccessDeserializer { access }
+    }
+}
+
+impl<'de, A> de::Deserializer<'de> for EnumAccessDeserializer<A>
+where
+    A: de::EnumAccess<'de>,
+{
+    type Error = A::Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_enum(self.access)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+mod private {
+    use crate::lib::*;
+
+    use crate::de::{
+        self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor,
+    };

    pub struct UnitOnly<E> {
        marker: PhantomData<E>,
@@ -1534,7 +1623,7 @@ mod private {
    }

    pub fn map_as_enum<A>(map: A) -> MapAsEnum<A> {
-        MapAsEnum { map: map }
+        MapAsEnum { map }
    }

    impl<'de, A> VariantAccess<'de> for MapAsEnum<A>
@@ -1558,10 +1647,7 @@ mod private {
        where
            V: Visitor<'de>,
        {
-            self.map.next_value_seed(SeedTupleVariant {
-                len: len,
-                visitor: visitor,
-            })
+            self.map.next_value_seed(SeedTupleVariant { len, visitor })
        }

        fn struct_variant<V>(
@@ -1572,8 +1658,7 @@ mod private {
        where
            V: Visitor<'de>,
        {
-            self.map
-                .next_value_seed(SeedStructVariant { visitor: visitor })
+            self.map.next_value_seed(SeedStructVariant { visitor })
        }
    }

@@ -0,0 +1,30 @@
+use crate::lib::fmt::{self, Write};
+use crate::lib::str;
+
+pub(super) struct Buf<'a> {
+    bytes: &'a mut [u8],
+    offset: usize,
+}
+
+impl<'a> Buf<'a> {
+    pub fn new(bytes: &'a mut [u8]) -> Self {
+        Buf { bytes, offset: 0 }
+    }
+
+    pub fn as_str(&self) -> &str {
+        let slice = &self.bytes[..self.offset];
+        unsafe { str::from_utf8_unchecked(slice) }
+    }
+}
+
+impl<'a> Write for Buf<'a> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        if self.offset + s.len() > self.bytes.len() {
+            Err(fmt::Error)
+        } else {
+            self.bytes[self.offset..self.offset + s.len()].copy_from_slice(s.as_bytes());
+            self.offset += s.len();
+            Ok(())
+        }
+    }
+}
@@ -1,82 +1,9 @@
-/// Conditional compilation depending on whether Serde is built with support for
-/// 128-bit integers.
-///
-/// Data formats that wish to support Rust compiler versions older than 1.26
-/// (or targets that lack 128-bit integers) may place the i128 / u128 methods
-/// of their Serializer and Deserializer behind this macro.
-///
-/// Data formats that require a minimum Rust compiler version of at least 1.26,
-/// or do not target platforms that lack 128-bit integers, do not need to
-/// bother with this macro and may assume support for 128-bit integers.
-///
-/// ```edition2018
-/// # use serde::__private::doc::Error;
-/// #
-/// # struct MySerializer;
-/// #
-/// use serde::{serde_if_integer128, Serializer};
-///
-/// impl Serializer for MySerializer {
-///     type Ok = ();
-///     type Error = Error;
-///
-///     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
-///         /* ... */
-/// #         unimplemented!()
-///     }
-///
-///     /* ... */
-///
-///     serde_if_integer128! {
-///         fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///
-///         fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///     }
-/// #
-/// #     serde::__serialize_unimplemented! {
-/// #         bool i8 i16 i32 u8 u16 u32 u64 f32 f64 char str bytes none some
-/// #         unit unit_struct unit_variant newtype_struct newtype_variant seq
-/// #         tuple tuple_struct tuple_variant map struct struct_variant
-/// #     }
-/// }
-/// ```
-///
-/// When Serde is built with support for 128-bit integers, this macro expands
-/// transparently into just the input tokens.
-///
-/// ```edition2018
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {
-///         $($tt)*
-///     };
-/// }
-/// ```
-///
-/// When built without support for 128-bit integers, this macro expands to
-/// nothing.
-///
-/// ```edition2018
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {};
-/// }
-/// ```
-#[cfg(integer128)]
+// No longer used. Old versions of serde used this macro for supporting targets
+// that did not yet have 128-bit integer support.
 #[macro_export]
+#[doc(hidden)]
 macro_rules! serde_if_integer128 {
    ($($tt:tt)*) => {
        $($tt)*
    };
 }
-
-#[cfg(not(integer128))]
-#[macro_export]
-#[doc(hidden)]
-macro_rules! serde_if_integer128 {
-    ($($tt:tt)*) => {};
-}
@@ -31,8 +31,7 @@
 //! for Serde by the community.
 //!
 //! - [JSON], the ubiquitous JavaScript Object Notation used by many HTTP APIs.
-//! - [Bincode], a compact binary format
-//!   used for IPC within the Servo rendering engine.
+//! - [Postcard], a no\_std and embedded-systems friendly compact binary format.
 //! - [CBOR], a Concise Binary Object Representation designed for small message
 //!   size without the need for version negotiation.
 //! - [YAML], a self-proclaimed human-friendly configuration language that ain't
@@ -45,8 +44,9 @@
 //! - [Avro], a binary format used within Apache Hadoop, with support for schema
 //!   definition.
 //! - [JSON5], a superset of JSON including some productions from ES5.
-//! - [Postcard], a no\_std and embedded-systems friendly compact binary format.
 //! - [URL] query strings, in the x-www-form-urlencoded format.
+//! - [Starlark], the format used for describing build targets by the Bazel and
+//!   Buck build systems. *(serialization only)*
 //! - [Envy], a way to deserialize environment variables into Rust structs.
 //!   *(deserialization only)*
 //! - [Envy Store], a way to deserialize [AWS Parameter Store] parameters into
@@ -54,91 +54,105 @@
 //! - [S-expressions], the textual representation of code and data used by the
 //!   Lisp language family.
 //! - [D-Bus]'s binary wire format.
-//! - [FlexBuffers], the schemaless cousin of Google's FlatBuffers zero-copy serialization format.
+//! - [FlexBuffers], the schemaless cousin of Google's FlatBuffers zero-copy
+//!   serialization format.
+//! - [Bencode], a simple binary format used in the BitTorrent protocol.
+//! - [Token streams], for processing Rust procedural macro input.
+//!   *(deserialization only)*
 //! - [DynamoDB Items], the format used by [rusoto_dynamodb] to transfer data to
 //!   and from DynamoDB.
+//! - [Hjson], a syntax extension to JSON designed around human reading and
+//!   editing. *(deserialization only)*
+//! - [CSV], Comma-separated values is a tabular text file format.
 //!
 //! [JSON]: https://github.com/serde-rs/json
-//! [Bincode]: https://github.com/servo/bincode
+//! [Postcard]: https://github.com/jamesmunns/postcard
 //! [CBOR]: https://github.com/enarx/ciborium
 //! [YAML]: https://github.com/dtolnay/serde-yaml
 //! [MessagePack]: https://github.com/3Hren/msgpack-rust
-//! [TOML]: https://github.com/alexcrichton/toml-rs
+//! [TOML]: https://docs.rs/toml
 //! [Pickle]: https://github.com/birkenfeld/serde-pickle
 //! [RON]: https://github.com/ron-rs/ron
-//! [BSON]: https://github.com/zonyitoo/bson-rs
-//! [Avro]: https://github.com/flavray/avro-rs
+//! [BSON]: https://github.com/mongodb/bson-rust
+//! [Avro]: https://docs.rs/apache-avro
 //! [JSON5]: https://github.com/callum-oakley/json5-rs
-//! [Postcard]: https://github.com/jamesmunns/postcard
 //! [URL]: https://docs.rs/serde_qs
+//! [Starlark]: https://github.com/dtolnay/serde-starlark
 //! [Envy]: https://github.com/softprops/envy
 //! [Envy Store]: https://github.com/softprops/envy-store
 //! [Cargo]: https://doc.rust-lang.org/cargo/reference/manifest.html
-//! [AWS Parameter Store]: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-paramstore.html
+//! [AWS Parameter Store]: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html
 //! [S-expressions]: https://github.com/rotty/lexpr-rs
 //! [D-Bus]: https://docs.rs/zvariant
 //! [FlexBuffers]: https://github.com/google/flatbuffers/tree/master/rust/flexbuffers
+//! [Bencode]: https://github.com/P3KI/bendy
+//! [Token streams]: https://github.com/oxidecomputer/serde_tokenstream
 //! [DynamoDB Items]: https://docs.rs/serde_dynamo
 //! [rusoto_dynamodb]: https://docs.rs/rusoto_dynamodb
+//! [Hjson]: https://github.com/Canop/deser-hjson
+//! [CSV]: https://docs.rs/csv

 ////////////////////////////////////////////////////////////////////////////////

 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.131")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.210")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
+// Show which crate feature enables conditionally compiled APIs in documentation.
+#![cfg_attr(docsrs, feature(doc_cfg, rustdoc_internals))]
+#![cfg_attr(docsrs, allow(internal_features))]
 // Unstable functionality only if the user asks for it. For tracking and
 // discussion of these features please refer to this issue:
 //
 //    https://github.com/serde-rs/serde/issues/812
 #![cfg_attr(feature = "unstable", feature(never_type))]
 #![allow(unknown_lints, bare_trait_objects, deprecated)]
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 // Ignored clippy and clippy_pedantic lints
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(
-        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
-        unnested_or_patterns,
-        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
-        semicolon_if_nothing_returned,
-        // not available in our oldest supported compiler
-        checked_conversions,
-        empty_enum,
-        redundant_field_names,
-        redundant_static_lifetimes,
-        // integer and float ser/de requires these sorts of casts
-        cast_possible_truncation,
-        cast_possible_wrap,
-        cast_sign_loss,
-        // things are often more readable this way
-        cast_lossless,
-        module_name_repetitions,
-        option_if_let_else,
-        single_match_else,
-        type_complexity,
-        use_self,
-        zero_prefixed_literal,
-        // correctly used
-        enum_glob_use,
-        let_underscore_drop,
-        map_err_ignore,
-        result_unit_err,
-        wildcard_imports,
-        // not practical
-        needless_pass_by_value,
-        similar_names,
-        too_many_lines,
-        // preference
-        doc_markdown,
-        unseparated_literal_suffix,
-        // false positive
-        needless_doctest_main,
-        // noisy
-        missing_errors_doc,
-        must_use_candidate,
-    )
+#![allow(
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
+    clippy::semicolon_if_nothing_returned,
+    // not available in our oldest supported compiler
+    clippy::empty_enum,
+    clippy::type_repetition_in_bounds, // https://github.com/rust-lang/rust-clippy/issues/8772
+    // integer and float ser/de requires these sorts of casts
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_precision_loss,
+    clippy::cast_sign_loss,
+    // things are often more readable this way
+    clippy::cast_lossless,
+    clippy::module_name_repetitions,
+    clippy::single_match_else,
+    clippy::type_complexity,
+    clippy::use_self,
+    clippy::zero_prefixed_literal,
+    // correctly used
+    clippy::derive_partial_eq_without_eq,
+    clippy::enum_glob_use,
+    clippy::explicit_auto_deref,
+    clippy::incompatible_msrv,
+    clippy::let_underscore_untyped,
+    clippy::map_err_ignore,
+    clippy::new_without_default,
+    clippy::result_unit_err,
+    clippy::wildcard_imports,
+    // not practical
+    clippy::needless_pass_by_value,
+    clippy::similar_names,
+    clippy::too_many_lines,
+    // preference
+    clippy::doc_markdown,
+    clippy::unseparated_literal_suffix,
+    // false positive
+    clippy::needless_doctest_main,
+    // noisy
+    clippy::missing_errors_doc,
+    clippy::must_use_candidate,
 )]
+// Restrictions
+#![deny(clippy::question_mark_used)]
 // Rustc lints.
 #![deny(missing_docs, unused_imports)]

@@ -158,21 +172,26 @@ mod lib {
        pub use std::*;
    }

-    pub use self::core::{cmp, iter, mem, num, ptr, slice, str};
    pub use self::core::{f32, f64};
    pub use self::core::{i16, i32, i64, i8, isize};
+    pub use self::core::{iter, num, ptr, str};
    pub use self::core::{u16, u32, u64, u8, usize};

+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub use self::core::{cmp, mem, slice};
+
    pub use self::core::cell::{Cell, RefCell};
-    pub use self::core::clone::{self, Clone};
-    pub use self::core::convert::{self, From, Into};
-    pub use self::core::default::{self, Default};
-    pub use self::core::fmt::{self, Debug, Display};
+    pub use self::core::clone;
+    pub use self::core::cmp::Reverse;
+    pub use self::core::convert;
+    pub use self::core::default;
+    pub use self::core::fmt::{self, Debug, Display, Write as FmtWrite};
    pub use self::core::marker::{self, PhantomData};
    pub use self::core::num::Wrapping;
-    pub use self::core::ops::Range;
-    pub use self::core::option::{self, Option};
-    pub use self::core::result::{self, Result};
+    pub use self::core::ops::{Bound, Range, RangeFrom, RangeInclusive, RangeTo};
+    pub use self::core::option;
+    pub use self::core::result;
+    pub use self::core::time::Duration;

    #[cfg(all(feature = "alloc", not(feature = "std")))]
    pub use alloc::borrow::{Cow, ToOwned};
@@ -209,13 +228,28 @@ mod lib {
    #[cfg(feature = "std")]
    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};

+    #[cfg(all(not(no_core_cstr), not(feature = "std")))]
+    pub use self::core::ffi::CStr;
    #[cfg(feature = "std")]
-    pub use std::{error, net};
+    pub use std::ffi::CStr;
+
+    #[cfg(all(not(no_core_cstr), feature = "alloc", not(feature = "std")))]
+    pub use alloc::ffi::CString;
+    #[cfg(feature = "std")]
+    pub use std::ffi::CString;
+
+    #[cfg(all(not(no_core_net), not(feature = "std")))]
+    pub use self::core::net;
+    #[cfg(feature = "std")]
+    pub use std::net;
+
+    #[cfg(feature = "std")]
+    pub use std::error;

    #[cfg(feature = "std")]
    pub use std::collections::{HashMap, HashSet};
    #[cfg(feature = "std")]
-    pub use std::ffi::{CStr, CString, OsStr, OsString};
+    pub use std::ffi::{OsStr, OsString};
    #[cfg(feature = "std")]
    pub use std::hash::{BuildHasher, Hash};
    #[cfg(feature = "std")]
@@ -227,28 +261,42 @@ mod lib {
    #[cfg(feature = "std")]
    pub use std::time::{SystemTime, UNIX_EPOCH};

-    #[cfg(all(feature = "std", collections_bound))]
-    pub use std::collections::Bound;
-
-    #[cfg(core_reverse)]
-    pub use self::core::cmp::Reverse;
-
-    #[cfg(ops_bound)]
-    pub use self::core::ops::Bound;
-
-    #[cfg(range_inclusive)]
-    pub use self::core::ops::RangeInclusive;
-
-    #[cfg(all(feature = "std", std_atomic))]
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
    pub use std::sync::atomic::{
        AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
        AtomicUsize, Ordering,
    };
-    #[cfg(all(feature = "std", std_atomic64))]
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
    pub use std::sync::atomic::{AtomicI64, AtomicU64};

-    #[cfg(any(core_duration, feature = "std"))]
-    pub use self::core::time::Duration;
+    #[cfg(all(feature = "std", not(no_target_has_atomic)))]
+    pub use std::sync::atomic::Ordering;
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
+    pub use std::sync::atomic::{AtomicBool, AtomicI8, AtomicU8};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "16"))]
+    pub use std::sync::atomic::{AtomicI16, AtomicU16};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "32"))]
+    pub use std::sync::atomic::{AtomicI32, AtomicU32};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "64"))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
+    pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
+
+    #[cfg(not(no_core_num_saturating))]
+    pub use self::core::num::Saturating;
+}
+
+// None of this crate's error handling needs the `From::from` error conversion
+// performed implicitly by the `?` operator or the standard library's `try!`
+// macro. This simplified macro gives a 5.5% improvement in compile time
+// compared to standard `try!`, and 9% improvement compared to `?`.
+macro_rules! tri {
+    ($expr:expr) => {
+        match $expr {
+            Ok(val) => val,
+            Err(err) => return Err(err),
+        }
+    };
 }

 ////////////////////////////////////////////////////////////////////////////////
@@ -262,25 +310,22 @@ mod integer128;
 pub mod de;
 pub mod ser;

+mod format;
+
 #[doc(inline)]
-pub use de::{Deserialize, Deserializer};
+pub use crate::de::{Deserialize, Deserializer};
 #[doc(inline)]
-pub use ser::{Serialize, Serializer};
+pub use crate::ser::{Serialize, Serializer};

 // Used by generated code and doc tests. Not public API.
 #[doc(hidden)]
 #[path = "private/mod.rs"]
 pub mod __private;

-#[allow(unused_imports)]
-use self::__private as export;
-#[allow(unused_imports)]
-use self::__private as private;
-
 #[path = "de/seed.rs"]
 mod seed;

-#[cfg(not(feature = "std"))]
+#[cfg(all(not(feature = "std"), no_core_error))]
 mod std_error;

 // Re-export #[derive(Serialize, Deserialize)].
@@ -289,9 +334,14 @@ mod std_error;
 // be annoying for crates that provide handwritten impls or data formats. They
 // would need to disable default features and then explicitly re-enable std.
 #[cfg(feature = "serde_derive")]
-#[allow(unused_imports)]
-#[macro_use]
 extern crate serde_derive;
+
+/// Derive macro available if serde is built with `features = ["derive"]`.
 #[cfg(feature = "serde_derive")]
-#[doc(hidden)]
-pub use serde_derive::*;
+#[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
+pub use serde_derive::{Deserialize, Serialize};
+
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+mod actually_private {
+    pub struct T;
+}
@@ -11,7 +11,7 @@
 /// input. This requires repetitive implementations of all the [`Deserializer`]
 /// trait methods.
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
 /// #
@@ -47,7 +47,7 @@
 /// methods so that they forward directly to [`Deserializer::deserialize_any`].
 /// You can choose which methods to forward.
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
 /// #
@@ -78,11 +78,10 @@
 /// called `V`. A different type parameter and a different lifetime can be
 /// specified explicitly if necessary.
 ///
-/// ```edition2018
-/// # use std::marker::PhantomData;
-/// #
+/// ```edition2021
 /// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
+/// # use std::marker::PhantomData;
 /// #
 /// # struct MyDeserializer<V>(PhantomData<V>);
 /// #
@@ -124,7 +123,7 @@ macro_rules! forward_to_deserialize_any {
 macro_rules! forward_to_deserialize_any_method {
    ($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
        #[inline]
-        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, Self::Error>
+        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, <Self as $crate::de::Deserializer<$l>>::Error>
        where
            $v: $crate::de::Visitor<$l>,
        {
@@ -155,9 +154,7 @@ macro_rules! forward_to_deserialize_any_helper {
        forward_to_deserialize_any_method!{deserialize_i64<$l, $v>()}
    };
    (i128<$l:tt, $v:ident>) => {
-        serde_if_integer128! {
-            forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
-        }
+        forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
    };
    (u8<$l:tt, $v:ident>) => {
        forward_to_deserialize_any_method!{deserialize_u8<$l, $v>()}
@@ -172,9 +169,7 @@ macro_rules! forward_to_deserialize_any_helper {
        forward_to_deserialize_any_method!{deserialize_u64<$l, $v>()}
    };
    (u128<$l:tt, $v:ident>) => {
-        serde_if_integer128! {
-            forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
-        }
+        forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
    };
    (f32<$l:tt, $v:ident>) => {
        forward_to_deserialize_any_method!{deserialize_f32<$l, $v>()}
@@ -1,8 +1,8 @@
 // Used only by Serde doc tests. Not public API.

-use lib::*;
+use crate::lib::*;

-use ser;
+use crate::ser;

 #[doc(hidden)]
 #[derive(Debug)]
@@ -56,7 +56,10 @@ macro_rules! __serialize_unimplemented {
 #[macro_export]
 macro_rules! __serialize_unimplemented_method {
    ($func:ident $(<$t:ident>)* ($($arg:ty),*) -> $ret:ident) => {
-        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error> {
+        fn $func $(<$t>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error>
+        where
+            $($t: ?Sized + $crate::Serialize,)*
+        {
            unimplemented!()
        }
    };
@@ -1,32 +1,30 @@
-#[cfg(serde_derive)]
+#[cfg(not(no_serde_derive))]
 pub mod de;
-#[cfg(serde_derive)]
+#[cfg(not(no_serde_derive))]
 pub mod ser;

-pub mod size_hint;
-
 // FIXME: #[cfg(doctest)] once https://github.com/rust-lang/rust/issues/67295 is fixed.
 pub mod doc;

-pub use lib::clone::Clone;
-pub use lib::convert::{From, Into};
-pub use lib::default::Default;
-pub use lib::fmt::{self, Formatter};
-pub use lib::marker::PhantomData;
-pub use lib::option::Option::{self, None, Some};
-pub use lib::ptr;
-pub use lib::result::Result::{self, Err, Ok};
+pub use crate::lib::clone::Clone;
+pub use crate::lib::convert::{From, Into};
+pub use crate::lib::default::Default;
+pub use crate::lib::fmt::{self, Formatter};
+pub use crate::lib::marker::PhantomData;
+pub use crate::lib::option::Option::{self, None, Some};
+pub use crate::lib::ptr;
+pub use crate::lib::result::Result::{self, Err, Ok};

 pub use self::string::from_utf8_lossy;

 #[cfg(any(feature = "alloc", feature = "std"))]
-pub use lib::{ToString, Vec};
+pub use crate::lib::{ToString, Vec};

-#[cfg(core_try_from)]
-pub use lib::convert::TryFrom;
+#[cfg(not(no_core_try_from))]
+pub use crate::lib::convert::TryFrom;

 mod string {
-    use lib::*;
+    use crate::lib::*;

    #[cfg(any(feature = "std", feature = "alloc"))]
    pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;

-use ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
+use crate::ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};

 #[cfg(any(feature = "std", feature = "alloc"))]
 use self::content::{
@@ -27,10 +27,10 @@ where
    T: Serialize,
 {
    value.serialize(TaggedSerializer {
-        type_ident: type_ident,
-        variant_ident: variant_ident,
-        tag: tag,
-        variant_name: variant_name,
+        type_ident,
+        variant_ident,
+        tag,
+        variant_name,
        delegate: serializer,
    })
 }
@@ -51,9 +51,6 @@ enum Unsupported {
    String,
    ByteArray,
    Optional,
-    Unit,
-    #[cfg(any(feature = "std", feature = "alloc"))]
-    UnitStruct,
    Sequence,
    Tuple,
    TupleStruct,
@@ -70,9 +67,6 @@ impl Display for Unsupported {
            Unsupported::String => formatter.write_str("a string"),
            Unsupported::ByteArray => formatter.write_str("a byte array"),
            Unsupported::Optional => formatter.write_str("an optional"),
-            Unsupported::Unit => formatter.write_str("unit"),
-            #[cfg(any(feature = "std", feature = "alloc"))]
-            Unsupported::UnitStruct => formatter.write_str("unit struct"),
            Unsupported::Sequence => formatter.write_str("a sequence"),
            Unsupported::Tuple => formatter.write_str("a tuple"),
            Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
@@ -176,20 +170,22 @@ where
        Err(self.bad_type(Unsupported::Optional))
    }

-    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        Err(self.bad_type(Unsupported::Optional))
    }

    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Unit))
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        map.end()
    }

    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(1)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
        map.end()
    }

@@ -199,24 +195,24 @@ where
        _: u32,
        inner_variant: &'static str,
    ) -> Result<Self::Ok, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_entry(inner_variant, &()));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(inner_variant, &()));
        map.end()
    }

-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
        self,
        _: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        value.serialize(self)
    }

-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
        self,
        _: &'static str,
        _: u32,
@@ -224,11 +220,11 @@ where
        inner_value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_entry(inner_variant, inner_value));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(inner_variant, inner_value));
        map.end()
    }

@@ -269,9 +265,9 @@ where
        inner_variant: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_key(inner_variant));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_key(inner_variant));
        Ok(SerializeTupleVariantAsMapValue::new(
            map,
            inner_variant,
@@ -280,8 +276,8 @@ where
    }

    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(len.map(|len| len + 1)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        let mut map = tri!(self.delegate.serialize_map(len.map(|len| len + 1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
        Ok(map)
    }

@@ -290,8 +286,8 @@ where
        name: &'static str,
        len: usize,
    ) -> Result<Self::SerializeStruct, Self::Error> {
-        let mut state = try!(self.delegate.serialize_struct(name, len + 1));
-        try!(state.serialize_field(self.tag, self.variant_name));
+        let mut state = tri!(self.delegate.serialize_struct(name, len + 1));
+        tri!(state.serialize_field(self.tag, self.variant_name));
        Ok(state)
    }

@@ -316,9 +312,9 @@ where
        inner_variant: &'static str,
        len: usize,
    ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_key(inner_variant));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_key(inner_variant));
        Ok(SerializeStructVariantAsMapValue::new(
            map,
            inner_variant,
@@ -327,9 +323,9 @@ where
    }

    #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Display,
+        T: ?Sized + Display,
    {
        Err(self.bad_type(Unsupported::String))
    }
@@ -337,9 +333,9 @@ where

 #[cfg(any(feature = "std", feature = "alloc"))]
 mod content {
-    use lib::*;
+    use crate::lib::*;

-    use ser::{self, Serialize, Serializer};
+    use crate::ser::{self, Serialize, Serializer};

    pub struct SerializeTupleVariantAsMapValue<M> {
        map: M,
@@ -350,8 +346,8 @@ mod content {
    impl<M> SerializeTupleVariantAsMapValue<M> {
        pub fn new(map: M, name: &'static str, len: usize) -> Self {
            SerializeTupleVariantAsMapValue {
-                map: map,
-                name: name,
+                map,
+                name,
                fields: Vec::with_capacity(len),
            }
        }
@@ -364,17 +360,17 @@ mod content {
        type Ok = M::Ok;
        type Error = M::Error;

-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), M::Error>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), M::Error>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
            self.fields.push(value);
            Ok(())
        }

        fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self
+            tri!(self
                .map
                .serialize_value(&Content::TupleStruct(self.name, self.fields)));
            self.map.end()
@@ -390,8 +386,8 @@ mod content {
    impl<M> SerializeStructVariantAsMapValue<M> {
        pub fn new(map: M, name: &'static str, len: usize) -> Self {
            SerializeStructVariantAsMapValue {
-                map: map,
-                name: name,
+                map,
+                name,
                fields: Vec::with_capacity(len),
            }
        }
@@ -404,21 +400,17 @@ mod content {
        type Ok = M::Ok;
        type Error = M::Error;

-        fn serialize_field<T: ?Sized>(
-            &mut self,
-            key: &'static str,
-            value: &T,
-        ) -> Result<(), M::Error>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), M::Error>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
            self.fields.push((key, value));
            Ok(())
        }

        fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self
+            tri!(self
                .map
                .serialize_value(&Content::Struct(self.name, self.fields)));
            self.map.end()
@@ -499,50 +491,50 @@ mod content {
                }
                Content::Seq(ref elements) => elements.serialize(serializer),
                Content::Tuple(ref elements) => {
-                    use ser::SerializeTuple;
-                    let mut tuple = try!(serializer.serialize_tuple(elements.len()));
+                    use crate::ser::SerializeTuple;
+                    let mut tuple = tri!(serializer.serialize_tuple(elements.len()));
                    for e in elements {
-                        try!(tuple.serialize_element(e));
+                        tri!(tuple.serialize_element(e));
                    }
                    tuple.end()
                }
                Content::TupleStruct(n, ref fields) => {
-                    use ser::SerializeTupleStruct;
-                    let mut ts = try!(serializer.serialize_tuple_struct(n, fields.len()));
+                    use crate::ser::SerializeTupleStruct;
+                    let mut ts = tri!(serializer.serialize_tuple_struct(n, fields.len()));
                    for f in fields {
-                        try!(ts.serialize_field(f));
+                        tri!(ts.serialize_field(f));
                    }
                    ts.end()
                }
                Content::TupleVariant(n, i, v, ref fields) => {
-                    use ser::SerializeTupleVariant;
-                    let mut tv = try!(serializer.serialize_tuple_variant(n, i, v, fields.len()));
+                    use crate::ser::SerializeTupleVariant;
+                    let mut tv = tri!(serializer.serialize_tuple_variant(n, i, v, fields.len()));
                    for f in fields {
-                        try!(tv.serialize_field(f));
+                        tri!(tv.serialize_field(f));
                    }
                    tv.end()
                }
                Content::Map(ref entries) => {
-                    use ser::SerializeMap;
-                    let mut map = try!(serializer.serialize_map(Some(entries.len())));
-                    for &(ref k, ref v) in entries {
-                        try!(map.serialize_entry(k, v));
+                    use crate::ser::SerializeMap;
+                    let mut map = tri!(serializer.serialize_map(Some(entries.len())));
+                    for (k, v) in entries {
+                        tri!(map.serialize_entry(k, v));
                    }
                    map.end()
                }
                Content::Struct(n, ref fields) => {
-                    use ser::SerializeStruct;
-                    let mut s = try!(serializer.serialize_struct(n, fields.len()));
+                    use crate::ser::SerializeStruct;
+                    let mut s = tri!(serializer.serialize_struct(n, fields.len()));
                    for &(k, ref v) in fields {
-                        try!(s.serialize_field(k, v));
+                        tri!(s.serialize_field(k, v));
                    }
                    s.end()
                }
                Content::StructVariant(n, i, v, ref fields) => {
-                    use ser::SerializeStructVariant;
-                    let mut sv = try!(serializer.serialize_struct_variant(n, i, v, fields.len()));
+                    use crate::ser::SerializeStructVariant;
+                    let mut sv = tri!(serializer.serialize_struct_variant(n, i, v, fields.len()));
                    for &(k, ref v) in fields {
-                        try!(sv.serialize_field(k, v));
+                        tri!(sv.serialize_field(k, v));
                    }
                    sv.end()
                }
@@ -635,11 +627,11 @@ mod content {
            Ok(Content::None)
        }

-        fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Content, E>
+        fn serialize_some<T>(self, value: &T) -> Result<Content, E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            Ok(Content::Some(Box::new(try!(value.serialize(self)))))
+            Ok(Content::Some(Box::new(tri!(value.serialize(self)))))
        }

        fn serialize_unit(self) -> Result<Content, E> {
@@ -659,21 +651,17 @@ mod content {
            Ok(Content::UnitVariant(name, variant_index, variant))
        }

-        fn serialize_newtype_struct<T: ?Sized>(
-            self,
-            name: &'static str,
-            value: &T,
-        ) -> Result<Content, E>
+        fn serialize_newtype_struct<T>(self, name: &'static str, value: &T) -> Result<Content, E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
            Ok(Content::NewtypeStruct(
                name,
-                Box::new(try!(value.serialize(self))),
+                Box::new(tri!(value.serialize(self))),
            ))
        }

-        fn serialize_newtype_variant<T: ?Sized>(
+        fn serialize_newtype_variant<T>(
            self,
            name: &'static str,
            variant_index: u32,
@@ -681,13 +669,13 @@ mod content {
            value: &T,
        ) -> Result<Content, E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
            Ok(Content::NewtypeVariant(
                name,
                variant_index,
                variant,
-                Box::new(try!(value.serialize(self))),
+                Box::new(tri!(value.serialize(self))),
            ))
        }

@@ -711,7 +699,7 @@ mod content {
            len: usize,
        ) -> Result<Self::SerializeTupleStruct, E> {
            Ok(SerializeTupleStruct {
-                name: name,
+                name,
                fields: Vec::with_capacity(len),
                error: PhantomData,
            })
@@ -725,9 +713,9 @@ mod content {
            len: usize,
        ) -> Result<Self::SerializeTupleVariant, E> {
            Ok(SerializeTupleVariant {
-                name: name,
-                variant_index: variant_index,
-                variant: variant,
+                name,
+                variant_index,
+                variant,
                fields: Vec::with_capacity(len),
                error: PhantomData,
            })
@@ -747,7 +735,7 @@ mod content {
            len: usize,
        ) -> Result<Self::SerializeStruct, E> {
            Ok(SerializeStruct {
-                name: name,
+                name,
                fields: Vec::with_capacity(len),
                error: PhantomData,
            })
@@ -761,9 +749,9 @@ mod content {
            len: usize,
        ) -> Result<Self::SerializeStructVariant, E> {
            Ok(SerializeStructVariant {
-                name: name,
-                variant_index: variant_index,
-                variant: variant,
+                name,
+                variant_index,
+                variant,
                fields: Vec::with_capacity(len),
                error: PhantomData,
            })
@@ -782,11 +770,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.elements.push(value);
            Ok(())
        }
@@ -808,11 +796,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.elements.push(value);
            Ok(())
        }
@@ -835,11 +823,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.fields.push(value);
            Ok(())
        }
@@ -864,11 +852,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.fields.push(value);
            Ok(())
        }
@@ -896,24 +884,24 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), E>
+        fn serialize_key<T>(&mut self, key: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let key = try!(key.serialize(ContentSerializer::<E>::new()));
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
            self.key = Some(key);
            Ok(())
        }

-        fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_value<T>(&mut self, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
            let key = self
                .key
                .take()
                .expect("serialize_value called before serialize_key");
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.entries.push((key, value));
            Ok(())
        }
@@ -922,13 +910,13 @@ mod content {
            Ok(Content::Map(self.entries))
        }

-        fn serialize_entry<K: ?Sized, V: ?Sized>(&mut self, key: &K, value: &V) -> Result<(), E>
+        fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), E>
        where
-            K: Serialize,
-            V: Serialize,
+            K: ?Sized + Serialize,
+            V: ?Sized + Serialize,
        {
-            let key = try!(key.serialize(ContentSerializer::<E>::new()));
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.entries.push((key, value));
            Ok(())
        }
@@ -947,11 +935,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.fields.push((key, value));
            Ok(())
        }
@@ -976,11 +964,11 @@ mod content {
        type Ok = Content;
        type Error = E;

-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
        where
-            T: Serialize,
+            T: ?Sized + Serialize,
        {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
            self.fields.push((key, value));
            Ok(())
        }
@@ -1025,7 +1013,7 @@ where
    type SerializeTupleStruct = Impossible<Self::Ok, M::Error>;
    type SerializeMap = FlatMapSerializeMap<'a, M>;
    type SerializeStruct = FlatMapSerializeStruct<'a, M>;
-    type SerializeTupleVariant = Impossible<Self::Ok, M::Error>;
+    type SerializeTupleVariant = FlatMapSerializeTupleVariantAsMapValue<'a, M>;
    type SerializeStructVariant = FlatMapSerializeStructVariantAsMapValue<'a, M>;

    fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
@@ -1088,9 +1076,9 @@ where
        Ok(())
    }

-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        value.serialize(self)
    }
@@ -1100,7 +1088,7 @@ where
    }

    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(Self::bad_type(Unsupported::UnitStruct))
+        Ok(())
    }

    fn serialize_unit_variant(
@@ -1112,18 +1100,18 @@ where
        Err(Self::bad_type(Unsupported::Enum))
    }

-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
        self,
        _: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        value.serialize(self)
    }

-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
        self,
        _: &'static str,
        _: u32,
@@ -1131,10 +1119,9 @@ where
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
-        try!(self.0.serialize_key(variant));
-        self.0.serialize_value(value)
+        self.0.serialize_entry(variant, value)
    }

    fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
@@ -1157,10 +1144,11 @@ where
        self,
        _: &'static str,
        _: u32,
-        _: &'static str,
+        variant: &'static str,
        _: usize,
    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        Err(Self::bad_type(Unsupported::Enum))
+        tri!(self.0.serialize_key(variant));
+        Ok(FlatMapSerializeTupleVariantAsMapValue::new(self.0))
    }

    fn serialize_map(self, _: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
@@ -1182,7 +1170,7 @@ where
        inner_variant: &'static str,
        _: usize,
    ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        try!(self.0.serialize_key(inner_variant));
+        tri!(self.0.serialize_key(inner_variant));
        Ok(FlatMapSerializeStructVariantAsMapValue::new(
            self.0,
            inner_variant,
@@ -1201,28 +1189,24 @@ where
    type Ok = ();
    type Error = M::Error;

-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        self.0.serialize_key(key)
    }

-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        self.0.serialize_value(value)
    }

-    fn serialize_entry<K: ?Sized, V: ?Sized>(
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
    where
-        K: Serialize,
-        V: Serialize,
+        K: ?Sized + Serialize,
+        V: ?Sized + Serialize,
    {
        self.0.serialize_entry(key, value)
    }
@@ -1243,13 +1227,9 @@ where
    type Ok = ();
    type Error = M::Error;

-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        self.0.serialize_entry(key, value)
    }
@@ -1259,6 +1239,52 @@ where
    }
 }

+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeTupleVariantAsMapValue<'a, M: 'a> {
+    map: &'a mut M,
+    fields: Vec<Content>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    fn new(map: &'a mut M) -> Self {
+        FlatMapSerializeTupleVariantAsMapValue {
+            map,
+            fields: Vec::new(),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeTupleVariant for FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
+    where
+        T: ?Sized + Serialize,
+    {
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+        self.fields.push(value);
+        Ok(())
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        tri!(self.map.serialize_value(&Content::Seq(self.fields)));
+        Ok(())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 #[cfg(any(feature = "std", feature = "alloc"))]
 pub struct FlatMapSerializeStructVariantAsMapValue<'a, M: 'a> {
    map: &'a mut M,
@@ -1273,8 +1299,8 @@ where
 {
    fn new(map: &'a mut M, name: &'static str) -> FlatMapSerializeStructVariantAsMapValue<'a, M> {
        FlatMapSerializeStructVariantAsMapValue {
-            map: map,
-            name: name,
+            map,
+            name,
            fields: Vec::new(),
        }
    }
@@ -1288,23 +1314,47 @@ where
    type Ok = ();
    type Error = M::Error;

-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
-        let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
        self.fields.push((key, value));
        Ok(())
    }

    fn end(self) -> Result<(), Self::Error> {
-        try!(self
+        tri!(self
            .map
            .serialize_value(&Content::Struct(self.name, self.fields)));
        Ok(())
    }
 }
+
+pub struct AdjacentlyTaggedEnumVariant {
+    pub enum_name: &'static str,
+    pub variant_index: u32,
+    pub variant_name: &'static str,
+}
+
+impl Serialize for AdjacentlyTaggedEnumVariant {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_unit_variant(self.enum_name, self.variant_index, self.variant_name)
+    }
+}
+
+// Error when Serialize for a non_exhaustive remote enum encounters a variant
+// that is not recognized.
+pub struct CannotSerializeVariant<T>(pub T);
+
+impl<T> Display for CannotSerializeVariant<T>
+where
+    T: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "enum variant cannot be serialized: {:?}", self.0)
+    }
+}
@@ -1,5 +1,5 @@
-use lib::*;
-use ser::{Error, Impossible, Serialize, Serializer};
+use crate::lib::*;
+use crate::ser::{Error, Impossible, Serialize, Serializer};

 impl Error for fmt::Error {
    fn custom<T: Display>(_msg: T) -> Self {
@@ -17,8 +17,9 @@ macro_rules! fmt_primitives {
    };
 }

-/// ```edition2018
-/// use serde::Serialize;
+/// ```edition2021
+/// use serde::ser::Serialize;
+/// use serde_derive::Serialize;
 /// use std::fmt::{self, Display};
 ///
 /// #[derive(Serialize)]
@@ -51,10 +52,12 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        serialize_i16: i16,
        serialize_i32: i32,
        serialize_i64: i64,
+        serialize_i128: i128,
        serialize_u8: u8,
        serialize_u16: u16,
        serialize_u32: u32,
        serialize_u64: u64,
+        serialize_u128: u128,
        serialize_f32: f32,
        serialize_f64: f64,
        serialize_char: char,
@@ -62,13 +65,6 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        serialize_unit_struct: &'static str,
    }

-    serde_if_integer128! {
-        fmt_primitives! {
-            serialize_i128: i128,
-            serialize_u128: u128,
-        }
-    }
-
    fn serialize_unit_variant(
        self,
        _name: &'static str,
@@ -78,9 +74,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        Display::fmt(variant, self)
    }

-    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> fmt::Result
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        Serialize::serialize(value, self)
    }
@@ -93,9 +89,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        Err(fmt::Error)
    }

-    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    fn serialize_some<T>(self, _value: &T) -> fmt::Result
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        Err(fmt::Error)
    }
@@ -104,7 +100,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        Err(fmt::Error)
    }

-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
        self,
        _name: &'static str,
        _variant_index: u32,
@@ -112,7 +108,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        _value: &T,
    ) -> fmt::Result
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        Err(fmt::Error)
    }
@@ -165,9 +161,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
        Err(fmt::Error)
    }

-    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    fn collect_str<T>(self, value: &T) -> fmt::Result
    where
-        T: Display,
+        T: ?Sized + Display,
    {
        Display::fmt(value, self)
    }
@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;

-use ser::{Error, Serialize, SerializeTuple, Serializer};
+use crate::ser::{Error, Serialize, SerializeTuple, Serializer};

 ////////////////////////////////////////////////////////////////////////////////

@@ -24,20 +24,17 @@ primitive_impl!(i8, serialize_i8);
 primitive_impl!(i16, serialize_i16);
 primitive_impl!(i32, serialize_i32);
 primitive_impl!(i64, serialize_i64);
+primitive_impl!(i128, serialize_i128);
 primitive_impl!(usize, serialize_u64 as u64);
 primitive_impl!(u8, serialize_u8);
 primitive_impl!(u16, serialize_u16);
 primitive_impl!(u32, serialize_u32);
 primitive_impl!(u64, serialize_u64);
+primitive_impl!(u128, serialize_u128);
 primitive_impl!(f32, serialize_f32);
 primitive_impl!(f64, serialize_f64);
 primitive_impl!(char, serialize_char);

-serde_if_integer128! {
-    primitive_impl!(i128, serialize_i128);
-    primitive_impl!(u128, serialize_u128);
-}
-
 ////////////////////////////////////////////////////////////////////////////////

 impl Serialize for str {
@@ -51,6 +48,7 @@ impl Serialize for str {
 }

 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for String {
    #[inline]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -72,7 +70,8 @@ impl<'a> Serialize for fmt::Arguments<'a> {

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_cstr)))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for CStr {
    #[inline]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -83,7 +82,8 @@ impl Serialize for CStr {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", all(not(no_core_cstr), feature = "alloc")))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for CString {
    #[inline]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -114,7 +114,10 @@ where

 ////////////////////////////////////////////////////////////////////////////////

-impl<T: ?Sized> Serialize for PhantomData<T> {
+impl<T> Serialize for PhantomData<T>
+where
+    T: ?Sized,
+{
    #[inline]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -133,7 +136,7 @@ impl<T> Serialize for [T; 0] {
    where
        S: Serializer,
    {
-        try!(serializer.serialize_tuple(0)).end()
+        tri!(serializer.serialize_tuple(0)).end()
    }
 }

@@ -149,9 +152,9 @@ macro_rules! array_impls {
                where
                    S: Serializer,
                {
-                    let mut seq = try!(serializer.serialize_tuple($len));
+                    let mut seq = tri!(serializer.serialize_tuple($len));
                    for e in self {
-                        try!(seq.serialize_element(e));
+                        tri!(seq.serialize_element(e));
                    }
                    seq.end()
                }
@@ -182,9 +185,35 @@ where
    }
 }

-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(not(no_relaxed_trait_bounds))]
 macro_rules! seq_impl {
-    ($ty:ident < T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)* >) => {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
+        impl<T $(, $typaram)*> Serialize for $ty<T $(, $typaram)*>
+        where
+            T: Serialize,
+        {
+            #[inline]
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: Serializer,
+            {
+                serializer.collect_seq(self)
+            }
+        }
+    }
+}
+
+#[cfg(no_relaxed_trait_bounds)]
+macro_rules! seq_impl {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
        impl<T $(, $typaram)*> Serialize for $ty<T $(, $typaram)*>
        where
            T: Serialize $(+ $tbound1 $(+ $tbound2)*)*,
@@ -201,23 +230,41 @@ macro_rules! seq_impl {
    }
 }

-#[cfg(any(feature = "std", feature = "alloc"))]
-seq_impl!(BinaryHeap<T: Ord>);
+seq_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    BinaryHeap<T: Ord>
+}

-#[cfg(any(feature = "std", feature = "alloc"))]
-seq_impl!(BTreeSet<T: Ord>);
+seq_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    BTreeSet<T: Ord>
+}

-#[cfg(feature = "std")]
-seq_impl!(HashSet<T: Eq + Hash, H: BuildHasher>);
+seq_impl! {
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    HashSet<T: Eq + Hash, H: BuildHasher>
+}

-#[cfg(any(feature = "std", feature = "alloc"))]
-seq_impl!(LinkedList<T>);
+seq_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    LinkedList<T>
+}

-#[cfg(any(feature = "std", feature = "alloc"))]
-seq_impl!(Vec<T>);
+seq_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    Vec<T>
+}

-#[cfg(any(feature = "std", feature = "alloc"))]
-seq_impl!(VecDeque<T>);
+seq_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    VecDeque<T>
+}

 ////////////////////////////////////////////////////////////////////////////////

@@ -230,16 +277,32 @@ where
        S: Serializer,
    {
        use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("Range", 2));
-        try!(state.serialize_field("start", &self.start));
-        try!(state.serialize_field("end", &self.end));
+        let mut state = tri!(serializer.serialize_struct("Range", 2));
+        tri!(state.serialize_field("start", &self.start));
+        tri!(state.serialize_field("end", &self.end));
+        state.end()
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+impl<Idx> Serialize for RangeFrom<Idx>
+where
+    Idx: Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        use super::SerializeStruct;
+        let mut state = tri!(serializer.serialize_struct("RangeFrom", 1));
+        tri!(state.serialize_field("start", &self.start));
        state.end()
    }
 }

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(range_inclusive)]
 impl<Idx> Serialize for RangeInclusive<Idx>
 where
    Idx: Serialize,
@@ -249,16 +312,32 @@ where
        S: Serializer,
    {
        use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("RangeInclusive", 2));
-        try!(state.serialize_field("start", &self.start()));
-        try!(state.serialize_field("end", &self.end()));
+        let mut state = tri!(serializer.serialize_struct("RangeInclusive", 2));
+        tri!(state.serialize_field("start", &self.start()));
+        tri!(state.serialize_field("end", &self.end()));
+        state.end()
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+impl<Idx> Serialize for RangeTo<Idx>
+where
+    Idx: Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        use super::SerializeStruct;
+        let mut state = tri!(serializer.serialize_struct("RangeTo", 1));
+        tri!(state.serialize_field("end", &self.end));
        state.end()
    }
 }

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(any(ops_bound, collections_bound))]
 impl<T> Serialize for Bound<T>
 where
    T: Serialize,
@@ -292,6 +371,7 @@ impl Serialize for () {
 }

 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl Serialize for ! {
    fn serialize<S>(&self, _serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -306,28 +386,46 @@ impl Serialize for ! {
 macro_rules! tuple_impls {
    ($($len:expr => ($($n:tt $name:ident)+))+) => {
        $(
+            #[cfg_attr(docsrs, doc(hidden))]
            impl<$($name),+> Serialize for ($($name,)+)
            where
                $($name: Serialize,)+
            {
-                #[inline]
-                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-                where
-                    S: Serializer,
-                {
-                    let mut tuple = try!(serializer.serialize_tuple($len));
-                    $(
-                        try!(tuple.serialize_element(&self.$n));
-                    )+
-                    tuple.end()
-                }
+                tuple_impl_body!($len => ($($n)+));
            }
        )+
-    }
+    };
+}
+
+macro_rules! tuple_impl_body {
+    ($len:expr => ($($n:tt)+)) => {
+        #[inline]
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            let mut tuple = tri!(serializer.serialize_tuple($len));
+            $(
+                tri!(tuple.serialize_element(&self.$n));
+            )+
+            tuple.end()
+        }
+    };
+}
+
+#[cfg_attr(docsrs, doc(fake_variadic))]
+#[cfg_attr(
+    docsrs,
+    doc = "This trait is implemented for tuples up to 16 items long."
+)]
+impl<T> Serialize for (T,)
+where
+    T: Serialize,
+{
+    tuple_impl_body!(1 => (0));
 }

 tuple_impls! {
-    1 => (0 T0)
    2 => (0 T0 1 T1)
    3 => (0 T0 1 T1 2 T2)
    4 => (0 T0 1 T1 2 T2 3 T3)
@@ -347,9 +445,36 @@ tuple_impls! {

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(not(no_relaxed_trait_bounds))]
 macro_rules! map_impl {
-    ($ty:ident < K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)* >) => {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
+        impl<K, V $(, $typaram)*> Serialize for $ty<K, V $(, $typaram)*>
+        where
+            K: Serialize,
+            V: Serialize,
+        {
+            #[inline]
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: Serializer,
+            {
+                serializer.collect_map(self)
+            }
+        }
+    }
+}
+
+#[cfg(no_relaxed_trait_bounds)]
+macro_rules! map_impl {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
        impl<K, V $(, $typaram)*> Serialize for $ty<K, V $(, $typaram)*>
        where
            K: Serialize $(+ $kbound1 $(+ $kbound2)*)*,
@@ -367,20 +492,26 @@ macro_rules! map_impl {
    }
 }

-#[cfg(any(feature = "std", feature = "alloc"))]
-map_impl!(BTreeMap<K: Ord, V>);
+map_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    BTreeMap<K: Ord, V>
+}

-#[cfg(feature = "std")]
-map_impl!(HashMap<K: Eq + Hash, V, H: BuildHasher>);
+map_impl! {
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    HashMap<K: Eq + Hash, V, H: BuildHasher>
+}

 ////////////////////////////////////////////////////////////////////////////////

 macro_rules! deref_impl {
    (
-        $(#[doc = $doc:tt])*
+        $(#[$attr:meta])*
        <$($desc:tt)+
    ) => {
-        $(#[doc = $doc])*
+        $(#[$attr])*
        impl <$($desc)+ {
            #[inline]
            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -393,13 +524,20 @@ macro_rules! deref_impl {
    };
 }

-deref_impl!(<'a, T: ?Sized> Serialize for &'a T where T: Serialize);
-deref_impl!(<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize);
+deref_impl! {
+    <'a, T> Serialize for &'a T where T: ?Sized + Serialize
+}

-#[cfg(any(feature = "std", feature = "alloc"))]
-deref_impl!(<T: ?Sized> Serialize for Box<T> where T: Serialize);
+deref_impl! {
+    <'a, T> Serialize for &'a mut T where T: ?Sized + Serialize
+}
+
+deref_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    <T> Serialize for Box<T> where T: ?Sized + Serialize
+}

-#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 deref_impl! {
    /// This impl requires the [`"rc"`] Cargo feature of Serde.
    ///
@@ -409,10 +547,11 @@ deref_impl! {
    /// repeated data.
    ///
    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
-    <T: ?Sized> Serialize for Rc<T> where T: Serialize
+    #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
+    <T> Serialize for Rc<T> where T: ?Sized + Serialize
 }

-#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 deref_impl! {
    /// This impl requires the [`"rc"`] Cargo feature of Serde.
    ///
@@ -422,11 +561,16 @@ deref_impl! {
    /// repeated data.
    ///
    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
-    <T: ?Sized> Serialize for Arc<T> where T: Serialize
+    #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
+    <T> Serialize for Arc<T> where T: ?Sized + Serialize
 }

-#[cfg(any(feature = "std", feature = "alloc"))]
-deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned);
+deref_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    <'a, T> Serialize for Cow<'a, T> where T: ?Sized + Serialize + ToOwned
+}

 ////////////////////////////////////////////////////////////////////////////////

@@ -434,9 +578,13 @@ deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwne
 ///
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-impl<T: ?Sized> Serialize for RcWeak<T>
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
+)]
+impl<T> Serialize for RcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -450,9 +598,13 @@ where
 ///
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-impl<T: ?Sized> Serialize for ArcWeak<T>
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
+)]
+impl<T> Serialize for ArcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -465,9 +617,8 @@ where
 ////////////////////////////////////////////////////////////////////////////////

 macro_rules! nonzero_integers {
-    ( $( $T: ident, )+ ) => {
+    ($($T:ident,)+) => {
        $(
-            #[cfg(num_nonzero)]
            impl Serialize for num::$T {
                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                where
@@ -485,31 +636,20 @@ nonzero_integers! {
    NonZeroU16,
    NonZeroU32,
    NonZeroU64,
+    NonZeroU128,
    NonZeroUsize,
 }

-#[cfg(num_nonzero_signed)]
+#[cfg(not(no_num_nonzero_signed))]
 nonzero_integers! {
    NonZeroI8,
    NonZeroI16,
    NonZeroI32,
    NonZeroI64,
+    NonZeroI128,
    NonZeroIsize,
 }

-// Currently 128-bit integers do not work on Emscripten targets so we need an
-// additional `#[cfg]`
-serde_if_integer128! {
-    nonzero_integers! {
-        NonZeroU128,
-    }
-
-    #[cfg(num_nonzero_signed)]
-    nonzero_integers! {
-        NonZeroI128,
-    }
-}
-
 impl<T> Serialize for Cell<T>
 where
    T: Serialize + Copy,
@@ -524,7 +664,7 @@ where

 impl<T> Serialize for RefCell<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -538,9 +678,10 @@ where
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<T> Serialize for Mutex<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -554,9 +695,10 @@ where
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<T> Serialize for RwLock<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -591,16 +733,15 @@ where

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(any(core_duration, feature = "std"))]
 impl Serialize for Duration {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("Duration", 2));
-        try!(state.serialize_field("secs", &self.as_secs()));
-        try!(state.serialize_field("nanos", &self.subsec_nanos()));
+        let mut state = tri!(serializer.serialize_struct("Duration", 2));
+        tri!(state.serialize_field("secs", &self.as_secs()));
+        tri!(state.serialize_field("nanos", &self.subsec_nanos()));
        state.end()
    }
 }
@@ -608,18 +749,20 @@ impl Serialize for Duration {
 ////////////////////////////////////////////////////////////////////////////////

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for SystemTime {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        use super::SerializeStruct;
-        let duration_since_epoch = self
-            .duration_since(UNIX_EPOCH)
-            .map_err(|_| S::Error::custom("SystemTime must be later than UNIX_EPOCH"))?;
-        let mut state = try!(serializer.serialize_struct("SystemTime", 2));
-        try!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
-        try!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
+        let duration_since_epoch = match self.duration_since(UNIX_EPOCH) {
+            Ok(duration_since_epoch) => duration_since_epoch,
+            Err(_) => return Err(S::Error::custom("SystemTime must be later than UNIX_EPOCH")),
+        };
+        let mut state = tri!(serializer.serialize_struct("SystemTime", 2));
+        tri!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
+        tri!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
        state.end()
    }
 }
@@ -630,27 +773,17 @@ impl Serialize for SystemTime {
 /// statically known to never have more than a constant `MAX_LEN` bytes.
 ///
 /// Panics if the `Display` impl tries to write more than `MAX_LEN` bytes.
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 macro_rules! serialize_display_bounded_length {
    ($value:expr, $max:expr, $serializer:expr) => {{
        let mut buffer = [0u8; $max];
-        let remaining_len = {
-            let mut remaining = &mut buffer[..];
-            write!(remaining, "{}", $value).unwrap();
-            remaining.len()
-        };
-        let written_len = buffer.len() - remaining_len;
-        let written = &buffer[..written_len];
-
-        // write! only provides fmt::Formatter to Display implementations, which
-        // has methods write_str and write_char but no method to write arbitrary
-        // bytes. Therefore `written` must be valid UTF-8.
-        let written_str = str::from_utf8(written).expect("must be valid UTF-8");
-        $serializer.serialize_str(written_str)
+        let mut writer = crate::format::Buf::new(&mut buffer);
+        write!(&mut writer, "{}", $value).unwrap();
+        $serializer.serialize_str(writer.as_str())
    }};
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::IpAddr {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -674,15 +807,15 @@ impl Serialize for net::IpAddr {
    }
 }

-#[cfg(feature = "std")]
-const DEC_DIGITS_LUT: &'static [u8] = b"\
+#[cfg(any(feature = "std", not(no_core_net)))]
+const DEC_DIGITS_LUT: &[u8] = b"\
      0001020304050607080910111213141516171819\
      2021222324252627282930313233343536373839\
      4041424344454647484950515253545556575859\
      6061626364656667686970717273747576777879\
      8081828384858687888990919293949596979899";

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 #[inline]
 fn format_u8(mut n: u8, out: &mut [u8]) -> usize {
    if n >= 100 {
@@ -703,7 +836,7 @@ fn format_u8(mut n: u8, out: &mut [u8]) -> usize {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 #[test]
 fn test_format_u8() {
    let mut i = 0u8;
@@ -720,7 +853,7 @@ fn test_format_u8() {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::Ipv4Addr {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -735,15 +868,16 @@ impl Serialize for net::Ipv4Addr {
                // Skip over delimiters that we initialized buf with
                written += format_u8(*oct, &mut buf[written + 1..]) + 1;
            }
-            // We've only written ASCII bytes to the buffer, so it is valid UTF-8
-            serializer.serialize_str(unsafe { str::from_utf8_unchecked(&buf[..written]) })
+            // Safety: We've only written ASCII bytes to the buffer, so it is valid UTF-8
+            let buf = unsafe { str::from_utf8_unchecked(&buf[..written]) };
+            serializer.serialize_str(buf)
        } else {
            self.octets().serialize(serializer)
        }
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::Ipv6Addr {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -759,7 +893,7 @@ impl Serialize for net::Ipv6Addr {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddr {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -783,7 +917,7 @@ impl Serialize for net::SocketAddr {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddrV4 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -799,7 +933,7 @@ impl Serialize for net::SocketAddrV4 {
    }
 }

-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddrV6 {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -821,6 +955,7 @@ impl Serialize for net::SocketAddrV6 {
 ////////////////////////////////////////////////////////////////////////////////

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for Path {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -834,6 +969,7 @@ impl Serialize for Path {
 }

 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for PathBuf {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -844,6 +980,7 @@ impl Serialize for PathBuf {
 }

 #[cfg(all(feature = "std", any(unix, windows)))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsStr {
    #[cfg(unix)]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -866,6 +1003,7 @@ impl Serialize for OsStr {
 }

 #[cfg(all(feature = "std", any(unix, windows)))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsString {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
@@ -890,7 +1028,20 @@ where
    }
 }

-#[cfg(core_reverse)]
+#[cfg(not(no_core_num_saturating))]
+impl<T> Serialize for Saturating<T>
+where
+    T: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.0.serialize(serializer)
+    }
+}
+
 impl<T> Serialize for Reverse<T>
 where
    T: Serialize,
@@ -906,30 +1057,40 @@ where

 ////////////////////////////////////////////////////////////////////////////////

-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 macro_rules! atomic_impl {
-    ($($ty:ident)*) => {
+    ($($ty:ident $size:expr)*) => {
        $(
+            #[cfg(any(no_target_has_atomic, target_has_atomic = $size))]
+            #[cfg_attr(docsrs, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
            impl Serialize for $ty {
                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                where
                    S: Serializer,
                {
-                    self.load(Ordering::SeqCst).serialize(serializer)
+                    // Matches the atomic ordering used in libcore for the Debug impl
+                    self.load(Ordering::Relaxed).serialize(serializer)
                }
            }
        )*
    }
 }

-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 atomic_impl! {
-    AtomicBool
-    AtomicI8 AtomicI16 AtomicI32 AtomicIsize
-    AtomicU8 AtomicU16 AtomicU32 AtomicUsize
+    AtomicBool "8"
+    AtomicI8 "8"
+    AtomicI16 "16"
+    AtomicI32 "32"
+    AtomicIsize "ptr"
+    AtomicU8 "8"
+    AtomicU16 "16"
+    AtomicU32 "32"
+    AtomicUsize "ptr"
 }

-#[cfg(all(feature = "std", std_atomic64))]
+#[cfg(all(feature = "std", not(no_std_atomic64)))]
 atomic_impl! {
-    AtomicI64 AtomicU64
+    AtomicI64 "64"
+    AtomicU64 "64"
 }
@@ -1,8 +1,8 @@
 //! This module contains `Impossible` serializer and its implementations.

-use lib::*;
+use crate::lib::*;

-use ser::{
+use crate::ser::{
    self, Serialize, SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant,
    SerializeTuple, SerializeTupleStruct, SerializeTupleVariant,
 };
@@ -15,7 +15,7 @@ use ser::{
 /// [`SerializeTuple`], [`SerializeTupleStruct`], [`SerializeTupleVariant`],
 /// [`SerializeMap`], [`SerializeStruct`], and [`SerializeStructVariant`].
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use serde::ser::{Serializer, Impossible};
 /// # use serde::__private::doc::Error;
 /// #
@@ -72,9 +72,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = value;
        match self.void {}
@@ -92,9 +92,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = value;
        match self.void {}
@@ -112,9 +112,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = value;
        match self.void {}
@@ -132,9 +132,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = value;
        match self.void {}
@@ -152,17 +152,17 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = key;
        match self.void {}
    }

-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = value;
        match self.void {}
@@ -180,9 +180,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = key;
        let _ = value;
@@ -201,9 +201,9 @@ where
    type Ok = Ok;
    type Error = Error;

-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
    where
-        T: Serialize,
+        T: ?Sized + Serialize,
    {
        let _ = key;
        let _ = value;
@@ -30,7 +30,7 @@
 //! # The Serializer trait
 //!
 //! [`Serializer`] implementations are provided by third-party crates, for
-//! example [`serde_json`], [`serde_yaml`] and [`bincode`].
+//! example [`serde_json`], [`serde_yaml`] and [`postcard`].
 //!
 //! A partial list of well-maintained formats is given on the [Serde
 //! website][data formats].
@@ -61,8 +61,8 @@
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
-//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
-//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Rc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -99,7 +99,7 @@
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
 //! [`Serialize`]: ../trait.Serialize.html
 //! [`Serializer`]: ../trait.Serializer.html
-//! [`bincode`]: https://github.com/servo/bincode
+//! [`postcard`]: https://github.com/jamesmunns/postcard
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 //! [`serde_derive`]: https://crates.io/crates/serde_derive
 //! [`serde_json`]: https://github.com/serde-rs/json
@@ -107,7 +107,7 @@
 //! [derive section of the manual]: https://serde.rs/derive.html
 //! [data formats]: https://serde.rs/#data-formats

-use lib::*;
+use crate::lib::*;

 mod fmt;
 mod impls;
@@ -115,12 +115,15 @@ mod impossible;

 pub use self::impossible::Impossible;

+#[cfg(all(not(feature = "std"), no_core_error))]
+#[doc(no_inline)]
+pub use crate::std_error::Error as StdError;
+#[cfg(not(any(feature = "std", no_core_error)))]
+#[doc(no_inline)]
+pub use core::error::Error as StdError;
 #[cfg(feature = "std")]
 #[doc(no_inline)]
 pub use std::error::Error as StdError;
-#[cfg(not(feature = "std"))]
-#[doc(no_inline)]
-pub use std_error::Error as StdError;

 ////////////////////////////////////////////////////////////////////////////////

@@ -146,7 +149,7 @@ macro_rules! declare_error_trait {
            /// For example, a filesystem [`Path`] may refuse to serialize
            /// itself if it contains invalid UTF-8 data.
            ///
-            /// ```edition2018
+            /// ```edition2021
            /// # struct Path;
            /// #
            /// # impl Path {
@@ -191,8 +194,8 @@ declare_error_trait!(Error: Sized + Debug + Display);
 /// by Serde.
 ///
 /// Serde provides `Serialize` implementations for many Rust primitive and
-/// standard library types. The complete list is [here][ser]. All of these can
-/// be serialized using Serde out of the box.
+/// standard library types. The complete list is [here][crate::ser]. All of
+/// these can be serialized using Serde out of the box.
 ///
 /// Additionally, Serde provides a procedural macro called [`serde_derive`] to
 /// automatically generate `Serialize` implementations for structs and enums in
@@ -212,14 +215,20 @@ declare_error_trait!(Error: Sized + Debug + Display);
 /// [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 /// [`serde_derive`]: https://crates.io/crates/serde_derive
 /// [derive section of the manual]: https://serde.rs/derive.html
-/// [ser]: https://docs.serde.rs/serde/ser/index.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        note = "for local types consider adding `#[derive(serde::Serialize)]` to your `{Self}` type",
+        note = "for types from other crates check whether the crate offers a `serde` feature flag",
+    )
+)]
 pub trait Serialize {
    /// Serialize this value into the given Serde serializer.
    ///
    /// See the [Implementing `Serialize`] section of the manual for more
    /// information about how to implement this method.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeStruct, Serializer};
    ///
    /// struct Person {
@@ -314,7 +323,7 @@ pub trait Serialize {
 ///    - For example the `E::S` in `enum E { S { r: u8, g: u8, b: u8 } }`.
 ///
 /// Many Serde serializers produce text or binary data as output, for example
-/// JSON or Bincode. This is not a requirement of the `Serializer` trait, and
+/// JSON or Postcard. This is not a requirement of the `Serializer` trait, and
 /// there are serializers that do not produce text or binary output. One example
 /// is the `serde_json::value::Serializer` (distinct from the main `serde_json`
 /// serializer) that produces a `serde_json::Value` data structure in memory as
@@ -386,7 +395,7 @@ pub trait Serializer: Sized {

    /// Serialize a `bool` value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -408,7 +417,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `i64` and
    /// forward to `serialize_i64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -430,7 +439,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `i64` and
    /// forward to `serialize_i64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -452,7 +461,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `i64` and
    /// forward to `serialize_i64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -470,7 +479,7 @@ pub trait Serializer: Sized {

    /// Serialize an `i64` value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -486,30 +495,27 @@ pub trait Serializer: Sized {
    /// ```
    fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>;

-    serde_if_integer128! {
-        /// Serialize an `i128` value.
-        ///
-        /// ```edition2018
-        /// # use serde::Serializer;
-        /// #
-        /// # serde::__private_serialize!();
-        /// #
-        /// impl Serialize for i128 {
-        ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        ///     where
-        ///         S: Serializer,
-        ///     {
-        ///         serializer.serialize_i128(*self)
-        ///     }
-        /// }
-        /// ```
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default behavior unconditionally returns an error.
-        fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
-            let _ = v;
-            Err(Error::custom("i128 is not supported"))
-        }
+    /// Serialize an `i128` value.
+    ///
+    /// ```edition2021
+    /// # use serde::Serializer;
+    /// #
+    /// # serde::__private_serialize!();
+    /// #
+    /// impl Serialize for i128 {
+    ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    ///     where
+    ///         S: Serializer,
+    ///     {
+    ///         serializer.serialize_i128(*self)
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// The default behavior unconditionally returns an error.
+    fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
+        let _ = v;
+        Err(Error::custom("i128 is not supported"))
    }

    /// Serialize a `u8` value.
@@ -518,7 +524,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `u64` and
    /// forward to `serialize_u64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -540,7 +546,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `u64` and
    /// forward to `serialize_u64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -562,7 +568,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `u64` and
    /// forward to `serialize_u64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -580,7 +586,7 @@ pub trait Serializer: Sized {

    /// Serialize a `u64` value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -596,30 +602,27 @@ pub trait Serializer: Sized {
    /// ```
    fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>;

-    serde_if_integer128! {
-        /// Serialize a `u128` value.
-        ///
-        /// ```edition2018
-        /// # use serde::Serializer;
-        /// #
-        /// # serde::__private_serialize!();
-        /// #
-        /// impl Serialize for u128 {
-        ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        ///     where
-        ///         S: Serializer,
-        ///     {
-        ///         serializer.serialize_u128(*self)
-        ///     }
-        /// }
-        /// ```
-        ///
-        /// This method is available only on Rust compiler versions >=1.26. The
-        /// default behavior unconditionally returns an error.
-        fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
-            let _ = v;
-            Err(Error::custom("u128 is not supported"))
-        }
+    /// Serialize a `u128` value.
+    ///
+    /// ```edition2021
+    /// # use serde::Serializer;
+    /// #
+    /// # serde::__private_serialize!();
+    /// #
+    /// impl Serialize for u128 {
+    ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    ///     where
+    ///         S: Serializer,
+    ///     {
+    ///         serializer.serialize_u128(*self)
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// The default behavior unconditionally returns an error.
+    fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
+        let _ = v;
+        Err(Error::custom("u128 is not supported"))
    }

    /// Serialize an `f32` value.
@@ -628,7 +631,7 @@ pub trait Serializer: Sized {
    /// reasonable implementation would be to cast the value to `f64` and
    /// forward to `serialize_f64`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -646,7 +649,7 @@ pub trait Serializer: Sized {

    /// Serialize an `f64` value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -667,7 +670,7 @@ pub trait Serializer: Sized {
    /// If the format does not support characters, it is reasonable to serialize
    /// it as a single element `str` or a `u32`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -685,7 +688,7 @@ pub trait Serializer: Sized {

    /// Serialize a `&str`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -709,7 +712,7 @@ pub trait Serializer: Sized {
    /// `serialize_seq`. If forwarded, the implementation looks usually just
    /// like this:
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::ser::{Serializer, SerializeSeq};
    /// # use serde::__private::doc::Error;
    /// #
@@ -738,7 +741,7 @@ pub trait Serializer: Sized {

    /// Serialize a [`None`] value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::{Serialize, Serializer};
    /// #
    /// # enum Option<T> {
@@ -771,7 +774,7 @@ pub trait Serializer: Sized {

    /// Serialize a [`Some(T)`] value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::{Serialize, Serializer};
    /// #
    /// # enum Option<T> {
@@ -800,13 +803,13 @@ pub trait Serializer: Sized {
    /// ```
    ///
    /// [`Some(T)`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Serialize a `()` value.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use serde::Serializer;
    /// #
    /// # serde::__private_serialize!();
@@ -826,7 +829,7 @@ pub trait Serializer: Sized {
    ///
    /// A reasonable implementation would be to forward to `serialize_unit`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    ///
    /// struct Nothing;
@@ -848,7 +851,7 @@ pub trait Serializer: Sized {
    /// this variant within the enum, and the `variant` is the name of the
    /// variant.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    ///
    /// enum E {
@@ -881,7 +884,7 @@ pub trait Serializer: Sized {
    /// wrappers around the data they contain. A reasonable implementation would
    /// be to forward to `value.serialize(self)`.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    ///
    /// struct Millimeters(u8);
@@ -895,13 +898,13 @@ pub trait Serializer: Sized {
    ///     }
    /// }
    /// ```
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
        self,
        name: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Serialize a newtype variant like `E::N` in `enum E { N(u8) }`.
    ///
@@ -909,7 +912,7 @@ pub trait Serializer: Sized {
    /// this variant within the enum, and the `variant` is the name of the
    /// variant. The `value` is the data contained within this newtype variant.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    ///
    /// enum E {
@@ -929,7 +932,7 @@ pub trait Serializer: Sized {
    ///     }
    /// }
    /// ```
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
        self,
        name: &'static str,
        variant_index: u32,
@@ -937,7 +940,7 @@ pub trait Serializer: Sized {
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Begin to serialize a variably sized sequence. This call must be
    /// followed by zero or more calls to `serialize_element`, then a call to
@@ -947,7 +950,7 @@ pub trait Serializer: Sized {
    /// not be computable before the sequence is iterated. Some serializers only
    /// support sequences whose length is known up front.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use std::marker::PhantomData;
    /// #
    /// # struct Vec<T>(PhantomData<T>);
@@ -960,14 +963,14 @@ pub trait Serializer: Sized {
    /// #
    /// # impl<'a, T> IntoIterator for &'a Vec<T> {
    /// #     type Item = &'a T;
-    /// #     type IntoIter = Box<Iterator<Item = &'a T>>;
+    /// #     type IntoIter = Box<dyn Iterator<Item = &'a T>>;
    /// #
    /// #     fn into_iter(self) -> Self::IntoIter {
    /// #         unimplemented!()
    /// #     }
    /// # }
    /// #
-    /// use serde::ser::{Serialize, Serializer, SerializeSeq};
+    /// use serde::ser::{Serialize, SerializeSeq, Serializer};
    ///
    /// impl<T> Serialize for Vec<T>
    /// where
@@ -992,8 +995,8 @@ pub trait Serializer: Sized {
    /// This call must be followed by zero or more calls to `serialize_element`,
    /// then a call to `end`.
    ///
-    /// ```edition2018
-    /// use serde::ser::{Serialize, Serializer, SerializeTuple};
+    /// ```edition2021
+    /// use serde::ser::{Serialize, SerializeTuple, Serializer};
    ///
    /// # mod fool {
    /// #     trait Serialize {}
@@ -1022,7 +1025,7 @@ pub trait Serializer: Sized {
    /// }
    /// ```
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeTuple, Serializer};
    ///
    /// const VRAM_SIZE: usize = 386;
@@ -1050,7 +1053,7 @@ pub trait Serializer: Sized {
    /// The `name` is the name of the tuple struct and the `len` is the number
    /// of data fields that will be serialized.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
    ///
    /// struct Rgb(u8, u8, u8);
@@ -1082,7 +1085,7 @@ pub trait Serializer: Sized {
    /// this variant within the enum, the `variant` is the name of the variant,
    /// and the `len` is the number of data fields that will be serialized.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeTupleVariant, Serializer};
    ///
    /// enum E {
@@ -1128,7 +1131,7 @@ pub trait Serializer: Sized {
    /// be computable before the map is iterated. Some serializers only support
    /// maps whose length is known up front.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use std::marker::PhantomData;
    /// #
    /// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>);
@@ -1141,14 +1144,14 @@ pub trait Serializer: Sized {
    /// #
    /// # impl<'a, K, V> IntoIterator for &'a HashMap<K, V> {
    /// #     type Item = (&'a K, &'a V);
-    /// #     type IntoIter = Box<Iterator<Item = (&'a K, &'a V)>>;
+    /// #     type IntoIter = Box<dyn Iterator<Item = (&'a K, &'a V)>>;
    /// #
    /// #     fn into_iter(self) -> Self::IntoIter {
    /// #         unimplemented!()
    /// #     }
    /// # }
    /// #
-    /// use serde::ser::{Serialize, Serializer, SerializeMap};
+    /// use serde::ser::{Serialize, SerializeMap, Serializer};
    ///
    /// impl<K, V> Serialize for HashMap<K, V>
    /// where
@@ -1174,9 +1177,10 @@ pub trait Serializer: Sized {
    /// then a call to `end`.
    ///
    /// The `name` is the name of the struct and the `len` is the number of
-    /// data fields that will be serialized.
+    /// data fields that will be serialized. `len` does not include fields
+    /// which are skipped with [`SerializeStruct::skip_field`].
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeStruct, Serializer};
    ///
    /// struct Rgb {
@@ -1211,8 +1215,10 @@ pub trait Serializer: Sized {
    /// The `name` is the name of the enum, the `variant_index` is the index of
    /// this variant within the enum, the `variant` is the name of the variant,
    /// and the `len` is the number of data fields that will be serialized.
+    /// `len` does not include fields which are skipped with
+    /// [`SerializeStructVariant::skip_field`].
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
    ///
    /// enum E {
@@ -1254,7 +1260,7 @@ pub trait Serializer: Sized {
    /// using [`serialize_seq`]. Implementors should not need to override this
    /// method.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    ///
    /// struct SecretlyOneHigher {
@@ -1277,22 +1283,9 @@ pub trait Serializer: Sized {
        I: IntoIterator,
        <I as IntoIterator>::Item: Serialize,
    {
-        let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter)));
-
-        #[cfg(iterator_try_fold)]
-        {
-            let mut iter = iter;
-            try!(iter.try_for_each(|item| serializer.serialize_element(&item)));
-        }
-
-        #[cfg(not(iterator_try_fold))]
-        {
-            for item in iter {
-                try!(serializer.serialize_element(&item));
-            }
-        }
-
+        let mut iter = iter.into_iter();
+        let mut serializer = tri!(self.serialize_seq(iterator_len_hint(&iter)));
+        tri!(iter.try_for_each(|item| serializer.serialize_element(&item)));
        serializer.end()
    }

@@ -1302,7 +1295,7 @@ pub trait Serializer: Sized {
    /// using [`serialize_map`]. Implementors should not need to override this
    /// method.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// use serde::{Serialize, Serializer};
    /// use std::collections::BTreeSet;
    ///
@@ -1328,22 +1321,9 @@ pub trait Serializer: Sized {
        V: Serialize,
        I: IntoIterator<Item = (K, V)>,
    {
-        let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter)));
-
-        #[cfg(iterator_try_fold)]
-        {
-            let mut iter = iter;
-            try!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value)));
-        }
-
-        #[cfg(not(iterator_try_fold))]
-        {
-            for (key, value) in iter {
-                try!(serializer.serialize_entry(&key, &value));
-            }
-        }
-
+        let mut iter = iter.into_iter();
+        let mut serializer = tri!(self.serialize_map(iterator_len_hint(&iter)));
+        tri!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value)));
        serializer.end()
    }

@@ -1353,7 +1333,7 @@ pub trait Serializer: Sized {
    /// delegates to [`serialize_str`]. Serializers are encouraged to provide a
    /// more efficient implementation if possible.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # struct DateTime;
    /// #
    /// # impl DateTime {
@@ -1368,9 +1348,7 @@ pub trait Serializer: Sized {
    ///     where
    ///         S: Serializer,
    ///     {
-    ///         serializer.collect_str(&format_args!("{:?}{:?}",
-    ///                                              self.naive_local(),
-    ///                                              self.offset()))
+    ///         serializer.collect_str(&format_args!("{:?}{:?}", self.naive_local(), self.offset()))
    ///     }
    /// }
    /// ```
@@ -1378,9 +1356,9 @@ pub trait Serializer: Sized {
    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
    /// [`serialize_str`]: #tymethod.serialize_str
    #[cfg(any(feature = "std", feature = "alloc"))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Display,
+        T: ?Sized + Display,
    {
        self.serialize_str(&value.to_string())
    }
@@ -1391,7 +1369,7 @@ pub trait Serializer: Sized {
    /// of this method. If no more sensible behavior is possible, the
    /// implementation is expected to return an error.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # struct DateTime;
    /// #
    /// # impl DateTime {
@@ -1406,16 +1384,14 @@ pub trait Serializer: Sized {
    ///     where
    ///         S: Serializer,
    ///     {
-    ///         serializer.collect_str(&format_args!("{:?}{:?}",
-    ///                                              self.naive_local(),
-    ///                                              self.offset()))
+    ///         serializer.collect_str(&format_args!("{:?}{:?}", self.naive_local(), self.offset()))
    ///     }
    /// }
    /// ```
    #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
-        T: Display;
+        T: ?Sized + Display;

    /// Determine whether `Serialize` implementations should serialize in
    /// human-readable form.
@@ -1423,10 +1399,10 @@ pub trait Serializer: Sized {
    /// Some types have a human-readable form that may be somewhat expensive to
    /// construct, as well as a binary form that is compact and efficient.
    /// Generally text-based formats like JSON and YAML will prefer to use the
-    /// human-readable one and binary formats like Bincode will prefer the
+    /// human-readable one and binary formats like Postcard will prefer the
    /// compact one.
    ///
-    /// ```edition2018
+    /// ```edition2021
    /// # use std::fmt::{self, Display};
    /// #
    /// # struct Timestamp;
@@ -1475,7 +1451,7 @@ pub trait Serializer: Sized {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use std::marker::PhantomData;
 /// #
 /// # struct Vec<T>(PhantomData<T>);
@@ -1488,13 +1464,13 @@ pub trait Serializer: Sized {
 /// #
 /// # impl<'a, T> IntoIterator for &'a Vec<T> {
 /// #     type Item = &'a T;
-/// #     type IntoIter = Box<Iterator<Item = &'a T>>;
+/// #     type IntoIter = Box<dyn Iterator<Item = &'a T>>;
 /// #     fn into_iter(self) -> Self::IntoIter {
 /// #         unimplemented!()
 /// #     }
 /// # }
 /// #
-/// use serde::ser::{Serialize, Serializer, SerializeSeq};
+/// use serde::ser::{Serialize, SerializeSeq, Serializer};
 ///
 /// impl<T> Serialize for Vec<T>
 /// where
@@ -1527,9 +1503,9 @@ pub trait SerializeSeq {
    type Error: Error;

    /// Serialize a sequence element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Finish serializing a sequence.
    fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1539,8 +1515,8 @@ pub trait SerializeSeq {
 ///
 /// # Example use
 ///
-/// ```edition2018
-/// use serde::ser::{Serialize, Serializer, SerializeTuple};
+/// ```edition2021
+/// use serde::ser::{Serialize, SerializeTuple, Serializer};
 ///
 /// # mod fool {
 /// #     trait Serialize {}
@@ -1569,7 +1545,7 @@ pub trait SerializeSeq {
 /// }
 /// ```
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use std::marker::PhantomData;
 /// #
 /// # struct Array<T>(PhantomData<T>);
@@ -1582,13 +1558,13 @@ pub trait SerializeSeq {
 /// #
 /// # impl<'a, T> IntoIterator for &'a Array<T> {
 /// #     type Item = &'a T;
-/// #     type IntoIter = Box<Iterator<Item = &'a T>>;
+/// #     type IntoIter = Box<dyn Iterator<Item = &'a T>>;
 /// #     fn into_iter(self) -> Self::IntoIter {
 /// #         unimplemented!()
 /// #     }
 /// # }
 /// #
-/// use serde::ser::{Serialize, Serializer, SerializeTuple};
+/// use serde::ser::{Serialize, SerializeTuple, Serializer};
 ///
 /// # mod fool {
 /// #     trait Serialize {}
@@ -1627,9 +1603,9 @@ pub trait SerializeTuple {
    type Error: Error;

    /// Serialize a tuple element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Finish serializing a tuple.
    fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1639,7 +1615,7 @@ pub trait SerializeTuple {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
 ///
 /// struct Rgb(u8, u8, u8);
@@ -1672,9 +1648,9 @@ pub trait SerializeTupleStruct {
    type Error: Error;

    /// Serialize a tuple struct field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Finish serializing a tuple struct.
    fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1684,7 +1660,7 @@ pub trait SerializeTupleStruct {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// use serde::ser::{Serialize, SerializeTupleVariant, Serializer};
 ///
 /// enum E {
@@ -1730,9 +1706,9 @@ pub trait SerializeTupleVariant {
    type Error: Error;

    /// Serialize a tuple variant field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Finish serializing a tuple variant.
    fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1742,7 +1718,7 @@ pub trait SerializeTupleVariant {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// # use std::marker::PhantomData;
 /// #
 /// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>);
@@ -1755,14 +1731,14 @@ pub trait SerializeTupleVariant {
 /// #
 /// # impl<'a, K, V> IntoIterator for &'a HashMap<K, V> {
 /// #     type Item = (&'a K, &'a V);
-/// #     type IntoIter = Box<Iterator<Item = (&'a K, &'a V)>>;
+/// #     type IntoIter = Box<dyn Iterator<Item = (&'a K, &'a V)>>;
 /// #
 /// #     fn into_iter(self) -> Self::IntoIter {
 /// #         unimplemented!()
 /// #     }
 /// # }
 /// #
-/// use serde::ser::{Serialize, Serializer, SerializeMap};
+/// use serde::ser::{Serialize, SerializeMap, Serializer};
 ///
 /// impl<K, V> Serialize for HashMap<K, V>
 /// where
@@ -1801,9 +1777,9 @@ pub trait SerializeMap {
    /// `serialize_entry` instead as it may be implemented more efficiently in
    /// some formats compared to a pair of calls to `serialize_key` and
    /// `serialize_value`.
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Serialize a map value.
    ///
@@ -1811,9 +1787,9 @@ pub trait SerializeMap {
    ///
    /// Calling `serialize_value` before `serialize_key` is incorrect and is
    /// allowed to panic or produce bogus results.
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Serialize a map entry consisting of a key and a value.
    ///
@@ -1832,16 +1808,12 @@ pub trait SerializeMap {
    /// [`Serialize`]: ../trait.Serialize.html
    /// [`serialize_key`]: #tymethod.serialize_key
    /// [`serialize_value`]: #tymethod.serialize_value
-    fn serialize_entry<K: ?Sized, V: ?Sized>(
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
    where
-        K: Serialize,
-        V: Serialize,
+        K: ?Sized + Serialize,
+        V: ?Sized + Serialize,
    {
-        try!(self.serialize_key(key));
+        tri!(self.serialize_key(key));
        self.serialize_value(value)
    }

@@ -1853,7 +1825,7 @@ pub trait SerializeMap {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// use serde::ser::{Serialize, SerializeStruct, Serializer};
 ///
 /// struct Rgb {
@@ -1890,15 +1862,13 @@ pub trait SerializeStruct {
    type Error: Error;

    /// Serialize a struct field.
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Indicate that a struct field has been skipped.
+    ///
+    /// The default implementation does nothing.
    #[inline]
    fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
        let _ = key;
@@ -1913,7 +1883,7 @@ pub trait SerializeStruct {
 ///
 /// # Example use
 ///
-/// ```edition2018
+/// ```edition2021
 /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
 ///
 /// enum E {
@@ -1956,15 +1926,13 @@ pub trait SerializeStructVariant {
    type Error: Error;

    /// Serialize a struct variant field.
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
    where
-        T: Serialize;
+        T: ?Sized + Serialize;

    /// Indicate that a struct variant field has been skipped.
+    ///
+    /// The default implementation does nothing.
    #[inline]
    fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
        let _ = key;
@@ -1,4 +1,4 @@
-use lib::{Debug, Display};
+use crate::lib::{Debug, Display};

 /// Either a re-export of std::error::Error or a new identical trait, depending
 /// on whether Serde's "std" feature is enabled.
@@ -9,7 +9,7 @@ use lib::{Debug, Display};
 /// generally provide their error types with a `std::error::Error` impl
 /// directly:
 ///
-/// ```edition2018
+/// ```edition2021
 /// #[derive(Debug)]
 /// struct MySerError {...}
 ///
@@ -29,7 +29,7 @@ use lib::{Debug, Display};
 /// std = ["serde/std"]
 /// ```
 ///
-/// ```edition2018
+/// ```edition2021
 /// #[cfg(feature = "std")]
 /// impl std::error::Error for MySerError {}
 /// ```
@@ -37,7 +37,7 @@ use lib::{Debug, Display};
 /// ... or else provide the std Error impl unconditionally via Serde's
 /// re-export:
 ///
-/// ```edition2018
+/// ```edition2021
 /// impl serde::ser::StdError for MySerError {}
 /// ```
 pub trait Error: Debug + Display {
@@ -1,16 +1,18 @@
 [package]
 name = "serde_derive"
-version = "1.0.131" # remember to update html_root_url
+version = "1.0.210"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-rust-version = "1.31"
-license = "MIT OR Apache-2.0"
+categories = ["no-std", "no-std::no-alloc"]
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
-homepage = "https://serde.rs"
-repository = "https://github.com/serde-rs/serde"
 documentation = "https://serde.rs/derive.html"
-keywords = ["serde", "serialization", "no_std"]
+edition = "2015"
+exclude = ["build.rs"]
+homepage = "https://serde.rs"
+keywords = ["serde", "serialization", "no_std", "derive"]
+license = "MIT OR Apache-2.0"
 readme = "crates-io.md"
-include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+repository = "https://github.com/serde-rs/serde"
+rust-version = "1.56"

 [features]
 default = []
@@ -21,12 +23,13 @@ name = "serde_derive"
 proc-macro = true

 [dependencies]
-proc-macro2 = "1.0"
-quote = "1.0"
-syn = "1.0.60"
+proc-macro2 = { workspace = true, features = ["proc-macro"] }
+quote = { workspace = true, features = ["proc-macro"] }
+syn = { workspace = true, features = ["clone-impls", "derive", "parsing", "printing", "proc-macro"] }

 [dev-dependencies]
-serde = { version = "1.0", path = "../serde" }
+serde = { version = "1", path = "../serde" }

 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
+rustdoc-args = ["--generate-link-to-definition"]
@@ -1,36 +1,8 @@
-use std::env;
-use std::process::Command;
-use std::str;
-
-// The rustc-cfg strings below are *not* public API. Please let us know by
-// opening a GitHub issue if your build environment requires some way to enable
-// these cfgs other than by executing our build script.
 fn main() {
-    let minor = match rustc_minor_version() {
-        Some(minor) => minor,
-        None => return,
-    };
+    // Warning: build.rs is not published to crates.io.

-    // Underscore const names stabilized in Rust 1.37:
-    // https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html#using-unnamed-const-items-for-macros
-    if minor >= 37 {
-        println!("cargo:rustc-cfg=underscore_consts");
-    }
-
-    // The ptr::addr_of! macro stabilized in Rust 1.51:
-    // https://blog.rust-lang.org/2021/03/25/Rust-1.51.0.html#stabilized-apis
-    if minor >= 51 {
-        println!("cargo:rustc-cfg=ptr_addr_of");
-    }
-}
-
-fn rustc_minor_version() -> Option<u32> {
-    let rustc = env::var_os("RUSTC")?;
-    let output = Command::new(rustc).arg("--version").output().ok()?;
-    let version = str::from_utf8(&output.stdout).ok()?;
-    let mut pieces = version.split('.');
-    if pieces.next() != Some("rustc 1") {
-        return None;
-    }
-    pieces.next()?.parse().ok()
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rustc-cfg=check_cfg");
+    println!("cargo:rustc-check-cfg=cfg(check_cfg)");
+    println!("cargo:rustc-check-cfg=cfg(exhaustive)");
 }
@@ -1,12 +1,9 @@
-use std::collections::HashSet;
-
-use syn;
-use syn::punctuated::{Pair, Punctuated};
-
-use internals::ast::{Container, Data};
-use internals::{attr, ungroup};
-
+use crate::internals::ast::{Container, Data};
+use crate::internals::{attr, ungroup};
 use proc_macro2::Span;
+use std::collections::HashSet;
+use syn::punctuated::{Pair, Punctuated};
+use syn::Token;

 // Remove the default from every type parameter because in the generated impls
 // they look like associated types: "error: associated type bindings are not
@@ -147,6 +144,7 @@ pub fn with_bound(

        fn visit_type(&mut self, ty: &'ast syn::Type) {
            match ty {
+                #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                syn::Type::Array(ty) => self.visit_type(&ty.elem),
                syn::Type::BareFn(ty) => {
                    for arg in &ty.inputs {
@@ -184,9 +182,6 @@ pub fn with_bound(

                syn::Type::Infer(_) | syn::Type::Never(_) | syn::Type::Verbatim(_) => {}

-                #[cfg(test)]
-                syn::Type::__TestExhaustive(_) => unimplemented!(),
-                #[cfg(not(test))]
                _ => {}
            }
        }
@@ -201,11 +196,14 @@ pub fn with_bound(
                syn::PathArguments::AngleBracketed(arguments) => {
                    for arg in &arguments.args {
                        match arg {
+                            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                            syn::GenericArgument::Type(arg) => self.visit_type(arg),
-                            syn::GenericArgument::Binding(arg) => self.visit_type(&arg.ty),
+                            syn::GenericArgument::AssocType(arg) => self.visit_type(&arg.ty),
                            syn::GenericArgument::Lifetime(_)
-                            | syn::GenericArgument::Constraint(_)
-                            | syn::GenericArgument::Const(_) => {}
+                            | syn::GenericArgument::Const(_)
+                            | syn::GenericArgument::AssocConst(_)
+                            | syn::GenericArgument::Constraint(_) => {}
+                            _ => {}
                        }
                    }
                }
@@ -227,8 +225,10 @@ pub fn with_bound(

        fn visit_type_param_bound(&mut self, bound: &'ast syn::TypeParamBound) {
            match bound {
+                #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                syn::TypeParamBound::Trait(bound) => self.visit_path(&bound.path),
-                syn::TypeParamBound::Lifetime(_) => {}
+                syn::TypeParamBound::Lifetime(_) | syn::TypeParamBound::Verbatim(_) => {}
+                _ => {}
            }
        }

@@ -253,7 +253,7 @@ pub fn with_bound(
    };
    match &cont.data {
        Data::Enum(variants) => {
-            for variant in variants.iter() {
+            for variant in variants {
                let relevant_fields = variant
                    .fields
                    .iter()
@@ -336,7 +336,7 @@ pub fn with_self_bound(

 pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Generics {
    let bound = syn::Lifetime::new(lifetime, Span::call_site());
-    let def = syn::LifetimeDef {
+    let def = syn::LifetimeParam {
        attrs: Vec::new(),
        lifetime: bound.clone(),
        colon_token: None,
@@ -1,23 +1,7 @@
-use proc_macro2::{Ident, TokenStream};
-use quote::format_ident;
-
-use syn;
-use try;
-
-pub fn wrap_in_const(
-    serde_path: Option<&syn::Path>,
-    trait_: &str,
-    ty: &Ident,
-    code: TokenStream,
-) -> TokenStream {
-    let try_replacement = try::replacement();
-
-    let dummy_const = if cfg!(underscore_consts) {
-        format_ident!("_")
-    } else {
-        format_ident!("_IMPL_{}_FOR_{}", trait_, unraw(ty))
-    };
+use proc_macro2::TokenStream;
+use quote::quote;

+pub fn wrap_in_const(serde_path: Option<&syn::Path>, code: TokenStream) -> TokenStream {
    let use_serde = match serde_path {
        Some(path) => quote! {
            use #path as _serde;
@@ -31,18 +15,9 @@ pub fn wrap_in_const(
    quote! {
        #[doc(hidden)]
        #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-        const #dummy_const: () = {
+        const _: () = {
            #use_serde
-            #try_replacement
            #code
        };
    }
 }
-
-#[allow(deprecated)]
-fn unraw(ident: &Ident) -> String {
-    // str::trim_start_matches was added in 1.30, trim_left_matches deprecated
-    // in 1.33. We currently support rustc back to 1.15 so we need to continue
-    // to use the deprecated one.
-    ident.to_string().trim_left_matches("r#").to_owned()
-}
@@ -1,6 +1,6 @@
 use proc_macro2::TokenStream;
 use quote::ToTokens;
-use syn::token;
+use syn::{token, Token};

 pub enum Fragment {
    /// Tokens that can be used as an expression.
@@ -1,10 +1,8 @@
 //! A Serde ast, parsed from the Syn ast and ready to generate Rust code.

-use internals::attr;
-use internals::check;
-use internals::{Ctxt, Derive};
-use syn;
+use crate::internals::{attr, check, Ctxt, Derive};
 use syn::punctuated::Punctuated;
+use syn::Token;

 /// A source data structure annotated with `#[derive(Serialize)]` and/or `#[derive(Deserialize)]`,
 /// parsed into an internal representation.
@@ -65,7 +63,7 @@ impl<'a> Container<'a> {
        item: &'a syn::DeriveInput,
        derive: Derive,
    ) -> Option<Container<'a>> {
-        let mut attrs = attr::Container::from_ast(cx, item);
+        let attrs = attr::Container::from_ast(cx, item);

        let mut data = match &item.data {
            syn::Data::Enum(data) => Data::Enum(enum_from_ast(cx, &data.variants, attrs.default())),
@@ -79,35 +77,27 @@ impl<'a> Container<'a> {
            }
        };

-        let mut has_flatten = false;
        match &mut data {
            Data::Enum(variants) => {
                for variant in variants {
                    variant.attrs.rename_by_rules(attrs.rename_all_rules());
                    for field in &mut variant.fields {
-                        if field.attrs.flatten() {
-                            has_flatten = true;
-                        }
-                        field
-                            .attrs
-                            .rename_by_rules(variant.attrs.rename_all_rules());
+                        field.attrs.rename_by_rules(
+                            variant
+                                .attrs
+                                .rename_all_rules()
+                                .or(attrs.rename_all_fields_rules()),
+                        );
                    }
                }
            }
            Data::Struct(_, fields) => {
                for field in fields {
-                    if field.attrs.flatten() {
-                        has_flatten = true;
-                    }
                    field.attrs.rename_by_rules(attrs.rename_all_rules());
                }
            }
        }

-        if has_flatten {
-            attrs.mark_has_flatten();
-        }
-
        let mut item = Container {
            ident: item.ident.clone(),
            attrs,
@@ -121,7 +111,7 @@ impl<'a> Container<'a> {
 }

 impl<'a> Data<'a> {
-    pub fn all_fields(&'a self) -> Box<Iterator<Item = &'a Field<'a>> + 'a> {
+    pub fn all_fields(&'a self) -> Box<dyn Iterator<Item = &'a Field<'a>> + 'a> {
        match self {
            Data::Enum(variants) => {
                Box::new(variants.iter().flat_map(|variant| variant.fields.iter()))
@@ -140,7 +130,7 @@ fn enum_from_ast<'a>(
    variants: &'a Punctuated<syn::Variant, Token![,]>,
    container_default: &attr::Default,
 ) -> Vec<Variant<'a>> {
-    variants
+    let variants: Vec<Variant> = variants
        .iter()
        .map(|variant| {
            let attrs = attr::Variant::from_ast(cx, variant);
@@ -154,7 +144,20 @@ fn enum_from_ast<'a>(
                original: variant,
            }
        })
-        .collect()
+        .collect();
+
+    let index_of_last_tagged_variant = variants
+        .iter()
+        .rposition(|variant| !variant.attrs.untagged());
+    if let Some(index_of_last_tagged_variant) = index_of_last_tagged_variant {
+        for variant in &variants[..index_of_last_tagged_variant] {
+            if variant.attrs.untagged() {
+                cx.error_spanned_by(&variant.ident, "all variants with the #[serde(untagged)] attribute must be placed at the end of the enum");
+            }
+        }
+    }
+
+    variants
 }

 fn struct_from_ast<'a>(
@@ -1,13 +1,8 @@
 //! Code to convert the Rust-styled field/variant (e.g. `my_field`, `MyType`) to the
 //! case of the source (e.g. `my-field`, `MY_FIELD`).

-// See https://users.rust-lang.org/t/psa-dealing-with-warning-unused-import-std-ascii-asciiext-in-today-s-nightly/13726
-#[allow(deprecated, unused_imports)]
-use std::ascii::AsciiExt;
-
-use std::fmt::{self, Debug, Display};
-
 use self::RenameRule::*;
+use std::fmt::{self, Debug, Display};

 /// The different possible ways to change case of fields in a struct, or variants in an enum.
 #[derive(Copy, Clone, PartialEq)]
@@ -59,8 +54,8 @@ impl RenameRule {
    }

    /// Apply a renaming rule to an enum variant, returning the version expected in the source.
-    pub fn apply_to_variant(&self, variant: &str) -> String {
-        match *self {
+    pub fn apply_to_variant(self, variant: &str) -> String {
+        match self {
            None | PascalCase => variant.to_owned(),
            LowerCase => variant.to_ascii_lowercase(),
            UpperCase => variant.to_ascii_uppercase(),
@@ -84,8 +79,8 @@ impl RenameRule {
    }

    /// Apply a renaming rule to a struct field, returning the version expected in the source.
-    pub fn apply_to_field(&self, field: &str) -> String {
-        match *self {
+    pub fn apply_to_field(self, field: &str) -> String {
+        match self {
            None | LowerCase | SnakeCase => field.to_owned(),
            UpperCase => field.to_ascii_uppercase(),
            PascalCase => {
@@ -112,6 +107,14 @@ impl RenameRule {
            ScreamingKebabCase => ScreamingSnakeCase.apply_to_field(field).replace('_', "-"),
        }
    }
+
+    /// Returns the `RenameRule` if it is not `None`, `rule_b` otherwise.
+    pub fn or(self, rule_b: Self) -> Self {
+        match self {
+            None => rule_b,
+            _ => self,
+        }
+    }
 }

 pub struct ParseError<'a> {
@@ -1,11 +1,13 @@
-use internals::ast::{Container, Data, Field, Style};
-use internals::attr::{Identifier, TagType};
-use internals::{ungroup, Ctxt, Derive};
+use crate::internals::ast::{Container, Data, Field, Style};
+use crate::internals::attr::{Default, Identifier, TagType};
+use crate::internals::{ungroup, Ctxt, Derive};
 use syn::{Member, Type};

-/// Cross-cutting checks that require looking at more than a single attrs
-/// object. Simpler checks should happen when parsing and building the attrs.
+// Cross-cutting checks that require looking at more than a single attrs object.
+// Simpler checks should happen when parsing and building the attrs.
 pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
+    check_default_on_tuple(cx, cont);
+    check_remote_generic(cx, cont);
    check_getter(cx, cont);
    check_flatten(cx, cont);
    check_identifier(cx, cont);
@@ -16,8 +18,63 @@ pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
    check_from_and_try_from(cx, cont);
 }

-/// Getters are only allowed inside structs (not enums) with the `remote`
-/// attribute.
+// If some field of a tuple struct is marked #[serde(default)] then all fields
+// after it must also be marked with that attribute, or the struct must have a
+// container-level serde(default) attribute. A field's default value is only
+// used for tuple fields if the sequence is exhausted at that point; that means
+// all subsequent fields will fail to deserialize if they don't have their own
+// default.
+fn check_default_on_tuple(cx: &Ctxt, cont: &Container) {
+    if let Default::None = cont.attrs.default() {
+        if let Data::Struct(Style::Tuple, fields) = &cont.data {
+            let mut first_default_index = None;
+            for (i, field) in fields.iter().enumerate() {
+                // Skipped fields automatically get the #[serde(default)]
+                // attribute. We are interested only on non-skipped fields here.
+                if field.attrs.skip_deserializing() {
+                    continue;
+                }
+                if let Default::None = field.attrs.default() {
+                    if let Some(first) = first_default_index {
+                        cx.error_spanned_by(
+                            field.ty,
+                            format!("field must have #[serde(default)] because previous field {} has #[serde(default)]", first),
+                        );
+                    }
+                    continue;
+                }
+                if first_default_index.is_none() {
+                    first_default_index = Some(i);
+                }
+            }
+        }
+    }
+}
+
+// Remote derive definition type must have either all of the generics of the
+// remote type:
+//
+//     #[serde(remote = "Generic")]
+//     struct Generic<T> {…}
+//
+// or none of them, i.e. defining impls for one concrete instantiation of the
+// remote type only:
+//
+//     #[serde(remote = "Generic<T>")]
+//     struct ConcreteDef {…}
+//
+fn check_remote_generic(cx: &Ctxt, cont: &Container) {
+    if let Some(remote) = cont.attrs.remote() {
+        let local_has_generic = !cont.generics.params.is_empty();
+        let remote_has_generic = !remote.segments.last().unwrap().arguments.is_none();
+        if local_has_generic && remote_has_generic {
+            cx.error_spanned_by(remote, "remove generic parameters from this path");
+        }
+    }
+}
+
+// Getters are only allowed inside structs (not enums) with the `remote`
+// attribute.
 fn check_getter(cx: &Ctxt, cont: &Container) {
    match cont.data {
        Data::Enum(_) => {
@@ -39,7 +96,7 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
    }
 }

-/// Flattening has some restrictions we can test.
+// Flattening has some restrictions we can test.
 fn check_flatten(cx: &Ctxt, cont: &Container) {
    match &cont.data {
        Data::Enum(variants) => {
@@ -78,18 +135,16 @@ fn check_flatten_field(cx: &Ctxt, style: Style, field: &Field) {
    }
 }

-/// The `other` attribute must be used at most once and it must be the last
-/// variant of an enum.
-///
-/// Inside a `variant_identifier` all variants must be unit variants. Inside a
-/// `field_identifier` all but possibly one variant must be unit variants. The
-/// last variant may be a newtype variant which is an implicit "other" case.
+// The `other` attribute must be used at most once and it must be the last
+// variant of an enum.
+//
+// Inside a `variant_identifier` all variants must be unit variants. Inside a
+// `field_identifier` all but possibly one variant must be unit variants. The
+// last variant may be a newtype variant which is an implicit "other" case.
 fn check_identifier(cx: &Ctxt, cont: &Container) {
    let variants = match &cont.data {
        Data::Enum(variants) => variants,
-        Data::Struct(_, _) => {
-            return;
-        }
+        Data::Struct(_, _) => return,
    };

    for (i, variant) in variants.iter().enumerate() {
@@ -166,17 +221,15 @@ fn check_identifier(cx: &Ctxt, cont: &Container) {
    }
 }

-/// Skip-(de)serializing attributes are not allowed on variants marked
-/// (de)serialize_with.
+// Skip-(de)serializing attributes are not allowed on variants marked
+// (de)serialize_with.
 fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
    let variants = match &cont.data {
        Data::Enum(variants) => variants,
-        Data::Struct(_, _) => {
-            return;
-        }
+        Data::Struct(_, _) => return,
    };

-    for variant in variants.iter() {
+    for variant in variants {
        if variant.attrs.serialize_with().is_some() {
            if variant.attrs.skip_serializing() {
                cx.error_spanned_by(
@@ -241,10 +294,9 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
    }
 }

-/// The tag of an internally-tagged struct variant must not be
-/// the same as either one of its fields, as this would result in
-/// duplicate keys in the serialized output and/or ambiguity in
-/// the to-be-deserialized input.
+// The tag of an internally-tagged struct variant must not be the same as either
+// one of its fields, as this would result in duplicate keys in the serialized
+// output and/or ambiguity in the to-be-deserialized input.
 fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
    let variants = match &cont.data {
        Data::Enum(variants) => variants,
@@ -266,9 +318,14 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
    for variant in variants {
        match variant.style {
            Style::Struct => {
+                if variant.attrs.untagged() {
+                    continue;
+                }
                for field in &variant.fields {
-                    let check_ser = !field.attrs.skip_serializing();
-                    let check_de = !field.attrs.skip_deserializing();
+                    let check_ser =
+                        !(field.attrs.skip_serializing() || variant.attrs.skip_serializing());
+                    let check_de =
+                        !(field.attrs.skip_deserializing() || variant.attrs.skip_deserializing());
                    let name = field.attrs.name();
                    let ser_name = name.serialize_name();

@@ -290,8 +347,8 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
    }
 }

-/// In the case of adjacently-tagged enums, the type and the
-/// contents tag must differ, for the same reason.
+// In the case of adjacently-tagged enums, the type and the contents tag must
+// differ, for the same reason.
 fn check_adjacent_tag_conflict(cx: &Ctxt, cont: &Container) {
    let (type_tag, content_tag) = match cont.attrs.tag() {
        TagType::Adjacent { tag, content } => (tag, content),
@@ -309,7 +366,7 @@ fn check_adjacent_tag_conflict(cx: &Ctxt, cont: &Container) {
    }
 }

-/// Enums and unit structs cannot be transparent.
+// Enums and unit structs cannot be transparent.
 fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
    if !cont.attrs.transparent() {
        return;
@@ -2,7 +2,6 @@ use quote::ToTokens;
 use std::cell::RefCell;
 use std::fmt::Display;
 use std::thread;
-use syn;

 /// A type to collect errors together and format them.
 ///
@@ -44,12 +43,19 @@ impl Ctxt {
    }

    /// Consume this object, producing a formatted error string if there are errors.
-    pub fn check(self) -> Result<(), Vec<syn::Error>> {
-        let errors = self.errors.borrow_mut().take().unwrap();
-        match errors.len() {
-            0 => Ok(()),
-            _ => Err(errors),
+    pub fn check(self) -> syn::Result<()> {
+        let mut errors = self.errors.borrow_mut().take().unwrap().into_iter();
+
+        let mut combined = match errors.next() {
+            Some(first) => first,
+            None => return Ok(()),
+        };
+
+        for rest in errors {
+            combined.combine(rest);
        }
+
+        Err(combined)
    }
 }

@@ -1,19 +1,18 @@
 pub mod ast;
 pub mod attr;

-mod ctxt;
-pub use self::ctxt::Ctxt;
-
-mod receiver;
-pub use self::receiver::replace_receiver;
-
 mod case;
 mod check;
+mod ctxt;
+mod receiver;
 mod respan;
 mod symbol;

 use syn::Type;

+pub use self::ctxt::Ctxt;
+pub use self::receiver::replace_receiver;
+
 #[derive(Copy, Clone)]
 pub enum Derive {
    Serialize,
@@ -1,11 +1,11 @@
-use internals::respan::respan;
+use crate::internals::respan::respan;
 use proc_macro2::Span;
 use quote::ToTokens;
 use std::mem;
 use syn::punctuated::Punctuated;
 use syn::{
    parse_quote, Data, DeriveInput, Expr, ExprPath, GenericArgument, GenericParam, Generics, Macro,
-    Path, PathArguments, QSelf, ReturnType, Type, TypeParamBound, TypePath, WherePredicate,
+    Path, PathArguments, QSelf, ReturnType, Token, Type, TypeParamBound, TypePath, WherePredicate,
 };

 pub fn replace_receiver(input: &mut DeriveInput) {
@@ -84,7 +84,7 @@ impl ReplaceReceiver<'_> {
            self.visit_type_mut_impl(ty);
            return;
        };
-        *ty = self.self_ty(span).into();
+        *ty = Type::Path(self.self_ty(span));
    }

    // `Self::Assoc` -> `<Receiver>::Assoc`
@@ -107,6 +107,7 @@ impl ReplaceReceiver<'_> {

    fn visit_type_mut_impl(&mut self, ty: &mut Type) {
        match ty {
+            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
            Type::Array(ty) => {
                self.visit_type_mut(&mut ty.elem);
                self.visit_expr_mut(&mut ty.len);
@@ -147,9 +148,6 @@ impl ReplaceReceiver<'_> {

            Type::Infer(_) | Type::Never(_) | Type::Verbatim(_) => {}

-            #[cfg(test)]
-            Type::__TestExhaustive(_) => unimplemented!(),
-            #[cfg(not(test))]
            _ => {}
        }
    }
@@ -180,11 +178,14 @@ impl ReplaceReceiver<'_> {
            PathArguments::AngleBracketed(arguments) => {
                for arg in &mut arguments.args {
                    match arg {
+                        #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                        GenericArgument::Type(arg) => self.visit_type_mut(arg),
-                        GenericArgument::Binding(arg) => self.visit_type_mut(&mut arg.ty),
+                        GenericArgument::AssocType(arg) => self.visit_type_mut(&mut arg.ty),
                        GenericArgument::Lifetime(_)
-                        | GenericArgument::Constraint(_)
-                        | GenericArgument::Const(_) => {}
+                        | GenericArgument::Const(_)
+                        | GenericArgument::AssocConst(_)
+                        | GenericArgument::Constraint(_) => {}
+                        _ => {}
                    }
                }
            }
@@ -206,8 +207,10 @@ impl ReplaceReceiver<'_> {

    fn visit_type_param_bound_mut(&mut self, bound: &mut TypeParamBound) {
        match bound {
+            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
            TypeParamBound::Trait(bound) => self.visit_path_mut(&mut bound.path),
-            TypeParamBound::Lifetime(_) => {}
+            TypeParamBound::Lifetime(_) | TypeParamBound::Verbatim(_) => {}
+            _ => {}
        }
    }

@@ -225,13 +228,15 @@ impl ReplaceReceiver<'_> {
        if let Some(where_clause) = &mut generics.where_clause {
            for predicate in &mut where_clause.predicates {
                match predicate {
+                    #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                    WherePredicate::Type(predicate) => {
                        self.visit_type_mut(&mut predicate.bounded_ty);
                        for bound in &mut predicate.bounds {
                            self.visit_type_param_bound_mut(bound);
                        }
                    }
-                    WherePredicate::Lifetime(_) | WherePredicate::Eq(_) => {}
+                    WherePredicate::Lifetime(_) => {}
+                    _ => {}
                }
            }
        }
@@ -13,15 +13,19 @@ pub const DEFAULT: Symbol = Symbol("default");
 pub const DENY_UNKNOWN_FIELDS: Symbol = Symbol("deny_unknown_fields");
 pub const DESERIALIZE: Symbol = Symbol("deserialize");
 pub const DESERIALIZE_WITH: Symbol = Symbol("deserialize_with");
+pub const EXPECTING: Symbol = Symbol("expecting");
 pub const FIELD_IDENTIFIER: Symbol = Symbol("field_identifier");
 pub const FLATTEN: Symbol = Symbol("flatten");
 pub const FROM: Symbol = Symbol("from");
 pub const GETTER: Symbol = Symbol("getter");
 pub const INTO: Symbol = Symbol("into");
+pub const NON_EXHAUSTIVE: Symbol = Symbol("non_exhaustive");
 pub const OTHER: Symbol = Symbol("other");
 pub const REMOTE: Symbol = Symbol("remote");
 pub const RENAME: Symbol = Symbol("rename");
 pub const RENAME_ALL: Symbol = Symbol("rename_all");
+pub const RENAME_ALL_FIELDS: Symbol = Symbol("rename_all_fields");
+pub const REPR: Symbol = Symbol("repr");
 pub const SERDE: Symbol = Symbol("serde");
 pub const SERIALIZE: Symbol = Symbol("serialize");
 pub const SERIALIZE_WITH: Symbol = Symbol("serialize_with");
@@ -35,7 +39,6 @@ pub const TRY_FROM: Symbol = Symbol("try_from");
 pub const UNTAGGED: Symbol = Symbol("untagged");
 pub const VARIANT_IDENTIFIER: Symbol = Symbol("variant_identifier");
 pub const WITH: Symbol = Symbol("with");
-pub const EXPECTING: Symbol = Symbol("expecting");

 impl PartialEq<Symbol> for Ident {
    fn eq(&self, word: &Symbol) -> bool {
@@ -1,7 +1,7 @@
 //! This crate provides Serde's two derive macros.
 //!
-//! ```edition2018
-//! # use serde_derive::{Serialize, Deserialize};
+//! ```edition2021
+//! # use serde_derive::{Deserialize, Serialize};
 //! #
 //! #[derive(Serialize, Deserialize)]
 //! # struct S;
@@ -13,8 +13,8 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html

-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.131")]
-#![allow(unknown_lints, bare_trait_objects)]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.210")]
+#![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(
    // clippy false positive: https://github.com/rust-lang/rust-clippy/issues/7054
@@ -22,6 +22,7 @@
    clippy::cognitive_complexity,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7575
    clippy::collapsible_match,
+    clippy::derive_partial_eq_without_eq,
    clippy::enum_variant_names,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
    clippy::manual_map,
@@ -42,7 +43,7 @@
    clippy::enum_glob_use,
    clippy::indexing_slicing,
    clippy::items_after_statements,
-    clippy::let_underscore_drop,
+    clippy::let_underscore_untyped,
    clippy::manual_assert,
    clippy::map_err_ignore,
    clippy::match_same_arms,
@@ -50,7 +51,6 @@
    clippy::match_wildcard_for_single_variants,
    clippy::module_name_repetitions,
    clippy::must_use_candidate,
-    clippy::option_if_let_else,
    clippy::similar_names,
    clippy::single_match_else,
    clippy::struct_excessive_bools,
@@ -60,18 +60,18 @@
    clippy::use_self,
    clippy::wildcard_imports
 )]
+#![cfg_attr(all(test, exhaustive), feature(non_exhaustive_omitted_patterns_lint))]

-#[macro_use]
+extern crate proc_macro2;
 extern crate quote;
-#[macro_use]
 extern crate syn;

 extern crate proc_macro;
-extern crate proc_macro2;

 mod internals;

 use proc_macro::TokenStream;
+use syn::parse_macro_input;
 use syn::DeriveInput;

 #[macro_use]
@@ -83,13 +83,13 @@ mod de;
 mod dummy;
 mod pretend;
 mod ser;
-mod try;
+mod this;

 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
    let mut input = parse_macro_input!(input as DeriveInput);
    ser::expand_derive_serialize(&mut input)
-        .unwrap_or_else(to_compile_errors)
+        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
 }

@@ -97,11 +97,6 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
    let mut input = parse_macro_input!(input as DeriveInput);
    de::expand_derive_deserialize(&mut input)
-        .unwrap_or_else(to_compile_errors)
+        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
 }
-
-fn to_compile_errors(errors: Vec<syn::Error>) -> proc_macro2::TokenStream {
-    let compile_errors = errors.iter().map(syn::Error::to_compile_error);
-    quote!(#(#compile_errors)*)
-}
@@ -1,7 +1,6 @@
+use crate::internals::ast::{Container, Data, Field, Style, Variant};
 use proc_macro2::TokenStream;
-use quote::format_ident;
-
-use internals::ast::{Container, Data, Field, Style, Variant};
+use quote::{format_ident, quote};

 // Suppress dead_code warnings that would otherwise appear when using a remote
 // derive. Other than this pretend code, a struct annotated with remote derive
@@ -65,14 +64,14 @@ pub fn pretend_used(cont: &Container, is_packed: bool) -> TokenStream {
 fn pretend_fields_used(cont: &Container, is_packed: bool) -> TokenStream {
    match &cont.data {
        Data::Enum(variants) => pretend_fields_used_enum(cont, variants),
-        Data::Struct(Style::Struct, fields) => {
+        Data::Struct(Style::Struct | Style::Tuple | Style::Newtype, fields) => {
            if is_packed {
                pretend_fields_used_struct_packed(cont, fields)
            } else {
                pretend_fields_used_struct(cont, fields)
            }
        }
-        Data::Struct(_, _) => quote!(),
+        Data::Struct(Style::Unit, _) => quote!(),
    }
 }

@@ -97,29 +96,14 @@ fn pretend_fields_used_struct_packed(cont: &Container, fields: &[Field]) -> Toke

    let members = fields.iter().map(|field| &field.member).collect::<Vec<_>>();

-    #[cfg(ptr_addr_of)]
-    {
-        quote! {
-            match _serde::__private::None::<&#type_ident #ty_generics> {
-                _serde::__private::Some(__v @ #type_ident { #(#members: _),* }) => {
-                    #(
-                        let _ = _serde::__private::ptr::addr_of!(__v.#members);
-                    )*
-                }
-                _ => {}
-            }
-        }
-    }
-
-    #[cfg(not(ptr_addr_of))]
-    {
-        let placeholders = (0usize..).map(|i| format_ident!("__v{}", i));
-
-        quote! {
-            match _serde::__private::None::<#type_ident #ty_generics> {
-                _serde::__private::Some(#type_ident { #(#members: #placeholders),* }) => {}
-                _ => {}
+    quote! {
+        match _serde::__private::None::<&#type_ident #ty_generics> {
+            _serde::__private::Some(__v @ #type_ident { #(#members: _),* }) => {
+                #(
+                    let _ = _serde::__private::ptr::addr_of!(__v.#members);
+                )*
            }
+            _ => {}
        }
    }
 }
@@ -131,13 +115,13 @@ fn pretend_fields_used_enum(cont: &Container, variants: &[Variant]) -> TokenStre
    let patterns = variants
        .iter()
        .filter_map(|variant| match variant.style {
-            Style::Struct => {
+            Style::Struct | Style::Tuple | Style::Newtype => {
                let variant_ident = &variant.ident;
                let members = variant.fields.iter().map(|field| &field.member);
                let placeholders = (0usize..).map(|i| format_ident!("__v{}", i));
                Some(quote!(#type_ident::#variant_ident { #(#members: #placeholders),* }))
            }
-            _ => None,
+            Style::Unit => None,
        })
        .collect::<Vec<_>>();

@@ -1,17 +1,13 @@
+use crate::fragment::{Fragment, Match, Stmts};
+use crate::internals::ast::{Container, Data, Field, Style, Variant};
+use crate::internals::{attr, replace_receiver, Ctxt, Derive};
+use crate::{bound, dummy, pretend, this};
 use proc_macro2::{Span, TokenStream};
+use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
-use syn::{self, Ident, Index, Member};
+use syn::{parse_quote, Ident, Index, Member};

-use bound;
-use dummy;
-use fragment::{Fragment, Match, Stmts};
-use internals::ast::{Container, Data, Field, Style, Variant};
-use internals::{attr, replace_receiver, Ctxt, Derive};
-use pretend;
-
-pub fn expand_derive_serialize(
-    input: &mut syn::DeriveInput,
-) -> Result<TokenStream, Vec<syn::Error>> {
+pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<TokenStream> {
    replace_receiver(input);

    let ctxt = Ctxt::new();
@@ -58,8 +54,6 @@ pub fn expand_derive_serialize(

    Ok(dummy::wrap_in_const(
        cont.attrs.custom_serde_path(),
-        "SERIALIZE",
-        ident,
        impl_block,
    ))
 }
@@ -82,9 +76,13 @@ struct Parameters {
    self_var: Ident,

    /// Path to the type the impl is for. Either a single `Ident` for local
-    /// types or `some::remote::Ident` for remote types. Does not include
-    /// generic parameters.
-    this: syn::Path,
+    /// types (does not include generic parameters) or `some::remote::Path` for
+    /// remote types.
+    this_type: syn::Path,
+
+    /// Same as `this_type` but using `::<T>` for generic parameters for use in
+    /// expression position.
+    this_value: syn::Path,

    /// Generics including any explicit and inferred bounds for the impl.
    generics: syn::Generics,
@@ -105,18 +103,15 @@ impl Parameters {
            Ident::new("self", Span::call_site())
        };

-        let this = match cont.attrs.remote() {
-            Some(remote) => remote.clone(),
-            None => cont.ident.clone().into(),
-        };
-
+        let this_type = this::this_type(cont);
+        let this_value = this::this_value(cont);
        let is_packed = cont.attrs.is_packed();
-
        let generics = build_generics(cont);

        Parameters {
            self_var,
-            this,
+            this_type,
+            this_value,
            generics,
            is_remote,
            is_packed,
@@ -126,7 +121,7 @@ impl Parameters {
    /// Type name to use in error messages and `&'static str` arguments to
    /// various Serializer methods.
    fn type_name(&self) -> String {
-        self.this.segments.last().unwrap().ident.to_string()
+        self.this_type.segments.last().unwrap().ident.to_string()
    }
 }

@@ -287,16 +282,25 @@ fn serialize_tuple_struct(
        .fold(quote!(0), |sum, expr| quote!(#sum + #expr));

    quote_block! {
-        let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_struct(__serializer, #type_name, #len));
+        let #let_mut __serde_state = _serde::Serializer::serialize_tuple_struct(__serializer, #type_name, #len)?;
        #(#serialize_stmts)*
        _serde::ser::SerializeTupleStruct::end(__serde_state)
    }
 }

 fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
-    assert!(fields.len() as u64 <= u64::from(u32::max_value()));
+    assert!(
+        fields.len() as u64 <= u64::from(u32::MAX),
+        "too many fields in {}: {}, maximum supported count is {}",
+        cattrs.name().serialize_name(),
+        fields.len(),
+        u32::MAX,
+    );

-    if cattrs.has_flatten() {
+    let has_non_skipped_flatten = fields
+        .iter()
+        .any(|field| field.attrs.flatten() && !field.attrs.skip_serializing());
+    if has_non_skipped_flatten {
        serialize_struct_as_map(params, fields, cattrs)
    } else {
        serialize_struct_as_struct(params, fields, cattrs)
@@ -309,7 +313,7 @@ fn serialize_struct_tag_field(cattrs: &attr::Container, struct_trait: &StructTra
            let type_name = cattrs.name().serialize_name();
            let func = struct_trait.serialize_field(Span::call_site());
            quote! {
-                try!(#func(&mut __serde_state, #tag, #type_name));
+                #func(&mut __serde_state, #tag, #type_name)?;
            }
        }
        _ => quote! {},
@@ -350,7 +354,7 @@ fn serialize_struct_as_struct(
        );

    quote_block! {
-        let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(__serializer, #type_name, #len));
+        let #let_mut __serde_state = _serde::Serializer::serialize_struct(__serializer, #type_name, #len)?;
        #tag_field
        #(#serialize_fields)*
        _serde::ser::SerializeStruct::end(__serde_state)
@@ -375,26 +379,8 @@ fn serialize_struct_as_map(

    let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);

-    let len = if cattrs.has_flatten() {
-        quote!(_serde::__private::None)
-    } else {
-        let len = serialized_fields
-            .map(|field| match field.attrs.skip_serializing_if() {
-                None => quote!(1),
-                Some(path) => {
-                    let field_expr = get_member(params, field, &field.member);
-                    quote!(if #path(#field_expr) { 0 } else { 1 })
-                }
-            })
-            .fold(
-                quote!(#tag_field_exists as usize),
-                |sum, expr| quote!(#sum + #expr),
-            );
-        quote!(_serde::__private::Some(#len))
-    };
-
    quote_block! {
-        let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(__serializer, #len));
+        let #let_mut __serde_state = _serde::Serializer::serialize_map(__serializer, _serde::__private::None)?;
        #tag_field
        #(#serialize_fields)*
        _serde::ser::SerializeMap::end(__serde_state)
@@ -402,11 +388,11 @@ fn serialize_struct_as_map(
 }

 fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Container) -> Fragment {
-    assert!(variants.len() as u64 <= u64::from(u32::max_value()));
+    assert!(variants.len() as u64 <= u64::from(u32::MAX));

    let self_var = &params.self_var;

-    let arms: Vec<_> = variants
+    let mut arms: Vec<_> = variants
        .iter()
        .enumerate()
        .map(|(variant_index, variant)| {
@@ -414,6 +400,12 @@ fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Cont
        })
        .collect();

+    if cattrs.remote().is_some() && cattrs.non_exhaustive() {
+        arms.push(quote! {
+            ref unrecognized => _serde::__private::Err(_serde::ser::Error::custom(_serde::__private::ser::CannotSerializeVariant(unrecognized))),
+        });
+    }
+
    quote_expr! {
        match *#self_var {
            #(#arms)*
@@ -427,7 +419,7 @@ fn serialize_variant(
    variant_index: u32,
    cattrs: &attr::Container,
 ) -> TokenStream {
-    let this = &params.this;
+    let this_value = &params.this_value;
    let variant_ident = &variant.ident;

    if variant.attrs.skip_serializing() {
@@ -445,47 +437,56 @@ fn serialize_variant(
            Style::Struct => quote!({ .. }),
        };
        quote! {
-            #this::#variant_ident #fields_pat => #skipped_err,
+            #this_value::#variant_ident #fields_pat => #skipped_err,
        }
    } else {
        // variant wasn't skipped
        let case = match variant.style {
            Style::Unit => {
                quote! {
-                    #this::#variant_ident
+                    #this_value::#variant_ident
                }
            }
            Style::Newtype => {
                quote! {
-                    #this::#variant_ident(ref __field0)
+                    #this_value::#variant_ident(ref __field0)
                }
            }
            Style::Tuple => {
                let field_names = (0..variant.fields.len())
                    .map(|i| Ident::new(&format!("__field{}", i), Span::call_site()));
                quote! {
-                    #this::#variant_ident(#(ref #field_names),*)
+                    #this_value::#variant_ident(#(ref #field_names),*)
                }
            }
            Style::Struct => {
                let members = variant.fields.iter().map(|f| &f.member);
                quote! {
-                    #this::#variant_ident { #(ref #members),* }
+                    #this_value::#variant_ident { #(ref #members),* }
                }
            }
        };

-        let body = Match(match cattrs.tag() {
-            attr::TagType::External => {
+        let body = Match(match (cattrs.tag(), variant.attrs.untagged()) {
+            (attr::TagType::External, false) => {
                serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
            }
-            attr::TagType::Internal { tag } => {
+            (attr::TagType::Internal { tag }, false) => {
                serialize_internally_tagged_variant(params, variant, cattrs, tag)
            }
-            attr::TagType::Adjacent { tag, content } => {
-                serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content)
+            (attr::TagType::Adjacent { tag, content }, false) => {
+                serialize_adjacently_tagged_variant(
+                    params,
+                    variant,
+                    cattrs,
+                    variant_index,
+                    tag,
+                    content,
+                )
+            }
+            (attr::TagType::None, _) | (_, true) => {
+                serialize_untagged_variant(params, variant, cattrs)
            }
-            attr::TagType::None => serialize_untagged_variant(params, variant, cattrs),
        });

        quote! {
@@ -562,7 +563,7 @@ fn serialize_externally_tagged_variant(
            },
            params,
            &variant.fields,
-            &type_name,
+            type_name,
        ),
    }
 }
@@ -596,10 +597,10 @@ fn serialize_internally_tagged_variant(
    match effective_style(variant) {
        Style::Unit => {
            quote_block! {
-                let mut __struct = try!(_serde::Serializer::serialize_struct(
-                    __serializer, #type_name, 1));
-                try!(_serde::ser::SerializeStruct::serialize_field(
-                    &mut __struct, #tag, #variant_name));
+                let mut __struct = _serde::Serializer::serialize_struct(
+                    __serializer, #type_name, 1)?;
+                _serde::ser::SerializeStruct::serialize_field(
+                    &mut __struct, #tag, #variant_name)?;
                _serde::ser::SerializeStruct::end(__struct)
            }
        }
@@ -627,7 +628,7 @@ fn serialize_internally_tagged_variant(
            StructVariant::InternallyTagged { tag, variant_name },
            params,
            &variant.fields,
-            &type_name,
+            type_name,
        ),
        Style::Tuple => unreachable!("checked in serde_derive_internals"),
    }
@@ -637,12 +638,20 @@ fn serialize_adjacently_tagged_variant(
    params: &Parameters,
    variant: &Variant,
    cattrs: &attr::Container,
+    variant_index: u32,
    tag: &str,
    content: &str,
 ) -> Fragment {
-    let this = &params.this;
+    let this_type = &params.this_type;
    let type_name = cattrs.name().serialize_name();
    let variant_name = variant.attrs.name().serialize_name();
+    let serialize_variant = quote! {
+        &_serde::__private::ser::AdjacentlyTaggedEnumVariant {
+            enum_name: #type_name,
+            variant_index: #variant_index,
+            variant_name: #variant_name,
+        }
+    };

    let inner = Stmts(if let Some(path) = variant.attrs.serialize_with() {
        let ser = wrap_serialize_variant_with(params, path, variant);
@@ -653,10 +662,10 @@ fn serialize_adjacently_tagged_variant(
        match effective_style(variant) {
            Style::Unit => {
                return quote_block! {
-                    let mut __struct = try!(_serde::Serializer::serialize_struct(
-                        __serializer, #type_name, 1));
-                    try!(_serde::ser::SerializeStruct::serialize_field(
-                        &mut __struct, #tag, #variant_name));
+                    let mut __struct = _serde::Serializer::serialize_struct(
+                        __serializer, #type_name, 1)?;
+                    _serde::ser::SerializeStruct::serialize_field(
+                        &mut __struct, #tag, #serialize_variant)?;
                    _serde::ser::SerializeStruct::end(__struct)
                };
            }
@@ -670,12 +679,12 @@ fn serialize_adjacently_tagged_variant(
                let span = field.original.span();
                let func = quote_spanned!(span=> _serde::ser::SerializeStruct::serialize_field);
                return quote_block! {
-                    let mut __struct = try!(_serde::Serializer::serialize_struct(
-                        __serializer, #type_name, 2));
-                    try!(_serde::ser::SerializeStruct::serialize_field(
-                        &mut __struct, #tag, #variant_name));
-                    try!(#func(
-                        &mut __struct, #content, #field_expr));
+                    let mut __struct = _serde::Serializer::serialize_struct(
+                        __serializer, #type_name, 2)?;
+                    _serde::ser::SerializeStruct::serialize_field(
+                        &mut __struct, #tag, #serialize_variant)?;
+                    #func(
+                        &mut __struct, #content, #field_expr)?;
                    _serde::ser::SerializeStruct::end(__struct)
                };
            }
@@ -686,13 +695,13 @@ fn serialize_adjacently_tagged_variant(
                StructVariant::Untagged,
                params,
                &variant.fields,
-                &variant_name,
+                variant_name,
            ),
        }
    });

    let fields_ty = variant.fields.iter().map(|f| &f.ty);
-    let fields_ident: &Vec<_> = &match variant.style {
+    let fields_ident: &[_] = &match variant.style {
        Style::Unit => {
            if variant.attrs.serialize_with().is_some() {
                vec![]
@@ -717,9 +726,10 @@ fn serialize_adjacently_tagged_variant(
    let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();

    quote_block! {
+        #[doc(hidden)]
        struct __AdjacentlyTagged #wrapper_generics #where_clause {
            data: (#(&'__a #fields_ty,)*),
-            phantom: _serde::__private::PhantomData<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
        }

        impl #wrapper_impl_generics _serde::Serialize for __AdjacentlyTagged #wrapper_ty_generics #where_clause {
@@ -734,15 +744,15 @@ fn serialize_adjacently_tagged_variant(
            }
        }

-        let mut __struct = try!(_serde::Serializer::serialize_struct(
-            __serializer, #type_name, 2));
-        try!(_serde::ser::SerializeStruct::serialize_field(
-            &mut __struct, #tag, #variant_name));
-        try!(_serde::ser::SerializeStruct::serialize_field(
+        let mut __struct = _serde::Serializer::serialize_struct(
+            __serializer, #type_name, 2)?;
+        _serde::ser::SerializeStruct::serialize_field(
+            &mut __struct, #tag, #serialize_variant)?;
+        _serde::ser::SerializeStruct::serialize_field(
            &mut __struct, #content, &__AdjacentlyTagged {
                data: (#(#fields_ident,)*),
-                phantom: _serde::__private::PhantomData::<#this #ty_generics>,
-            }));
+                phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+            })?;
        _serde::ser::SerializeStruct::end(__struct)
    }
 }
@@ -781,16 +791,16 @@ fn serialize_untagged_variant(
        Style::Tuple => serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields),
        Style::Struct => {
            let type_name = cattrs.name().serialize_name();
-            serialize_struct_variant(StructVariant::Untagged, params, &variant.fields, &type_name)
+            serialize_struct_variant(StructVariant::Untagged, params, &variant.fields, type_name)
        }
    }
 }

-enum TupleVariant {
+enum TupleVariant<'a> {
    ExternallyTagged {
-        type_name: String,
+        type_name: &'a str,
        variant_index: u32,
-        variant_name: String,
+        variant_name: &'a str,
    },
    Untagged,
 }
@@ -832,21 +842,21 @@ fn serialize_tuple_variant(
            variant_name,
        } => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_variant(
+                let #let_mut __serde_state = _serde::Serializer::serialize_tuple_variant(
                    __serializer,
                    #type_name,
                    #variant_index,
                    #variant_name,
-                    #len));
+                    #len)?;
                #(#serialize_stmts)*
                _serde::ser::SerializeTupleVariant::end(__serde_state)
            }
        }
        TupleVariant::Untagged => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple(
+                let #let_mut __serde_state = _serde::Serializer::serialize_tuple(
                    __serializer,
-                    #len));
+                    #len)?;
                #(#serialize_stmts)*
                _serde::ser::SerializeTuple::end(__serde_state)
            }
@@ -857,17 +867,17 @@ fn serialize_tuple_variant(
 enum StructVariant<'a> {
    ExternallyTagged {
        variant_index: u32,
-        variant_name: String,
+        variant_name: &'a str,
    },
    InternallyTagged {
        tag: &'a str,
-        variant_name: String,
+        variant_name: &'a str,
    },
    Untagged,
 }

-fn serialize_struct_variant<'a>(
-    context: StructVariant<'a>,
+fn serialize_struct_variant(
+    context: StructVariant,
    params: &Parameters,
    fields: &[Field],
    name: &str,
@@ -909,40 +919,40 @@ fn serialize_struct_variant<'a>(
            variant_name,
        } => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct_variant(
+                let #let_mut __serde_state = _serde::Serializer::serialize_struct_variant(
                    __serializer,
                    #name,
                    #variant_index,
                    #variant_name,
                    #len,
-                ));
+                )?;
                #(#serialize_fields)*
                _serde::ser::SerializeStructVariant::end(__serde_state)
            }
        }
        StructVariant::InternallyTagged { tag, variant_name } => {
            quote_block! {
-                let mut __serde_state = try!(_serde::Serializer::serialize_struct(
+                let mut __serde_state = _serde::Serializer::serialize_struct(
                    __serializer,
                    #name,
                    #len + 1,
-                ));
-                try!(_serde::ser::SerializeStruct::serialize_field(
+                )?;
+                _serde::ser::SerializeStruct::serialize_field(
                    &mut __serde_state,
                    #tag,
                    #variant_name,
-                ));
+                )?;
                #(#serialize_fields)*
                _serde::ser::SerializeStruct::end(__serde_state)
            }
        }
        StructVariant::Untagged => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(
+                let #let_mut __serde_state = _serde::Serializer::serialize_struct(
                    __serializer,
                    #name,
                    #len,
-                ));
+                )?;
                #(#serialize_fields)*
                _serde::ser::SerializeStruct::end(__serde_state)
            }
@@ -950,8 +960,8 @@ fn serialize_struct_variant<'a>(
    }
 }

-fn serialize_struct_variant_with_flatten<'a>(
-    context: StructVariant<'a>,
+fn serialize_struct_variant_with_flatten(
+    context: StructVariant,
    params: &Parameters,
    fields: &[Field],
    name: &str,
@@ -971,7 +981,7 @@ fn serialize_struct_variant_with_flatten<'a>(
            variant_index,
            variant_name,
        } => {
-            let this = &params.this;
+            let this_type = &params.this_type;
            let fields_ty = fields.iter().map(|f| &f.ty);
            let members = &fields.iter().map(|f| &f.member).collect::<Vec<_>>();

@@ -980,9 +990,10 @@ fn serialize_struct_variant_with_flatten<'a>(
            let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();

            quote_block! {
+                #[doc(hidden)]
                struct __EnumFlatten #wrapper_generics #where_clause {
                    data: (#(&'__a #fields_ty,)*),
-                    phantom: _serde::__private::PhantomData<#this #ty_generics>,
+                    phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
                }

                impl #wrapper_impl_generics _serde::Serialize for __EnumFlatten #wrapper_ty_generics #where_clause {
@@ -991,9 +1002,9 @@ fn serialize_struct_variant_with_flatten<'a>(
                        __S: _serde::Serializer,
                    {
                        let (#(#members,)*) = self.data;
-                        let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+                        let #let_mut __serde_state = _serde::Serializer::serialize_map(
                            __serializer,
-                            _serde::__private::None));
+                            _serde::__private::None)?;
                        #(#serialize_fields)*
                        _serde::ser::SerializeMap::end(__serde_state)
                    }
@@ -1006,29 +1017,29 @@ fn serialize_struct_variant_with_flatten<'a>(
                    #variant_name,
                    &__EnumFlatten {
                        data: (#(#members,)*),
-                        phantom: _serde::__private::PhantomData::<#this #ty_generics>,
+                        phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
                    })
            }
        }
        StructVariant::InternallyTagged { tag, variant_name } => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+                let #let_mut __serde_state = _serde::Serializer::serialize_map(
                    __serializer,
-                    _serde::__private::None));
-                try!(_serde::ser::SerializeMap::serialize_entry(
+                    _serde::__private::None)?;
+                _serde::ser::SerializeMap::serialize_entry(
                    &mut __serde_state,
                    #tag,
                    #variant_name,
-                ));
+                )?;
                #(#serialize_fields)*
                _serde::ser::SerializeMap::end(__serde_state)
            }
        }
        StructVariant::Untagged => {
            quote_block! {
-                let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+                let #let_mut __serde_state = _serde::Serializer::serialize_map(
                    __serializer,
-                    _serde::__private::None));
+                    _serde::__private::None)?;
                #(#serialize_fields)*
                _serde::ser::SerializeMap::end(__serde_state)
            }
@@ -1073,7 +1084,7 @@ fn serialize_tuple_struct_visitor(
            let span = field.original.span();
            let func = tuple_trait.serialize_element(span);
            let ser = quote! {
-                try!(#func(&mut __serde_state, #field_expr));
+                #func(&mut __serde_state, #field_expr)?;
            };

            match skip {
@@ -1117,12 +1128,12 @@ fn serialize_struct_visitor(
            let ser = if field.attrs.flatten() {
                let func = quote_spanned!(span=> _serde::Serialize::serialize);
                quote! {
-                    try!(#func(&#field_expr, _serde::__private::ser::FlatMapSerializer(&mut __serde_state)));
+                    #func(&#field_expr, _serde::__private::ser::FlatMapSerializer(&mut __serde_state))?;
                }
            } else {
                let func = struct_trait.serialize_field(span);
                quote! {
-                    try!(#func(&mut __serde_state, #key_expr, #field_expr));
+                    #func(&mut __serde_state, #key_expr, #field_expr)?;
                }
            };

@@ -1134,7 +1145,7 @@ fn serialize_struct_visitor(
                            if !#skip {
                                #ser
                            } else {
-                                try!(#skip_func(&mut __serde_state, #key_expr));
+                                #skip_func(&mut __serde_state, #key_expr)?;
                            }
                        }
                    } else {
@@ -1192,7 +1203,7 @@ fn wrap_serialize_with(
    field_tys: &[&syn::Type],
    field_exprs: &[TokenStream],
 ) -> TokenStream {
-    let this = &params.this;
+    let this_type = &params.this_type;
    let (_, ty_generics, where_clause) = params.generics.split_for_impl();

    let wrapper_generics = if field_exprs.is_empty() {
@@ -1210,9 +1221,10 @@ fn wrap_serialize_with(
    });

    quote!({
+        #[doc(hidden)]
        struct __SerializeWith #wrapper_impl_generics #where_clause {
            values: (#(&'__a #field_tys, )*),
-            phantom: _serde::__private::PhantomData<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
        }

        impl #wrapper_impl_generics _serde::Serialize for __SerializeWith #wrapper_ty_generics #where_clause {
@@ -1226,14 +1238,14 @@ fn wrap_serialize_with(

        &__SerializeWith {
            values: (#(#field_exprs, )*),
-            phantom: _serde::__private::PhantomData::<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
        }
    })
 }

 // Serialization of an empty struct results in code like:
 //
-//     let mut __serde_state = try!(serializer.serialize_struct("S", 0));
+//     let mut __serde_state = serializer.serialize_struct("S", 0)?;
 //     _serde::ser::SerializeStruct::end(__serde_state)
 //
 // where we want to omit the `mut` to avoid a warning.
@@ -0,0 +1,32 @@
+use crate::internals::ast::Container;
+use syn::{Path, PathArguments, Token};
+
+pub fn this_type(cont: &Container) -> Path {
+    if let Some(remote) = cont.attrs.remote() {
+        let mut this = remote.clone();
+        for segment in &mut this.segments {
+            if let PathArguments::AngleBracketed(arguments) = &mut segment.arguments {
+                arguments.colon2_token = None;
+            }
+        }
+        this
+    } else {
+        Path::from(cont.ident.clone())
+    }
+}
+
+pub fn this_value(cont: &Container) -> Path {
+    if let Some(remote) = cont.attrs.remote() {
+        let mut this = remote.clone();
+        for segment in &mut this.segments {
+            if let PathArguments::AngleBracketed(arguments) = &mut segment.arguments {
+                if arguments.colon2_token.is_none() {
+                    arguments.colon2_token = Some(Token![::](arguments.lt_token.span));
+                }
+            }
+        }
+        this
+    } else {
+        Path::from(cont.ident.clone())
+    }
+}
@@ -1,24 +0,0 @@
-use proc_macro2::{Punct, Spacing, TokenStream};
-
-// None of our generated code requires the `From::from` error conversion
-// performed by the standard library's `try!` macro. With this simplified macro
-// we see a significant improvement in type checking and borrow checking time of
-// the generated code and a slight improvement in binary size.
-pub fn replacement() -> TokenStream {
-    // Cannot pass `$expr` to `quote!` prior to Rust 1.17.0 so interpolate it.
-    let dollar = Punct::new('$', Spacing::Alone);
-
-    quote! {
-        #[allow(unused_macros)]
-        macro_rules! try {
-            (#dollar __expr:expr) => {
-                match #dollar __expr {
-                    _serde::__private::Ok(__val) => __val,
-                    _serde::__private::Err(__err) => {
-                        return _serde::__private::Err(__err);
-                    }
-                }
-            }
-        }
-    }
-}
@@ -1,23 +1,25 @@
 [package]
 name = "serde_derive_internals"
-version = "0.26.0" # remember to update html_root_url
+version = "0.29.1"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-rust-version = "1.31"
-license = "MIT OR Apache-2.0"
 description = "AST representation used by Serde derive macros. Unstable."
-homepage = "https://serde.rs"
-repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.rs/serde_derive_internals"
+edition = "2015"
+exclude = ["build.rs"]
+homepage = "https://serde.rs"
 keywords = ["serde", "serialization"]
-include = ["lib.rs", "src/**/*.rs", "LICENSE-APACHE", "LICENSE-MIT"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/serde-rs/serde"
+rust-version = "1.56"

 [lib]
 path = "lib.rs"

 [dependencies]
-proc-macro2 = "1.0"
-quote = "1.0"
-syn = { version = "1.0.60", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
+proc-macro2 = { workspace = true }
+quote = { workspace = true }
+syn = { workspace = true, features = ["clone-impls", "derive", "parsing", "printing"] }

 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
+rustdoc-args = ["--generate-link-to-definition"]
@@ -1,6 +1,17 @@
 use std::path::Path;

 fn main() {
+    // Warning: build.rs is not published to crates.io.
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=src/mod.rs");
+
+    println!("cargo:rustc-cfg=check_cfg");
+    println!("cargo:rustc-check-cfg=cfg(check_cfg)");
+    println!("cargo:rustc-check-cfg=cfg(exhaustive)");
+    println!("cargo:rustc-check-cfg=cfg(serde_build_from_git)");
+    println!("cargo:rustc-check-cfg=cfg(feature, values(\"deserialize_in_place\"))");
+
    // Sometimes on Windows the git checkout does not correctly wire up the
    // symlink from serde_derive_internals/src to serde_derive/src/internals.
    // When this happens we'll just build based on relative paths within the git
@@ -1,10 +1,11 @@
-#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.26.0")]
-#![allow(unknown_lints, bare_trait_objects)]
+#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.29.1")]
+#![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(
    clippy::cognitive_complexity,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7575
    clippy::collapsible_match,
+    clippy::derive_partial_eq_without_eq,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
    clippy::manual_map,
    clippy::missing_panics_doc,
@@ -21,7 +22,7 @@
    clippy::doc_markdown,
    clippy::enum_glob_use,
    clippy::items_after_statements,
-    clippy::let_underscore_drop,
+    clippy::let_underscore_untyped,
    clippy::manual_assert,
    clippy::match_same_arms,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6984
@@ -29,18 +30,18 @@
    clippy::missing_errors_doc,
    clippy::module_name_repetitions,
    clippy::must_use_candidate,
+    clippy::return_self_not_must_use,
    clippy::similar_names,
+    clippy::single_match_else,
    clippy::struct_excessive_bools,
    clippy::too_many_lines,
    clippy::unused_self,
    clippy::wildcard_imports
 )]

-#[macro_use]
-extern crate syn;
-
 extern crate proc_macro2;
 extern crate quote;
+extern crate syn;

 #[cfg_attr(serde_build_from_git, path = "../serde_derive/src/internals/mod.rs")]
 #[cfg_attr(not(serde_build_from_git), path = "src/mod.rs")]
@@ -1,23 +0,0 @@
-[package]
-name = "serde_test"
-version = "1.0.131" # remember to update html_root_url
-authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-rust-version = "1.15"
-license = "MIT OR Apache-2.0"
-description = "Token De/Serializer for testing De/Serialize implementations"
-homepage = "https://serde.rs"
-repository = "https://github.com/serde-rs/serde"
-documentation = "https://docs.serde.rs/serde_test/"
-keywords = ["serde", "serialization"]
-readme = "crates-io.md"
-include = ["src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
-
-[dependencies]
-serde = { version = "1.0.60", path = "../serde" }
-
-[dev-dependencies]
-serde = { version = "1.0", path = "../serde" }
-serde_derive = { version = "1.0", path = "../serde_derive" }
-
-[package.metadata.docs.rs]
-targets = ["x86_64-unknown-linux-gnu"]
@@ -1 +0,0 @@
-../LICENSE-APACHE
@@ -1 +0,0 @@
-../LICENSE-MIT
@@ -1 +0,0 @@
-../README.md
@@ -1,30 +0,0 @@
-use std::env;
-use std::process::Command;
-use std::str;
-
-// The rustc-cfg strings below are *not* public API. Please let us know by
-// opening a GitHub issue if your build environment requires some way to enable
-// these cfgs other than by executing our build script.
-fn main() {
-    let minor = match rustc_minor_version() {
-        Some(minor) => minor,
-        None => return,
-    };
-
-    // #[track_caller] stabilized in Rust 1.46:
-    // https://blog.rust-lang.org/2020/08/27/Rust-1.46.0.html#track_caller
-    if minor >= 46 {
-        println!("cargo:rustc-cfg=track_caller");
-    }
-}
-
-fn rustc_minor_version() -> Option<u32> {
-    let rustc = env::var_os("RUSTC")?;
-    let output = Command::new(rustc).arg("--version").output().ok()?;
-    let version = str::from_utf8(&output.stdout).ok()?;
-    let mut pieces = version.split('.');
-    if pieces.next() != Some("rustc 1") {
-        return None;
-    }
-    pieces.next()?.parse().ok()
-}
@@ -1 +0,0 @@
-../crates-io.md
@@ -1,223 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-use de::Deserializer;
-use ser::Serializer;
-use token::Token;
-
-use std::fmt::Debug;
-
-/// Runs both `assert_ser_tokens` and `assert_de_tokens`.
-///
-/// ```edition2018
-/// # use serde::{Serialize, Deserialize};
-/// # use serde_test::{assert_tokens, Token};
-/// #
-/// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-/// struct S {
-///     a: u8,
-///     b: u8,
-/// }
-///
-/// let s = S { a: 0, b: 0 };
-/// assert_tokens(&s, &[
-///     Token::Struct { name: "S", len: 2 },
-///     Token::Str("a"),
-///     Token::U8(0),
-///     Token::Str("b"),
-///     Token::U8(0),
-///     Token::StructEnd,
-/// ]);
-/// ```
-#[cfg_attr(track_caller, track_caller)]
-pub fn assert_tokens<'de, T>(value: &T, tokens: &'de [Token])
-where
-    T: Serialize + Deserialize<'de> + PartialEq + Debug,
-{
-    assert_ser_tokens(value, tokens);
-    assert_de_tokens(value, tokens);
-}
-
-/// Asserts that `value` serializes to the given `tokens`.
-///
-/// ```edition2018
-/// # use serde::{Serialize, Deserialize};
-/// # use serde_test::{assert_ser_tokens, Token};
-/// #
-/// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-/// struct S {
-///     a: u8,
-///     b: u8,
-/// }
-///
-/// let s = S { a: 0, b: 0 };
-/// assert_ser_tokens(&s, &[
-///     Token::Struct { name: "S", len: 2 },
-///     Token::Str("a"),
-///     Token::U8(0),
-///     Token::Str("b"),
-///     Token::U8(0),
-///     Token::StructEnd,
-/// ]);
-/// ```
-#[cfg_attr(track_caller, track_caller)]
-pub fn assert_ser_tokens<T>(value: &T, tokens: &[Token])
-where
-    T: Serialize,
-{
-    let mut ser = Serializer::new(tokens);
-    match value.serialize(&mut ser) {
-        Ok(_) => {}
-        Err(err) => panic!("value failed to serialize: {}", err),
-    }
-
-    if ser.remaining() > 0 {
-        panic!("{} remaining tokens", ser.remaining());
-    }
-}
-
-/// Asserts that `value` serializes to the given `tokens`, and then yields
-/// `error`.
-///
-/// ```edition2018
-/// use std::sync::{Arc, Mutex};
-/// use std::thread;
-///
-/// use serde::Serialize;
-/// use serde_test::{assert_ser_tokens_error, Token};
-///
-/// #[derive(Serialize)]
-/// struct Example {
-///     lock: Arc<Mutex<u32>>,
-/// }
-///
-/// fn main() {
-///     let example = Example { lock: Arc::new(Mutex::new(0)) };
-///     let lock = example.lock.clone();
-///
-///     let _ = thread::spawn(move || {
-///         // This thread will acquire the mutex first, unwrapping the result
-///         // of `lock` because the lock has not been poisoned.
-///         let _guard = lock.lock().unwrap();
-///
-///         // This panic while holding the lock (`_guard` is in scope) will
-///         // poison the mutex.
-///         panic!()
-///     }).join();
-///
-///     let expected = &[
-///         Token::Struct { name: "Example", len: 1 },
-///         Token::Str("lock"),
-///     ];
-///     let error = "lock poison error while serializing";
-///     assert_ser_tokens_error(&example, expected, error);
-/// }
-/// ```
-#[cfg_attr(track_caller, track_caller)]
-pub fn assert_ser_tokens_error<T>(value: &T, tokens: &[Token], error: &str)
-where
-    T: Serialize,
-{
-    let mut ser = Serializer::new(tokens);
-    match value.serialize(&mut ser) {
-        Ok(_) => panic!("value serialized successfully"),
-        Err(e) => assert_eq!(e, *error),
-    }
-
-    if ser.remaining() > 0 {
-        panic!("{} remaining tokens", ser.remaining());
-    }
-}
-
-/// Asserts that the given `tokens` deserialize into `value`.
-///
-/// ```edition2018
-/// # use serde::{Serialize, Deserialize};
-/// # use serde_test::{assert_de_tokens, Token};
-/// #
-/// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-/// struct S {
-///     a: u8,
-///     b: u8,
-/// }
-///
-/// let s = S { a: 0, b: 0 };
-/// assert_de_tokens(&s, &[
-///     Token::Struct { name: "S", len: 2 },
-///     Token::Str("a"),
-///     Token::U8(0),
-///     Token::Str("b"),
-///     Token::U8(0),
-///     Token::StructEnd,
-/// ]);
-/// ```
-#[cfg_attr(track_caller, track_caller)]
-pub fn assert_de_tokens<'de, T>(value: &T, tokens: &'de [Token])
-where
-    T: Deserialize<'de> + PartialEq + Debug,
-{
-    let mut de = Deserializer::new(tokens);
-    let mut deserialized_val = match T::deserialize(&mut de) {
-        Ok(v) => {
-            assert_eq!(v, *value);
-            v
-        }
-        Err(e) => panic!("tokens failed to deserialize: {}", e),
-    };
-    if de.remaining() > 0 {
-        panic!("{} remaining tokens", de.remaining());
-    }
-
-    // Do the same thing for deserialize_in_place. This isn't *great* because a
-    // no-op impl of deserialize_in_place can technically succeed here. Still,
-    // this should catch a lot of junk.
-    let mut de = Deserializer::new(tokens);
-    match T::deserialize_in_place(&mut de, &mut deserialized_val) {
-        Ok(()) => {
-            assert_eq!(deserialized_val, *value);
-        }
-        Err(e) => panic!("tokens failed to deserialize_in_place: {}", e),
-    }
-    if de.remaining() > 0 {
-        panic!("{} remaining tokens", de.remaining());
-    }
-}
-
-/// Asserts that the given `tokens` yield `error` when deserializing.
-///
-/// ```edition2018
-/// # use serde::{Serialize, Deserialize};
-/// # use serde_test::{assert_de_tokens_error, Token};
-/// #
-/// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-/// #[serde(deny_unknown_fields)]
-/// struct S {
-///     a: u8,
-///     b: u8,
-/// }
-///
-/// assert_de_tokens_error::<S>(
-///     &[
-///         Token::Struct { name: "S", len: 2 },
-///         Token::Str("x"),
-///     ],
-///     "unknown field `x`, expected `a` or `b`",
-/// );
-/// ```
-#[cfg_attr(track_caller, track_caller)]
-pub fn assert_de_tokens_error<'de, T>(tokens: &'de [Token], error: &str)
-where
-    T: Deserialize<'de>,
-{
-    let mut de = Deserializer::new(tokens);
-    match T::deserialize(&mut de) {
-        Ok(_) => panic!("tokens deserialized successfully"),
-        Err(e) => assert_eq!(e, *error),
-    }
-
-    // There may be one token left if a peek caused the error
-    de.next_token_opt();
-
-    if de.remaining() > 0 {
-        panic!("{} remaining tokens", de.remaining());
-    }
-}
@@ -1,847 +0,0 @@
-use std::fmt;
-
-use serde::ser::{
-    SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant, SerializeTuple,
-    SerializeTupleStruct, SerializeTupleVariant,
-};
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
-
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Readable<T: ?Sized>(T);
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Compact<T: ?Sized>(T);
-
-/// Trait to determine whether a value is represented in human-readable or
-/// compact form.
-///
-/// ```edition2018
-/// use serde::{Deserialize, Deserializer, Serialize, Serializer};
-/// use serde_test::{assert_tokens, Configure, Token};
-///
-/// #[derive(Debug, PartialEq)]
-/// struct Example(u8, u8);
-///
-/// impl Serialize for Example {
-///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-///     where
-///         S: Serializer,
-///     {
-///         if serializer.is_human_readable() {
-///             format!("{}.{}", self.0, self.1).serialize(serializer)
-///         } else {
-///             (self.0, self.1).serialize(serializer)
-///         }
-///     }
-/// }
-///
-/// impl<'de> Deserialize<'de> for Example {
-///     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-///     where
-///         D: Deserializer<'de>,
-///     {
-///         use serde::de::Error;
-///         if deserializer.is_human_readable() {
-///             let s = String::deserialize(deserializer)?;
-///             let parts: Vec<_> = s.split('.').collect();
-///             Ok(Example(
-///                 parts[0].parse().map_err(D::Error::custom)?,
-///                 parts[1].parse().map_err(D::Error::custom)?,
-///             ))
-///         } else {
-///             let (x, y) = Deserialize::deserialize(deserializer)?;
-///             Ok(Example(x, y))
-///         }
-///     }
-/// }
-///
-/// fn main() {
-///     assert_tokens(
-///         &Example(1, 0).compact(),
-///         &[
-///             Token::Tuple { len: 2 },
-///             Token::U8(1),
-///             Token::U8(0),
-///             Token::TupleEnd,
-///         ],
-///     );
-///     assert_tokens(&Example(1, 0).readable(), &[Token::Str("1.0")]);
-/// }
-/// ```
-pub trait Configure {
-    /// Marks `self` as using `is_human_readable == true`
-    fn readable(self) -> Readable<Self>
-    where
-        Self: Sized,
-    {
-        Readable(self)
-    }
-    /// Marks `self` as using `is_human_readable == false`
-    fn compact(self) -> Compact<Self>
-    where
-        Self: Sized,
-    {
-        Compact(self)
-    }
-}
-
-impl<T: ?Sized> Configure for T {}
-
-impl<T: ?Sized> Serialize for Readable<T>
-where
-    T: Serialize,
-{
-    #[inline]
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        self.0.serialize(Readable(serializer))
-    }
-}
-impl<T: ?Sized> Serialize for Compact<T>
-where
-    T: Serialize,
-{
-    #[inline]
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        self.0.serialize(Compact(serializer))
-    }
-}
-impl<'de, T> Deserialize<'de> for Readable<T>
-where
-    T: Deserialize<'de>,
-{
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        T::deserialize(Readable(deserializer)).map(Readable)
-    }
-}
-impl<'de, T> Deserialize<'de> for Compact<T>
-where
-    T: Deserialize<'de>,
-{
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        T::deserialize(Compact(deserializer)).map(Compact)
-    }
-}
-
-impl<'de, T> DeserializeSeed<'de> for Readable<T>
-where
-    T: DeserializeSeed<'de>,
-{
-    type Value = T::Value;
-
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        self.0.deserialize(Readable(deserializer))
-    }
-}
-impl<'de, T> DeserializeSeed<'de> for Compact<T>
-where
-    T: DeserializeSeed<'de>,
-{
-    type Value = T::Value;
-
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        self.0.deserialize(Compact(deserializer))
-    }
-}
-
-macro_rules! forward_method {
-    ($name: ident (self $(, $arg: ident : $arg_type: ty)* ) -> $return_type: ty) => {
-        fn $name (self $(, $arg : $arg_type)* ) -> $return_type {
-            (self.0).$name( $($arg),* )
-        }
-    };
-}
-
-macro_rules! forward_serialize_methods {
-    ( $( $name: ident $arg_type: ty ),* ) => {
-        $(
-            forward_method!($name(self, v : $arg_type) -> Result<Self::Ok, Self::Error>);
-        )*
-    };
-}
-
-macro_rules! impl_serializer {
-    ($wrapper:ident, $is_human_readable:expr) => {
-        impl<S> Serializer for $wrapper<S>
-        where
-            S: Serializer,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-
-            type SerializeSeq = $wrapper<S::SerializeSeq>;
-            type SerializeTuple = $wrapper<S::SerializeTuple>;
-            type SerializeTupleStruct = $wrapper<S::SerializeTupleStruct>;
-            type SerializeTupleVariant = $wrapper<S::SerializeTupleVariant>;
-            type SerializeMap = $wrapper<S::SerializeMap>;
-            type SerializeStruct = $wrapper<S::SerializeStruct>;
-            type SerializeStructVariant = $wrapper<S::SerializeStructVariant>;
-
-            fn is_human_readable(&self) -> bool {
-                $is_human_readable
-            }
-
-            forward_serialize_methods! {
-                serialize_bool bool,
-                serialize_i8 i8,
-                serialize_i16 i16,
-                serialize_i32 i32,
-                serialize_i64 i64,
-                serialize_u8 u8,
-                serialize_u16 u16,
-                serialize_u32 u32,
-                serialize_u64 u64,
-                serialize_f32 f32,
-                serialize_f64 f64,
-                serialize_char char,
-                serialize_str &str,
-                serialize_bytes &[u8],
-                serialize_unit_struct &'static str
-
-            }
-
-            fn serialize_unit(self) -> Result<S::Ok, S::Error> {
-                self.0.serialize_unit()
-            }
-
-            fn serialize_unit_variant(
-                self,
-                name: &'static str,
-                variant_index: u32,
-                variant: &'static str,
-            ) -> Result<S::Ok, S::Error> {
-                self.0.serialize_unit_variant(name, variant_index, variant)
-            }
-
-            fn serialize_newtype_struct<T: ?Sized>(
-                self,
-                name: &'static str,
-                value: &T,
-            ) -> Result<S::Ok, S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_newtype_struct(name, &$wrapper(value))
-            }
-
-            fn serialize_newtype_variant<T: ?Sized>(
-                self,
-                name: &'static str,
-                variant_index: u32,
-                variant: &'static str,
-                value: &T,
-            ) -> Result<S::Ok, S::Error>
-            where
-                T: Serialize,
-            {
-                self.0
-                    .serialize_newtype_variant(name, variant_index, variant, &$wrapper(value))
-            }
-
-            fn serialize_none(self) -> Result<S::Ok, Self::Error> {
-                self.0.serialize_none()
-            }
-
-            fn serialize_some<T: ?Sized>(self, value: &T) -> Result<S::Ok, Self::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_some(&$wrapper(value))
-            }
-
-            fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-                self.0.serialize_seq(len).map($wrapper)
-            }
-
-            fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, Self::Error> {
-                self.0.serialize_tuple(len).map($wrapper)
-            }
-
-            fn serialize_tuple_struct(
-                self,
-                name: &'static str,
-                len: usize,
-            ) -> Result<Self::SerializeTupleStruct, Self::Error> {
-                self.0.serialize_tuple_struct(name, len).map($wrapper)
-            }
-
-            fn serialize_tuple_variant(
-                self,
-                name: &'static str,
-                variant_index: u32,
-                variant: &'static str,
-                len: usize,
-            ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-                self.0
-                    .serialize_tuple_variant(name, variant_index, variant, len)
-                    .map($wrapper)
-            }
-
-            fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
-                self.0.serialize_map(len).map($wrapper)
-            }
-
-            fn serialize_struct(
-                self,
-                name: &'static str,
-                len: usize,
-            ) -> Result<Self::SerializeStruct, Self::Error> {
-                self.0.serialize_struct(name, len).map($wrapper)
-            }
-
-            fn serialize_struct_variant(
-                self,
-                name: &'static str,
-                variant_index: u32,
-                variant: &'static str,
-                len: usize,
-            ) -> Result<Self::SerializeStructVariant, Self::Error> {
-                self.0
-                    .serialize_struct_variant(name, variant_index, variant, len)
-                    .map($wrapper)
-            }
-        }
-
-        impl<S> SerializeSeq for $wrapper<S>
-        where
-            S: SerializeSeq,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_element(&$wrapper(value))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeTuple for $wrapper<S>
-        where
-            S: SerializeTuple,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_element(&$wrapper(value))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeTupleStruct for $wrapper<S>
-        where
-            S: SerializeTupleStruct,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_field(&$wrapper(value))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeTupleVariant for $wrapper<S>
-        where
-            S: SerializeTupleVariant,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_field(&$wrapper(value))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeMap for $wrapper<S>
-        where
-            S: SerializeMap,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_key(&$wrapper(key))
-            }
-            fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_value(&$wrapper(value))
-            }
-            fn serialize_entry<K: ?Sized, V: ?Sized>(
-                &mut self,
-                key: &K,
-                value: &V,
-            ) -> Result<(), S::Error>
-            where
-                K: Serialize,
-                V: Serialize,
-            {
-                self.0.serialize_entry(key, &$wrapper(value))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeStruct for $wrapper<S>
-        where
-            S: SerializeStruct,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_field<T: ?Sized>(
-                &mut self,
-                name: &'static str,
-                field: &T,
-            ) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_field(name, &$wrapper(field))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-
-        impl<S> SerializeStructVariant for $wrapper<S>
-        where
-            S: SerializeStructVariant,
-        {
-            type Ok = S::Ok;
-            type Error = S::Error;
-            fn serialize_field<T: ?Sized>(
-                &mut self,
-                name: &'static str,
-                field: &T,
-            ) -> Result<(), S::Error>
-            where
-                T: Serialize,
-            {
-                self.0.serialize_field(name, &$wrapper(field))
-            }
-            fn end(self) -> Result<S::Ok, S::Error> {
-                self.0.end()
-            }
-        }
-    };
-}
-
-impl_serializer!(Readable, true);
-impl_serializer!(Compact, false);
-
-use serde::de::{DeserializeSeed, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor};
-
-macro_rules! forward_deserialize_methods {
-    ( $wrapper : ident ( $( $name: ident ),* ) ) => {
-        $(
-            fn $name<V>(self, visitor: V) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                (self.0).$name($wrapper(visitor))
-            }
-        )*
-    };
-}
-
-macro_rules! impl_deserializer {
-    ($wrapper:ident, $is_human_readable:expr) => {
-        impl<'de, D> Deserializer<'de> for $wrapper<D>
-        where
-            D: Deserializer<'de>,
-        {
-            type Error = D::Error;
-
-            forward_deserialize_methods! {
-                $wrapper (
-                    deserialize_any,
-                    deserialize_bool,
-                    deserialize_u8,
-                    deserialize_u16,
-                    deserialize_u32,
-                    deserialize_u64,
-                    deserialize_i8,
-                    deserialize_i16,
-                    deserialize_i32,
-                    deserialize_i64,
-                    deserialize_f32,
-                    deserialize_f64,
-                    deserialize_char,
-                    deserialize_str,
-                    deserialize_string,
-                    deserialize_bytes,
-                    deserialize_byte_buf,
-                    deserialize_option,
-                    deserialize_unit,
-                    deserialize_seq,
-                    deserialize_map,
-                    deserialize_identifier,
-                    deserialize_ignored_any
-                )
-            }
-
-            fn deserialize_unit_struct<V>(
-                self,
-                name: &'static str,
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.deserialize_unit_struct(name, $wrapper(visitor))
-            }
-            fn deserialize_newtype_struct<V>(
-                self,
-                name: &'static str,
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.deserialize_newtype_struct(name, $wrapper(visitor))
-            }
-            fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.deserialize_tuple(len, $wrapper(visitor))
-            }
-            fn deserialize_tuple_struct<V>(
-                self,
-                name: &'static str,
-                len: usize,
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0
-                    .deserialize_tuple_struct(name, len, $wrapper(visitor))
-            }
-            fn deserialize_struct<V>(
-                self,
-                name: &'static str,
-                fields: &'static [&'static str],
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.deserialize_struct(name, fields, $wrapper(visitor))
-            }
-            fn deserialize_enum<V>(
-                self,
-                name: &'static str,
-                variants: &'static [&'static str],
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.deserialize_enum(name, variants, $wrapper(visitor))
-            }
-
-            fn is_human_readable(&self) -> bool {
-                $is_human_readable
-            }
-        }
-
-        impl<'de, D> Visitor<'de> for $wrapper<D>
-        where
-            D: Visitor<'de>,
-        {
-            type Value = D::Value;
-            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                self.0.expecting(formatter)
-            }
-            fn visit_bool<E>(self, v: bool) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_bool(v)
-            }
-            fn visit_i8<E>(self, v: i8) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_i8(v)
-            }
-            fn visit_i16<E>(self, v: i16) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_i16(v)
-            }
-            fn visit_i32<E>(self, v: i32) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_i32(v)
-            }
-            fn visit_i64<E>(self, v: i64) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_i64(v)
-            }
-            fn visit_u8<E>(self, v: u8) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_u8(v)
-            }
-            fn visit_u16<E>(self, v: u16) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_u16(v)
-            }
-            fn visit_u32<E>(self, v: u32) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_u32(v)
-            }
-            fn visit_u64<E>(self, v: u64) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_u64(v)
-            }
-            fn visit_f32<E>(self, v: f32) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_f32(v)
-            }
-            fn visit_f64<E>(self, v: f64) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_f64(v)
-            }
-            fn visit_char<E>(self, v: char) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_char(v)
-            }
-            fn visit_str<E>(self, v: &str) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_str(v)
-            }
-            fn visit_borrowed_str<E>(self, v: &'de str) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_borrowed_str(v)
-            }
-            fn visit_string<E>(self, v: String) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_string(v)
-            }
-            fn visit_bytes<E>(self, v: &[u8]) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_bytes(v)
-            }
-            fn visit_borrowed_bytes<E>(self, v: &'de [u8]) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_borrowed_bytes(v)
-            }
-            fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_byte_buf(v)
-            }
-            fn visit_none<E>(self) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_none()
-            }
-            fn visit_some<D2>(self, deserializer: D2) -> Result<Self::Value, D2::Error>
-            where
-                D2: Deserializer<'de>,
-            {
-                self.0.visit_some($wrapper(deserializer))
-            }
-            fn visit_unit<E>(self) -> Result<D::Value, E>
-            where
-                E: Error,
-            {
-                self.0.visit_unit()
-            }
-            fn visit_newtype_struct<D2>(self, deserializer: D2) -> Result<Self::Value, D2::Error>
-            where
-                D2: Deserializer<'de>,
-            {
-                self.0.visit_newtype_struct($wrapper(deserializer))
-            }
-            fn visit_seq<V>(self, seq: V) -> Result<D::Value, V::Error>
-            where
-                V: SeqAccess<'de>,
-            {
-                self.0.visit_seq($wrapper(seq))
-            }
-            fn visit_map<V>(self, map: V) -> Result<D::Value, V::Error>
-            where
-                V: MapAccess<'de>,
-            {
-                self.0.visit_map($wrapper(map))
-            }
-            fn visit_enum<V>(self, data: V) -> Result<D::Value, V::Error>
-            where
-                V: EnumAccess<'de>,
-            {
-                self.0.visit_enum($wrapper(data))
-            }
-        }
-
-        impl<'de, D> SeqAccess<'de> for $wrapper<D>
-        where
-            D: SeqAccess<'de>,
-        {
-            type Error = D::Error;
-            fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, D::Error>
-            where
-                T: DeserializeSeed<'de>,
-            {
-                self.0.next_element_seed($wrapper(seed))
-            }
-            fn size_hint(&self) -> Option<usize> {
-                self.0.size_hint()
-            }
-        }
-
-        impl<'de, D> MapAccess<'de> for $wrapper<D>
-        where
-            D: MapAccess<'de>,
-        {
-            type Error = D::Error;
-            fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, D::Error>
-            where
-                K: DeserializeSeed<'de>,
-            {
-                self.0.next_key_seed($wrapper(seed))
-            }
-            fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, D::Error>
-            where
-                V: DeserializeSeed<'de>,
-            {
-                self.0.next_value_seed($wrapper(seed))
-            }
-            fn next_entry_seed<K, V>(
-                &mut self,
-                kseed: K,
-                vseed: V,
-            ) -> Result<Option<(K::Value, V::Value)>, D::Error>
-            where
-                K: DeserializeSeed<'de>,
-                V: DeserializeSeed<'de>,
-            {
-                self.0.next_entry_seed($wrapper(kseed), $wrapper(vseed))
-            }
-            fn size_hint(&self) -> Option<usize> {
-                self.0.size_hint()
-            }
-        }
-
-        impl<'de, D> EnumAccess<'de> for $wrapper<D>
-        where
-            D: EnumAccess<'de>,
-        {
-            type Error = D::Error;
-            type Variant = $wrapper<D::Variant>;
-            fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error>
-            where
-                V: DeserializeSeed<'de>,
-            {
-                self.0
-                    .variant_seed($wrapper(seed))
-                    .map(|(value, variant)| (value, $wrapper(variant)))
-            }
-        }
-
-        impl<'de, D> VariantAccess<'de> for $wrapper<D>
-        where
-            D: VariantAccess<'de>,
-        {
-            type Error = D::Error;
-            fn unit_variant(self) -> Result<(), D::Error> {
-                self.0.unit_variant()
-            }
-            fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, D::Error>
-            where
-                T: DeserializeSeed<'de>,
-            {
-                self.0.newtype_variant_seed($wrapper(seed))
-            }
-            fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.tuple_variant(len, $wrapper(visitor))
-            }
-            fn struct_variant<V>(
-                self,
-                fields: &'static [&'static str],
-                visitor: V,
-            ) -> Result<V::Value, D::Error>
-            where
-                V: Visitor<'de>,
-            {
-                self.0.struct_variant(fields, $wrapper(visitor))
-            }
-        }
-    };
-}
-
-impl_deserializer!(Readable, true);
-impl_deserializer!(Compact, false);
@@ -1,683 +0,0 @@
-use serde::de::value::{MapAccessDeserializer, SeqAccessDeserializer};
-use serde::de::{
-    self, Deserialize, DeserializeSeed, EnumAccess, IntoDeserializer, MapAccess, SeqAccess,
-    VariantAccess, Visitor,
-};
-
-use error::Error;
-use token::Token;
-
-#[derive(Debug)]
-pub struct Deserializer<'de> {
-    tokens: &'de [Token],
-}
-
-macro_rules! assert_next_token {
-    ($de:expr, $expected:expr) => {
-        match $de.next_token_opt() {
-            Some(token) if token == $expected => {}
-            Some(other) => panic!(
-                "expected Token::{} but deserialization wants Token::{}",
-                other, $expected
-            ),
-            None => panic!(
-                "end of tokens but deserialization wants Token::{}",
-                $expected
-            ),
-        }
-    };
-}
-
-macro_rules! unexpected {
-    ($token:expr) => {
-        panic!("deserialization did not expect this token: {}", $token)
-    };
-}
-
-macro_rules! end_of_tokens {
-    () => {
-        panic!("ran out of tokens to deserialize")
-    };
-}
-
-impl<'de> Deserializer<'de> {
-    pub fn new(tokens: &'de [Token]) -> Self {
-        Deserializer { tokens: tokens }
-    }
-
-    fn peek_token_opt(&self) -> Option<Token> {
-        self.tokens.first().cloned()
-    }
-
-    fn peek_token(&self) -> Token {
-        match self.peek_token_opt() {
-            Some(token) => token,
-            None => end_of_tokens!(),
-        }
-    }
-
-    pub fn next_token_opt(&mut self) -> Option<Token> {
-        match self.tokens.split_first() {
-            Some((&first, rest)) => {
-                self.tokens = rest;
-                Some(first)
-            }
-            None => None,
-        }
-    }
-
-    fn next_token(&mut self) -> Token {
-        match self.tokens.split_first() {
-            Some((&first, rest)) => {
-                self.tokens = rest;
-                first
-            }
-            None => end_of_tokens!(),
-        }
-    }
-
-    pub fn remaining(&self) -> usize {
-        self.tokens.len()
-    }
-
-    fn visit_seq<V>(
-        &mut self,
-        len: Option<usize>,
-        end: Token,
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        let value = visitor.visit_seq(DeserializerSeqVisitor {
-            de: self,
-            len: len,
-            end: end,
-        })?;
-        assert_next_token!(self, end);
-        Ok(value)
-    }
-
-    fn visit_map<V>(
-        &mut self,
-        len: Option<usize>,
-        end: Token,
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        let value = visitor.visit_map(DeserializerMapVisitor {
-            de: self,
-            len: len,
-            end: end,
-        })?;
-        assert_next_token!(self, end);
-        Ok(value)
-    }
-}
-
-impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
-    type Error = Error;
-
-    forward_to_deserialize_any! {
-        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
-        bytes byte_buf unit seq map identifier ignored_any
-    }
-
-    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        let token = self.next_token();
-        match token {
-            Token::Bool(v) => visitor.visit_bool(v),
-            Token::I8(v) => visitor.visit_i8(v),
-            Token::I16(v) => visitor.visit_i16(v),
-            Token::I32(v) => visitor.visit_i32(v),
-            Token::I64(v) => visitor.visit_i64(v),
-            Token::U8(v) => visitor.visit_u8(v),
-            Token::U16(v) => visitor.visit_u16(v),
-            Token::U32(v) => visitor.visit_u32(v),
-            Token::U64(v) => visitor.visit_u64(v),
-            Token::F32(v) => visitor.visit_f32(v),
-            Token::F64(v) => visitor.visit_f64(v),
-            Token::Char(v) => visitor.visit_char(v),
-            Token::Str(v) => visitor.visit_str(v),
-            Token::BorrowedStr(v) => visitor.visit_borrowed_str(v),
-            Token::String(v) => visitor.visit_string(v.to_owned()),
-            Token::Bytes(v) => visitor.visit_bytes(v),
-            Token::BorrowedBytes(v) => visitor.visit_borrowed_bytes(v),
-            Token::ByteBuf(v) => visitor.visit_byte_buf(v.to_vec()),
-            Token::None => visitor.visit_none(),
-            Token::Some => visitor.visit_some(self),
-            Token::Unit | Token::UnitStruct { .. } => visitor.visit_unit(),
-            Token::NewtypeStruct { .. } => visitor.visit_newtype_struct(self),
-            Token::Seq { len } => self.visit_seq(len, Token::SeqEnd, visitor),
-            Token::Tuple { len } => self.visit_seq(Some(len), Token::TupleEnd, visitor),
-            Token::TupleStruct { len, .. } => {
-                self.visit_seq(Some(len), Token::TupleStructEnd, visitor)
-            }
-            Token::Map { len } => self.visit_map(len, Token::MapEnd, visitor),
-            Token::Struct { len, .. } => self.visit_map(Some(len), Token::StructEnd, visitor),
-            Token::Enum { .. } => {
-                let variant = self.next_token();
-                let next = self.peek_token();
-                match (variant, next) {
-                    (Token::Str(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_str(variant)
-                    }
-                    (Token::BorrowedStr(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_borrowed_str(variant)
-                    }
-                    (Token::String(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_string(variant.to_string())
-                    }
-                    (Token::Bytes(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_bytes(variant)
-                    }
-                    (Token::BorrowedBytes(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_borrowed_bytes(variant)
-                    }
-                    (Token::ByteBuf(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_byte_buf(variant.to_vec())
-                    }
-                    (Token::U8(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_u8(variant)
-                    }
-                    (Token::U16(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_u16(variant)
-                    }
-                    (Token::U32(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_u32(variant)
-                    }
-                    (Token::U64(variant), Token::Unit) => {
-                        self.next_token();
-                        visitor.visit_u64(variant)
-                    }
-                    (variant, Token::Unit) => unexpected!(variant),
-                    (variant, _) => {
-                        visitor.visit_map(EnumMapVisitor::new(self, variant, EnumFormat::Any))
-                    }
-                }
-            }
-            Token::UnitVariant { variant, .. } => visitor.visit_str(variant),
-            Token::NewtypeVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
-                self,
-                Token::Str(variant),
-                EnumFormat::Any,
-            )),
-            Token::TupleVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
-                self,
-                Token::Str(variant),
-                EnumFormat::Seq,
-            )),
-            Token::StructVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
-                self,
-                Token::Str(variant),
-                EnumFormat::Map,
-            )),
-            Token::SeqEnd
-            | Token::TupleEnd
-            | Token::TupleStructEnd
-            | Token::MapEnd
-            | Token::StructEnd
-            | Token::TupleVariantEnd
-            | Token::StructVariantEnd => {
-                unexpected!(token);
-            }
-        }
-    }
-
-    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::Unit | Token::None => {
-                self.next_token();
-                visitor.visit_none()
-            }
-            Token::Some => {
-                self.next_token();
-                visitor.visit_some(self)
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_enum<V>(
-        self,
-        name: &'static str,
-        _variants: &'static [&'static str],
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::Enum { name: n } if name == n => {
-                self.next_token();
-
-                visitor.visit_enum(DeserializerEnumVisitor { de: self })
-            }
-            Token::UnitVariant { name: n, .. }
-            | Token::NewtypeVariant { name: n, .. }
-            | Token::TupleVariant { name: n, .. }
-            | Token::StructVariant { name: n, .. }
-                if name == n =>
-            {
-                visitor.visit_enum(DeserializerEnumVisitor { de: self })
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_unit_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::UnitStruct { .. } => {
-                assert_next_token!(self, Token::UnitStruct { name: name });
-                visitor.visit_unit()
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_newtype_struct<V>(
-        self,
-        name: &'static str,
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::NewtypeStruct { .. } => {
-                assert_next_token!(self, Token::NewtypeStruct { name: name });
-                visitor.visit_newtype_struct(self)
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::Unit | Token::UnitStruct { .. } => {
-                self.next_token();
-                visitor.visit_unit()
-            }
-            Token::Seq { .. } => {
-                self.next_token();
-                self.visit_seq(Some(len), Token::SeqEnd, visitor)
-            }
-            Token::Tuple { .. } => {
-                self.next_token();
-                self.visit_seq(Some(len), Token::TupleEnd, visitor)
-            }
-            Token::TupleStruct { .. } => {
-                self.next_token();
-                self.visit_seq(Some(len), Token::TupleStructEnd, visitor)
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_tuple_struct<V>(
-        self,
-        name: &'static str,
-        len: usize,
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::Unit => {
-                self.next_token();
-                visitor.visit_unit()
-            }
-            Token::UnitStruct { .. } => {
-                assert_next_token!(self, Token::UnitStruct { name: name });
-                visitor.visit_unit()
-            }
-            Token::Seq { .. } => {
-                self.next_token();
-                self.visit_seq(Some(len), Token::SeqEnd, visitor)
-            }
-            Token::Tuple { .. } => {
-                self.next_token();
-                self.visit_seq(Some(len), Token::TupleEnd, visitor)
-            }
-            Token::TupleStruct { len: n, .. } => {
-                assert_next_token!(self, Token::TupleStruct { name: name, len: n });
-                self.visit_seq(Some(len), Token::TupleStructEnd, visitor)
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn deserialize_struct<V>(
-        self,
-        name: &'static str,
-        fields: &'static [&'static str],
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.peek_token() {
-            Token::Struct { len: n, .. } => {
-                assert_next_token!(self, Token::Struct { name: name, len: n });
-                self.visit_map(Some(fields.len()), Token::StructEnd, visitor)
-            }
-            Token::Map { .. } => {
-                self.next_token();
-                self.visit_map(Some(fields.len()), Token::MapEnd, visitor)
-            }
-            _ => self.deserialize_any(visitor),
-        }
-    }
-
-    fn is_human_readable(&self) -> bool {
-        panic!(
-            "Types which have different human-readable and compact representations \
-             must explicitly mark their test cases with `serde_test::Configure`"
-        );
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerSeqVisitor<'a, 'de: 'a> {
-    de: &'a mut Deserializer<'de>,
-    len: Option<usize>,
-    end: Token,
-}
-
-impl<'de, 'a> SeqAccess<'de> for DeserializerSeqVisitor<'a, 'de> {
-    type Error = Error;
-
-    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-    where
-        T: DeserializeSeed<'de>,
-    {
-        if self.de.peek_token_opt() == Some(self.end) {
-            return Ok(None);
-        }
-        self.len = self.len.map(|len| len.saturating_sub(1));
-        seed.deserialize(&mut *self.de).map(Some)
-    }
-
-    fn size_hint(&self) -> Option<usize> {
-        self.len
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerMapVisitor<'a, 'de: 'a> {
-    de: &'a mut Deserializer<'de>,
-    len: Option<usize>,
-    end: Token,
-}
-
-impl<'de, 'a> MapAccess<'de> for DeserializerMapVisitor<'a, 'de> {
-    type Error = Error;
-
-    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
-    where
-        K: DeserializeSeed<'de>,
-    {
-        if self.de.peek_token_opt() == Some(self.end) {
-            return Ok(None);
-        }
-        self.len = self.len.map(|len| len.saturating_sub(1));
-        seed.deserialize(&mut *self.de).map(Some)
-    }
-
-    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
-    where
-        V: DeserializeSeed<'de>,
-    {
-        seed.deserialize(&mut *self.de)
-    }
-
-    fn size_hint(&self) -> Option<usize> {
-        self.len
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerEnumVisitor<'a, 'de: 'a> {
-    de: &'a mut Deserializer<'de>,
-}
-
-impl<'de, 'a> EnumAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
-    type Error = Error;
-    type Variant = Self;
-
-    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self), Error>
-    where
-        V: DeserializeSeed<'de>,
-    {
-        match self.de.peek_token() {
-            Token::UnitVariant { variant: v, .. }
-            | Token::NewtypeVariant { variant: v, .. }
-            | Token::TupleVariant { variant: v, .. }
-            | Token::StructVariant { variant: v, .. } => {
-                let de = v.into_deserializer();
-                let value = seed.deserialize(de)?;
-                Ok((value, self))
-            }
-            _ => {
-                let value = seed.deserialize(&mut *self.de)?;
-                Ok((value, self))
-            }
-        }
-    }
-}
-
-impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
-    type Error = Error;
-
-    fn unit_variant(self) -> Result<(), Error> {
-        match self.de.peek_token() {
-            Token::UnitVariant { .. } => {
-                self.de.next_token();
-                Ok(())
-            }
-            _ => Deserialize::deserialize(self.de),
-        }
-    }
-
-    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
-    where
-        T: DeserializeSeed<'de>,
-    {
-        match self.de.peek_token() {
-            Token::NewtypeVariant { .. } => {
-                self.de.next_token();
-                seed.deserialize(self.de)
-            }
-            _ => seed.deserialize(self.de),
-        }
-    }
-
-    fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.de.peek_token() {
-            Token::TupleVariant { len: enum_len, .. } => {
-                let token = self.de.next_token();
-
-                if len == enum_len {
-                    self.de
-                        .visit_seq(Some(len), Token::TupleVariantEnd, visitor)
-                } else {
-                    unexpected!(token);
-                }
-            }
-            Token::Seq {
-                len: Some(enum_len),
-            } => {
-                let token = self.de.next_token();
-
-                if len == enum_len {
-                    self.de.visit_seq(Some(len), Token::SeqEnd, visitor)
-                } else {
-                    unexpected!(token);
-                }
-            }
-            _ => de::Deserializer::deserialize_any(self.de, visitor),
-        }
-    }
-
-    fn struct_variant<V>(
-        self,
-        fields: &'static [&'static str],
-        visitor: V,
-    ) -> Result<V::Value, Error>
-    where
-        V: Visitor<'de>,
-    {
-        match self.de.peek_token() {
-            Token::StructVariant { len: enum_len, .. } => {
-                let token = self.de.next_token();
-
-                if fields.len() == enum_len {
-                    self.de
-                        .visit_map(Some(fields.len()), Token::StructVariantEnd, visitor)
-                } else {
-                    unexpected!(token);
-                }
-            }
-            Token::Map {
-                len: Some(enum_len),
-            } => {
-                let token = self.de.next_token();
-
-                if fields.len() == enum_len {
-                    self.de
-                        .visit_map(Some(fields.len()), Token::MapEnd, visitor)
-                } else {
-                    unexpected!(token);
-                }
-            }
-            _ => de::Deserializer::deserialize_any(self.de, visitor),
-        }
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct EnumMapVisitor<'a, 'de: 'a> {
-    de: &'a mut Deserializer<'de>,
-    variant: Option<Token>,
-    format: EnumFormat,
-}
-
-enum EnumFormat {
-    Seq,
-    Map,
-    Any,
-}
-
-impl<'a, 'de> EnumMapVisitor<'a, 'de> {
-    fn new(de: &'a mut Deserializer<'de>, variant: Token, format: EnumFormat) -> Self {
-        EnumMapVisitor {
-            de: de,
-            variant: Some(variant),
-            format: format,
-        }
-    }
-}
-
-impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> {
-    type Error = Error;
-
-    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
-    where
-        K: DeserializeSeed<'de>,
-    {
-        match self.variant.take() {
-            Some(Token::Str(variant)) => seed.deserialize(variant.into_deserializer()).map(Some),
-            Some(Token::Bytes(variant)) => seed
-                .deserialize(BytesDeserializer { value: variant })
-                .map(Some),
-            Some(Token::U32(variant)) => seed.deserialize(variant.into_deserializer()).map(Some),
-            Some(other) => unexpected!(other),
-            None => Ok(None),
-        }
-    }
-
-    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
-    where
-        V: DeserializeSeed<'de>,
-    {
-        match self.format {
-            EnumFormat::Seq => {
-                let value = {
-                    let visitor = DeserializerSeqVisitor {
-                        de: self.de,
-                        len: None,
-                        end: Token::TupleVariantEnd,
-                    };
-                    seed.deserialize(SeqAccessDeserializer::new(visitor))?
-                };
-                assert_next_token!(self.de, Token::TupleVariantEnd);
-                Ok(value)
-            }
-            EnumFormat::Map => {
-                let value = {
-                    let visitor = DeserializerMapVisitor {
-                        de: self.de,
-                        len: None,
-                        end: Token::StructVariantEnd,
-                    };
-                    seed.deserialize(MapAccessDeserializer::new(visitor))?
-                };
-                assert_next_token!(self.de, Token::StructVariantEnd);
-                Ok(value)
-            }
-            EnumFormat::Any => seed.deserialize(&mut *self.de),
-        }
-    }
-}
-
-struct BytesDeserializer {
-    value: &'static [u8],
-}
-
-impl<'de> de::Deserializer<'de> for BytesDeserializer {
-    type Error = Error;
-
-    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-    where
-        V: de::Visitor<'de>,
-    {
-        visitor.visit_bytes(self.value)
-    }
-
-    forward_to_deserialize_any! {
-        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
-        bytes byte_buf option unit unit_struct newtype_struct seq tuple
-        tuple_struct map struct enum identifier ignored_any
-    }
-}
@@ -1,43 +0,0 @@
-use std::error;
-use std::fmt::{self, Display};
-
-use serde::{de, ser};
-
-#[derive(Clone, Debug)]
-pub struct Error {
-    msg: String,
-}
-
-impl ser::Error for Error {
-    fn custom<T: Display>(msg: T) -> Self {
-        Error {
-            msg: msg.to_string(),
-        }
-    }
-}
-
-impl de::Error for Error {
-    fn custom<T: Display>(msg: T) -> Self {
-        Error {
-            msg: msg.to_string(),
-        }
-    }
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        formatter.write_str(&self.msg)
-    }
-}
-
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        &self.msg
-    }
-}
-
-impl PartialEq<str> for Error {
-    fn eq(&self, other: &str) -> bool {
-        self.msg == other
-    }
-}
@@ -1,190 +0,0 @@
-//! This crate provides a convenient concise way to write unit tests for
-//! implementations of [`Serialize`] and [`Deserialize`].
-//!
-//! [`Serialize`]: https://docs.serde.rs/serde/ser/trait.Serialize.html
-//! [`Deserialize`]: https://docs.serde.rs/serde/de/trait.Deserialize.html
-//!
-//! The `Serialize` impl for a value can be characterized by the sequence of
-//! [`Serializer`] calls that are made in the course of serializing the value,
-//! so `serde_test` provides a [`Token`] abstraction which corresponds roughly
-//! to `Serializer` method calls. There is an [`assert_ser_tokens`] function to
-//! test that a value serializes to a particular sequence of method calls, an
-//! [`assert_de_tokens`] function to test that a value can be deserialized from
-//! a particular sequence of method calls, and an [`assert_tokens`] function to
-//! test both directions. There are also functions to test expected failure
-//! conditions.
-//!
-//! [`Serializer`]: https://docs.serde.rs/serde/ser/trait.Serializer.html
-//! [`Token`]: https://docs.serde.rs/serde_test/enum.Token.html
-//! [`assert_ser_tokens`]: https://docs.serde.rs/serde_test/fn.assert_ser_tokens.html
-//! [`assert_de_tokens`]: https://docs.serde.rs/serde_test/fn.assert_de_tokens.html
-//! [`assert_tokens`]: https://docs.serde.rs/serde_test/fn.assert_tokens.html
-//!
-//! Here is an example from the [`linked-hash-map`] crate.
-//!
-//! [`linked-hash-map`]: https://github.com/contain-rs/linked-hash-map
-//!
-//! ```edition2018
-//! # const IGNORE: &str = stringify! {
-//! use linked_hash_map::LinkedHashMap;
-//! # };
-//! use serde_test::{Token, assert_tokens};
-//!
-//! # use std::fmt;
-//! # use std::marker::PhantomData;
-//! #
-//! # use serde::ser::{Serialize, Serializer, SerializeMap};
-//! # use serde::de::{Deserialize, Deserializer, Visitor, MapAccess};
-//! #
-//! # // Dumb imitation of LinkedHashMap.
-//! # #[derive(PartialEq, Debug)]
-//! # struct LinkedHashMap<K, V>(Vec<(K, V)>);
-//! #
-//! # impl<K, V> LinkedHashMap<K, V> {
-//! #     fn new() -> Self {
-//! #         LinkedHashMap(Vec::new())
-//! #     }
-//! #
-//! #     fn insert(&mut self, k: K, v: V) {
-//! #         self.0.push((k, v));
-//! #     }
-//! # }
-//! #
-//! # impl<K, V> Serialize for LinkedHashMap<K, V>
-//! # where
-//! #     K: Serialize,
-//! #     V: Serialize,
-//! # {
-//! #     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-//! #     where
-//! #         S: Serializer,
-//! #     {
-//! #         let mut map = serializer.serialize_map(Some(self.0.len()))?;
-//! #         for &(ref k, ref v) in &self.0 {
-//! #             map.serialize_entry(k, v)?;
-//! #         }
-//! #         map.end()
-//! #     }
-//! # }
-//! #
-//! # struct LinkedHashMapVisitor<K, V>(PhantomData<(K, V)>);
-//! #
-//! # impl<'de, K, V> Visitor<'de> for LinkedHashMapVisitor<K, V>
-//! # where
-//! #     K: Deserialize<'de>,
-//! #     V: Deserialize<'de>,
-//! # {
-//! #     type Value = LinkedHashMap<K, V>;
-//! #
-//! #     fn expecting(&self, _: &mut fmt::Formatter) -> fmt::Result {
-//! #         unimplemented!()
-//! #     }
-//! #
-//! #     fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
-//! #     where
-//! #         M: MapAccess<'de>,
-//! #     {
-//! #         let mut map = LinkedHashMap::new();
-//! #         while let Some((key, value)) = access.next_entry()? {
-//! #             map.insert(key, value);
-//! #         }
-//! #         Ok(map)
-//! #     }
-//! # }
-//! #
-//! # impl<'de, K, V> Deserialize<'de> for LinkedHashMap<K, V>
-//! # where
-//! #     K: Deserialize<'de>,
-//! #     V: Deserialize<'de>,
-//! # {
-//! #     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-//! #     where
-//! #         D: Deserializer<'de>,
-//! #     {
-//! #         deserializer.deserialize_map(LinkedHashMapVisitor(PhantomData))
-//! #     }
-//! # }
-//! #
-//! #[test]
-//! # fn not_a_test_ser_de_empty() {}
-//! fn test_ser_de_empty() {
-//!     let map = LinkedHashMap::<char, u32>::new();
-//!
-//!     assert_tokens(&map, &[
-//!         Token::Map { len: Some(0) },
-//!         Token::MapEnd,
-//!     ]);
-//! }
-//!
-//! #[test]
-//! # fn not_a_test_ser_de() {}
-//! fn test_ser_de() {
-//!     let mut map = LinkedHashMap::new();
-//!     map.insert('b', 20);
-//!     map.insert('a', 10);
-//!     map.insert('c', 30);
-//!
-//!     assert_tokens(&map, &[
-//!         Token::Map { len: Some(3) },
-//!         Token::Char('b'),
-//!         Token::I32(20),
-//!
-//!         Token::Char('a'),
-//!         Token::I32(10),
-//!
-//!         Token::Char('c'),
-//!         Token::I32(30),
-//!         Token::MapEnd,
-//!     ]);
-//! }
-//! #
-//! # fn main() {
-//! #     test_ser_de_empty();
-//! #     test_ser_de();
-//! # }
-//! ```
-
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.131")]
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-// Ignored clippy lints
-#![cfg_attr(feature = "cargo-clippy", allow(float_cmp, needless_doctest_main))]
-// Ignored clippy_pedantic lints
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(
-        cloned_instead_of_copied,
-        empty_line_after_outer_attr,
-        manual_assert,
-        missing_docs_in_private_items,
-        missing_panics_doc,
-        module_name_repetitions,
-        must_use_candidate,
-        redundant_field_names,
-        too_many_lines,
-        use_debug,
-        use_self
-    )
-)]
-
-#[macro_use]
-extern crate serde;
-
-mod de;
-mod error;
-mod ser;
-
-mod assert;
-mod configure;
-mod token;
-
-pub use assert::{
-    assert_de_tokens, assert_de_tokens_error, assert_ser_tokens, assert_ser_tokens_error,
-    assert_tokens,
-};
-pub use token::Token;
-
-pub use configure::{Compact, Configure, Readable};
-
-// Not public API.
-#[doc(hidden)]
-pub use de::Deserializer;
@@ -1,464 +0,0 @@
-use serde::{ser, Serialize};
-
-use error::Error;
-use token::Token;
-
-/// A `Serializer` that ensures that a value serializes to a given list of
-/// tokens.
-#[derive(Debug)]
-pub struct Serializer<'a> {
-    tokens: &'a [Token],
-}
-
-impl<'a> Serializer<'a> {
-    /// Creates the serializer.
-    pub fn new(tokens: &'a [Token]) -> Self {
-        Serializer { tokens: tokens }
-    }
-
-    /// Pulls the next token off of the serializer, ignoring it.
-    fn next_token(&mut self) -> Option<Token> {
-        if let Some((&first, rest)) = self.tokens.split_first() {
-            self.tokens = rest;
-            Some(first)
-        } else {
-            None
-        }
-    }
-
-    pub fn remaining(&self) -> usize {
-        self.tokens.len()
-    }
-}
-
-macro_rules! assert_next_token {
-    ($ser:expr, $actual:ident) => {{
-        assert_next_token!($ser, stringify!($actual), Token::$actual, true);
-    }};
-    ($ser:expr, $actual:ident($v:expr)) => {{
-        assert_next_token!(
-            $ser,
-            format_args!(concat!(stringify!($actual), "({:?})"), $v),
-            Token::$actual(v),
-            v == $v
-        );
-    }};
-    ($ser:expr, $actual:ident { $($k:ident),* }) => {{
-        let compare = ($($k,)*);
-        let field_format = || {
-            use std::fmt::Write;
-            let mut buffer = String::new();
-            $(
-                write!(&mut buffer, concat!(stringify!($k), ": {:?}, "), $k).unwrap();
-            )*
-            buffer
-        };
-        assert_next_token!(
-            $ser,
-            format_args!(concat!(stringify!($actual), " {{ {}}}"), field_format()),
-            Token::$actual { $($k),* },
-            ($($k,)*) == compare
-        );
-    }};
-    ($ser:expr, $actual:expr, $pat:pat, $guard:expr) => {
-        match $ser.next_token() {
-            Some($pat) if $guard => {}
-            Some(expected) => {
-                panic!("expected Token::{} but serialized as {}",
-                       expected, $actual);
-            }
-            None => {
-                panic!("expected end of tokens, but {} was serialized",
-                       $actual);
-            }
-        }
-    };
-}
-
-impl<'s, 'a> ser::Serializer for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    type SerializeSeq = Self;
-    type SerializeTuple = Self;
-    type SerializeTupleStruct = Self;
-    type SerializeTupleVariant = Variant<'s, 'a>;
-    type SerializeMap = Self;
-    type SerializeStruct = Self;
-    type SerializeStructVariant = Variant<'s, 'a>;
-
-    fn serialize_bool(self, v: bool) -> Result<(), Error> {
-        assert_next_token!(self, Bool(v));
-        Ok(())
-    }
-
-    fn serialize_i8(self, v: i8) -> Result<(), Error> {
-        assert_next_token!(self, I8(v));
-        Ok(())
-    }
-
-    fn serialize_i16(self, v: i16) -> Result<(), Error> {
-        assert_next_token!(self, I16(v));
-        Ok(())
-    }
-
-    fn serialize_i32(self, v: i32) -> Result<(), Error> {
-        assert_next_token!(self, I32(v));
-        Ok(())
-    }
-
-    fn serialize_i64(self, v: i64) -> Result<(), Error> {
-        assert_next_token!(self, I64(v));
-        Ok(())
-    }
-
-    fn serialize_u8(self, v: u8) -> Result<(), Error> {
-        assert_next_token!(self, U8(v));
-        Ok(())
-    }
-
-    fn serialize_u16(self, v: u16) -> Result<(), Error> {
-        assert_next_token!(self, U16(v));
-        Ok(())
-    }
-
-    fn serialize_u32(self, v: u32) -> Result<(), Error> {
-        assert_next_token!(self, U32(v));
-        Ok(())
-    }
-
-    fn serialize_u64(self, v: u64) -> Result<(), Error> {
-        assert_next_token!(self, U64(v));
-        Ok(())
-    }
-
-    fn serialize_f32(self, v: f32) -> Result<(), Error> {
-        assert_next_token!(self, F32(v));
-        Ok(())
-    }
-
-    fn serialize_f64(self, v: f64) -> Result<(), Error> {
-        assert_next_token!(self, F64(v));
-        Ok(())
-    }
-
-    fn serialize_char(self, v: char) -> Result<(), Error> {
-        assert_next_token!(self, Char(v));
-        Ok(())
-    }
-
-    fn serialize_str(self, v: &str) -> Result<(), Error> {
-        match self.tokens.first() {
-            Some(&Token::BorrowedStr(_)) => assert_next_token!(self, BorrowedStr(v)),
-            Some(&Token::String(_)) => assert_next_token!(self, String(v)),
-            _ => assert_next_token!(self, Str(v)),
-        }
-        Ok(())
-    }
-
-    fn serialize_bytes(self, v: &[u8]) -> Result<(), Self::Error> {
-        match self.tokens.first() {
-            Some(&Token::BorrowedBytes(_)) => assert_next_token!(self, BorrowedBytes(v)),
-            Some(&Token::ByteBuf(_)) => assert_next_token!(self, ByteBuf(v)),
-            _ => assert_next_token!(self, Bytes(v)),
-        }
-        Ok(())
-    }
-
-    fn serialize_unit(self) -> Result<(), Error> {
-        assert_next_token!(self, Unit);
-        Ok(())
-    }
-
-    fn serialize_unit_struct(self, name: &'static str) -> Result<(), Error> {
-        assert_next_token!(self, UnitStruct { name });
-        Ok(())
-    }
-
-    fn serialize_unit_variant(
-        self,
-        name: &'static str,
-        _variant_index: u32,
-        variant: &'static str,
-    ) -> Result<(), Error> {
-        if self.tokens.first() == Some(&Token::Enum { name: name }) {
-            self.next_token();
-            assert_next_token!(self, Str(variant));
-            assert_next_token!(self, Unit);
-        } else {
-            assert_next_token!(self, UnitVariant { name, variant });
-        }
-        Ok(())
-    }
-
-    fn serialize_newtype_struct<T: ?Sized>(self, name: &'static str, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        assert_next_token!(self, NewtypeStruct { name });
-        value.serialize(self)
-    }
-
-    fn serialize_newtype_variant<T: ?Sized>(
-        self,
-        name: &'static str,
-        _variant_index: u32,
-        variant: &'static str,
-        value: &T,
-    ) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        if self.tokens.first() == Some(&Token::Enum { name: name }) {
-            self.next_token();
-            assert_next_token!(self, Str(variant));
-        } else {
-            assert_next_token!(self, NewtypeVariant { name, variant });
-        }
-        value.serialize(self)
-    }
-
-    fn serialize_none(self) -> Result<(), Error> {
-        assert_next_token!(self, None);
-        Ok(())
-    }
-
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        assert_next_token!(self, Some);
-        value.serialize(self)
-    }
-
-    fn serialize_seq(self, len: Option<usize>) -> Result<Self, Error> {
-        assert_next_token!(self, Seq { len });
-        Ok(self)
-    }
-
-    fn serialize_tuple(self, len: usize) -> Result<Self, Error> {
-        assert_next_token!(self, Tuple { len });
-        Ok(self)
-    }
-
-    fn serialize_tuple_struct(self, name: &'static str, len: usize) -> Result<Self, Error> {
-        assert_next_token!(self, TupleStruct { name, len });
-        Ok(self)
-    }
-
-    fn serialize_tuple_variant(
-        self,
-        name: &'static str,
-        _variant_index: u32,
-        variant: &'static str,
-        len: usize,
-    ) -> Result<Self::SerializeTupleVariant, Error> {
-        if self.tokens.first() == Some(&Token::Enum { name: name }) {
-            self.next_token();
-            assert_next_token!(self, Str(variant));
-            let len = Some(len);
-            assert_next_token!(self, Seq { len });
-            Ok(Variant {
-                ser: self,
-                end: Token::SeqEnd,
-            })
-        } else {
-            assert_next_token!(self, TupleVariant { name, variant, len });
-            Ok(Variant {
-                ser: self,
-                end: Token::TupleVariantEnd,
-            })
-        }
-    }
-
-    fn serialize_map(self, len: Option<usize>) -> Result<Self, Error> {
-        assert_next_token!(self, Map { len });
-        Ok(self)
-    }
-
-    fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self, Error> {
-        assert_next_token!(self, Struct { name, len });
-        Ok(self)
-    }
-
-    fn serialize_struct_variant(
-        self,
-        name: &'static str,
-        _variant_index: u32,
-        variant: &'static str,
-        len: usize,
-    ) -> Result<Self::SerializeStructVariant, Error> {
-        if self.tokens.first() == Some(&Token::Enum { name: name }) {
-            self.next_token();
-            assert_next_token!(self, Str(variant));
-            let len = Some(len);
-            assert_next_token!(self, Map { len });
-            Ok(Variant {
-                ser: self,
-                end: Token::MapEnd,
-            })
-        } else {
-            assert_next_token!(self, StructVariant { name, variant, len });
-            Ok(Variant {
-                ser: self,
-                end: Token::StructVariantEnd,
-            })
-        }
-    }
-
-    fn is_human_readable(&self) -> bool {
-        panic!(
-            "Types which have different human-readable and compact representations \
-             must explicitly mark their test cases with `serde_test::Configure`"
-        );
-    }
-}
-
-pub struct Variant<'s, 'a: 's> {
-    ser: &'s mut Serializer<'a>,
-    end: Token,
-}
-
-impl<'s, 'a> ser::SerializeSeq for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        value.serialize(&mut **self)
-    }
-
-    fn end(self) -> Result<(), Error> {
-        assert_next_token!(self, SeqEnd);
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeTuple for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        value.serialize(&mut **self)
-    }
-
-    fn end(self) -> Result<(), Error> {
-        assert_next_token!(self, TupleEnd);
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeTupleStruct for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        value.serialize(&mut **self)
-    }
-
-    fn end(self) -> Result<(), Error> {
-        assert_next_token!(self, TupleStructEnd);
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeTupleVariant for Variant<'s, 'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
-    where
-        T: Serialize,
-    {
-        value.serialize(&mut *self.ser)
-    }
-
-    fn end(self) -> Result<(), Error> {
-        match self.end {
-            Token::TupleVariantEnd => assert_next_token!(self.ser, TupleVariantEnd),
-            Token::SeqEnd => assert_next_token!(self.ser, SeqEnd),
-            _ => unreachable!(),
-        }
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeMap for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
-    where
-        T: Serialize,
-    {
-        key.serialize(&mut **self)
-    }
-
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
-    where
-        T: Serialize,
-    {
-        value.serialize(&mut **self)
-    }
-
-    fn end(self) -> Result<(), Self::Error> {
-        assert_next_token!(self, MapEnd);
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeStruct for &'s mut Serializer<'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
-    where
-        T: Serialize,
-    {
-        key.serialize(&mut **self)?;
-        value.serialize(&mut **self)
-    }
-
-    fn end(self) -> Result<(), Self::Error> {
-        assert_next_token!(self, StructEnd);
-        Ok(())
-    }
-}
-
-impl<'s, 'a> ser::SerializeStructVariant for Variant<'s, 'a> {
-    type Ok = ();
-    type Error = Error;
-
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
-    where
-        T: Serialize,
-    {
-        key.serialize(&mut *self.ser)?;
-        value.serialize(&mut *self.ser)
-    }
-
-    fn end(self) -> Result<(), Self::Error> {
-        match self.end {
-            Token::StructVariantEnd => assert_next_token!(self.ser, StructVariantEnd),
-            Token::MapEnd => assert_next_token!(self.ser, MapEnd),
-            _ => unreachable!(),
-        }
-        Ok(())
-    }
-}
@@ -1,519 +0,0 @@
-use std::fmt::{self, Debug, Display};
-
-#[derive(Copy, Clone, PartialEq, Debug)]
-pub enum Token {
-    /// A serialized `bool`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&true, &[Token::Bool(true)]);
-    /// ```
-    Bool(bool),
-
-    /// A serialized `i8`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0i8, &[Token::I8(0)]);
-    /// ```
-    I8(i8),
-
-    /// A serialized `i16`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0i16, &[Token::I16(0)]);
-    /// ```
-    I16(i16),
-
-    /// A serialized `i32`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0i32, &[Token::I32(0)]);
-    /// ```
-    I32(i32),
-
-    /// A serialized `i64`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0i64, &[Token::I64(0)]);
-    /// ```
-    I64(i64),
-
-    /// A serialized `u8`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0u8, &[Token::U8(0)]);
-    /// ```
-    U8(u8),
-
-    /// A serialized `u16`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0u16, &[Token::U16(0)]);
-    /// ```
-    U16(u16),
-
-    /// A serialized `u32`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0u32, &[Token::U32(0)]);
-    /// ```
-    U32(u32),
-
-    /// A serialized `u64`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0u64, &[Token::U64(0)]);
-    /// ```
-    U64(u64),
-
-    /// A serialized `f32`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0f32, &[Token::F32(0.0)]);
-    /// ```
-    F32(f32),
-
-    /// A serialized `f64`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&0f64, &[Token::F64(0.0)]);
-    /// ```
-    F64(f64),
-
-    /// A serialized `char`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&'\n', &[Token::Char('\n')]);
-    /// ```
-    Char(char),
-
-    /// A serialized `str`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let s = String::from("transient");
-    /// assert_tokens(&s, &[Token::Str("transient")]);
-    /// ```
-    Str(&'static str),
-
-    /// A borrowed `str`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let s: &str = "borrowed";
-    /// assert_tokens(&s, &[Token::BorrowedStr("borrowed")]);
-    /// ```
-    BorrowedStr(&'static str),
-
-    /// A serialized `String`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let s = String::from("owned");
-    /// assert_tokens(&s, &[Token::String("owned")]);
-    /// ```
-    String(&'static str),
-
-    /// A serialized `[u8]`
-    Bytes(&'static [u8]),
-
-    /// A borrowed `[u8]`.
-    BorrowedBytes(&'static [u8]),
-
-    /// A serialized `ByteBuf`
-    ByteBuf(&'static [u8]),
-
-    /// A serialized `Option<T>` containing none.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let opt = None::<char>;
-    /// assert_tokens(&opt, &[Token::None]);
-    /// ```
-    None,
-
-    /// The header to a serialized `Option<T>` containing some value.
-    ///
-    /// The tokens of the value follow after this header.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let opt = Some('c');
-    /// assert_tokens(&opt, &[
-    ///     Token::Some,
-    ///     Token::Char('c'),
-    /// ]);
-    /// ```
-    Some,
-
-    /// A serialized `()`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// assert_tokens(&(), &[Token::Unit]);
-    /// ```
-    Unit,
-
-    /// A serialized unit struct of the given name.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// struct X;
-    ///
-    /// assert_tokens(&X, &[Token::UnitStruct { name: "X" }]);
-    /// # }
-    /// ```
-    UnitStruct { name: &'static str },
-
-    /// A unit variant of an enum.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// enum E {
-    ///     A,
-    /// }
-    ///
-    /// let a = E::A;
-    /// assert_tokens(&a, &[Token::UnitVariant { name: "E", variant: "A" }]);
-    /// # }
-    /// ```
-    UnitVariant {
-        name: &'static str,
-        variant: &'static str,
-    },
-
-    /// The header to a serialized newtype struct of the given name.
-    ///
-    /// After this header is the value contained in the newtype struct.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// struct N(String);
-    ///
-    /// let n = N("newtype".to_owned());
-    /// assert_tokens(&n, &[
-    ///     Token::NewtypeStruct { name: "N" },
-    ///     Token::String("newtype"),
-    /// ]);
-    /// # }
-    /// ```
-    NewtypeStruct { name: &'static str },
-
-    /// The header to a newtype variant of an enum.
-    ///
-    /// After this header is the value contained in the newtype variant.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// enum E {
-    ///     B(u8),
-    /// }
-    ///
-    /// let b = E::B(0);
-    /// assert_tokens(&b, &[
-    ///     Token::NewtypeVariant { name: "E", variant: "B" },
-    ///     Token::U8(0),
-    /// ]);
-    /// # }
-    /// ```
-    NewtypeVariant {
-        name: &'static str,
-        variant: &'static str,
-    },
-
-    /// The header to a sequence.
-    ///
-    /// After this header are the elements of the sequence, followed by
-    /// `SeqEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let vec = vec!['a', 'b', 'c'];
-    /// assert_tokens(&vec, &[
-    ///     Token::Seq { len: Some(3) },
-    ///     Token::Char('a'),
-    ///     Token::Char('b'),
-    ///     Token::Char('c'),
-    ///     Token::SeqEnd,
-    /// ]);
-    /// ```
-    Seq { len: Option<usize> },
-
-    /// An indicator of the end of a sequence.
-    SeqEnd,
-
-    /// The header to a tuple.
-    ///
-    /// After this header are the elements of the tuple, followed by `TupleEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// let tuple = ('a', 100);
-    /// assert_tokens(&tuple, &[
-    ///     Token::Tuple { len: 2 },
-    ///     Token::Char('a'),
-    ///     Token::I32(100),
-    ///     Token::TupleEnd,
-    /// ]);
-    /// ```
-    Tuple { len: usize },
-
-    /// An indicator of the end of a tuple.
-    TupleEnd,
-
-    /// The header to a tuple struct.
-    ///
-    /// After this header are the fields of the tuple struct, followed by
-    /// `TupleStructEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// struct T(u8, u8);
-    ///
-    /// let t = T(0, 0);
-    /// assert_tokens(&t, &[
-    ///     Token::TupleStruct { name: "T", len: 2 },
-    ///     Token::U8(0),
-    ///     Token::U8(0),
-    ///     Token::TupleStructEnd,
-    /// ]);
-    /// # }
-    /// ```
-    TupleStruct { name: &'static str, len: usize },
-
-    /// An indicator of the end of a tuple struct.
-    TupleStructEnd,
-
-    /// The header to a tuple variant of an enum.
-    ///
-    /// After this header are the fields of the tuple variant, followed by
-    /// `TupleVariantEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// enum E {
-    ///     C(u8, u8),
-    /// }
-    ///
-    /// let c = E::C(0, 0);
-    /// assert_tokens(&c, &[
-    ///     Token::TupleVariant { name: "E", variant: "C", len: 2 },
-    ///     Token::U8(0),
-    ///     Token::U8(0),
-    ///     Token::TupleVariantEnd,
-    /// ]);
-    /// # }
-    /// ```
-    TupleVariant {
-        name: &'static str,
-        variant: &'static str,
-        len: usize,
-    },
-
-    /// An indicator of the end of a tuple variant.
-    TupleVariantEnd,
-
-    /// The header to a map.
-    ///
-    /// After this header are the entries of the map, followed by `MapEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// use std::collections::BTreeMap;
-    ///
-    /// let mut map = BTreeMap::new();
-    /// map.insert('A', 65);
-    /// map.insert('Z', 90);
-    ///
-    /// assert_tokens(&map, &[
-    ///     Token::Map { len: Some(2) },
-    ///     Token::Char('A'),
-    ///     Token::I32(65),
-    ///     Token::Char('Z'),
-    ///     Token::I32(90),
-    ///     Token::MapEnd,
-    /// ]);
-    /// ```
-    Map { len: Option<usize> },
-
-    /// An indicator of the end of a map.
-    MapEnd,
-
-    /// The header of a struct.
-    ///
-    /// After this header are the fields of the struct, followed by `StructEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// struct S {
-    ///     a: u8,
-    ///     b: u8,
-    /// }
-    ///
-    /// let s = S { a: 0, b: 0 };
-    /// assert_tokens(&s, &[
-    ///     Token::Struct { name: "S", len: 2 },
-    ///     Token::Str("a"),
-    ///     Token::U8(0),
-    ///     Token::Str("b"),
-    ///     Token::U8(0),
-    ///     Token::StructEnd,
-    /// ]);
-    /// # }
-    /// ```
-    Struct { name: &'static str, len: usize },
-
-    /// An indicator of the end of a struct.
-    StructEnd,
-
-    /// The header of a struct variant of an enum.
-    ///
-    /// After this header are the fields of the struct variant, followed by
-    /// `StructVariantEnd`.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// enum E {
-    ///     D { d: u8 },
-    /// }
-    ///
-    /// let d = E::D { d: 0 };
-    /// assert_tokens(&d, &[
-    ///     Token::StructVariant { name: "E", variant: "D", len: 1 },
-    ///     Token::Str("d"),
-    ///     Token::U8(0),
-    ///     Token::StructVariantEnd,
-    /// ]);
-    /// # }
-    /// ```
-    StructVariant {
-        name: &'static str,
-        variant: &'static str,
-        len: usize,
-    },
-
-    /// An indicator of the end of a struct variant.
-    StructVariantEnd,
-
-    /// The header to an enum of the given name.
-    ///
-    /// ```edition2018
-    /// # use serde::{Serialize, Deserialize};
-    /// # use serde_test::{assert_tokens, Token};
-    /// #
-    /// # fn main() {
-    /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
-    /// enum E {
-    ///     A,
-    ///     B(u8),
-    ///     C(u8, u8),
-    ///     D { d: u8 },
-    /// }
-    ///
-    /// let a = E::A;
-    /// assert_tokens(&a, &[
-    ///     Token::Enum { name: "E" },
-    ///     Token::Str("A"),
-    ///     Token::Unit,
-    /// ]);
-    ///
-    /// let b = E::B(0);
-    /// assert_tokens(&b, &[
-    ///     Token::Enum { name: "E" },
-    ///     Token::Str("B"),
-    ///     Token::U8(0),
-    /// ]);
-    ///
-    /// let c = E::C(0, 0);
-    /// assert_tokens(&c, &[
-    ///     Token::Enum { name: "E" },
-    ///     Token::Str("C"),
-    ///     Token::Seq { len: Some(2) },
-    ///     Token::U8(0),
-    ///     Token::U8(0),
-    ///     Token::SeqEnd,
-    /// ]);
-    ///
-    /// let d = E::D { d: 0 };
-    /// assert_tokens(&d, &[
-    ///     Token::Enum { name: "E" },
-    ///     Token::Str("D"),
-    ///     Token::Map { len: Some(1) },
-    ///     Token::Str("d"),
-    ///     Token::U8(0),
-    ///     Token::MapEnd,
-    /// ]);
-    /// # }
-    /// ```
-    Enum { name: &'static str },
-}
-
-impl Display for Token {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Debug::fmt(self, formatter)
-    }
-}
@@ -4,23 +4,18 @@ version = "0.0.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 edition = "2018"
 publish = false
-build = "build.rs"

 [features]
-expandtest = []
 unstable = ["serde/unstable"]

 [dependencies]
 serde = { path = "../serde" }

-[build-dependencies]
-toolchain_find = "0.1"
-
 [dev-dependencies]
+automod = "1.0.1"
 fnv = "1.0"
-macrotest = "=1.0.0"
 rustversion = "1.0"
-serde = { path = "../serde", features = ["rc", "derive"] }
+serde = { path = "../serde", features = ["rc"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }
-serde_test = { path = "../serde_test" }
-trybuild = { version = "1.0.49", features = ["diff"] }
+serde_test = "1.0.176"
+trybuild = { version = "1.0.97", features = ["diff"] }
@@ -1,29 +0,0 @@
-use std::process::{Command, ExitStatus, Stdio};
-
-fn has_cargo_expand() -> bool {
-    let cargo_expand = if cfg!(windows) {
-        "cargo-expand.exe"
-    } else {
-        "cargo-expand"
-    };
-
-    Command::new(cargo_expand)
-        .arg("--version")
-        .stdin(Stdio::null())
-        .stdout(Stdio::null())
-        .stderr(Stdio::null())
-        .status()
-        .as_ref()
-        .map(ExitStatus::success)
-        .unwrap_or(false)
-}
-
-fn has_rustfmt() -> bool {
-    toolchain_find::find_installed_component("rustfmt").is_some()
-}
-
-fn main() {
-    if cfg!(feature = "expandtest") && has_cargo_expand() && has_rustfmt() {
-        println!("cargo:rustc-cfg=expandtest");
-    }
-}
@@ -1,11 +1,13 @@
 [package]
 name = "serde_derive_tests_no_std"
 version = "0.0.0"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
 edition = "2018"
 publish = false

 [dependencies]
 libc = { version = "0.2", default-features = false }
-serde = { path = "../../serde", default-features = false, features = ["derive"] }
+serde = { path = "../../serde", default-features = false }
+serde_derive = { path = "../../serde_derive" }

 [workspace]
@@ -1,3 +1,4 @@
+#![allow(internal_features)]
 #![feature(lang_items, start)]
 #![no_std]

@@ -19,24 +20,24 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {

 //////////////////////////////////////////////////////////////////////////////

-use serde::{Serialize, Deserialize};
+use serde_derive::{Deserialize, Serialize};

 #[derive(Serialize, Deserialize)]
-struct Unit;
+pub struct Unit;

 #[derive(Serialize, Deserialize)]
-struct Newtype(u8);
+pub struct Newtype(u8);

 #[derive(Serialize, Deserialize)]
-struct Tuple(u8, u8);
+pub struct Tuple(u8, u8);

 #[derive(Serialize, Deserialize)]
-struct Struct {
+pub struct Struct {
    f: u8,
 }

 #[derive(Serialize, Deserialize)]
-enum Enum {
+pub enum Enum {
    Unit,
    Newtype(u8),
    Tuple(u8, u8),
@@ -1,5 +1,7 @@
-#[cfg_attr(target_os = "emscripten", ignore)]
-#[rustversion::attr(not(nightly), ignore)]
+#[cfg_attr(target_os = "emscripten", ignore = "disabled on Emscripten")]
+#[rustversion::attr(not(nightly), ignore = "requires nightly")]
+#[cfg_attr(miri, ignore = "incompatible with miri")]
+#[allow(unused_attributes)]
 #[test]
 fn ui() {
    let t = trybuild::TestCases::new();
@@ -1,13 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-enum DeEnum<B, C, D> {
-    Unit,
-    Seq(i8, B, C, D),
-    Map { a: i8, b: B, c: C, d: D },
-
-    // Make sure we can support more than one variant.
-    _Unit2,
-    _Seq2(i8, B, C, D),
-    _Map2 { a: i8, b: B, c: C, d: D },
-}
@@ -1,410 +0,0 @@
-use serde::{Deserialize, Serialize};
-trait AssociatedType {
-    type X;
-}
-impl AssociatedType for i32 {
-    type X = i32;
-}
-struct DefaultTyParam<T: AssociatedType<X = i32> = i32> {
-    phantom: PhantomData<T>,
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<T: AssociatedType<X = i32>> _serde::Serialize for DefaultTyParam<T> {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            let mut __serde_state = match _serde::Serializer::serialize_struct(
-                __serializer,
-                "DefaultTyParam",
-                false as usize + 1,
-            ) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeStruct::serialize_field(
-                &mut __serde_state,
-                "phantom",
-                &self.phantom,
-            ) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            _serde::ser::SerializeStruct::end(__serde_state)
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, T: AssociatedType<X = i32>> _serde::Deserialize<'de> for DefaultTyParam<T> {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "phantom" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"phantom" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, T: AssociatedType<X = i32>> {
-                marker: _serde::__private::PhantomData<DefaultTyParam<T>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, T: AssociatedType<X = i32>> _serde::de::Visitor<'de> for __Visitor<'de, T> {
-                type Value = DefaultTyParam<T>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct DefaultTyParam")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<PhantomData<T>>(
-                        &mut __seq,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"struct DefaultTyParam with 1 element",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(DefaultTyParam { phantom: __field0 })
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: _serde::__private::Option<PhantomData<T>> =
-                        _serde::__private::None;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if _serde::__private::Option::is_some(&__field0) {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field(
-                                            "phantom",
-                                        ),
-                                    );
-                                }
-                                __field0 = _serde::__private::Some(
-                                    match _serde::de::MapAccess::next_value::<PhantomData<T>>(
-                                        &mut __map,
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    },
-                                );
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    let __field0 = match __field0 {
-                        _serde::__private::Some(__field0) => __field0,
-                        _serde::__private::None => {
-                            match _serde::__private::de::missing_field("phantom") {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            }
-                        }
-                    };
-                    _serde::__private::Ok(DefaultTyParam { phantom: __field0 })
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["phantom"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "DefaultTyParam",
-                FIELDS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<DefaultTyParam<T>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "phantom" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"phantom" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, 'place, T: AssociatedType<X = i32> + 'place> {
-                place: &'place mut DefaultTyParam<T>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, T: AssociatedType<X = i32> + 'place> _serde::de::Visitor<'de>
-                for __Visitor<'de, 'place, T>
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct DefaultTyParam")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.phantom),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"struct DefaultTyParam with 1 element",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: bool = false;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if __field0 {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field(
-                                            "phantom",
-                                        ),
-                                    );
-                                }
-                                match _serde::de::MapAccess::next_value_seed(
-                                    &mut __map,
-                                    _serde::__private::de::InPlaceSeed(&mut self.place.phantom),
-                                ) {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                                __field0 = true;
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    if !__field0 {
-                        self.place.phantom = match _serde::__private::de::missing_field("phantom") {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        };
-                    };
-                    _serde::__private::Ok(())
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["phantom"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "DefaultTyParam",
-                FIELDS,
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,14 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-trait AssociatedType {
-    type X;
-}
-
-impl AssociatedType for i32 {
-    type X = i32;
-}
-
-#[derive(Serialize, Deserialize)]
-struct DefaultTyParam<T: AssociatedType<X = i32> = i32> {
-    phantom: PhantomData<T>,
-}
@@ -1,590 +0,0 @@
-use serde::{Deserialize, Serialize};
-pub enum GenericEnum<T, U> {
-    Unit,
-    NewType(T),
-    Seq(T, U),
-    Map { x: T, y: U },
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<T, U> _serde::Serialize for GenericEnum<T, U>
-    where
-        T: _serde::Serialize,
-        U: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            match *self {
-                GenericEnum::Unit => _serde::Serializer::serialize_unit_variant(
-                    __serializer,
-                    "GenericEnum",
-                    0u32,
-                    "Unit",
-                ),
-                GenericEnum::NewType(ref __field0) => {
-                    _serde::Serializer::serialize_newtype_variant(
-                        __serializer,
-                        "GenericEnum",
-                        1u32,
-                        "NewType",
-                        __field0,
-                    )
-                }
-                GenericEnum::Seq(ref __field0, ref __field1) => {
-                    let mut __serde_state = match _serde::Serializer::serialize_tuple_variant(
-                        __serializer,
-                        "GenericEnum",
-                        2u32,
-                        "Seq",
-                        0 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field0,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeTupleVariant::end(__serde_state)
-                }
-                GenericEnum::Map { ref x, ref y } => {
-                    let mut __serde_state = match _serde::Serializer::serialize_struct_variant(
-                        __serializer,
-                        "GenericEnum",
-                        3u32,
-                        "Map",
-                        0 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "x",
-                        x,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "y",
-                        y,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeStructVariant::end(__serde_state)
-                }
-            }
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, T, U> _serde::Deserialize<'de> for GenericEnum<T, U>
-    where
-        T: _serde::Deserialize<'de>,
-        U: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __field1,
-                __field2,
-                __field3,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        1u64 => _serde::__private::Ok(__Field::__field1),
-                        2u64 => _serde::__private::Ok(__Field::__field2),
-                        3u64 => _serde::__private::Ok(__Field::__field3),
-                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"variant index 0 <= i < 4",
-                        )),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "Unit" => _serde::__private::Ok(__Field::__field0),
-                        "NewType" => _serde::__private::Ok(__Field::__field1),
-                        "Seq" => _serde::__private::Ok(__Field::__field2),
-                        "Map" => _serde::__private::Ok(__Field::__field3),
-                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
-                            __value, VARIANTS,
-                        )),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"Unit" => _serde::__private::Ok(__Field::__field0),
-                        b"NewType" => _serde::__private::Ok(__Field::__field1),
-                        b"Seq" => _serde::__private::Ok(__Field::__field2),
-                        b"Map" => _serde::__private::Ok(__Field::__field3),
-                        _ => {
-                            let __value = &_serde::__private::from_utf8_lossy(__value);
-                            _serde::__private::Err(_serde::de::Error::unknown_variant(
-                                __value, VARIANTS,
-                            ))
-                        }
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, T, U>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                type Value = GenericEnum<T, U>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "enum GenericEnum")
-                }
-                fn visit_enum<__A>(
-                    self,
-                    __data: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::EnumAccess<'de>,
-                {
-                    match match _serde::de::EnumAccess::variant(__data) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        (__Field::__field0, __variant) => {
-                            match _serde::de::VariantAccess::unit_variant(__variant) {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            };
-                            _serde::__private::Ok(GenericEnum::Unit)
-                        }
-                        (__Field::__field1, __variant) => _serde::__private::Result::map(
-                            _serde::de::VariantAccess::newtype_variant::<T>(__variant),
-                            GenericEnum::NewType,
-                        ),
-                        (__Field::__field2, __variant) => {
-                            struct __Visitor<'de, T, U>
-                            where
-                                T: _serde::Deserialize<'de>,
-                                U: _serde::Deserialize<'de>,
-                            {
-                                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
-                                lifetime: _serde::__private::PhantomData<&'de ()>,
-                            }
-                            impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
-                            where
-                                T: _serde::Deserialize<'de>,
-                                U: _serde::Deserialize<'de>,
-                            {
-                                type Value = GenericEnum<T, U>;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "tuple variant GenericEnum::Seq",
-                                    )
-                                }
-                                #[inline]
-                                fn visit_seq<__A>(
-                                    self,
-                                    mut __seq: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::SeqAccess<'de>,
-                                {
-                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
-                                        T,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "tuple variant GenericEnum::Seq with 2 elements")) ;
-                                        }
-                                    };
-                                    let __field1 = match match _serde::de::SeqAccess::next_element::<
-                                        U,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (1usize , & "tuple variant GenericEnum::Seq with 2 elements")) ;
-                                        }
-                                    };
-                                    _serde::__private::Ok(GenericEnum::Seq(__field0, __field1))
-                                }
-                            }
-                            _serde::de::VariantAccess::tuple_variant(
-                                __variant,
-                                2usize,
-                                __Visitor {
-                                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
-                                    lifetime: _serde::__private::PhantomData,
-                                },
-                            )
-                        }
-                        (__Field::__field3, __variant) => {
-                            #[allow(non_camel_case_types)]
-                            enum __Field {
-                                __field0,
-                                __field1,
-                                __ignore,
-                            }
-                            struct __FieldVisitor;
-                            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                                type Value = __Field;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "field identifier",
-                                    )
-                                }
-                                fn visit_u64<__E>(
-                                    self,
-                                    __value: u64,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        0u64 => _serde::__private::Ok(__Field::__field0),
-                                        1u64 => _serde::__private::Ok(__Field::__field1),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_str<__E>(
-                                    self,
-                                    __value: &str,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        "x" => _serde::__private::Ok(__Field::__field0),
-                                        "y" => _serde::__private::Ok(__Field::__field1),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_bytes<__E>(
-                                    self,
-                                    __value: &[u8],
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        b"x" => _serde::__private::Ok(__Field::__field0),
-                                        b"y" => _serde::__private::Ok(__Field::__field1),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                            }
-                            impl<'de> _serde::Deserialize<'de> for __Field {
-                                #[inline]
-                                fn deserialize<__D>(
-                                    __deserializer: __D,
-                                ) -> _serde::__private::Result<Self, __D::Error>
-                                where
-                                    __D: _serde::Deserializer<'de>,
-                                {
-                                    _serde::Deserializer::deserialize_identifier(
-                                        __deserializer,
-                                        __FieldVisitor,
-                                    )
-                                }
-                            }
-                            struct __Visitor<'de, T, U>
-                            where
-                                T: _serde::Deserialize<'de>,
-                                U: _serde::Deserialize<'de>,
-                            {
-                                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
-                                lifetime: _serde::__private::PhantomData<&'de ()>,
-                            }
-                            impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
-                            where
-                                T: _serde::Deserialize<'de>,
-                                U: _serde::Deserialize<'de>,
-                            {
-                                type Value = GenericEnum<T, U>;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "struct variant GenericEnum::Map",
-                                    )
-                                }
-                                #[inline]
-                                fn visit_seq<__A>(
-                                    self,
-                                    mut __seq: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::SeqAccess<'de>,
-                                {
-                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
-                                        T,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant GenericEnum::Map with 2 elements")) ;
-                                        }
-                                    };
-                                    let __field1 = match match _serde::de::SeqAccess::next_element::<
-                                        U,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (1usize , & "struct variant GenericEnum::Map with 2 elements")) ;
-                                        }
-                                    };
-                                    _serde::__private::Ok(GenericEnum::Map {
-                                        x: __field0,
-                                        y: __field1,
-                                    })
-                                }
-                                #[inline]
-                                fn visit_map<__A>(
-                                    self,
-                                    mut __map: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::MapAccess<'de>,
-                                {
-                                    let mut __field0: _serde::__private::Option<T> =
-                                        _serde::__private::None;
-                                    let mut __field1: _serde::__private::Option<U> =
-                                        _serde::__private::None;
-                                    while let _serde::__private::Some(__key) =
-                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
-                                        {
-                                            _serde::__private::Ok(__val) => __val,
-                                            _serde::__private::Err(__err) => {
-                                                return _serde::__private::Err(__err);
-                                            }
-                                        }
-                                    {
-                                        match __key {
-                                            __Field::__field0 => {
-                                                if _serde::__private::Option::is_some(&__field0) {
-                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("x")) ;
-                                                }
-                                                __field0 = _serde::__private::Some(
-                                                    match _serde::de::MapAccess::next_value::<T>(
-                                                        &mut __map,
-                                                    ) {
-                                                        _serde::__private::Ok(__val) => __val,
-                                                        _serde::__private::Err(__err) => {
-                                                            return _serde::__private::Err(__err);
-                                                        }
-                                                    },
-                                                );
-                                            }
-                                            __Field::__field1 => {
-                                                if _serde::__private::Option::is_some(&__field1) {
-                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("y")) ;
-                                                }
-                                                __field1 = _serde::__private::Some(
-                                                    match _serde::de::MapAccess::next_value::<U>(
-                                                        &mut __map,
-                                                    ) {
-                                                        _serde::__private::Ok(__val) => __val,
-                                                        _serde::__private::Err(__err) => {
-                                                            return _serde::__private::Err(__err);
-                                                        }
-                                                    },
-                                                );
-                                            }
-                                            _ => {
-                                                let _ = match _serde::de::MapAccess::next_value::<
-                                                    _serde::de::IgnoredAny,
-                                                >(
-                                                    &mut __map
-                                                ) {
-                                                    _serde::__private::Ok(__val) => __val,
-                                                    _serde::__private::Err(__err) => {
-                                                        return _serde::__private::Err(__err);
-                                                    }
-                                                };
-                                            }
-                                        }
-                                    }
-                                    let __field0 = match __field0 {
-                                        _serde::__private::Some(__field0) => __field0,
-                                        _serde::__private::None => {
-                                            match _serde::__private::de::missing_field("x") {
-                                                _serde::__private::Ok(__val) => __val,
-                                                _serde::__private::Err(__err) => {
-                                                    return _serde::__private::Err(__err);
-                                                }
-                                            }
-                                        }
-                                    };
-                                    let __field1 = match __field1 {
-                                        _serde::__private::Some(__field1) => __field1,
-                                        _serde::__private::None => {
-                                            match _serde::__private::de::missing_field("y") {
-                                                _serde::__private::Ok(__val) => __val,
-                                                _serde::__private::Err(__err) => {
-                                                    return _serde::__private::Err(__err);
-                                                }
-                                            }
-                                        }
-                                    };
-                                    _serde::__private::Ok(GenericEnum::Map {
-                                        x: __field0,
-                                        y: __field1,
-                                    })
-                                }
-                            }
-                            const FIELDS: &'static [&'static str] = &["x", "y"];
-                            _serde::de::VariantAccess::struct_variant(
-                                __variant,
-                                FIELDS,
-                                __Visitor {
-                                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
-                                    lifetime: _serde::__private::PhantomData,
-                                },
-                            )
-                        }
-                    }
-                }
-            }
-            const VARIANTS: &'static [&'static str] = &["Unit", "NewType", "Seq", "Map"];
-            _serde::Deserializer::deserialize_enum(
-                __deserializer,
-                "GenericEnum",
-                VARIANTS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,9 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-pub enum GenericEnum<T, U> {
-    Unit,
-    NewType(T),
-    Seq(T, U),
-    Map { x: T, y: U },
-}
@@ -1,594 +0,0 @@
-use serde::{Deserialize, Serialize};
-pub struct GenericStruct<T> {
-    x: T,
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<T> _serde::Serialize for GenericStruct<T>
-    where
-        T: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            let mut __serde_state = match _serde::Serializer::serialize_struct(
-                __serializer,
-                "GenericStruct",
-                false as usize + 1,
-            ) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "x", &self.x) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            _serde::ser::SerializeStruct::end(__serde_state)
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, T> _serde::Deserialize<'de> for GenericStruct<T>
-    where
-        T: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "x" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"x" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<GenericStruct<T>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, T> _serde::de::Visitor<'de> for __Visitor<'de, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                type Value = GenericStruct<T>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct GenericStruct")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"struct GenericStruct with 1 element",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(GenericStruct { x: __field0 })
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: _serde::__private::Option<T> = _serde::__private::None;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if _serde::__private::Option::is_some(&__field0) {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("x"),
-                                    );
-                                }
-                                __field0 = _serde::__private::Some(
-                                    match _serde::de::MapAccess::next_value::<T>(&mut __map) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    },
-                                );
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    let __field0 = match __field0 {
-                        _serde::__private::Some(__field0) => __field0,
-                        _serde::__private::None => {
-                            match _serde::__private::de::missing_field("x") {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            }
-                        }
-                    };
-                    _serde::__private::Ok(GenericStruct { x: __field0 })
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["x"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "GenericStruct",
-                FIELDS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<GenericStruct<T>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "x" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"x" => _serde::__private::Ok(__Field::__field0),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, 'place, T: 'place>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                place: &'place mut GenericStruct<T>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, T: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct GenericStruct")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.x),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"struct GenericStruct with 1 element",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: bool = false;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if __field0 {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("x"),
-                                    );
-                                }
-                                match _serde::de::MapAccess::next_value_seed(
-                                    &mut __map,
-                                    _serde::__private::de::InPlaceSeed(&mut self.place.x),
-                                ) {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                                __field0 = true;
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    if !__field0 {
-                        self.place.x = match _serde::__private::de::missing_field("x") {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        };
-                    };
-                    _serde::__private::Ok(())
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["x"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "GenericStruct",
-                FIELDS,
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
-pub struct GenericNewTypeStruct<T>(T);
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<T> _serde::Serialize for GenericNewTypeStruct<T>
-    where
-        T: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            _serde::Serializer::serialize_newtype_struct(
-                __serializer,
-                "GenericNewTypeStruct",
-                &self.0,
-            )
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, T> _serde::Deserialize<'de> for GenericNewTypeStruct<T>
-    where
-        T: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<GenericNewTypeStruct<T>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, T> _serde::de::Visitor<'de> for __Visitor<'de, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                type Value = GenericNewTypeStruct<T>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct GenericNewTypeStruct",
-                    )
-                }
-                #[inline]
-                fn visit_newtype_struct<__E>(
-                    self,
-                    __e: __E,
-                ) -> _serde::__private::Result<Self::Value, __E::Error>
-                where
-                    __E: _serde::Deserializer<'de>,
-                {
-                    let __field0: T = match <T as _serde::Deserialize>::deserialize(__e) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::__private::Ok(GenericNewTypeStruct(__field0))
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"tuple struct GenericNewTypeStruct with 1 element",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(GenericNewTypeStruct(__field0))
-                }
-            }
-            _serde::Deserializer::deserialize_newtype_struct(
-                __deserializer,
-                "GenericNewTypeStruct",
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<GenericNewTypeStruct<T>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, 'place, T: 'place>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                place: &'place mut GenericNewTypeStruct<T>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, T: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T>
-            where
-                T: _serde::Deserialize<'de>,
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct GenericNewTypeStruct",
-                    )
-                }
-                #[inline]
-                fn visit_newtype_struct<__E>(
-                    self,
-                    __e: __E,
-                ) -> _serde::__private::Result<Self::Value, __E::Error>
-                where
-                    __E: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserialize::deserialize_in_place(__e, &mut self.place.0)
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"tuple struct GenericNewTypeStruct with 1 element",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-            }
-            _serde::Deserializer::deserialize_newtype_struct(
-                __deserializer,
-                "GenericNewTypeStruct",
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,9 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-pub struct GenericStruct<T> {
-    x: T,
-}
-
-#[derive(Serialize, Deserialize)]
-pub struct GenericNewTypeStruct<T>(T);
@@ -1,172 +0,0 @@
-use serde::{Deserialize, Serialize};
-pub struct GenericTupleStruct<T, U>(T, U);
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, T, U> _serde::Deserialize<'de> for GenericTupleStruct<T, U>
-    where
-        T: _serde::Deserialize<'de>,
-        U: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, T, U>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<GenericTupleStruct<T, U>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                type Value = GenericTupleStruct<T, U>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct GenericTupleStruct",
-                    )
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"tuple struct GenericTupleStruct with 2 elements",
-                            ));
-                        }
-                    };
-                    let __field1 = match match _serde::de::SeqAccess::next_element::<U>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                1usize,
-                                &"tuple struct GenericTupleStruct with 2 elements",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(GenericTupleStruct(__field0, __field1))
-                }
-            }
-            _serde::Deserializer::deserialize_tuple_struct(
-                __deserializer,
-                "GenericTupleStruct",
-                2usize,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<GenericTupleStruct<T, U>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, 'place, T: 'place, U: 'place>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                place: &'place mut GenericTupleStruct<T, U>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, T: 'place, U: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T, U>
-            where
-                T: _serde::Deserialize<'de>,
-                U: _serde::Deserialize<'de>,
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct GenericTupleStruct",
-                    )
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"tuple struct GenericTupleStruct with 2 elements",
-                        ));
-                    }
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.1),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            1usize,
-                            &"tuple struct GenericTupleStruct with 2 elements",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-            }
-            _serde::Deserializer::deserialize_tuple_struct(
-                __deserializer,
-                "GenericTupleStruct",
-                2usize,
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,4 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Deserialize)]
-pub struct GenericTupleStruct<T, U>(T, U);
@@ -1,607 +0,0 @@
-use serde::{Deserialize, Serialize};
-enum Lifetimes<'a> {
-    LifetimeSeq(&'a i32),
-    NoLifetimeSeq(i32),
-    LifetimeMap { a: &'a i32 },
-    NoLifetimeMap { a: i32 },
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'a> _serde::Serialize for Lifetimes<'a> {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            match *self {
-                Lifetimes::LifetimeSeq(ref __field0) => {
-                    _serde::Serializer::serialize_newtype_variant(
-                        __serializer,
-                        "Lifetimes",
-                        0u32,
-                        "LifetimeSeq",
-                        __field0,
-                    )
-                }
-                Lifetimes::NoLifetimeSeq(ref __field0) => {
-                    _serde::Serializer::serialize_newtype_variant(
-                        __serializer,
-                        "Lifetimes",
-                        1u32,
-                        "NoLifetimeSeq",
-                        __field0,
-                    )
-                }
-                Lifetimes::LifetimeMap { ref a } => {
-                    let mut __serde_state = match _serde::Serializer::serialize_struct_variant(
-                        __serializer,
-                        "Lifetimes",
-                        2u32,
-                        "LifetimeMap",
-                        0 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "a",
-                        a,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeStructVariant::end(__serde_state)
-                }
-                Lifetimes::NoLifetimeMap { ref a } => {
-                    let mut __serde_state = match _serde::Serializer::serialize_struct_variant(
-                        __serializer,
-                        "Lifetimes",
-                        3u32,
-                        "NoLifetimeMap",
-                        0 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "a",
-                        a,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeStructVariant::end(__serde_state)
-                }
-            }
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, 'a> _serde::Deserialize<'de> for Lifetimes<'a> {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __field1,
-                __field2,
-                __field3,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        1u64 => _serde::__private::Ok(__Field::__field1),
-                        2u64 => _serde::__private::Ok(__Field::__field2),
-                        3u64 => _serde::__private::Ok(__Field::__field3),
-                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"variant index 0 <= i < 4",
-                        )),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "LifetimeSeq" => _serde::__private::Ok(__Field::__field0),
-                        "NoLifetimeSeq" => _serde::__private::Ok(__Field::__field1),
-                        "LifetimeMap" => _serde::__private::Ok(__Field::__field2),
-                        "NoLifetimeMap" => _serde::__private::Ok(__Field::__field3),
-                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
-                            __value, VARIANTS,
-                        )),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"LifetimeSeq" => _serde::__private::Ok(__Field::__field0),
-                        b"NoLifetimeSeq" => _serde::__private::Ok(__Field::__field1),
-                        b"LifetimeMap" => _serde::__private::Ok(__Field::__field2),
-                        b"NoLifetimeMap" => _serde::__private::Ok(__Field::__field3),
-                        _ => {
-                            let __value = &_serde::__private::from_utf8_lossy(__value);
-                            _serde::__private::Err(_serde::de::Error::unknown_variant(
-                                __value, VARIANTS,
-                            ))
-                        }
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, 'a> {
-                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
-                type Value = Lifetimes<'a>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "enum Lifetimes")
-                }
-                fn visit_enum<__A>(
-                    self,
-                    __data: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::EnumAccess<'de>,
-                {
-                    match match _serde::de::EnumAccess::variant(__data) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        (__Field::__field0, __variant) => _serde::__private::Result::map(
-                            _serde::de::VariantAccess::newtype_variant::<&'a i32>(__variant),
-                            Lifetimes::LifetimeSeq,
-                        ),
-                        (__Field::__field1, __variant) => _serde::__private::Result::map(
-                            _serde::de::VariantAccess::newtype_variant::<i32>(__variant),
-                            Lifetimes::NoLifetimeSeq,
-                        ),
-                        (__Field::__field2, __variant) => {
-                            #[allow(non_camel_case_types)]
-                            enum __Field {
-                                __field0,
-                                __ignore,
-                            }
-                            struct __FieldVisitor;
-                            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                                type Value = __Field;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "field identifier",
-                                    )
-                                }
-                                fn visit_u64<__E>(
-                                    self,
-                                    __value: u64,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        0u64 => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_str<__E>(
-                                    self,
-                                    __value: &str,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        "a" => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_bytes<__E>(
-                                    self,
-                                    __value: &[u8],
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        b"a" => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                            }
-                            impl<'de> _serde::Deserialize<'de> for __Field {
-                                #[inline]
-                                fn deserialize<__D>(
-                                    __deserializer: __D,
-                                ) -> _serde::__private::Result<Self, __D::Error>
-                                where
-                                    __D: _serde::Deserializer<'de>,
-                                {
-                                    _serde::Deserializer::deserialize_identifier(
-                                        __deserializer,
-                                        __FieldVisitor,
-                                    )
-                                }
-                            }
-                            struct __Visitor<'de, 'a> {
-                                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
-                                lifetime: _serde::__private::PhantomData<&'de ()>,
-                            }
-                            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
-                                type Value = Lifetimes<'a>;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "struct variant Lifetimes::LifetimeMap",
-                                    )
-                                }
-                                #[inline]
-                                fn visit_seq<__A>(
-                                    self,
-                                    mut __seq: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::SeqAccess<'de>,
-                                {
-                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
-                                        &'a i32,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant Lifetimes::LifetimeMap with 1 element")) ;
-                                        }
-                                    };
-                                    _serde::__private::Ok(Lifetimes::LifetimeMap { a: __field0 })
-                                }
-                                #[inline]
-                                fn visit_map<__A>(
-                                    self,
-                                    mut __map: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::MapAccess<'de>,
-                                {
-                                    let mut __field0: _serde::__private::Option<&'a i32> =
-                                        _serde::__private::None;
-                                    while let _serde::__private::Some(__key) =
-                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
-                                        {
-                                            _serde::__private::Ok(__val) => __val,
-                                            _serde::__private::Err(__err) => {
-                                                return _serde::__private::Err(__err);
-                                            }
-                                        }
-                                    {
-                                        match __key {
-                                            __Field::__field0 => {
-                                                if _serde::__private::Option::is_some(&__field0) {
-                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("a")) ;
-                                                }
-                                                __field0 = _serde::__private::Some(
-                                                    match _serde::de::MapAccess::next_value::<&'a i32>(
-                                                        &mut __map,
-                                                    ) {
-                                                        _serde::__private::Ok(__val) => __val,
-                                                        _serde::__private::Err(__err) => {
-                                                            return _serde::__private::Err(__err);
-                                                        }
-                                                    },
-                                                );
-                                            }
-                                            _ => {
-                                                let _ = match _serde::de::MapAccess::next_value::<
-                                                    _serde::de::IgnoredAny,
-                                                >(
-                                                    &mut __map
-                                                ) {
-                                                    _serde::__private::Ok(__val) => __val,
-                                                    _serde::__private::Err(__err) => {
-                                                        return _serde::__private::Err(__err);
-                                                    }
-                                                };
-                                            }
-                                        }
-                                    }
-                                    let __field0 = match __field0 {
-                                        _serde::__private::Some(__field0) => __field0,
-                                        _serde::__private::None => {
-                                            match _serde::__private::de::missing_field("a") {
-                                                _serde::__private::Ok(__val) => __val,
-                                                _serde::__private::Err(__err) => {
-                                                    return _serde::__private::Err(__err);
-                                                }
-                                            }
-                                        }
-                                    };
-                                    _serde::__private::Ok(Lifetimes::LifetimeMap { a: __field0 })
-                                }
-                            }
-                            const FIELDS: &'static [&'static str] = &["a"];
-                            _serde::de::VariantAccess::struct_variant(
-                                __variant,
-                                FIELDS,
-                                __Visitor {
-                                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
-                                    lifetime: _serde::__private::PhantomData,
-                                },
-                            )
-                        }
-                        (__Field::__field3, __variant) => {
-                            #[allow(non_camel_case_types)]
-                            enum __Field {
-                                __field0,
-                                __ignore,
-                            }
-                            struct __FieldVisitor;
-                            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                                type Value = __Field;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "field identifier",
-                                    )
-                                }
-                                fn visit_u64<__E>(
-                                    self,
-                                    __value: u64,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        0u64 => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_str<__E>(
-                                    self,
-                                    __value: &str,
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        "a" => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                                fn visit_bytes<__E>(
-                                    self,
-                                    __value: &[u8],
-                                ) -> _serde::__private::Result<Self::Value, __E>
-                                where
-                                    __E: _serde::de::Error,
-                                {
-                                    match __value {
-                                        b"a" => _serde::__private::Ok(__Field::__field0),
-                                        _ => _serde::__private::Ok(__Field::__ignore),
-                                    }
-                                }
-                            }
-                            impl<'de> _serde::Deserialize<'de> for __Field {
-                                #[inline]
-                                fn deserialize<__D>(
-                                    __deserializer: __D,
-                                ) -> _serde::__private::Result<Self, __D::Error>
-                                where
-                                    __D: _serde::Deserializer<'de>,
-                                {
-                                    _serde::Deserializer::deserialize_identifier(
-                                        __deserializer,
-                                        __FieldVisitor,
-                                    )
-                                }
-                            }
-                            struct __Visitor<'de, 'a> {
-                                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
-                                lifetime: _serde::__private::PhantomData<&'de ()>,
-                            }
-                            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
-                                type Value = Lifetimes<'a>;
-                                fn expecting(
-                                    &self,
-                                    __formatter: &mut _serde::__private::Formatter,
-                                ) -> _serde::__private::fmt::Result
-                                {
-                                    _serde::__private::Formatter::write_str(
-                                        __formatter,
-                                        "struct variant Lifetimes::NoLifetimeMap",
-                                    )
-                                }
-                                #[inline]
-                                fn visit_seq<__A>(
-                                    self,
-                                    mut __seq: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::SeqAccess<'de>,
-                                {
-                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
-                                        i32,
-                                    >(
-                                        &mut __seq
-                                    ) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    } {
-                                        _serde::__private::Some(__value) => __value,
-                                        _serde::__private::None => {
-                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant Lifetimes::NoLifetimeMap with 1 element")) ;
-                                        }
-                                    };
-                                    _serde::__private::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
-                                }
-                                #[inline]
-                                fn visit_map<__A>(
-                                    self,
-                                    mut __map: __A,
-                                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                                where
-                                    __A: _serde::de::MapAccess<'de>,
-                                {
-                                    let mut __field0: _serde::__private::Option<i32> =
-                                        _serde::__private::None;
-                                    while let _serde::__private::Some(__key) =
-                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
-                                        {
-                                            _serde::__private::Ok(__val) => __val,
-                                            _serde::__private::Err(__err) => {
-                                                return _serde::__private::Err(__err);
-                                            }
-                                        }
-                                    {
-                                        match __key {
-                                            __Field::__field0 => {
-                                                if _serde::__private::Option::is_some(&__field0) {
-                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("a")) ;
-                                                }
-                                                __field0 = _serde::__private::Some(
-                                                    match _serde::de::MapAccess::next_value::<i32>(
-                                                        &mut __map,
-                                                    ) {
-                                                        _serde::__private::Ok(__val) => __val,
-                                                        _serde::__private::Err(__err) => {
-                                                            return _serde::__private::Err(__err);
-                                                        }
-                                                    },
-                                                );
-                                            }
-                                            _ => {
-                                                let _ = match _serde::de::MapAccess::next_value::<
-                                                    _serde::de::IgnoredAny,
-                                                >(
-                                                    &mut __map
-                                                ) {
-                                                    _serde::__private::Ok(__val) => __val,
-                                                    _serde::__private::Err(__err) => {
-                                                        return _serde::__private::Err(__err);
-                                                    }
-                                                };
-                                            }
-                                        }
-                                    }
-                                    let __field0 = match __field0 {
-                                        _serde::__private::Some(__field0) => __field0,
-                                        _serde::__private::None => {
-                                            match _serde::__private::de::missing_field("a") {
-                                                _serde::__private::Ok(__val) => __val,
-                                                _serde::__private::Err(__err) => {
-                                                    return _serde::__private::Err(__err);
-                                                }
-                                            }
-                                        }
-                                    };
-                                    _serde::__private::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
-                                }
-                            }
-                            const FIELDS: &'static [&'static str] = &["a"];
-                            _serde::de::VariantAccess::struct_variant(
-                                __variant,
-                                FIELDS,
-                                __Visitor {
-                                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
-                                    lifetime: _serde::__private::PhantomData,
-                                },
-                            )
-                        }
-                    }
-                }
-            }
-            const VARIANTS: &'static [&'static str] = &[
-                "LifetimeSeq",
-                "NoLifetimeSeq",
-                "LifetimeMap",
-                "NoLifetimeMap",
-            ];
-            _serde::Deserializer::deserialize_enum(
-                __deserializer,
-                "Lifetimes",
-                VARIANTS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,9 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-enum Lifetimes<'a> {
-    LifetimeSeq(&'a i32),
-    NoLifetimeSeq(i32),
-    LifetimeMap { a: &'a i32 },
-    NoLifetimeMap { a: i32 },
-}
@@ -1,628 +0,0 @@
-use serde::{Deserialize, Serialize};
-struct SerNamedMap<'a, 'b, A: 'a, B: 'b, C> {
-    a: &'a A,
-    b: &'b mut B,
-    c: C,
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'a, 'b, A: 'a, B: 'b, C> _serde::Serialize for SerNamedMap<'a, 'b, A, B, C>
-    where
-        A: _serde::Serialize,
-        B: _serde::Serialize,
-        C: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            let mut __serde_state = match _serde::Serializer::serialize_struct(
-                __serializer,
-                "SerNamedMap",
-                false as usize + 1 + 1 + 1,
-            ) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "a", &self.a) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "b", &self.b) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "c", &self.c) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            _serde::ser::SerializeStruct::end(__serde_state)
-        }
-    }
-};
-struct DeNamedMap<A, B, C> {
-    a: A,
-    b: B,
-    c: C,
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, A, B, C> _serde::Deserialize<'de> for DeNamedMap<A, B, C>
-    where
-        A: _serde::Deserialize<'de>,
-        B: _serde::Deserialize<'de>,
-        C: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __field1,
-                __field2,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        1u64 => _serde::__private::Ok(__Field::__field1),
-                        2u64 => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "a" => _serde::__private::Ok(__Field::__field0),
-                        "b" => _serde::__private::Ok(__Field::__field1),
-                        "c" => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"a" => _serde::__private::Ok(__Field::__field0),
-                        b"b" => _serde::__private::Ok(__Field::__field1),
-                        b"c" => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<DeNamedMap<A, B, C>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, A, B, C> _serde::de::Visitor<'de> for __Visitor<'de, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                type Value = DeNamedMap<A, B, C>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct DeNamedMap")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"struct DeNamedMap with 3 elements",
-                            ));
-                        }
-                    };
-                    let __field1 = match match _serde::de::SeqAccess::next_element::<B>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                1usize,
-                                &"struct DeNamedMap with 3 elements",
-                            ));
-                        }
-                    };
-                    let __field2 = match match _serde::de::SeqAccess::next_element::<C>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                2usize,
-                                &"struct DeNamedMap with 3 elements",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(DeNamedMap {
-                        a: __field0,
-                        b: __field1,
-                        c: __field2,
-                    })
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: _serde::__private::Option<A> = _serde::__private::None;
-                    let mut __field1: _serde::__private::Option<B> = _serde::__private::None;
-                    let mut __field2: _serde::__private::Option<C> = _serde::__private::None;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if _serde::__private::Option::is_some(&__field0) {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("a"),
-                                    );
-                                }
-                                __field0 = _serde::__private::Some(
-                                    match _serde::de::MapAccess::next_value::<A>(&mut __map) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    },
-                                );
-                            }
-                            __Field::__field1 => {
-                                if _serde::__private::Option::is_some(&__field1) {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("b"),
-                                    );
-                                }
-                                __field1 = _serde::__private::Some(
-                                    match _serde::de::MapAccess::next_value::<B>(&mut __map) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    },
-                                );
-                            }
-                            __Field::__field2 => {
-                                if _serde::__private::Option::is_some(&__field2) {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("c"),
-                                    );
-                                }
-                                __field2 = _serde::__private::Some(
-                                    match _serde::de::MapAccess::next_value::<C>(&mut __map) {
-                                        _serde::__private::Ok(__val) => __val,
-                                        _serde::__private::Err(__err) => {
-                                            return _serde::__private::Err(__err);
-                                        }
-                                    },
-                                );
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    let __field0 = match __field0 {
-                        _serde::__private::Some(__field0) => __field0,
-                        _serde::__private::None => {
-                            match _serde::__private::de::missing_field("a") {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            }
-                        }
-                    };
-                    let __field1 = match __field1 {
-                        _serde::__private::Some(__field1) => __field1,
-                        _serde::__private::None => {
-                            match _serde::__private::de::missing_field("b") {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            }
-                        }
-                    };
-                    let __field2 = match __field2 {
-                        _serde::__private::Some(__field2) => __field2,
-                        _serde::__private::None => {
-                            match _serde::__private::de::missing_field("c") {
-                                _serde::__private::Ok(__val) => __val,
-                                _serde::__private::Err(__err) => {
-                                    return _serde::__private::Err(__err);
-                                }
-                            }
-                        }
-                    };
-                    _serde::__private::Ok(DeNamedMap {
-                        a: __field0,
-                        b: __field1,
-                        c: __field2,
-                    })
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["a", "b", "c"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "DeNamedMap",
-                FIELDS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<DeNamedMap<A, B, C>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {
-                __field0,
-                __field1,
-                __field2,
-                __ignore,
-            }
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        0u64 => _serde::__private::Ok(__Field::__field0),
-                        1u64 => _serde::__private::Ok(__Field::__field1),
-                        2u64 => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        "a" => _serde::__private::Ok(__Field::__field0),
-                        "b" => _serde::__private::Ok(__Field::__field1),
-                        "c" => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        b"a" => _serde::__private::Ok(__Field::__field0),
-                        b"b" => _serde::__private::Ok(__Field::__field1),
-                        b"c" => _serde::__private::Ok(__Field::__field2),
-                        _ => _serde::__private::Ok(__Field::__ignore),
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de, 'place, A: 'place, B: 'place, C: 'place>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                place: &'place mut DeNamedMap<A, B, C>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, A: 'place, B: 'place, C: 'place> _serde::de::Visitor<'de>
-                for __Visitor<'de, 'place, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "struct DeNamedMap")
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.a),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"struct DeNamedMap with 3 elements",
-                        ));
-                    }
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.b),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            1usize,
-                            &"struct DeNamedMap with 3 elements",
-                        ));
-                    }
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.c),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            2usize,
-                            &"struct DeNamedMap with 3 elements",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-                #[inline]
-                fn visit_map<__A>(
-                    self,
-                    mut __map: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::MapAccess<'de>,
-                {
-                    let mut __field0: bool = false;
-                    let mut __field1: bool = false;
-                    let mut __field2: bool = false;
-                    while let _serde::__private::Some(__key) =
-                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        }
-                    {
-                        match __key {
-                            __Field::__field0 => {
-                                if __field0 {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("a"),
-                                    );
-                                }
-                                match _serde::de::MapAccess::next_value_seed(
-                                    &mut __map,
-                                    _serde::__private::de::InPlaceSeed(&mut self.place.a),
-                                ) {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                                __field0 = true;
-                            }
-                            __Field::__field1 => {
-                                if __field1 {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("b"),
-                                    );
-                                }
-                                match _serde::de::MapAccess::next_value_seed(
-                                    &mut __map,
-                                    _serde::__private::de::InPlaceSeed(&mut self.place.b),
-                                ) {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                                __field1 = true;
-                            }
-                            __Field::__field2 => {
-                                if __field2 {
-                                    return _serde::__private::Err(
-                                        <__A::Error as _serde::de::Error>::duplicate_field("c"),
-                                    );
-                                }
-                                match _serde::de::MapAccess::next_value_seed(
-                                    &mut __map,
-                                    _serde::__private::de::InPlaceSeed(&mut self.place.c),
-                                ) {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                                __field2 = true;
-                            }
-                            _ => {
-                                let _ = match _serde::de::MapAccess::next_value::<
-                                    _serde::de::IgnoredAny,
-                                >(&mut __map)
-                                {
-                                    _serde::__private::Ok(__val) => __val,
-                                    _serde::__private::Err(__err) => {
-                                        return _serde::__private::Err(__err);
-                                    }
-                                };
-                            }
-                        }
-                    }
-                    if !__field0 {
-                        self.place.a = match _serde::__private::de::missing_field("a") {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        };
-                    };
-                    if !__field1 {
-                        self.place.b = match _serde::__private::de::missing_field("b") {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        };
-                    };
-                    if !__field2 {
-                        self.place.c = match _serde::__private::de::missing_field("c") {
-                            _serde::__private::Ok(__val) => __val,
-                            _serde::__private::Err(__err) => {
-                                return _serde::__private::Err(__err);
-                            }
-                        };
-                    };
-                    _serde::__private::Ok(())
-                }
-            }
-            const FIELDS: &'static [&'static str] = &["a", "b", "c"];
-            _serde::Deserializer::deserialize_struct(
-                __deserializer,
-                "DeNamedMap",
-                FIELDS,
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,15 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize)]
-struct SerNamedMap<'a, 'b, A: 'a, B: 'b, C> {
-    a: &'a A,
-    b: &'b mut B,
-    c: C,
-}
-
-#[derive(Deserialize)]
-struct DeNamedMap<A, B, C> {
-    a: A,
-    b: B,
-    c: C,
-}
@@ -1,259 +0,0 @@
-use serde::{Deserialize, Serialize};
-struct SerNamedTuple<'a, 'b, A: 'a, B: 'b, C>(&'a A, &'b mut B, C);
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'a, 'b, A: 'a, B: 'b, C> _serde::Serialize for SerNamedTuple<'a, 'b, A, B, C>
-    where
-        A: _serde::Serialize,
-        B: _serde::Serialize,
-        C: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            let mut __serde_state = match _serde::Serializer::serialize_tuple_struct(
-                __serializer,
-                "SerNamedTuple",
-                0 + 1 + 1 + 1,
-            ) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.0) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.1) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.2) {
-                _serde::__private::Ok(__val) => __val,
-                _serde::__private::Err(__err) => {
-                    return _serde::__private::Err(__err);
-                }
-            };
-            _serde::ser::SerializeTupleStruct::end(__serde_state)
-        }
-    }
-};
-struct DeNamedTuple<A, B, C>(A, B, C);
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de, A, B, C> _serde::Deserialize<'de> for DeNamedTuple<A, B, C>
-    where
-        A: _serde::Deserialize<'de>,
-        B: _serde::Deserialize<'de>,
-        C: _serde::Deserialize<'de>,
-    {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                marker: _serde::__private::PhantomData<DeNamedTuple<A, B, C>>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, A, B, C> _serde::de::Visitor<'de> for __Visitor<'de, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                type Value = DeNamedTuple<A, B, C>;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct DeNamedTuple",
-                    )
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                0usize,
-                                &"tuple struct DeNamedTuple with 3 elements",
-                            ));
-                        }
-                    };
-                    let __field1 = match match _serde::de::SeqAccess::next_element::<B>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                1usize,
-                                &"tuple struct DeNamedTuple with 3 elements",
-                            ));
-                        }
-                    };
-                    let __field2 = match match _serde::de::SeqAccess::next_element::<C>(&mut __seq)
-                    {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        _serde::__private::Some(__value) => __value,
-                        _serde::__private::None => {
-                            return _serde::__private::Err(_serde::de::Error::invalid_length(
-                                2usize,
-                                &"tuple struct DeNamedTuple with 3 elements",
-                            ));
-                        }
-                    };
-                    _serde::__private::Ok(DeNamedTuple(__field0, __field1, __field2))
-                }
-            }
-            _serde::Deserializer::deserialize_tuple_struct(
-                __deserializer,
-                "DeNamedTuple",
-                3usize,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<DeNamedTuple<A, B, C>>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-        fn deserialize_in_place<__D>(
-            __deserializer: __D,
-            __place: &mut Self,
-        ) -> _serde::__private::Result<(), __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor<'de, 'place, A: 'place, B: 'place, C: 'place>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                place: &'place mut DeNamedTuple<A, B, C>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de, 'place, A: 'place, B: 'place, C: 'place> _serde::de::Visitor<'de>
-                for __Visitor<'de, 'place, A, B, C>
-            where
-                A: _serde::Deserialize<'de>,
-                B: _serde::Deserialize<'de>,
-                C: _serde::Deserialize<'de>,
-            {
-                type Value = ();
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(
-                        __formatter,
-                        "tuple struct DeNamedTuple",
-                    )
-                }
-                #[inline]
-                fn visit_seq<__A>(
-                    self,
-                    mut __seq: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::SeqAccess<'de>,
-                {
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            0usize,
-                            &"tuple struct DeNamedTuple with 3 elements",
-                        ));
-                    }
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.1),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            1usize,
-                            &"tuple struct DeNamedTuple with 3 elements",
-                        ));
-                    }
-                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
-                        &mut __seq,
-                        _serde::__private::de::InPlaceSeed(&mut self.place.2),
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    } {
-                        return _serde::__private::Err(_serde::de::Error::invalid_length(
-                            2usize,
-                            &"tuple struct DeNamedTuple with 3 elements",
-                        ));
-                    }
-                    _serde::__private::Ok(())
-                }
-            }
-            _serde::Deserializer::deserialize_tuple_struct(
-                __deserializer,
-                "DeNamedTuple",
-                3usize,
-                __Visitor {
-                    place: __place,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,7 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize)]
-struct SerNamedTuple<'a, 'b, A: 'a, B: 'b, C>(&'a A, &'b mut B, C);
-
-#[derive(Deserialize)]
-struct DeNamedTuple<A, B, C>(A, B, C);
@@ -1,52 +0,0 @@
-use serde::{Deserialize, Serialize};
-struct NamedUnit;
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl _serde::Serialize for NamedUnit {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            _serde::Serializer::serialize_unit_struct(__serializer, "NamedUnit")
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de> _serde::Deserialize<'de> for NamedUnit {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            struct __Visitor;
-            impl<'de> _serde::de::Visitor<'de> for __Visitor {
-                type Value = NamedUnit;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "unit struct NamedUnit")
-                }
-                #[inline]
-                fn visit_unit<__E>(self) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    _serde::__private::Ok(NamedUnit)
-                }
-            }
-            _serde::Deserializer::deserialize_unit_struct(__deserializer, "NamedUnit", __Visitor)
-        }
-    }
-};
@@ -1,4 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-struct NamedUnit;
@@ -1,271 +0,0 @@
-use serde::Serialize;
-enum SerEnum<'a, B: 'a, C: 'a, D>
-where
-    D: 'a,
-{
-    Unit,
-    Seq(i8, B, &'a C, &'a mut D),
-    Map { a: i8, b: B, c: &'a C, d: &'a mut D },
-    _Unit2,
-    _Seq2(i8, B, &'a C, &'a mut D),
-    _Map2 { a: i8, b: B, c: &'a C, d: &'a mut D },
-}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'a, B: 'a, C: 'a, D> _serde::Serialize for SerEnum<'a, B, C, D>
-    where
-        D: 'a,
-        B: _serde::Serialize,
-        C: _serde::Serialize,
-        D: _serde::Serialize,
-    {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            match *self {
-                SerEnum::Unit => _serde::Serializer::serialize_unit_variant(
-                    __serializer,
-                    "SerEnum",
-                    0u32,
-                    "Unit",
-                ),
-                SerEnum::Seq(ref __field0, ref __field1, ref __field2, ref __field3) => {
-                    let mut __serde_state = match _serde::Serializer::serialize_tuple_variant(
-                        __serializer,
-                        "SerEnum",
-                        1u32,
-                        "Seq",
-                        0 + 1 + 1 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field0,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field2,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field3,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeTupleVariant::end(__serde_state)
-                }
-                SerEnum::Map {
-                    ref a,
-                    ref b,
-                    ref c,
-                    ref d,
-                } => {
-                    let mut __serde_state = match _serde::Serializer::serialize_struct_variant(
-                        __serializer,
-                        "SerEnum",
-                        2u32,
-                        "Map",
-                        0 + 1 + 1 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "a",
-                        a,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "b",
-                        b,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "c",
-                        c,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "d",
-                        d,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeStructVariant::end(__serde_state)
-                }
-                SerEnum::_Unit2 => _serde::Serializer::serialize_unit_variant(
-                    __serializer,
-                    "SerEnum",
-                    3u32,
-                    "_Unit2",
-                ),
-                SerEnum::_Seq2(ref __field0, ref __field1, ref __field2, ref __field3) => {
-                    let mut __serde_state = match _serde::Serializer::serialize_tuple_variant(
-                        __serializer,
-                        "SerEnum",
-                        4u32,
-                        "_Seq2",
-                        0 + 1 + 1 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field0,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field2,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeTupleVariant::serialize_field(
-                        &mut __serde_state,
-                        __field3,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeTupleVariant::end(__serde_state)
-                }
-                SerEnum::_Map2 {
-                    ref a,
-                    ref b,
-                    ref c,
-                    ref d,
-                } => {
-                    let mut __serde_state = match _serde::Serializer::serialize_struct_variant(
-                        __serializer,
-                        "SerEnum",
-                        5u32,
-                        "_Map2",
-                        0 + 1 + 1 + 1 + 1,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "a",
-                        a,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "b",
-                        b,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "c",
-                        c,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    match _serde::ser::SerializeStructVariant::serialize_field(
-                        &mut __serde_state,
-                        "d",
-                        d,
-                    ) {
-                        _serde::__private::Ok(__val) => __val,
-                        _serde::__private::Err(__err) => {
-                            return _serde::__private::Err(__err);
-                        }
-                    };
-                    _serde::ser::SerializeStructVariant::end(__serde_state)
-                }
-            }
-        }
-    }
-};
@@ -1,16 +0,0 @@
-use serde::Serialize;
-
-#[derive(Serialize)]
-enum SerEnum<'a, B: 'a, C: 'a, D>
-where
-    D: 'a,
-{
-    Unit,
-    Seq(i8, B, &'a C, &'a mut D),
-    Map { a: i8, b: B, c: &'a C, d: &'a mut D },
-
-    // Make sure we can support more than one variant.
-    _Unit2,
-    _Seq2(i8, B, &'a C, &'a mut D),
-    _Map2 { a: i8, b: B, c: &'a C, d: &'a mut D },
-}
@@ -1,132 +0,0 @@
-use serde::{Deserialize, Serialize};
-enum Void {}
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl _serde::Serialize for Void {
-        fn serialize<__S>(
-            &self,
-            __serializer: __S,
-        ) -> _serde::__private::Result<__S::Ok, __S::Error>
-        where
-            __S: _serde::Serializer,
-        {
-            match *self {}
-        }
-    }
-};
-#[doc(hidden)]
-#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _: () = {
-    #[allow(unused_extern_crates, clippy::useless_attribute)]
-    extern crate serde as _serde;
-    #[automatically_derived]
-    impl<'de> _serde::Deserialize<'de> for Void {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
-        where
-            __D: _serde::Deserializer<'de>,
-        {
-            #[allow(non_camel_case_types)]
-            enum __Field {}
-            struct __FieldVisitor;
-            impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
-                type Value = __Field;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
-                }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"variant index 0 <= i < 0",
-                        )),
-                    }
-                }
-                fn visit_str<__E>(
-                    self,
-                    __value: &str,
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
-                            __value, VARIANTS,
-                        )),
-                    }
-                }
-                fn visit_bytes<__E>(
-                    self,
-                    __value: &[u8],
-                ) -> _serde::__private::Result<Self::Value, __E>
-                where
-                    __E: _serde::de::Error,
-                {
-                    match __value {
-                        _ => {
-                            let __value = &_serde::__private::from_utf8_lossy(__value);
-                            _serde::__private::Err(_serde::de::Error::unknown_variant(
-                                __value, VARIANTS,
-                            ))
-                        }
-                    }
-                }
-            }
-            impl<'de> _serde::Deserialize<'de> for __Field {
-                #[inline]
-                fn deserialize<__D>(
-                    __deserializer: __D,
-                ) -> _serde::__private::Result<Self, __D::Error>
-                where
-                    __D: _serde::Deserializer<'de>,
-                {
-                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
-                }
-            }
-            struct __Visitor<'de> {
-                marker: _serde::__private::PhantomData<Void>,
-                lifetime: _serde::__private::PhantomData<&'de ()>,
-            }
-            impl<'de> _serde::de::Visitor<'de> for __Visitor<'de> {
-                type Value = Void;
-                fn expecting(
-                    &self,
-                    __formatter: &mut _serde::__private::Formatter,
-                ) -> _serde::__private::fmt::Result {
-                    _serde::__private::Formatter::write_str(__formatter, "enum Void")
-                }
-                fn visit_enum<__A>(
-                    self,
-                    __data: __A,
-                ) -> _serde::__private::Result<Self::Value, __A::Error>
-                where
-                    __A: _serde::de::EnumAccess<'de>,
-                {
-                    _serde::__private::Result::map(
-                        _serde::de::EnumAccess::variant::<__Field>(__data),
-                        |(__impossible, _)| match __impossible {},
-                    )
-                }
-            }
-            const VARIANTS: &'static [&'static str] = &[];
-            _serde::Deserializer::deserialize_enum(
-                __deserializer,
-                "Void",
-                VARIANTS,
-                __Visitor {
-                    marker: _serde::__private::PhantomData::<Void>,
-                    lifetime: _serde::__private::PhantomData,
-                },
-            )
-        }
-    }
-};
@@ -1,4 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize)]
-enum Void {}
@@ -1,8 +0,0 @@
-#[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg_attr(not(expandtest), ignore)]
-#[rustversion::attr(not(nightly), ignore)]
-#[allow(unused_attributes)]
-#[test]
-fn expandtest() {
-    macrotest::expand("tests/expand/*.rs");
-}
@@ -1,93 +1,79 @@
+#![allow(unused_macro_rules)]
+
+use serde_test::Token;
+use std::iter;
+
 macro_rules! btreeset {
    () => {
        BTreeSet::new()
    };
-    ($($value:expr),+) => {
-        {
-            let mut set = BTreeSet::new();
-            $(set.insert($value);)+
-            set
-        }
-    }
+    ($($value:expr),+) => {{
+        let mut set = BTreeSet::new();
+        $(set.insert($value);)+
+        set
+    }};
 }

 macro_rules! btreemap {
    () => {
        BTreeMap::new()
    };
-    ($($key:expr => $value:expr),+) => {
-        {
-            let mut map = BTreeMap::new();
-            $(map.insert($key, $value);)+
-            map
-        }
-    }
+    ($($key:expr => $value:expr),+) => {{
+        let mut map = BTreeMap::new();
+        $(map.insert($key, $value);)+
+        map
+    }};
 }

 macro_rules! hashset {
    () => {
        HashSet::new()
    };
-    ($($value:expr),+) => {
-        {
-            let mut set = HashSet::new();
-            $(set.insert($value);)+
-            set
-        }
-    };
-    ($hasher:ident @ $($value:expr),+) => {
-        {
-            use std::hash::BuildHasherDefault;
-            let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
-            $(set.insert($value);)+
-            set
-        }
-    }
+    ($($value:expr),+) => {{
+        let mut set = HashSet::new();
+        $(set.insert($value);)+
+        set
+    }};
+    ($hasher:ident @ $($value:expr),+) => {{
+        use std::hash::BuildHasherDefault;
+        let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
+        $(set.insert($value);)+
+        set
+    }};
 }

 macro_rules! hashmap {
    () => {
        HashMap::new()
    };
-    ($($key:expr => $value:expr),+) => {
-        {
-            let mut map = HashMap::new();
-            $(map.insert($key, $value);)+
-            map
-        }
-    };
-    ($hasher:ident @ $($key:expr => $value:expr),+) => {
-        {
-            use std::hash::BuildHasherDefault;
-            let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
-            $(map.insert($key, $value);)+
-            map
-        }
+    ($($key:expr => $value:expr),+) => {{
+        let mut map = HashMap::new();
+        $(map.insert($key, $value);)+
+        map
+    }};
+    ($hasher:ident @ $($key:expr => $value:expr),+) => {{
+        use std::hash::BuildHasherDefault;
+        let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
+        $(map.insert($key, $value);)+
+        map
+    }};
+}
+
+pub trait SingleTokenIntoIterator {
+    fn into_iter(self) -> iter::Once<Token>;
+}
+
+impl SingleTokenIntoIterator for Token {
+    fn into_iter(self) -> iter::Once<Token> {
+        iter::once(self)
    }
 }

-macro_rules! seq_impl {
-    (seq $first:expr,) => {
-        seq_impl!(seq $first)
-    };
-    ($first:expr,) => {
-        seq_impl!($first)
-    };
-    (seq $first:expr) => {
-        $first.into_iter()
-    };
-    ($first:expr) => {
-        Some($first).into_iter()
-    };
-    (seq $first:expr , $( $elem: tt)*) => {
-        $first.into_iter().chain(seq!( $($elem)* ))
-    };
-    ($first:expr , $($elem: tt)*) => {
-        Some($first).into_iter().chain(seq!( $($elem)* ))
-    }
-}
 macro_rules! seq {
-    ($($tt: tt)*) => {
-        seq_impl!($($tt)*).collect::<Vec<_>>()
-    };
+    ($($elem:expr),* $(,)?) => {{
+        use crate::macros::SingleTokenIntoIterator;
+        let mut vec = Vec::new();
+        $(<Vec<Token> as Extend<Token>>::extend(&mut vec, $elem.into_iter());)*
+        vec
+    }};
 }
@@ -0,0 +1,3 @@
+mod regression {
+    automod::dir!("tests/regression");
+}
@@ -0,0 +1,66 @@
+#![allow(dead_code)] // we do not read enum fields
+
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+pub struct Nested;
+
+#[derive(Deserialize)]
+pub enum ExternallyTagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+pub enum ExternallyTagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}
+
+// Internally tagged enums cannot contain tuple variants so not tested here
+
+#[derive(Deserialize)]
+#[serde(tag = "tag", content = "content")]
+pub enum AdjacentlyTagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(tag = "tag", content = "content")]
+pub enum AdjacentlyTagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub enum Untagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub enum Untagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}
@@ -0,0 +1,51 @@
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+pub struct Nested;
+
+#[derive(Deserialize)]
+pub enum ExternallyTagged {
+    Flatten {
+        #[serde(flatten)]
+        #[allow(dead_code)]
+        nested: Nested,
+        #[allow(dead_code)]
+        string: &'static str,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(tag = "tag")]
+pub enum InternallyTagged {
+    Flatten {
+        #[serde(flatten)]
+        #[allow(dead_code)]
+        nested: Nested,
+        #[allow(dead_code)]
+        string: &'static str,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(tag = "tag", content = "content")]
+pub enum AdjacentlyTagged {
+    Flatten {
+        #[serde(flatten)]
+        #[allow(dead_code)]
+        nested: Nested,
+        #[allow(dead_code)]
+        string: &'static str,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub enum UntaggedWorkaround {
+    Flatten {
+        #[serde(flatten)]
+        #[allow(dead_code)]
+        nested: Nested,
+        #[allow(dead_code)]
+        string: &'static str,
+    },
+}
@@ -0,0 +1,11 @@
+use serde_derive::Deserialize;
+
+macro_rules! bug {
+    ($serde_path:literal) => {
+        #[derive(Deserialize)]
+        #[serde(crate = $serde_path)]
+        pub struct Struct;
+    };
+}
+
+bug!("serde");
@@ -0,0 +1,5 @@
+use serde_derive::Serialize;
+
+#[derive(Serialize)]
+#[serde()]
+pub struct S;
@@ -0,0 +1,41 @@
+use serde_derive::{Serialize, Deserialize};
+use serde_test::{assert_tokens, Token};
+
+#[derive(Serialize, Deserialize, Debug, PartialEq)]
+enum Enum {
+    Simple {
+        a: i32,
+    },
+    Flatten {
+        #[serde(flatten)]
+        flatten: (),
+        a: i32,
+    },
+}
+
+#[test]
+fn simple_variant() {
+    assert_tokens(
+        &Enum::Simple { a: 42 },
+        &[
+            Token::StructVariant { name: "Enum", variant: "Simple", len: 1 },
+            Token::Str("a"),
+            Token::I32(42),
+            Token::StructVariantEnd,
+        ]
+    );
+}
+
+#[test]
+fn flatten_variant() {
+    assert_tokens(
+        &Enum::Flatten { flatten: (), a: 42 },
+        &[
+            Token::NewtypeVariant { name: "Enum", variant: "Flatten" },
+            Token::Map { len: None },
+            Token::Str("a"),
+            Token::I32(42),
+            Token::MapEnd,
+        ]
+    );
+}
@@ -0,0 +1,18 @@
+#![allow(dead_code)] // we do not read enum fields
+
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
+pub enum A {
+    B {
+        c: String,
+    },
+    D {
+        #[serde(flatten)]
+        e: E,
+    },
+}
+
+#[derive(Deserialize)]
+pub struct E {}
@@ -1,8 +1,13 @@
-#![allow(clippy::items_after_statements, clippy::used_underscore_binding)]
+#![allow(
+    clippy::derive_partial_eq_without_eq,
+    clippy::items_after_statements,
+    clippy::used_underscore_binding
+)]

-use serde::{Deserialize, Deserializer};
+use serde::de::value::{BorrowedStrDeserializer, MapDeserializer};
+use serde::de::{Deserialize, Deserializer, IntoDeserializer};
+use serde_derive::Deserialize;
 use serde_test::{assert_de_tokens, assert_de_tokens_error, Token};
-
 use std::borrow::Cow;

 #[test]
@@ -126,20 +131,22 @@ fn test_cow() {
        borrowed: Cow<'b, str>,
    }

-    let tokens = &[
-        Token::Struct {
-            name: "Cows",
-            len: 2,
-        },
-        Token::Str("copied"),
-        Token::BorrowedStr("copied"),
-        Token::Str("borrowed"),
-        Token::BorrowedStr("borrowed"),
-        Token::StructEnd,
-    ];
+    struct BorrowedStr(&'static str);

-    let mut de = serde_test::Deserializer::new(tokens);
-    let cows = Cows::deserialize(&mut de).unwrap();
+    impl<'de> IntoDeserializer<'de> for BorrowedStr {
+        type Deserializer = BorrowedStrDeserializer<'de, serde::de::value::Error>;
+
+        fn into_deserializer(self) -> Self::Deserializer {
+            BorrowedStrDeserializer::new(self.0)
+        }
+    }
+
+    let de = MapDeserializer::new(IntoIterator::into_iter([
+        ("copied", BorrowedStr("copied")),
+        ("borrowed", BorrowedStr("borrowed")),
+    ]));
+
+    let cows = Cows::deserialize(de).unwrap();

    match cows.copied {
        Cow::Owned(ref s) if s == "copied" => {}
@@ -155,7 +162,7 @@ fn test_cow() {
 #[test]
 fn test_lifetimes() {
    #[derive(Deserialize)]
-    struct Cows<'a, 'b> {
+    pub struct Cows<'a, 'b> {
        _copied: Cow<'a, str>,

        #[serde(borrow)]
@@ -171,7 +178,7 @@ fn test_lifetimes() {
    }

    #[derive(Deserialize)]
-    struct Wrap<'a, 'b> {
+    pub struct Wrap<'a, 'b> {
        #[serde(borrow = "'b")]
        _cows: Cows<'a, 'b>,
    }
--- a/Show More
+++ b/Show More