Release 1.0.115

Support flattening a Unit

.github/ISSUE_TEMPLATE/4-discussion.md

@@ -1,7 +0,0 @@
----
-name: Help or discussion
-about: This is the right place
-
----
-
-

.github/workflows/ci.yml

@@ -0,0 +1,163 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+  schedule: [cron: "40 1 * * *"]
+
+jobs:
+  test:
+    name: Test suite
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@nightly
+      - run: cd test_suite && cargo test --features unstable
+
+  windows:
+    name: Test suite (windows)
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@nightly
+      - run: cd test_suite && cargo test --features unstable -- --skip ui --exact
+
+  stable:
+    name: Rust stable
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@stable
+      - 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
+
+  beta:
+    name: Rust beta
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@beta
+      - run: cd serde && cargo build --features rc
+      - run: cd test_suite && cargo test
+
+  nightly:
+    name: Rust nightly ${{matrix.os == 'windows' && '(windows)' || ''}}
+    runs-on: ${{matrix.os}}-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu, windows]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@nightly
+      - run: cd serde && cargo build
+      - run: cd serde && cargo build --no-default-features
+      - run: cd serde && cargo build --no-default-features --features alloc
+      - run: cd serde && cargo build --no-default-features --features rc,alloc
+      - run: cd serde && cargo test --features derive,rc,unstable
+      - run: cd test_suite/no_std && cargo build
+        if: matrix.os != 'windows'
+
+  msrv:
+    name: Rust 1.13.0
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@1.13.0
+      - name: Get timestamp for cache
+        id: date
+        run: echo ::set-output name=yearmo::$(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
+
+  build:
+    name: Rust ${{matrix.rust}}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        rust: [1.19.0, 1.20.0, 1.21.0, 1.25.0, 1.26.0, 1.34.0]
+    steps:
+      - uses: actions/checkout@v2
+      - 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: ${{matrix.rust}}
+        # Work around failing to parse manifest because editions are unstable.
+      - run: sed -i /test_suite/d Cargo.toml
+      - run: cd serde && cargo build --no-default-features
+      - run: cd serde && cargo build
+
+  derive:
+    name: Rust 1.31.0
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@1.31.0
+      - run: cd serde_derive && cargo check
+
+  alloc:
+    name: Rust 1.36.0
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@1.36.0
+      - run: cd serde && cargo build --no-default-features --features alloc
+
+  emscripten:
+    name: Emscripten
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 9
+      - name: Install cargo-web
+        run: |
+          CARGO_WEB_RELEASE=$(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
+
+  clippy:
+    name: Clippy
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@clippy
+        # The need for -Aredundant_field_names here is a Clippy bug.
+        # https://github.com/rust-lang/rust-clippy/issues/5356
+      - run: cd serde && cargo clippy --features rc,unstable -- -D clippy::all -A clippy::redundant_field_names
+      - run: cd serde_derive && cargo clippy -- -D clippy::all
+      - run: cd serde_test && cargo clippy -- -D clippy::all -A clippy::redundant_field_names
+      - run: cd test_suite && cargo clippy --tests --features unstable -- -D clippy::all -A clippy::redundant_field_names
+      - run: cd test_suite/no_std && cargo clippy -- -D clippy::all -A clippy::redundant_field_names

.travis.yml

@@ -1,95 +0,0 @@
-language: rust
-
-matrix:
-  include:
-    - rust: stable
-      script:
-        - cd "${TRAVIS_BUILD_DIR}/serde"
-        - cargo build --features rc
-        - cargo build --no-default-features
-        - cd "${TRAVIS_BUILD_DIR}/serde_test"
-        - cargo build
-        - cargo test
-
-    - rust: beta
-      script:
-        - cd "${TRAVIS_BUILD_DIR}/serde"
-        - cargo build --features rc
-        - cd "${TRAVIS_BUILD_DIR}/test_suite"
-        - cargo test
-
-    - rust: nightly
-      script:
-        - cd "${TRAVIS_BUILD_DIR}/serde"
-        - cargo build
-        - cargo build --no-default-features
-        - cargo build --no-default-features --features alloc
-        - cargo build --no-default-features --features rc,alloc
-        - cargo test --features rc,unstable
-        - cd "${TRAVIS_BUILD_DIR}/test_suite/deps"
-        - cargo build
-        - cd "${TRAVIS_BUILD_DIR}/test_suite"
-        - cargo test --features unstable
-        - cd "${TRAVIS_BUILD_DIR}/test_suite/no_std"
-        - cargo build
-
-    - rust: 1.13.0
-      script:
-        - cd "${TRAVIS_BUILD_DIR}/serde"
-        - cargo build --features rc
-        - cargo build --no-default-features
-        - cd "${TRAVIS_BUILD_DIR}/serde_test"
-        - cargo build
-
-    - rust: 1.15.0
-      script:
-        - cd "${TRAVIS_BUILD_DIR}/serde_derive"
-        - cargo build
-
-    - rust: 1.20.0
-    - rust: 1.21.0
-    - rust: 1.25.0
-    - rust: 1.26.0
-
-    - rust: nightly
-      name: Clippy
-      script:
-        - rustup component add clippy-preview || travis_terminate 0
-        - cargo clippy -- -Dclippy
-        - cd "${TRAVIS_BUILD_DIR}/serde"
-        - cargo clippy --features rc,unstable -- -Dclippy
-        - cd "${TRAVIS_BUILD_DIR}/serde_derive"
-        - cargo clippy -- -Dclippy
-        - cd "${TRAVIS_BUILD_DIR}/serde_test"
-        - cargo clippy -- -Dclippy
-        - cd "${TRAVIS_BUILD_DIR}/test_suite"
-        - cargo clippy --features unstable -- -Dclippy
-        - cd "${TRAVIS_BUILD_DIR}/test_suite/no_std"
-        - cargo clippy -- -Dclippy
-
-    - rust: nightly
-      name: Emscripten
-      script:
-        - 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"
-
-        - nvm install 9
-        - mkdir -p ~/.cargo/bin
-        - curl -L "${CARGO_WEB_URL}" | gzip -d > ~/.cargo/bin/cargo-web
-        - chmod +x ~/.cargo/bin/cargo-web
-
-        - cd "${TRAVIS_BUILD_DIR}/test_suite"
-        - cargo web test --target=asmjs-unknown-emscripten --nodejs
-        - cargo web test --target=wasm32-unknown-emscripten --nodejs
-
-  allow_failures:
-    - rust: nightly
-      name: Clippy
-    - rust: nightly
-      name: Emscripten
-
-script:
-  - cd "${TRAVIS_BUILD_DIR}/serde"
-  - cargo build --no-default-features
-  - cargo build

CONTRIBUTING.md

@@ -4,11 +4,6 @@ Serde welcomes contribution from everyone in the form of suggestions, bug
 reports, pull requests, and feedback. This document gives some guidance if you
 are thinking of helping us.
 
-Please reach out here in a GitHub issue or in the #serde IRC channel on
-[`irc.mozilla.org`] if we can do anything to help you contribute.
-
-[`irc.mozilla.org`]: https://wiki.mozilla.org/IRC
-
 ## Submitting bug reports and feature requests
 
 Serde development is spread across lots of repositories, but this serde-rs/serde

README.md

@@ -1,11 +1,13 @@
-# Serde   [![Build Status]][travis] [![Latest Version]][crates.io] [![Rustc Version 1.13+]][rustc]
+# Serde   [![Build Status]][actions] [![Latest Version]][crates.io] [![serde: rustc 1.13+]][Rust 1.13] [![serde_derive: rustc 1.31+]][Rust 1.31]
 
-[Build Status]: https://api.travis-ci.org/serde-rs/serde.svg?branch=master
-[travis]: https://travis-ci.org/serde-rs/serde
+[Build Status]: https://img.shields.io/github/workflow/status/serde-rs/serde/CI/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
-[Rustc Version 1.13+]: https://img.shields.io/badge/rustc-1.13+-lightgray.svg
-[rustc]: https://blog.rust-lang.org/2016/11/10/Rust-1.13.html
+[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
+[Rust 1.31]: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html
 
 **Serde is a framework for *ser*ializing and *de*serializing Rust data structures efficiently and generically.**
 
@@ -25,19 +27,17 @@ You may be looking for:
 <details>
 <summary>
 Click to show Cargo.toml.
-<a href="https://play.rust-lang.org/?gist=9003c5b88c1f4989941925d7190c6eec" target="_blank">Run this code in the playground.</a>
+<a href="https://play.rust-lang.org/?edition=2018&gist=72755f28f99afc95e01d63174b28c1f5" target="_blank">Run this code in the playground.</a>
 </summary>
 
 ```toml
 [dependencies]
 
 # The core APIs, including the Serialize and Deserialize traits. Always
-# required when using Serde.
-serde = "1.0"
-
-# Support for #[derive(Serialize, Deserialize)]. Required if you want Serde
-# to work for structs and enums defined in your crate.
-serde_derive = "1.0"
+# required when using Serde. The "derive" feature is only required when
+# using #[derive(Serialize, Deserialize)] to make Serde work with structs
+# and enums defined in your crate.
+serde = { version = "1.0", features = ["derive"] }
 
 # Each data format lives in its own crate; the sample code below uses JSON
 # but you may be using a different one.
@@ -48,11 +48,7 @@ serde_json = "1.0"
 <p></p>
 
 ```rust
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
+use serde::{Serialize, Deserialize};
 
 #[derive(Serialize, Deserialize, Debug)]
 struct Point {
@@ -79,27 +75,37 @@ fn main() {
 
 ## Getting help
 
-Serde developers live in the #serde channel on [`irc.mozilla.org`][irc]. The
-\#rust channel is also a good resource with generally faster response time but
-less specific knowledge about Serde. If IRC is not your thing or you don't get a
-good response, we are happy to respond to [GitHub issues][issues] as well.
+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.
 
-[irc]: https://wiki.mozilla.org/IRC
-[issues]: https://github.com/serde-rs/serde/issues/new/choose
+[#general]: https://discord.com/channels/273534239310479360/274215136414400513
+[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[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
+[discourse]: https://users.rust-lang.org
 
-## License
+<br>
 
-Serde is licensed under either of
+#### License
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
-   http://www.apache.org/licenses/LICENSE-2.0)
- * MIT license ([LICENSE-MIT](LICENSE-MIT) or
-   http://opensource.org/licenses/MIT)
+<sup>
+Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
+2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
+</sup>
 
-at your option.
-
-### Contribution
+<br>
 
+<sub>
 Unless you explicitly state otherwise, any contribution intentionally submitted
 for inclusion in Serde by you, as defined in the Apache-2.0 license, shall be
 dual licensed as above, without any additional terms or conditions.
+</sub>

appveyor.yml

@@ -1,41 +0,0 @@
-environment:
-  matrix:
-    - APPVEYOR_RUST_CHANNEL: stable
-    - APPVEYOR_RUST_CHANNEL: nightly
-
-install:
-  # Install rust, x86_64-pc-windows-msvc host
-  - curl -sSf -o rustup-init.exe https://win.rustup.rs/
-  - rustup-init.exe -y --default-host x86_64-pc-windows-msvc --default-toolchain %APPVEYOR_RUST_CHANNEL%
-  - set PATH=C:\msys64\usr\bin;%PATH%;C:\Users\appveyor\.cargo\bin
-  - rustc -vV
-  - cargo -vV
-
-build: false
-
-for:
-  - matrix:
-      only:
-        - APPVEYOR_RUST_CHANNEL: stable
-    test_script:
-      - cd %APPVEYOR_BUILD_FOLDER%\serde
-      - cargo build --features rc
-      - cargo build --no-default-features
-      - cd %APPVEYOR_BUILD_FOLDER%\serde_test
-      - cargo build
-      - cargo test
-
-  - matrix:
-      only:
-        - APPVEYOR_RUST_CHANNEL: nightly
-    test_script:
-      - cd %APPVEYOR_BUILD_FOLDER%\serde
-      - cargo build
-      - cargo build --no-default-features
-      - cargo build --no-default-features --features alloc
-      - cargo build --no-default-features --features rc,alloc
-      - cargo test --features rc,unstable
-      - cd %APPVEYOR_BUILD_FOLDER%\test_suite\deps
-      - cargo build
-      - cd %APPVEYOR_BUILD_FOLDER%\test_suite
-      - cargo test --features unstable

crates-io.md

@@ -16,11 +16,7 @@ You may be looking for:
 ## Serde in action
 
 ```rust
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
+use serde::{Serialize, Deserialize};
 
 #[derive(Serialize, Deserialize, Debug)]
 struct Point {
@@ -47,10 +43,20 @@ fn main() {
 
 ## Getting help
 
-Serde developers live in the #serde channel on [`irc.mozilla.org`][irc]. The
-\#rust channel is also a good resource with generally faster response time but
-less specific knowledge about Serde. If IRC is not your thing or you don't get a
-good response, we are happy to respond to [GitHub issues][issues] as well.
+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.
 
-[irc]: https://wiki.mozilla.org/IRC
-[issues]: https://github.com/serde-rs/serde/issues/new/choose
+[#general]: https://discord.com/channels/273534239310479360/274215136414400513
+[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[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
+[discourse]: https://users.rust-lang.org

rustfmt.toml

@@ -1 +0,0 @@
-error_on_line_overflow = false

serde/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "serde"
-version = "1.0.81" # remember to update html_root_url
+version = "1.0.115" # remember to update html_root_url and serde_derive dependency
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 description = "A generic serialization/deserialization framework"
 homepage = "https://serde.rs"
 repository = "https://github.com/serde-rs/serde"
@@ -10,49 +10,28 @@ documentation = "https://docs.serde.rs/serde/"
 keywords = ["serde", "serialization", "no_std"]
 categories = ["encoding"]
 readme = "crates-io.md"
-include = ["Cargo.toml", "build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 build = "build.rs"
 
-[badges]
-travis-ci = { repository = "serde-rs/serde" }
-appveyor = { repository = "serde-rs/serde" }
-
 [dependencies]
-serde_derive = { version = "1.0", optional = true, path = "../serde_derive" }
+serde_derive = { version = "=1.0.115", optional = true, path = "../serde_derive" }
 
 [dev-dependencies]
 serde_derive = { version = "1.0", path = "../serde_derive" }
 
+[package.metadata.playground]
+features = ["derive", "rc"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
 
 ### FEATURES #################################################################
 
 [features]
 default = ["std"]
 
-# Re-export the derive(Serialize, Deserialize) macros. This is intended for
-# library crates that provide optional Serde impls behind a Cargo cfg of their
-# own.
-#
-# Mainly this is a workaround for limitations associated with
-# rust-lang/cargo#1286 in which a library crate cannot use one "serde" cfg in
-# Cargo to enable dependencies on both serde and serde_derive crates.
-#
-# The recommended way to provide optional Serde support that requires derive is
-# as follows. In particular, please do not name your library's Serde feature
-# anything other than "serde".
-#
-#     [dependencies]
-#     serde = { version = "1.0", optional = true, features = ["derive"] }
-#
-# Within the library, these optional Serde derives would be written like this.
-#
-#     #[cfg(feature = "serde")]
-#     #[macro_use]
-#     extern crate serde;
-#
-#     #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#     struct ...
-#
+# Provide derive(Serialize, Deserialize) macros.
 derive = ["serde_derive"]
 
 # Provide impls for common standard library types like Vec<T> and HashMap<K, V>.
@@ -68,11 +47,7 @@ unstable = []
 # Provide impls for types in the Rust core allocation and collections library
 # including String, Box<T>, Vec<T>, and Cow<T>. This is a subset of std but may
 # be enabled without depending on all of std.
-#
-# Requires a dependency on the unstable core allocation library:
-#
-#    https://doc.rust-lang.org/alloc/
-alloc = ["unstable"]
+alloc = []
 
 # Opt into impls for Rc<T> and Arc<T>. Serializing and deserializing these types
 # does not preserve identity and may result in multiple copies of the same data.

serde/build.rs

@@ -14,10 +14,27 @@ fn main() {
     let target = env::var("TARGET").unwrap();
     let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";
 
-    // CString::into_boxed_c_str stabilized in Rust 1.20:
+    // 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:
@@ -49,10 +66,35 @@ fn main() {
     }
 
     // Non-zero integers stabilized in Rust 1.28:
-    // https://github.com/rust-lang/rust/pull/50808
+    // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
     if minor >= 28 {
         println!("cargo:rustc-cfg=num_nonzero");
     }
+
+    // TryFrom, Atomic types, and non-zero signed integers 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");
+
+        // 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.
+        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");
+        let has_atomic32 = has_atomic64 || emscripten;
+        if has_atomic64 {
+            println!("cargo:rustc-cfg=std_atomic64");
+        }
+        if has_atomic32 {
+            println!("cargo:rustc-cfg=std_atomic");
+        }
+    }
 }
 
 fn rustc_minor_version() -> Option<u32> {

serde/src/de/ignored_any.rs

@@ -1,6 +1,8 @@
 use lib::*;
 
-use de::{Deserialize, Deserializer, Error, MapAccess, SeqAccess, Visitor};
+use de::{
+    Deserialize, Deserializer, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor,
+};
 
 /// An efficient way of discarding data from a deserializer.
 ///
@@ -8,7 +10,7 @@ use de::{Deserialize, Deserializer, Error, MapAccess, SeqAccess, Visitor};
 /// any type, except that it does not store any information about the data that
 /// gets deserialized.
 ///
-/// ```rust
+/// ```edition2018
 /// use std::fmt;
 /// use std::marker::PhantomData;
 ///
@@ -21,7 +23,7 @@ use de::{Deserialize, Deserializer, Error, MapAccess, SeqAccess, Visitor};
 /// ///
 /// /// For example to deserialize only the element at index 3:
 /// ///
-/// /// ```rust
+/// /// ```
 /// /// NthElement::new(3).deserialize(deserializer)
 /// /// ```
 /// pub struct NthElement<T> {
@@ -205,6 +207,13 @@ impl<'de> Visitor<'de> for IgnoredAny {
         let _ = bytes;
         Ok(IgnoredAny)
     }
+
+    fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error>
+    where
+        A: EnumAccess<'de>,
+    {
+        data.variant::<IgnoredAny>()?.1.newtype_variant()
+    }
 }
 
 impl<'de> Deserialize<'de> for IgnoredAny {

serde/src/de/impls.rs

@@ -90,10 +90,13 @@ macro_rules! visit_integer_method {
         {
             match FromPrimitive::$from_method(v) {
                 Some(v) => Ok(v),
-                None => Err(Error::invalid_value(Unexpected::$group(v as $group_ty), &self)),
+                None => Err(Error::invalid_value(
+                    Unexpected::$group(v as $group_ty),
+                    &self,
+                )),
             }
         }
-    }
+    };
 }
 
 macro_rules! visit_float_method {
@@ -105,7 +108,7 @@ macro_rules! visit_float_method {
         {
             Ok(v as Self::Value)
         }
-    }
+    };
 }
 
 macro_rules! impl_deserialize_num {
@@ -578,6 +581,9 @@ macro_rules! forwarded_impl {
 #[cfg(all(feature = "std", de_boxed_c_str))]
 forwarded_impl!((), Box<CStr>, CString::into_boxed_c_str);
 
+#[cfg(core_reverse)]
+forwarded_impl!((T), Reverse<T>, Reverse);
+
 ////////////////////////////////////////////////////////////////////////////////
 
 struct OptionVisitor<T> {
@@ -787,7 +793,8 @@ seq_impl!(
     BinaryHeap::clear,
     BinaryHeap::with_capacity(size_hint::cautious(seq.size_hint())),
     BinaryHeap::reserve,
-    BinaryHeap::push);
+    BinaryHeap::push
+);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 seq_impl!(
@@ -796,7 +803,8 @@ seq_impl!(
     BTreeSet::clear,
     BTreeSet::new(),
     nop_reserve,
-    BTreeSet::insert);
+    BTreeSet::insert
+);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 seq_impl!(
@@ -962,7 +970,7 @@ impl<'de, T> Deserialize<'de> for [T; 0] {
 }
 
 macro_rules! array_impls {
-    ($($len:expr => ($($n:tt $name:ident)+))+) => {
+    ($($len:expr => ($($n:tt)+))+) => {
         $(
             impl<'de, T> Visitor<'de> for ArrayVisitor<[T; $len]>
             where
@@ -979,14 +987,12 @@ macro_rules! array_impls {
                 where
                     A: SeqAccess<'de>,
                 {
-                    $(
-                        let $name = match try!(seq.next_element()) {
+                    Ok([$(
+                        match try!(seq.next_element()) {
                             Some(val) => val,
                             None => return Err(Error::invalid_length($n, &self)),
-                        };
-                    )+
-
-                    Ok([$($name),+])
+                        }
+                    ),+])
                 }
             }
 
@@ -1042,38 +1048,38 @@ macro_rules! array_impls {
 }
 
 array_impls! {
-    1 => (0 a)
-    2 => (0 a 1 b)
-    3 => (0 a 1 b 2 c)
-    4 => (0 a 1 b 2 c 3 d)
-    5 => (0 a 1 b 2 c 3 d 4 e)
-    6 => (0 a 1 b 2 c 3 d 4 e 5 f)
-    7 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g)
-    8 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h)
-    9 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i)
-    10 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j)
-    11 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k)
-    12 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l)
-    13 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m)
-    14 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n)
-    15 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o)
-    16 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p)
-    17 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q)
-    18 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r)
-    19 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s)
-    20 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t)
-    21 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u)
-    22 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v)
-    23 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w)
-    24 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x)
-    25 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y)
-    26 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z)
-    27 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa)
-    28 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab)
-    29 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac)
-    30 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad)
-    31 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae)
-    32 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae 31 af)
+    1 => (0)
+    2 => (0 1)
+    3 => (0 1 2)
+    4 => (0 1 2 3)
+    5 => (0 1 2 3 4)
+    6 => (0 1 2 3 4 5)
+    7 => (0 1 2 3 4 5 6)
+    8 => (0 1 2 3 4 5 6 7)
+    9 => (0 1 2 3 4 5 6 7 8)
+    10 => (0 1 2 3 4 5 6 7 8 9)
+    11 => (0 1 2 3 4 5 6 7 8 9 10)
+    12 => (0 1 2 3 4 5 6 7 8 9 10 11)
+    13 => (0 1 2 3 4 5 6 7 8 9 10 11 12)
+    14 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13)
+    15 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14)
+    16 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)
+    17 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16)
+    18 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17)
+    19 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18)
+    20 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
+    21 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)
+    22 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21)
+    23 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22)
+    24 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23)
+    25 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24)
+    26 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25)
+    27 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26)
+    28 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27)
+    29 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28)
+    30 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29)
+    31 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)
+    32 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1577,6 +1583,24 @@ impl<'de> Visitor<'de> for PathBufVisitor {
     {
         Ok(From::from(v))
     }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        str::from_utf8(v)
+            .map(From::from)
+            .map_err(|_| Error::invalid_value(Unexpected::Bytes(v), &self))
+    }
+
+    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        String::from_utf8(v)
+            .map(From::from)
+            .map_err(|e| Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self))
+    }
 }
 
 #[cfg(feature = "std")]
@@ -1589,6 +1613,9 @@ impl<'de> Deserialize<'de> for PathBuf {
     }
 }
 
+#[cfg(all(feature = "std", de_boxed_path))]
+forwarded_impl!((), Box<Path>, PathBuf::into_boxed_path);
+
 ////////////////////////////////////////////////////////////////////////////////
 
 // If this were outside of the serde crate, it would just use:
@@ -2269,6 +2296,117 @@ mod range {
 
 ////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(any(ops_bound, collections_bound))]
+impl<'de, T> Deserialize<'de> for Bound<T>
+where
+    T: Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        enum Field {
+            Unbounded,
+            Included,
+            Excluded,
+        }
+
+        impl<'de> Deserialize<'de> for Field {
+            #[inline]
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                struct FieldVisitor;
+
+                impl<'de> Visitor<'de> for FieldVisitor {
+                    type Value = Field;
+
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                        formatter.write_str("`Unbounded`, `Included` or `Excluded`")
+                    }
+
+                    fn visit_u32<E>(self, value: u32) -> Result<Self::Value, E>
+                    where
+                        E: Error,
+                    {
+                        match value {
+                            0 => Ok(Field::Unbounded),
+                            1 => Ok(Field::Included),
+                            2 => Ok(Field::Excluded),
+                            _ => Err(Error::invalid_value(
+                                Unexpected::Unsigned(value as u64),
+                                &self,
+                            )),
+                        }
+                    }
+
+                    fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+                    where
+                        E: Error,
+                    {
+                        match value {
+                            "Unbounded" => Ok(Field::Unbounded),
+                            "Included" => Ok(Field::Included),
+                            "Excluded" => Ok(Field::Excluded),
+                            _ => Err(Error::unknown_variant(value, VARIANTS)),
+                        }
+                    }
+
+                    fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E>
+                    where
+                        E: Error,
+                    {
+                        match value {
+                            b"Unbounded" => Ok(Field::Unbounded),
+                            b"Included" => Ok(Field::Included),
+                            b"Excluded" => Ok(Field::Excluded),
+                            _ => match str::from_utf8(value) {
+                                Ok(value) => Err(Error::unknown_variant(value, VARIANTS)),
+                                Err(_) => {
+                                    Err(Error::invalid_value(Unexpected::Bytes(value), &self))
+                                }
+                            },
+                        }
+                    }
+                }
+
+                deserializer.deserialize_identifier(FieldVisitor)
+            }
+        }
+
+        struct BoundVisitor<T>(PhantomData<Bound<T>>);
+
+        impl<'de, T> Visitor<'de> for BoundVisitor<T>
+        where
+            T: Deserialize<'de>,
+        {
+            type Value = Bound<T>;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("enum Bound")
+            }
+
+            fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error>
+            where
+                A: EnumAccess<'de>,
+            {
+                match try!(data.variant()) {
+                    (Field::Unbounded, v) => v.unit_variant().map(|()| Bound::Unbounded),
+                    (Field::Included, v) => v.newtype_variant().map(Bound::Included),
+                    (Field::Excluded, v) => v.newtype_variant().map(Bound::Excluded),
+                }
+            }
+        }
+
+        const VARIANTS: &'static [&'static str] = &["Unbounded", "Included", "Excluded"];
+
+        deserializer.deserialize_enum("Bound", VARIANTS, BoundVisitor(PhantomData))
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 macro_rules! nonzero_integers {
     ( $( $T: ident, )+ ) => {
         $(
@@ -2290,7 +2428,6 @@ macro_rules! nonzero_integers {
 }
 
 nonzero_integers! {
-    // Not including signed NonZeroI* since they might be removed
     NonZeroU8,
     NonZeroU16,
     NonZeroU32,
@@ -2298,12 +2435,26 @@ nonzero_integers! {
     NonZeroUsize,
 }
 
+#[cfg(num_nonzero_signed)]
+nonzero_integers! {
+    NonZeroI8,
+    NonZeroI16,
+    NonZeroI32,
+    NonZeroI64,
+    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,
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -2431,3 +2582,31 @@ where
         Deserialize::deserialize(deserializer).map(Wrapping)
     }
 }
+
+#[cfg(all(feature = "std", std_atomic))]
+macro_rules! atomic_impl {
+    ($($ty:ident)*) => {
+        $(
+            impl<'de> Deserialize<'de> for $ty {
+                fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+                where
+                    D: Deserializer<'de>,
+                {
+                    Deserialize::deserialize(deserializer).map(Self::new)
+                }
+            }
+        )*
+    };
+}
+
+#[cfg(all(feature = "std", std_atomic))]
+atomic_impl! {
+    AtomicBool
+    AtomicI8 AtomicI16 AtomicI32 AtomicIsize
+    AtomicU8 AtomicU16 AtomicU32 AtomicUsize
+}
+
+#[cfg(all(feature = "std", std_atomic64))]
+atomic_impl! {
+    AtomicI64 AtomicU64
+}

serde/src/de/mod.rs

@@ -59,13 +59,13 @@
 //!    - Box\<T\>
 //!    - Box\<\[T\]\>
 //!    - Box\<str\>
-//!    - Rc\<T\>
-//!    - Arc\<T\>
 //!    - Cow\<'a, T\>
 //!    - Cell\<T\>
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
+//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -89,6 +89,7 @@
 //!    - PathBuf
 //!    - Range\<T\>
 //!    - RangeInclusive\<T\>
+//!    - Bound\<T\>
 //!    - num::NonZero*
 //!    - `!` *(unstable)*
 //!  - **Net types**:
@@ -124,6 +125,13 @@ mod utf8;
 
 pub use self::ignored_any::IgnoredAny;
 
+#[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;
+
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! declare_error_trait {
@@ -153,7 +161,7 @@ macro_rules! declare_error_trait {
             ///
             /// The message should not be capitalized and should not end with a period.
             ///
-            /// ```rust
+            /// ```edition2018
             /// # use std::str::FromStr;
             /// #
             /// # struct IpAddr;
@@ -173,7 +181,7 @@ macro_rules! declare_error_trait {
             ///     where
             ///         D: Deserializer<'de>,
             ///     {
-            ///         let s = try!(String::deserialize(deserializer));
+            ///         let s = String::deserialize(deserializer)?;
             ///         s.parse().map_err(de::Error::custom)
             ///     }
             /// }
@@ -237,12 +245,16 @@ macro_rules! declare_error_trait {
             #[cold]
             fn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self {
                 if expected.is_empty() {
-                    Error::custom(format_args!("unknown variant `{}`, there are no variants",
-                                               variant))
+                    Error::custom(format_args!(
+                        "unknown variant `{}`, there are no variants",
+                        variant
+                    ))
                 } else {
-                    Error::custom(format_args!("unknown variant `{}`, expected {}",
-                                               variant,
-                                               OneOf { names: expected }))
+                    Error::custom(format_args!(
+                        "unknown variant `{}`, expected {}",
+                        variant,
+                        OneOf { names: expected }
+                    ))
                 }
             }
 
@@ -251,12 +263,16 @@ macro_rules! declare_error_trait {
             #[cold]
             fn unknown_field(field: &str, expected: &'static [&'static str]) -> Self {
                 if expected.is_empty() {
-                    Error::custom(format_args!("unknown field `{}`, there are no fields",
-                                               field))
+                    Error::custom(format_args!(
+                        "unknown field `{}`, there are no fields",
+                        field
+                    ))
                 } else {
-                    Error::custom(format_args!("unknown field `{}`, expected {}",
-                                               field,
-                                               OneOf { names: expected }))
+                    Error::custom(format_args!(
+                        "unknown field `{}`, expected {}",
+                        field,
+                        OneOf { names: expected }
+                    ))
                 }
             }
 
@@ -279,7 +295,7 @@ macro_rules! declare_error_trait {
 }
 
 #[cfg(feature = "std")]
-declare_error_trait!(Error: Sized + error::Error);
+declare_error_trait!(Error: Sized + StdError);
 
 #[cfg(not(feature = "std"))]
 declare_error_trait!(Error: Sized + Debug + Display);
@@ -290,7 +306,7 @@ 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.
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::fmt;
 /// #
 /// # use serde::de::{self, Unexpected, Visitor};
@@ -415,7 +431,7 @@ impl<'a> fmt::Display for Unexpected<'a> {
 /// Within the context of a `Visitor` implementation, the `Visitor` itself
 /// (`&self`) is an implementation of this trait.
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::fmt;
 /// #
 /// # use serde::de::{self, Unexpected, Visitor};
@@ -440,7 +456,7 @@ impl<'a> fmt::Display for Unexpected<'a> {
 ///
 /// Outside of a `Visitor`, `&"..."` can be used.
 ///
-/// ```rust
+/// ```edition2018
 /// # use serde::de::{self, Unexpected};
 /// #
 /// # fn example<E>() -> Result<(), E>
@@ -561,7 +577,7 @@ pub trait Deserialize<'de>: Sized {
 /// from the input string, but a `from_reader` function may only deserialize
 /// owned data.
 ///
-/// ```rust
+/// ```edition2018
 /// # use serde::de::{Deserialize, DeserializeOwned};
 /// # use std::io::{Read, Result};
 /// #
@@ -600,7 +616,7 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 ///
 /// The canonical API for stateless deserialization looks like this:
 ///
-/// ```rust
+/// ```edition2018
 /// # use serde::Deserialize;
 /// #
 /// # enum Error {}
@@ -614,7 +630,7 @@ 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:
 ///
-/// ```rust
+/// ```edition2018
 /// # use serde::de::DeserializeSeed;
 /// #
 /// # enum Error {}
@@ -647,7 +663,7 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 /// into it. This requires stateful deserialization using the `DeserializeSeed`
 /// trait.
 ///
-/// ```rust
+/// ```edition2018
 /// use std::fmt;
 /// use std::marker::PhantomData;
 ///
@@ -778,7 +794,7 @@ where
 ///
 /// The role of this trait is to define the deserialization half of the [Serde
 /// data model], which is a way to categorize every Rust data type into one of
-/// 29 possible types. Each method of the `Serializer` trait corresponds to one
+/// 29 possible types. Each method of the `Deserializer` trait corresponds to one
 /// of the types of the data model.
 ///
 /// Implementations of `Deserialize` map themselves into this data model by
@@ -1137,7 +1153,7 @@ pub trait Deserializer<'de>: Sized {
     /// human-readable one and binary formats like Bincode will prefer the
     /// compact one.
     ///
-    /// ```
+    /// ```edition2018
     /// # use std::ops::Add;
     /// # use std::str::FromStr;
     /// #
@@ -1214,7 +1230,7 @@ pub trait Deserializer<'de>: Sized {
 ///
 /// # Example
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::fmt;
 /// #
 /// # use serde::de::{self, Unexpected, Visitor};
@@ -1255,7 +1271,7 @@ pub trait Visitor<'de>: Sized {
     /// "an integer between 0 and 64". The message should not be capitalized and
     /// should not end with a period.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use std::fmt;
     /// #
     /// # struct S {
@@ -1996,7 +2012,7 @@ pub trait VariantAccess<'de>: Sized {
     /// If the data contains a different type of variant, the following
     /// `invalid_type` error should be constructed:
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
     /// #
     /// # struct X;
@@ -2036,7 +2052,7 @@ pub trait VariantAccess<'de>: Sized {
     /// If the data contains a different type of variant, the following
     /// `invalid_type` error should be constructed:
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
     /// #
     /// # struct X;
@@ -2092,7 +2108,7 @@ pub trait VariantAccess<'de>: Sized {
     /// If the data contains a different type of variant, the following
     /// `invalid_type` error should be constructed:
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
     /// #
     /// # struct X;
@@ -2139,7 +2155,7 @@ pub trait VariantAccess<'de>: Sized {
     /// If the data contains a different type of variant, the following
     /// `invalid_type` error should be constructed:
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected};
     /// #
     /// # struct X;
@@ -2199,14 +2215,10 @@ pub trait VariantAccess<'de>: Sized {
 ///
 /// # Example
 ///
-/// ```rust
-/// #[macro_use]
-/// extern crate serde_derive;
-///
-/// extern crate serde;
-///
+/// ```edition2018
 /// use std::str::FromStr;
-/// use serde::de::{value, Deserialize, IntoDeserializer};
+/// use serde::Deserialize;
+/// use serde::de::{value, IntoDeserializer};
 ///
 /// #[derive(Deserialize)]
 /// enum Setting {
@@ -2221,8 +2233,6 @@ pub trait VariantAccess<'de>: Sized {
 ///         Self::deserialize(s.into_deserializer())
 ///     }
 /// }
-/// #
-/// # fn main() {}
 /// ```
 pub trait IntoDeserializer<'de, E: Error = value::Error> {
     /// The type of the deserializer being converted into.

serde/src/de/value.rs

@@ -1,14 +1,10 @@
 //! Building blocks for deserializing basic values using the `IntoDeserializer`
 //! trait.
 //!
-//! ```rust
-//! #[macro_use]
-//! extern crate serde_derive;
-//!
-//! extern crate serde;
-//!
+//! ```edition2018
 //! use std::str::FromStr;
-//! use serde::de::{value, Deserialize, IntoDeserializer};
+//! use serde::Deserialize;
+//! use serde::de::{value, IntoDeserializer};
 //!
 //! #[derive(Deserialize)]
 //! enum Setting {
@@ -23,8 +19,6 @@
 //!         Self::deserialize(s.into_deserializer())
 //!     }
 //! }
-//! #
-//! # fn main() {}
 //! ```
 
 use lib::*;
@@ -1293,10 +1287,40 @@ where
         visitor.visit_map(self.map)
     }
 
+    fn deserialize_enum<V>(
+        self,
+        _name: &str,
+        _variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_enum(self)
+    }
+
     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
+        tuple_struct map struct identifier ignored_any
+    }
+}
+
+impl<'de, A> de::EnumAccess<'de> for MapAccessDeserializer<A>
+where
+    A: de::MapAccess<'de>,
+{
+    type Error = A::Error;
+    type Variant = private::MapAsEnum<A>;
+
+    fn variant_seed<T>(mut self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        match 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")),
+        }
     }
 }
 
@@ -1305,7 +1329,7 @@ where
 mod private {
     use lib::*;
 
-    use de::{self, Unexpected};
+    use de::{self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor};
 
     #[derive(Clone, Debug)]
     pub struct UnitOnly<E> {
@@ -1366,6 +1390,92 @@ mod private {
         }
     }
 
+    #[derive(Clone, Debug)]
+    pub struct MapAsEnum<A> {
+        map: A,
+    }
+
+    pub fn map_as_enum<A>(map: A) -> MapAsEnum<A> {
+        MapAsEnum { map: map }
+    }
+
+    impl<'de, A> VariantAccess<'de> for MapAsEnum<A>
+    where
+        A: MapAccess<'de>,
+    {
+        type Error = A::Error;
+
+        fn unit_variant(mut self) -> Result<(), Self::Error> {
+            self.map.next_value()
+        }
+
+        fn newtype_variant_seed<T>(mut self, seed: T) -> Result<T::Value, Self::Error>
+        where
+            T: DeserializeSeed<'de>,
+        {
+            self.map.next_value_seed(seed)
+        }
+
+        fn tuple_variant<V>(mut self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.map.next_value_seed(SeedTupleVariant {
+                len: len,
+                visitor: visitor,
+            })
+        }
+
+        fn struct_variant<V>(
+            mut self,
+            _fields: &'static [&'static str],
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.map
+                .next_value_seed(SeedStructVariant { visitor: visitor })
+        }
+    }
+
+    struct SeedTupleVariant<V> {
+        len: usize,
+        visitor: V,
+    }
+
+    impl<'de, V> DeserializeSeed<'de> for SeedTupleVariant<V>
+    where
+        V: Visitor<'de>,
+    {
+        type Value = V::Value;
+
+        fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            deserializer.deserialize_tuple(self.len, self.visitor)
+        }
+    }
+
+    struct SeedStructVariant<V> {
+        visitor: V,
+    }
+
+    impl<'de, V> DeserializeSeed<'de> for SeedStructVariant<V>
+    where
+        V: Visitor<'de>,
+    {
+        type Value = V::Value;
+
+        fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            deserializer.deserialize_map(self.visitor)
+        }
+    }
+
     /// Avoid having to restate the generic types on `MapDeserializer`. The
     /// `Iterator::Item` contains enough information to figure out K and V.
     pub trait Pair {

serde/src/export.rs

@@ -9,7 +9,10 @@ pub use lib::result::Result::{self, Err, Ok};
 pub use self::string::from_utf8_lossy;
 
 #[cfg(any(feature = "alloc", feature = "std"))]
-pub use lib::Vec;
+pub use lib::{ToString, Vec};
+
+#[cfg(core_try_from)]
+pub use lib::convert::TryFrom;
 
 mod string {
     use lib::*;

serde/src/integer128.rs

@@ -1,22 +1,20 @@
 /// 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 may
-/// place the i128 / u128 methods of their Serializer and Deserializer behind
-/// this macro.
+/// 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
-/// do not need to bother with this macro and may assume support for 128-bit
-/// integers.
+/// 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.
 ///
-/// ```rust
-/// #[macro_use]
-/// extern crate serde;
-///
-/// use serde::Serializer;
+/// ```edition2018
 /// # use serde::private::ser::Error;
 /// #
 /// # struct MySerializer;
+/// #
+/// use serde::{serde_if_integer128, Serializer};
 ///
 /// impl Serializer for MySerializer {
 ///     type Ok = ();
@@ -41,20 +39,18 @@
 ///         }
 ///     }
 /// #
-/// #     __serialize_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
 /// #     }
 /// }
-/// #
-/// # fn main() {}
 /// ```
 ///
 /// When Serde is built with support for 128-bit integers, this macro expands
 /// transparently into just the input tokens.
 ///
-/// ```rust
+/// ```edition2018
 /// macro_rules! serde_if_integer128 {
 ///     ($($tt:tt)*) => {
 ///         $($tt)*
@@ -65,7 +61,7 @@
 /// When built without support for 128-bit integers, this macro expands to
 /// nothing.
 ///
-/// ```rust
+/// ```edition2018
 /// macro_rules! serde_if_integer128 {
 ///     ($($tt:tt)*) => {};
 /// }

serde/src/lib.rs

@@ -37,8 +37,8 @@
 //!   used for IPC within the Servo rendering engine.
 //! - [CBOR], a Concise Binary Object Representation designed for small message
 //!   size without the need for version negotiation.
-//! - [YAML], a popular human-friendly configuration language that ain't markup
-//!   language.
+//! - [YAML], a self-proclaimed human-friendly configuration language that ain't
+//!   markup language.
 //! - [MessagePack], an efficient binary format that resembles a compact JSON.
 //! - [TOML], a minimal configuration format used by [Cargo].
 //! - [Pickle], a format common in the Python world.
@@ -46,13 +46,17 @@
 //! - [BSON], the data storage and network transfer format used by MongoDB.
 //! - [Avro], a binary format used within Apache Hadoop, with support for schema
 //!   definition.
-//! - [Hjson], a variant of JSON designed to be readable and writable by humans.
 //! - [JSON5], A superset of JSON including some productions from ES5.
+//! - [Postcard], a no\_std and embedded-systems friendly compact binary format.
 //! - [URL], the x-www-form-urlencoded format.
 //! - [Envy], a way to deserialize environment variables into Rust structs.
 //!   *(deserialization only)*
 //! - [Envy Store], a way to deserialize [AWS Parameter Store] parameters into
 //!   Rust structs. *(deserialization only)*
+//! - [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.
 //!
 //! [JSON]: https://github.com/serde-rs/json
 //! [Bincode]: https://github.com/TyOverby/bincode
@@ -64,74 +68,74 @@
 //! [RON]: https://github.com/ron-rs/ron
 //! [BSON]: https://github.com/zonyitoo/bson-rs
 //! [Avro]: https://github.com/flavray/avro-rs
-//! [Hjson]: https://github.com/laktak/hjson-rust
 //! [JSON5]: https://github.com/callum-oakley/json5-rs
+//! [Postcard]: https://github.com/jamesmunns/postcard
 //! [URL]: https://github.com/nox/serde_urlencoded
 //! [Envy]: https://github.com/softprops/envy
 //! [Envy Store]: https://github.com/softprops/envy-store
 //! [Cargo]: http://doc.crates.io/manifest.html
 //! [AWS Parameter Store]: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-paramstore.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
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.81")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.115")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // 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(specialization, never_type))]
-#![cfg_attr(feature = "alloc", feature(alloc))]
+#![cfg_attr(feature = "unstable", feature(never_type))]
+#![allow(unknown_lints, bare_trait_objects, deprecated)]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
-// Whitelisted clippy lints
+// Ignored clippy and clippy_pedantic lints
 #![cfg_attr(
     feature = "cargo-clippy",
     allow(
-        cast_lossless,
-        const_static_lifetime,
-        doc_markdown,
-        linkedlist,
-        needless_pass_by_value,
+        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+        unnested_or_patterns,
+        // 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,
-        unreadable_literal,
-        zero_prefixed_literal
+        use_self,
+        zero_prefixed_literal,
+        // correctly used
+        enum_glob_use,
+        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,
     )
 )]
-// Whitelisted clippy_pedantic lints
-#![cfg_attr(feature = "cargo-clippy", allow(
-// integer and float ser/de requires these sorts of casts
-    cast_possible_truncation,
-    cast_possible_wrap,
-    cast_precision_loss,
-    cast_sign_loss,
-// simplifies some macros
-    invalid_upcast_comparisons,
-// things are often more readable this way
-    decimal_literal_representation,
-    option_unwrap_used,
-    result_unwrap_used,
-    shadow_reuse,
-    single_match_else,
-    stutter,
-    use_self,
-// not practical
-    indexing_slicing,
-    many_single_char_names,
-    missing_docs_in_private_items,
-    similar_names,
-// alternative is not stable
-    empty_enum,
-    use_debug,
-))]
-// Blacklisted Rust lints.
-//
-// Compiler bug involving unused_imports:
-// https://github.com/rust-lang/rust/issues/51661
-#![deny(missing_docs, /*unused_imports*/)]
+// Rustc lints.
+#![forbid(unsafe_code)]
+#![deny(missing_docs, unused_imports)]
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -172,7 +176,7 @@ mod lib {
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::string::{String, ToString};
     #[cfg(feature = "std")]
-    pub use std::string::String;
+    pub use std::string::{String, ToString};
 
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::vec::Vec;
@@ -219,11 +223,28 @@ mod lib {
     #[cfg(feature = "std")]
     pub use std::time::{SystemTime, UNIX_EPOCH};
 
-    #[cfg(any(core_duration, feature = "std"))]
-    pub use self::core::time::Duration;
+    #[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))]
+    pub use std::sync::atomic::{
+        AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
+        AtomicUsize, Ordering,
+    };
+    #[cfg(all(feature = "std", std_atomic64))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+
+    #[cfg(any(core_duration, feature = "std"))]
+    pub use self::core::time::Duration;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -250,42 +271,11 @@ pub mod export;
 #[doc(hidden)]
 pub mod private;
 
+#[cfg(not(feature = "std"))]
+mod std_error;
+
 // Re-export #[derive(Serialize, Deserialize)].
 //
-// This is a workaround for https://github.com/rust-lang/cargo/issues/1286.
-// Without this re-export, crates that put Serde derives behind a cfg_attr would
-// need to use some silly feature name that depends on both serde and
-// serde_derive.
-//
-//     [features]
-//     serde-impls = ["serde", "serde_derive"]
-//
-//     [dependencies]
-//     serde = { version = "1.0", optional = true }
-//     serde_derive = { version = "1.0", optional = true }
-//
-//     # Used like this:
-//     # #[cfg(feature = "serde-impls")]
-//     # #[macro_use]
-//     # extern crate serde_derive;
-//     #
-//     # #[cfg_attr(feature = "serde-impls", derive(Serialize, Deserialize))]
-//     # struct S { /* ... */ }
-//
-// The re-exported derives allow crates to use "serde" as the name of their
-// Serde feature which is more intuitive.
-//
-//     [dependencies]
-//     serde = { version = "1.0", optional = true, features = ["derive"] }
-//
-//     # Used like this:
-//     # #[cfg(feature = "serde")]
-//     # #[macro_use]
-//     # extern crate serde;
-//     #
-//     # #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-//     # struct S { /* ... */ }
-//
 // The reason re-exporting is not enabled by default is that disabling it would
 // be annoying for crates that provide handwritten impls or data formats. They
 // would need to disable default features and then explicitly re-enable std.

serde/src/macros.rs

@@ -11,10 +11,8 @@
 /// input. This requires repetitive implementations of all the [`Deserializer`]
 /// trait methods.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde;
-/// #
+/// ```edition2018
+/// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
 /// #
 /// # struct MyDeserializer;
@@ -43,18 +41,14 @@
 /// #         tuple_struct map struct enum identifier ignored_any
 /// #     }
 /// # }
-/// #
-/// # fn main() {}
 /// ```
 ///
 /// The `forward_to_deserialize_any!` macro implements these simple forwarding
 /// methods so that they forward directly to [`Deserializer::deserialize_any`].
 /// You can choose which methods to forward.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde;
-/// #
+/// ```edition2018
+/// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
 /// #
 /// # struct MyDeserializer;
@@ -77,8 +71,6 @@
 ///         tuple_struct map struct enum identifier ignored_any
 ///     }
 /// }
-/// #
-/// # fn main() {}
 /// ```
 ///
 /// The macro assumes the convention that your `Deserializer` lifetime parameter
@@ -86,12 +78,10 @@
 /// called `V`. A different type parameter and a different lifetime can be
 /// specified explicitly if necessary.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde;
-/// #
+/// ```edition2018
 /// # use std::marker::PhantomData;
 /// #
+/// # use serde::forward_to_deserialize_any;
 /// # use serde::de::{value, Deserializer, Visitor};
 /// #
 /// # struct MyDeserializer<V>(PhantomData<V>);
@@ -113,8 +103,6 @@
 ///     tuple_struct map struct enum identifier ignored_any
 /// }
 /// # }
-/// #
-/// # fn main() {}
 /// ```
 ///
 /// [`Deserializer`]: trait.Deserializer.html

serde/src/private/de.rs

@@ -53,9 +53,10 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-pub fn borrow_cow_str<'de: 'a, 'a, D>(deserializer: D) -> Result<Cow<'a, str>, D::Error>
+pub fn borrow_cow_str<'de: 'a, 'a, D, R>(deserializer: D) -> Result<R, D::Error>
 where
     D: Deserializer<'de>,
+    R: From<Cow<'a, str>>,
 {
     struct CowStrVisitor;
 
@@ -121,13 +122,14 @@ where
         }
     }
 
-    deserializer.deserialize_str(CowStrVisitor)
+    deserializer.deserialize_str(CowStrVisitor).map(From::from)
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-pub fn borrow_cow_bytes<'de: 'a, 'a, D>(deserializer: D) -> Result<Cow<'a, [u8]>, D::Error>
+pub fn borrow_cow_bytes<'de: 'a, 'a, D, R>(deserializer: D) -> Result<R, D::Error>
 where
     D: Deserializer<'de>,
+    R: From<Cow<'a, [u8]>>,
 {
     struct CowBytesVisitor;
 
@@ -181,7 +183,9 @@ where
         }
     }
 
-    deserializer.deserialize_bytes(CowBytesVisitor)
+    deserializer
+        .deserialize_bytes(CowBytesVisitor)
+        .map(From::from)
 }
 
 pub mod size_hint {
@@ -1420,6 +1424,7 @@ mod content {
                 Content::ByteBuf(v) => visitor.visit_byte_buf(v),
                 Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
                 Content::U8(v) => visitor.visit_u8(v),
+                Content::U64(v) => visitor.visit_u64(v),
                 _ => Err(self.invalid_type(&visitor)),
             }
         }
@@ -1557,7 +1562,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),
@@ -2123,6 +2128,7 @@ mod content {
                 Content::ByteBuf(ref v) => visitor.visit_bytes(v),
                 Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
                 Content::U8(v) => visitor.visit_u8(v),
+                Content::U64(v) => visitor.visit_u64(v),
                 _ => Err(self.invalid_type(&visitor)),
             }
         }
@@ -2246,7 +2252,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),
@@ -2468,7 +2474,7 @@ mod content {
         where
             M: MapAccess<'de>,
         {
-            while let Some(_) = try!(access.next_entry::<IgnoredAny, IgnoredAny>()) {}
+            while try!(access.next_entry::<IgnoredAny, IgnoredAny>()).is_some() {}
             Ok(())
         }
     }
@@ -2508,6 +2514,13 @@ mod content {
         {
             Ok(())
         }
+
+        fn visit_none<E>(self) -> Result<(), E>
+        where
+            E: de::Error,
+        {
+            Ok(())
+        }
     }
 }
 
@@ -2709,7 +2722,7 @@ where
         }
 
         Err(Error::custom(format_args!(
-            "no variant of enum {} not found in flattened data",
+            "no variant of enum {} found in flattened data",
             name
         )))
     }
@@ -2750,6 +2763,13 @@ where
         }
     }
 
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_unit()
+    }
+
     forward_to_deserialize_other! {
         deserialize_bool()
         deserialize_i8()
@@ -2767,7 +2787,6 @@ where
         deserialize_string()
         deserialize_bytes()
         deserialize_byte_buf()
-        deserialize_unit()
         deserialize_unit_struct(&'static str)
         deserialize_seq()
         deserialize_tuple(usize)

serde/src/private/ser.rs

@@ -1032,7 +1032,7 @@ impl<'a, M> FlatMapSerializer<'a, M>
 where
     M: SerializeMap + 'a,
 {
-    fn bad_type(self, what: Unsupported) -> M::Error {
+    fn bad_type(what: Unsupported) -> M::Error {
         ser::Error::custom(format_args!(
             "can only flatten structs and maps (got {})",
             what
@@ -1057,59 +1057,59 @@ where
     type SerializeStructVariant = FlatMapSerializeStructVariantAsMapValue<'a, M>;
 
     fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Boolean))
+        Err(Self::bad_type(Unsupported::Boolean))
     }
 
     fn serialize_i8(self, _: i8) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_i16(self, _: i16) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_i32(self, _: i32) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_i64(self, _: i64) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_u8(self, _: u8) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_u16(self, _: u16) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_u32(self, _: u32) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_u64(self, _: u64) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Integer))
+        Err(Self::bad_type(Unsupported::Integer))
     }
 
     fn serialize_f32(self, _: f32) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Float))
+        Err(Self::bad_type(Unsupported::Float))
     }
 
     fn serialize_f64(self, _: f64) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Float))
+        Err(Self::bad_type(Unsupported::Float))
     }
 
     fn serialize_char(self, _: char) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Char))
+        Err(Self::bad_type(Unsupported::Char))
     }
 
     fn serialize_str(self, _: &str) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::String))
+        Err(Self::bad_type(Unsupported::String))
     }
 
     fn serialize_bytes(self, _: &[u8]) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::ByteArray))
+        Err(Self::bad_type(Unsupported::ByteArray))
     }
 
     fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
@@ -1124,11 +1124,11 @@ where
     }
 
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Unit))
+        Ok(())
     }
 
     fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::UnitStruct))
+        Err(Self::bad_type(Unsupported::UnitStruct))
     }
 
     fn serialize_unit_variant(
@@ -1137,7 +1137,7 @@ where
         _: u32,
         _: &'static str,
     ) -> Result<Self::Ok, Self::Error> {
-        Err(self.bad_type(Unsupported::Enum))
+        Err(Self::bad_type(Unsupported::Enum))
     }
 
     fn serialize_newtype_struct<T: ?Sized>(
@@ -1166,11 +1166,11 @@ where
     }
 
     fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-        Err(self.bad_type(Unsupported::Sequence))
+        Err(Self::bad_type(Unsupported::Sequence))
     }
 
     fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
-        Err(self.bad_type(Unsupported::Tuple))
+        Err(Self::bad_type(Unsupported::Tuple))
     }
 
     fn serialize_tuple_struct(
@@ -1178,7 +1178,7 @@ where
         _: &'static str,
         _: usize,
     ) -> Result<Self::SerializeTupleStruct, Self::Error> {
-        Err(self.bad_type(Unsupported::TupleStruct))
+        Err(Self::bad_type(Unsupported::TupleStruct))
     }
 
     fn serialize_tuple_variant(
@@ -1188,7 +1188,7 @@ where
         _: &'static str,
         _: usize,
     ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        Err(self.bad_type(Unsupported::Enum))
+        Err(Self::bad_type(Unsupported::Enum))
     }
 
     fn serialize_map(self, _: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
@@ -1243,6 +1243,18 @@ where
         self.0.serialize_value(value)
     }
 
+    fn serialize_entry<K: ?Sized, V: ?Sized>(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Self::Error>
+    where
+        K: Serialize,
+        V: Serialize,
+    {
+        self.0.serialize_entry(key, value)
+    }
+
     fn end(self) -> Result<(), Self::Error> {
         Ok(())
     }

serde/src/ser/fmt.rs

@@ -0,0 +1,174 @@
+use lib::*;
+use ser::{Error, Impossible, Serialize, Serializer};
+
+impl Error for fmt::Error {
+    fn custom<T: Display>(_msg: T) -> Self {
+        fmt::Error
+    }
+}
+
+macro_rules! fmt_primitives {
+    ($($f:ident: $t:ty,)*) => {
+        $(
+            fn $f(self, v: $t) -> fmt::Result {
+                Display::fmt(&v, self)
+            }
+        )*
+    };
+}
+
+/// ```edition2018
+/// use serde::Serialize;
+/// use std::fmt::{self, Display};
+///
+/// #[derive(Serialize)]
+/// #[serde(rename_all = "kebab-case")]
+/// pub enum MessageType {
+///     StartRequest,
+///     EndRequest,
+/// }
+///
+/// impl Display for MessageType {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         self.serialize(f)
+///     }
+/// }
+/// ```
+impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
+    type Ok = ();
+    type Error = fmt::Error;
+    type SerializeSeq = Impossible<(), fmt::Error>;
+    type SerializeTuple = Impossible<(), fmt::Error>;
+    type SerializeTupleStruct = Impossible<(), fmt::Error>;
+    type SerializeTupleVariant = Impossible<(), fmt::Error>;
+    type SerializeMap = Impossible<(), fmt::Error>;
+    type SerializeStruct = Impossible<(), fmt::Error>;
+    type SerializeStructVariant = Impossible<(), fmt::Error>;
+
+    fmt_primitives! {
+        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_unit_struct: &'static str,
+    }
+
+    serde_if_integer128! {
+        fmt_primitives! {
+            serialize_i128: i128,
+            serialize_u128: u128,
+        }
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        variant: &'static str,
+    ) -> fmt::Result {
+        Display::fmt(variant, self)
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Serialize::serialize(value, self)
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_none(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_unit(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    where
+        T: Display,
+    {
+        Display::fmt(value, self)
+    }
+}

serde/src/ser/impls.rs

@@ -160,10 +160,12 @@ macro_rules! array_impls {
     }
 }
 
-array_impls!(01 02 03 04 05 06 07 08 09 10
-             11 12 13 14 15 16 17 18 19 20
-             21 22 23 24 25 26 27 28 29 30
-             31 32);
+array_impls! {
+    01 02 03 04 05 06 07 08 09 10
+    11 12 13 14 15 16 17 18 19 20
+    21 22 23 24 25 26 27 28 29 30
+    31 32
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -256,6 +258,29 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(any(ops_bound, collections_bound))]
+impl<T> Serialize for Bound<T>
+where
+    T: Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        match *self {
+            Bound::Unbounded => serializer.serialize_unit_variant("Bound", 0, "Unbounded"),
+            Bound::Included(ref value) => {
+                serializer.serialize_newtype_variant("Bound", 1, "Included", value)
+            }
+            Bound::Excluded(ref value) => {
+                serializer.serialize_newtype_variant("Bound", 2, "Excluded", value)
+            }
+        }
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 impl Serialize for () {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -456,7 +481,6 @@ macro_rules! nonzero_integers {
 }
 
 nonzero_integers! {
-    // Not including signed NonZeroI* since they might be removed
     NonZeroU8,
     NonZeroU16,
     NonZeroU32,
@@ -464,12 +488,26 @@ nonzero_integers! {
     NonZeroUsize,
 }
 
+#[cfg(num_nonzero_signed)]
+nonzero_integers! {
+    NonZeroI8,
+    NonZeroI16,
+    NonZeroI32,
+    NonZeroI64,
+    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>
@@ -578,7 +616,7 @@ impl Serialize for SystemTime {
         use super::SerializeStruct;
         let duration_since_epoch = self
             .duration_since(UNIX_EPOCH)
-            .expect("SystemTime must be later than 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()));
@@ -595,7 +633,7 @@ impl Serialize for SystemTime {
 #[cfg(feature = "std")]
 macro_rules! serialize_display_bounded_length {
     ($value:expr, $max:expr, $serializer:expr) => {{
-        let mut buffer: [u8; $max] = unsafe { mem::uninitialized() };
+        let mut buffer = [0u8; $max];
         let remaining_len = {
             let mut remaining = &mut buffer[..];
             write!(remaining, "{}", $value).unwrap();
@@ -607,7 +645,7 @@ macro_rules! serialize_display_bounded_length {
         // 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 = unsafe { str::from_utf8_unchecked(written) };
+        let written_str = str::from_utf8(written).expect("must be valid UTF-8");
         $serializer.serialize_str(written_str)
     }};
 }
@@ -799,3 +837,47 @@ where
         self.0.serialize(serializer)
     }
 }
+
+#[cfg(core_reverse)]
+impl<T> Serialize for Reverse<T>
+where
+    T: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.0.serialize(serializer)
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(all(feature = "std", std_atomic))]
+macro_rules! atomic_impl {
+    ($($ty:ident)*) => {
+        $(
+            impl Serialize for $ty {
+                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+                where
+                    S: Serializer,
+                {
+                    self.load(Ordering::SeqCst).serialize(serializer)
+                }
+            }
+        )*
+    }
+}
+
+#[cfg(all(feature = "std", std_atomic))]
+atomic_impl! {
+    AtomicBool
+    AtomicI8 AtomicI16 AtomicI32 AtomicIsize
+    AtomicU8 AtomicU16 AtomicU32 AtomicUsize
+}
+
+#[cfg(all(feature = "std", std_atomic64))]
+atomic_impl! {
+    AtomicI64 AtomicU64
+}

serde/src/ser/impossible.rs

@@ -15,10 +15,7 @@ use ser::{
 /// [`SerializeTuple`], [`SerializeTupleStruct`], [`SerializeTupleVariant`],
 /// [`SerializeMap`], [`SerializeStruct`], and [`SerializeStructVariant`].
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde;
-/// #
+/// ```edition2018
 /// # use serde::ser::{Serializer, Impossible};
 /// # use serde::private::ser::Error;
 /// #
@@ -44,14 +41,12 @@ use ser::{
 ///     }
 ///
 ///     /* other Serializer methods */
-/// #     __serialize_unimplemented! {
+/// #     serde::__serialize_unimplemented! {
 /// #         bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str bytes none some
 /// #         unit unit_struct unit_variant newtype_struct newtype_variant
 /// #         tuple tuple_struct tuple_variant map struct struct_variant
 /// #     }
 /// }
-/// #
-/// # fn main() {}
 /// ```
 ///
 /// [`Serializer`]: trait.Serializer.html

serde/src/ser/mod.rs

@@ -56,13 +56,13 @@
 //!    - PhantomData\<T\>
 //!  - **Wrapper types**:
 //!    - Box\<T\>
-//!    - Rc\<T\>
-//!    - Arc\<T\>
 //!    - Cow\<'a, T\>
 //!    - Cell\<T\>
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
+//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -84,6 +84,7 @@
 //!    - PathBuf
 //!    - Range\<T\>
 //!    - RangeInclusive\<T\>
+//!    - Bound\<T\>
 //!    - num::NonZero*
 //!    - `!` *(unstable)*
 //!  - **Net types**:
@@ -108,11 +109,19 @@
 
 use lib::*;
 
+mod fmt;
 mod impls;
 mod impossible;
 
 pub use self::impossible::Impossible;
 
+#[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;
+
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! declare_error_trait {
@@ -137,7 +146,7 @@ macro_rules! declare_error_trait {
             /// For example, a filesystem [`Path`] may refuse to serialize
             /// itself if it contains invalid UTF-8 data.
             ///
-            /// ```rust
+            /// ```edition2018
             /// # struct Path;
             /// #
             /// # impl Path {
@@ -171,7 +180,7 @@ macro_rules! declare_error_trait {
 }
 
 #[cfg(feature = "std")]
-declare_error_trait!(Error: Sized + error::Error);
+declare_error_trait!(Error: Sized + StdError);
 
 #[cfg(not(feature = "std"))]
 declare_error_trait!(Error: Sized + Debug + Display);
@@ -210,7 +219,7 @@ pub trait Serialize {
     /// See the [Implementing `Serialize`] section of the manual for more
     /// information about how to implement this method.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeStruct, Serializer};
     ///
     /// struct Person {
@@ -377,13 +386,10 @@ pub trait Serializer: Sized {
 
     /// Serialize a `bool` value.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for bool {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -393,8 +399,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_bool(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error>;
 
@@ -404,13 +408,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `i64` and
     /// forward to `serialize_i64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for i8 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -420,8 +421,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_i8(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error>;
 
@@ -431,13 +430,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `i64` and
     /// forward to `serialize_i64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for i16 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -447,8 +443,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_i16(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error>;
 
@@ -458,13 +452,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `i64` and
     /// forward to `serialize_i64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for i32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -474,20 +465,15 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_i32(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize an `i64` value.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for i64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -497,21 +483,16 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_i64(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>;
 
     serde_if_integer128! {
         /// Serialize an `i128` value.
         ///
-        /// ```rust
-        /// # #[macro_use]
-        /// # extern crate serde;
-        /// #
+        /// ```edition2018
         /// # use serde::Serializer;
         /// #
-        /// # __private_serialize!();
+        /// # serde::__private_serialize!();
         /// #
         /// impl Serialize for i128 {
         ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -521,8 +502,6 @@ pub trait Serializer: Sized {
         ///         serializer.serialize_i128(*self)
         ///     }
         /// }
-        /// #
-        /// # fn main() {}
         /// ```
         ///
         /// This method is available only on Rust compiler versions >=1.26. The
@@ -539,13 +518,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `u64` and
     /// forward to `serialize_u64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for u8 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -555,8 +531,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_u8(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error>;
 
@@ -566,13 +540,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `u64` and
     /// forward to `serialize_u64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for u16 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -582,8 +553,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_u16(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error>;
 
@@ -593,13 +562,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `u64` and
     /// forward to `serialize_u64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for u32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -609,20 +575,15 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_u32(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize a `u64` value.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for u64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -632,21 +593,16 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_u64(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>;
 
     serde_if_integer128! {
         /// Serialize a `u128` value.
         ///
-        /// ```rust
-        /// # #[macro_use]
-        /// # extern crate serde;
-        /// #
+        /// ```edition2018
         /// # use serde::Serializer;
         /// #
-        /// # __private_serialize!();
+        /// # serde::__private_serialize!();
         /// #
         /// impl Serialize for u128 {
         ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -656,8 +612,6 @@ pub trait Serializer: Sized {
         ///         serializer.serialize_u128(*self)
         ///     }
         /// }
-        /// #
-        /// # fn main() {}
         /// ```
         ///
         /// This method is available only on Rust compiler versions >=1.26. The
@@ -674,13 +628,10 @@ pub trait Serializer: Sized {
     /// reasonable implementation would be to cast the value to `f64` and
     /// forward to `serialize_f64`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for f32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -690,20 +641,15 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_f32(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize an `f64` value.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for f64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -713,8 +659,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_f64(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error>;
 
@@ -723,13 +667,10 @@ 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`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for char {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -739,20 +680,15 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_char(*self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize a `&str`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for str {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -762,8 +698,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_str(self)
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error>;
 
@@ -775,10 +709,7 @@ pub trait Serializer: Sized {
     /// `serialize_seq`. If forwarded, the implementation looks usually just
     /// like this:
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::ser::{Serializer, SerializeSeq};
     /// # use serde::private::ser::Error;
     /// #
@@ -796,22 +727,18 @@ pub trait Serializer: Sized {
     ///     seq.end()
     /// }
     /// #
-    /// #     __serialize_unimplemented! {
+    /// #     serde::__serialize_unimplemented! {
     /// #         bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str none some
     /// #         unit unit_struct unit_variant newtype_struct newtype_variant
     /// #         seq tuple tuple_struct tuple_variant map struct struct_variant
     /// #     }
     /// # }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize a [`None`] value.
     ///
-    /// ```rust
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::{Serialize, Serializer};
     /// #
     /// # enum Option<T> {
@@ -819,7 +746,7 @@ pub trait Serializer: Sized {
     /// #     None,
     /// # }
     /// #
-    /// # use Option::{Some, None};
+    /// # use self::Option::{Some, None};
     /// #
     /// impl<T> Serialize for Option<T>
     /// where
@@ -844,9 +771,7 @@ pub trait Serializer: Sized {
 
     /// Serialize a [`Some(T)`] value.
     ///
-    /// ```rust
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::{Serialize, Serializer};
     /// #
     /// # enum Option<T> {
@@ -854,7 +779,7 @@ pub trait Serializer: Sized {
     /// #     None,
     /// # }
     /// #
-    /// # use Option::{Some, None};
+    /// # use self::Option::{Some, None};
     /// #
     /// impl<T> Serialize for Option<T>
     /// where
@@ -881,13 +806,10 @@ pub trait Serializer: Sized {
 
     /// Serialize a `()` value.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde;
-    /// #
+    /// ```edition2018
     /// # use serde::Serializer;
     /// #
-    /// # __private_serialize!();
+    /// # serde::__private_serialize!();
     /// #
     /// impl Serialize for () {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -897,8 +819,6 @@ pub trait Serializer: Sized {
     ///         serializer.serialize_unit()
     ///     }
     /// }
-    /// #
-    /// # fn main() {}
     /// ```
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error>;
 
@@ -906,7 +826,7 @@ pub trait Serializer: Sized {
     ///
     /// A reasonable implementation would be to forward to `serialize_unit`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     ///
     /// struct Nothing;
@@ -928,7 +848,7 @@ pub trait Serializer: Sized {
     /// this variant within the enum, and the `variant` is the name of the
     /// variant.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     ///
     /// enum E {
@@ -961,7 +881,7 @@ pub trait Serializer: Sized {
     /// wrappers around the data they contain. A reasonable implementation would
     /// be to forward to `value.serialize(self)`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     ///
     /// struct Millimeters(u8);
@@ -989,7 +909,7 @@ 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.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     ///
     /// enum E {
@@ -1027,7 +947,7 @@ pub trait Serializer: Sized {
     /// not be computable before the sequence is iterated. Some serializers only
     /// support sequences whose length is known up front.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use std::marker::PhantomData;
     /// #
     /// # struct Vec<T>(PhantomData<T>);
@@ -1072,7 +992,7 @@ pub trait Serializer: Sized {
     /// This call must be followed by zero or more calls to `serialize_element`,
     /// then a call to `end`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, Serializer, SerializeTuple};
     ///
     /// # mod fool {
@@ -1102,7 +1022,7 @@ pub trait Serializer: Sized {
     /// }
     /// ```
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeTuple, Serializer};
     ///
     /// const VRAM_SIZE: usize = 386;
@@ -1130,7 +1050,7 @@ 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.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
     ///
     /// struct Rgb(u8, u8, u8);
@@ -1162,7 +1082,7 @@ 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.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeTupleVariant, Serializer};
     ///
     /// enum E {
@@ -1208,7 +1128,7 @@ pub trait Serializer: Sized {
     /// be computable before the map is iterated. Some serializers only support
     /// maps whose length is known up front.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use std::marker::PhantomData;
     /// #
     /// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>);
@@ -1256,7 +1176,7 @@ pub trait Serializer: Sized {
     /// The `name` is the name of the struct and the `len` is the number of
     /// data fields that will be serialized.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeStruct, Serializer};
     ///
     /// struct Rgb {
@@ -1292,7 +1212,7 @@ 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.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
     ///
     /// enum E {
@@ -1334,7 +1254,7 @@ pub trait Serializer: Sized {
     /// using [`serialize_seq`]. Implementors should not need to override this
     /// method.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     ///
     /// struct SecretlyOneHigher {
@@ -1358,7 +1278,7 @@ pub trait Serializer: Sized {
         <I as IntoIterator>::Item: Serialize,
     {
         let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_seq(iter.len_hint()));
+        let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter)));
         for item in iter {
             try!(serializer.serialize_element(&item));
         }
@@ -1371,7 +1291,7 @@ pub trait Serializer: Sized {
     /// using [`serialize_map`]. Implementors should not need to override this
     /// method.
     ///
-    /// ```rust
+    /// ```edition2018
     /// use serde::{Serialize, Serializer};
     /// use std::collections::BTreeSet;
     ///
@@ -1398,7 +1318,7 @@ pub trait Serializer: Sized {
         I: IntoIterator<Item = (K, V)>,
     {
         let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_map(iter.len_hint()));
+        let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter)));
         for (key, value) in iter {
             try!(serializer.serialize_entry(&key, &value));
         }
@@ -1411,7 +1331,7 @@ pub trait Serializer: Sized {
     /// delegates to [`serialize_str`]. Serializers are encouraged to provide a
     /// more efficient implementation if possible.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # struct DateTime;
     /// #
     /// # impl DateTime {
@@ -1440,10 +1360,7 @@ pub trait Serializer: Sized {
     where
         T: Display,
     {
-        use lib::fmt::Write;
-        let mut string = String::new();
-        write!(string, "{}", value).unwrap();
-        self.serialize_str(&string)
+        self.serialize_str(&value.to_string())
     }
 
     /// Serialize a string produced by an implementation of `Display`.
@@ -1452,7 +1369,7 @@ pub trait Serializer: Sized {
     /// of this method. If no more sensible behavior is possible, the
     /// implementation is expected to return an error.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # struct DateTime;
     /// #
     /// # impl DateTime {
@@ -1487,7 +1404,7 @@ pub trait Serializer: Sized {
     /// human-readable one and binary formats like Bincode will prefer the
     /// compact one.
     ///
-    /// ```
+    /// ```edition2018
     /// # use std::fmt::{self, Display};
     /// #
     /// # struct Timestamp;
@@ -1536,7 +1453,7 @@ pub trait Serializer: Sized {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::marker::PhantomData;
 /// #
 /// # struct Vec<T>(PhantomData<T>);
@@ -1600,7 +1517,7 @@ pub trait SerializeSeq {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// use serde::ser::{Serialize, Serializer, SerializeTuple};
 ///
 /// # mod fool {
@@ -1630,7 +1547,7 @@ pub trait SerializeSeq {
 /// }
 /// ```
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::marker::PhantomData;
 /// #
 /// # struct Array<T>(PhantomData<T>);
@@ -1700,7 +1617,7 @@ pub trait SerializeTuple {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
 ///
 /// struct Rgb(u8, u8, u8);
@@ -1745,7 +1662,7 @@ pub trait SerializeTupleStruct {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// use serde::ser::{Serialize, SerializeTupleVariant, Serializer};
 ///
 /// enum E {
@@ -1803,7 +1720,7 @@ pub trait SerializeTupleVariant {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// # use std::marker::PhantomData;
 /// #
 /// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>);
@@ -1914,7 +1831,7 @@ pub trait SerializeMap {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// use serde::ser::{Serialize, SerializeStruct, Serializer};
 ///
 /// struct Rgb {
@@ -1974,7 +1891,7 @@ pub trait SerializeStruct {
 ///
 /// # Example use
 ///
-/// ```rust
+/// ```edition2018
 /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
 ///
 /// enum E {
@@ -2036,35 +1953,6 @@ pub trait SerializeStructVariant {
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
-trait LenHint: Iterator {
-    fn len_hint(&self) -> Option<usize>;
-}
-
-impl<I> LenHint for I
-where
-    I: Iterator,
-{
-    #[cfg(not(feature = "unstable"))]
-    fn len_hint(&self) -> Option<usize> {
-        iterator_len_hint(self)
-    }
-
-    #[cfg(feature = "unstable")]
-    default fn len_hint(&self) -> Option<usize> {
-        iterator_len_hint(self)
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl<I> LenHint for I
-where
-    I: ExactSizeIterator,
-{
-    fn len_hint(&self) -> Option<usize> {
-        Some(self.len())
-    }
-}
-
 fn iterator_len_hint<I>(iter: &I) -> Option<usize>
 where
     I: Iterator,

serde/src/std_error.rs

@@ -0,0 +1,48 @@
+use 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.
+///
+/// Serde's error traits [`serde::ser::Error`] and [`serde::de::Error`] require
+/// [`std::error::Error`] as a supertrait, but only when Serde is built with
+/// "std" enabled. Data formats that don't care about no\_std support should
+/// generally provide their error types with a `std::error::Error` impl
+/// directly:
+///
+/// ```edition2018
+/// #[derive(Debug)]
+/// struct MySerError {...}
+///
+/// impl serde::ser::Error for MySerError {...}
+///
+/// impl std::fmt::Display for MySerError {...}
+///
+/// // We don't support no_std!
+/// impl std::error::Error for MySerError {}
+/// ```
+///
+/// Data formats that *do* support no\_std may either have a "std" feature of
+/// their own:
+///
+/// ```toml
+/// [features]
+/// std = ["serde/std"]
+/// ```
+///
+/// ```edition2018
+/// #[cfg(feature = "std")]
+/// impl std::error::Error for MySerError {}
+/// ```
+///
+/// ... or else provide the std Error impl unconditionally via Serde's
+/// re-export:
+///
+/// ```edition2018
+/// impl serde::ser::StdError for MySerError {}
+/// ```
+pub trait Error: Debug + Display {
+    /// The underlying cause of this error, if any.
+    fn source(&self) -> Option<&(Error + 'static)> {
+        None
+    }
+}

serde_derive/Cargo.toml

@@ -1,19 +1,15 @@
 [package]
 name = "serde_derive"
-version = "1.0.81" # remember to update html_root_url
+version = "1.0.115" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 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"]
 readme = "crates-io.md"
-include = ["Cargo.toml", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
-
-[badges]
-travis-ci = { repository = "serde-rs/serde" }
-appveyor = { repository = "serde-rs/serde" }
+include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [features]
 default = []
@@ -24,9 +20,12 @@ name = "serde_derive"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "0.4"
-quote = "0.6.3"
-syn = { version = "0.15.22", features = ["visit"] }
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "1.0.33", features = ["visit"] }
 
 [dev-dependencies]
 serde = { version = "1.0", path = "../serde" }
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

serde_derive/build.rs

@@ -0,0 +1,30 @@
+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,
+    };
+
+    // 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");
+    }
+}
+
+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()
+}

serde_derive/src/bound.rs

@@ -5,7 +5,7 @@ use syn::punctuated::{Pair, Punctuated};
 use syn::visit::{self, Visit};
 
 use internals::ast::{Container, Data};
-use internals::attr;
+use internals::{attr, ungroup};
 
 use proc_macro2::Span;
 
@@ -17,8 +17,8 @@ pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
         params: generics
             .params
             .iter()
-            .map(|param| match *param {
-                syn::GenericParam::Type(ref param) => syn::GenericParam::Type(syn::TypeParam {
+            .map(|param| match param {
+                syn::GenericParam::Type(param) => syn::GenericParam::Type(syn::TypeParam {
                     eq_token: None,
                     default: None,
                     ..param.clone()
@@ -63,8 +63,8 @@ pub fn with_where_predicates_from_variants(
     generics: &syn::Generics,
     from_variant: fn(&attr::Variant) -> Option<&[syn::WherePredicate]>,
 ) -> syn::Generics {
-    let variants = match cont.data {
-        Data::Enum(ref variants) => variants,
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
         Data::Struct(_, _) => {
             return generics.clone();
         }
@@ -114,8 +114,8 @@ pub fn with_bound(
     }
     impl<'ast> Visit<'ast> for FindTyParams<'ast> {
         fn visit_field(&mut self, field: &'ast syn::Field) {
-            if let syn::Type::Path(ref ty) = field.ty {
-                if let Some(Pair::Punctuated(ref t, _)) = ty.path.segments.first() {
+            if let syn::Type::Path(ty) = ungroup(&field.ty) {
+                if let Some(Pair::Punctuated(t, _)) = ty.path.segments.pairs().next() {
                     if self.all_type_params.contains(&t.ident) {
                         self.associated_type_usage.push(ty);
                     }
@@ -126,7 +126,7 @@ pub fn with_bound(
 
         fn visit_path(&mut self, path: &'ast syn::Path) {
             if let Some(seg) = path.segments.last() {
-                if seg.into_value().ident == "PhantomData" {
+                if seg.ident == "PhantomData" {
                     // Hardcoded exception, because PhantomData<T> implements
                     // Serialize and Deserialize whether or not T implements it.
                     return;
@@ -156,12 +156,12 @@ pub fn with_bound(
         .collect();
 
     let mut visitor = FindTyParams {
-        all_type_params: all_type_params,
+        all_type_params,
         relevant_type_params: HashSet::new(),
         associated_type_usage: Vec::new(),
     };
-    match cont.data {
-        Data::Enum(ref variants) => {
+    match &cont.data {
+        Data::Enum(variants) => {
             for variant in variants.iter() {
                 let relevant_fields = variant
                     .fields
@@ -172,7 +172,7 @@ pub fn with_bound(
                 }
             }
         }
-        Data::Struct(_, ref fields) => {
+        Data::Struct(_, fields) => {
             for field in fields.iter().filter(|field| filter(&field.attrs, None)) {
                 visitor.visit_field(field.original);
             }
@@ -255,11 +255,11 @@ pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Gen
     let params = Some(syn::GenericParam::Lifetime(def))
         .into_iter()
         .chain(generics.params.iter().cloned().map(|mut param| {
-            match param {
-                syn::GenericParam::Lifetime(ref mut param) => {
+            match &mut param {
+                syn::GenericParam::Lifetime(param) => {
                     param.bounds.push(bound.clone());
                 }
-                syn::GenericParam::Type(ref mut param) => {
+                syn::GenericParam::Type(param) => {
                     param
                         .bounds
                         .push(syn::TypeParamBound::Lifetime(bound.clone()));
@@ -271,7 +271,7 @@ pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Gen
         .collect();
 
     syn::Generics {
-        params: params,
+        params,
         ..generics.clone()
     }
 }
@@ -291,14 +291,14 @@ fn type_of_item(cont: &Container) -> syn::Type {
                             .generics
                             .params
                             .iter()
-                            .map(|param| match *param {
-                                syn::GenericParam::Type(ref param) => {
+                            .map(|param| match param {
+                                syn::GenericParam::Type(param) => {
                                     syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
                                         qself: None,
                                         path: param.ident.clone().into(),
                                     }))
                                 }
-                                syn::GenericParam::Lifetime(ref param) => {
+                                syn::GenericParam::Lifetime(param) => {
                                     syn::GenericArgument::Lifetime(param.lifetime.clone())
                                 }
                                 syn::GenericParam::Const(_) => {

serde_derive/src/dummy.rs

@@ -0,0 +1,48 @@
+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))
+    };
+
+    let use_serde = match serde_path {
+        Some(path) => quote! {
+            use #path as _serde;
+        },
+        None => quote! {
+            #[allow(rust_2018_idioms, clippy::useless_attribute)]
+            extern crate serde as _serde;
+        },
+    };
+
+    quote! {
+        #[doc(hidden)]
+        #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+        const #dummy_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()
+}

serde_derive/src/fragment.rs

@@ -27,9 +27,9 @@ macro_rules! quote_block {
 pub struct Expr(pub Fragment);
 impl ToTokens for Expr {
     fn to_tokens(&self, out: &mut TokenStream) {
-        match self.0 {
-            Fragment::Expr(ref expr) => expr.to_tokens(out),
-            Fragment::Block(ref block) => {
+        match &self.0 {
+            Fragment::Expr(expr) => expr.to_tokens(out),
+            Fragment::Block(block) => {
                 token::Brace::default().surround(out, |out| block.to_tokens(out));
             }
         }
@@ -40,9 +40,9 @@ impl ToTokens for Expr {
 pub struct Stmts(pub Fragment);
 impl ToTokens for Stmts {
     fn to_tokens(&self, out: &mut TokenStream) {
-        match self.0 {
-            Fragment::Expr(ref expr) => expr.to_tokens(out),
-            Fragment::Block(ref block) => block.to_tokens(out),
+        match &self.0 {
+            Fragment::Expr(expr) => expr.to_tokens(out),
+            Fragment::Block(block) => block.to_tokens(out),
         }
     }
 }
@@ -52,12 +52,12 @@ impl ToTokens for Stmts {
 pub struct Match(pub Fragment);
 impl ToTokens for Match {
     fn to_tokens(&self, out: &mut TokenStream) {
-        match self.0 {
-            Fragment::Expr(ref expr) => {
+        match &self.0 {
+            Fragment::Expr(expr) => {
                 expr.to_tokens(out);
                 <Token![,]>::default().to_tokens(out);
             }
-            Fragment::Block(ref block) => {
+            Fragment::Block(block) => {
                 token::Brace::default().surround(out, |out| block.to_tokens(out));
             }
         }
@@ -66,9 +66,9 @@ impl ToTokens for Match {
 
 impl AsRef<TokenStream> for Fragment {
     fn as_ref(&self) -> &TokenStream {
-        match *self {
-            Fragment::Expr(ref expr) => expr,
-            Fragment::Block(ref block) => block,
+        match self {
+            Fragment::Expr(expr) => expr,
+            Fragment::Block(block) => block,
         }
     }
 }

serde_derive/src/internals/ast.rs

@@ -60,14 +60,16 @@ pub enum Style {
 
 impl<'a> Container<'a> {
     /// Convert the raw Syn ast into a parsed container object, collecting errors in `cx`.
-    pub fn from_ast(cx: &Ctxt, item: &'a syn::DeriveInput, derive: Derive) -> Option<Container<'a>> {
+    pub fn from_ast(
+        cx: &Ctxt,
+        item: &'a syn::DeriveInput,
+        derive: Derive,
+    ) -> Option<Container<'a>> {
         let mut attrs = attr::Container::from_ast(cx, item);
 
-        let mut data = match item.data {
-            syn::Data::Enum(ref data) => {
-                Data::Enum(enum_from_ast(cx, &data.variants, attrs.default()))
-            }
-            syn::Data::Struct(ref data) => {
+        let mut data = match &item.data {
+            syn::Data::Enum(data) => Data::Enum(enum_from_ast(cx, &data.variants, attrs.default())),
+            syn::Data::Struct(data) => {
                 let (style, fields) = struct_from_ast(cx, &data.fields, None, attrs.default());
                 Data::Struct(style, fields)
             }
@@ -78,24 +80,26 @@ impl<'a> Container<'a> {
         };
 
         let mut has_flatten = false;
-        match data {
-            Data::Enum(ref mut variants) => {
+        match &mut data {
+            Data::Enum(variants) => {
                 for variant in variants {
-                    variant.attrs.rename_by_rule(attrs.rename_all());
+                    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_rule(variant.attrs.rename_all());
+                        field
+                            .attrs
+                            .rename_by_rules(variant.attrs.rename_all_rules());
                     }
                 }
             }
-            Data::Struct(_, ref mut fields) => {
+            Data::Struct(_, fields) => {
                 for field in fields {
                     if field.attrs.flatten() {
                         has_flatten = true;
                     }
-                    field.attrs.rename_by_rule(attrs.rename_all());
+                    field.attrs.rename_by_rules(attrs.rename_all_rules());
                 }
             }
         }
@@ -106,8 +110,8 @@ impl<'a> Container<'a> {
 
         let mut item = Container {
             ident: item.ident.clone(),
-            attrs: attrs,
-            data: data,
+            attrs,
+            data,
             generics: &item.generics,
             original: item,
         };
@@ -118,11 +122,11 @@ impl<'a> Container<'a> {
 
 impl<'a> Data<'a> {
     pub fn all_fields(&'a self) -> Box<Iterator<Item = &'a Field<'a>> + 'a> {
-        match *self {
-            Data::Enum(ref variants) => {
+        match self {
+            Data::Enum(variants) => {
                 Box::new(variants.iter().flat_map(|variant| variant.fields.iter()))
             }
-            Data::Struct(_, ref fields) => Box::new(fields.iter()),
+            Data::Struct(_, fields) => Box::new(fields.iter()),
         }
     }
 
@@ -144,9 +148,9 @@ fn enum_from_ast<'a>(
                 struct_from_ast(cx, &variant.fields, Some(&attrs), container_default);
             Variant {
                 ident: variant.ident.clone(),
-                attrs: attrs,
-                style: style,
-                fields: fields,
+                attrs,
+                style,
+                fields,
                 original: variant,
             }
         })
@@ -159,16 +163,16 @@ fn struct_from_ast<'a>(
     attrs: Option<&attr::Variant>,
     container_default: &attr::Default,
 ) -> (Style, Vec<Field<'a>>) {
-    match *fields {
-        syn::Fields::Named(ref fields) => (
+    match fields {
+        syn::Fields::Named(fields) => (
             Style::Struct,
             fields_from_ast(cx, &fields.named, attrs, container_default),
         ),
-        syn::Fields::Unnamed(ref fields) if fields.unnamed.len() == 1 => (
+        syn::Fields::Unnamed(fields) if fields.unnamed.len() == 1 => (
             Style::Newtype,
             fields_from_ast(cx, &fields.unnamed, attrs, container_default),
         ),
-        syn::Fields::Unnamed(ref fields) => (
+        syn::Fields::Unnamed(fields) => (
             Style::Tuple,
             fields_from_ast(cx, &fields.unnamed, attrs, container_default),
         ),
@@ -186,8 +190,8 @@ fn fields_from_ast<'a>(
         .iter()
         .enumerate()
         .map(|(i, field)| Field {
-            member: match field.ident {
-                Some(ref ident) => syn::Member::Named(ident.clone()),
+            member: match &field.ident {
+                Some(ident) => syn::Member::Named(ident.clone()),
                 None => syn::Member::Unnamed(i.into()),
             },
             attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),

serde_derive/src/internals/case.rs

@@ -10,7 +10,7 @@ use std::str::FromStr;
 use self::RenameRule::*;
 
 /// The different possible ways to change case of fields in a struct, or variants in an enum.
-#[derive(PartialEq)]
+#[derive(Copy, Clone, PartialEq)]
 pub enum RenameRule {
     /// Don't apply a default rename rule.
     None,

serde_derive/src/internals/check.rs

@@ -1,6 +1,6 @@
 use internals::ast::{Container, Data, Field, Style};
-use internals::attr::{EnumTag, Identifier};
-use internals::{Ctxt, Derive};
+use internals::attr::{Identifier, TagType};
+use internals::{ungroup, Ctxt, Derive};
 use syn::{Member, Type};
 
 /// Cross-cutting checks that require looking at more than a single attrs
@@ -13,6 +13,7 @@ pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
     check_internal_tag_field_name_conflict(cx, cont);
     check_adjacent_tag_conflict(cx, cont);
     check_transparent(cx, cont, derive);
+    check_from_and_try_from(cx, cont);
 }
 
 /// Getters are only allowed inside structs (not enums) with the `remote`
@@ -31,8 +32,7 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
             if cont.data.has_getter() && cont.attrs.remote().is_none() {
                 cx.error_spanned_by(
                     cont.original,
-                    "#[serde(getter = \"...\")] can only be used in structs \
-                     that have #[serde(remote = \"...\")]",
+                    "#[serde(getter = \"...\")] can only be used in structs that have #[serde(remote = \"...\")]",
                 );
             }
         }
@@ -41,17 +41,17 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
 
 /// Flattening has some restrictions we can test.
 fn check_flatten(cx: &Ctxt, cont: &Container) {
-    match cont.data {
-        Data::Enum(ref variants) => {
+    match &cont.data {
+        Data::Enum(variants) => {
             for variant in variants {
                 for field in &variant.fields {
                     check_flatten_field(cx, variant.style, field);
                 }
             }
         }
-        Data::Struct(style, ref fields) => {
+        Data::Struct(style, fields) => {
             for field in fields {
-                check_flatten_field(cx, style, field);
+                check_flatten_field(cx, *style, field);
             }
         }
     }
@@ -76,25 +76,6 @@ fn check_flatten_field(cx: &Ctxt, style: Style, field: &Field) {
         }
         _ => {}
     }
-    if field.attrs.skip_serializing() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_serializing)]",
-        );
-    } else if field.attrs.skip_serializing_if().is_some() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_serializing_if = \"...\")]",
-        );
-    } else if field.attrs.skip_deserializing() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_deserializing)]",
-        );
-    }
 }
 
 /// The `other` attribute must be used at most once and it must be the last
@@ -104,8 +85,8 @@ fn check_flatten_field(cx: &Ctxt, style: Style, field: &Field) {
 /// `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(ref variants) => variants,
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
         Data::Struct(_, _) => {
             return;
         }
@@ -127,7 +108,7 @@ fn check_identifier(cx: &Ctxt, cont: &Container) {
             }
 
             // Variant with `other` attribute cannot appear in untagged enum
-            (_, Identifier::No, true, &EnumTag::None) => {
+            (_, Identifier::No, true, &TagType::None) => {
                 cx.error_spanned_by(
                     variant.original,
                     "#[serde(other)] cannot appear on untagged enum",
@@ -188,8 +169,8 @@ fn check_identifier(cx: &Ctxt, cont: &Container) {
 /// 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(ref variants) => variants,
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
         Data::Struct(_, _) => {
             return;
         }
@@ -198,52 +179,62 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
     for variant in variants.iter() {
         if variant.attrs.serialize_with().is_some() {
             if variant.attrs.skip_serializing() {
-                cx.error_spanned_by(variant.original, format!(
-                    "variant `{}` cannot have both #[serde(serialize_with)] and \
-                     #[serde(skip_serializing)]",
-                    variant.ident
-                ));
+                cx.error_spanned_by(
+                    variant.original,
+                    format!(
+                        "variant `{}` cannot have both #[serde(serialize_with)] and #[serde(skip_serializing)]",
+                        variant.ident
+                    ),
+                );
             }
 
             for field in &variant.fields {
                 let member = member_message(&field.member);
 
                 if field.attrs.skip_serializing() {
-                    cx.error_spanned_by(variant.original, format!(
-                        "variant `{}` cannot have both #[serde(serialize_with)] and \
-                         a field {} marked with #[serde(skip_serializing)]",
-                        variant.ident, member
-                    ));
+                    cx.error_spanned_by(
+                        variant.original,
+                        format!(
+                            "variant `{}` cannot have both #[serde(serialize_with)] and a field {} marked with #[serde(skip_serializing)]",
+                            variant.ident, member
+                        ),
+                    );
                 }
 
                 if field.attrs.skip_serializing_if().is_some() {
-                    cx.error_spanned_by(variant.original, format!(
-                        "variant `{}` cannot have both #[serde(serialize_with)] and \
-                         a field {} marked with #[serde(skip_serializing_if)]",
-                        variant.ident, member
-                    ));
+                    cx.error_spanned_by(
+                        variant.original,
+                        format!(
+                            "variant `{}` cannot have both #[serde(serialize_with)] and a field {} marked with #[serde(skip_serializing_if)]",
+                            variant.ident, member
+                        ),
+                    );
                 }
             }
         }
 
         if variant.attrs.deserialize_with().is_some() {
             if variant.attrs.skip_deserializing() {
-                cx.error_spanned_by(variant.original, format!(
-                    "variant `{}` cannot have both #[serde(deserialize_with)] and \
-                     #[serde(skip_deserializing)]",
-                    variant.ident
-                ));
+                cx.error_spanned_by(
+                    variant.original,
+                    format!(
+                        "variant `{}` cannot have both #[serde(deserialize_with)] and #[serde(skip_deserializing)]",
+                        variant.ident
+                    ),
+                );
             }
 
             for field in &variant.fields {
                 if field.attrs.skip_deserializing() {
                     let member = member_message(&field.member);
 
-                    cx.error_spanned_by(variant.original, format!(
-                        "variant `{}` cannot have both #[serde(deserialize_with)] \
-                         and a field {} marked with #[serde(skip_deserializing)]",
-                        variant.ident, member
-                    ));
+                    cx.error_spanned_by(
+                        variant.original,
+                        format!(
+                            "variant `{}` cannot have both #[serde(deserialize_with)] and a field {} marked with #[serde(skip_deserializing)]",
+                            variant.ident, member
+                        ),
+                    );
                 }
             }
         }
@@ -255,20 +246,22 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
 /// 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(ref variants) => variants,
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
         Data::Struct(_, _) => return,
     };
 
-    let tag = match *cont.attrs.tag() {
-        EnumTag::Internal { ref tag } => tag.as_str(),
-        EnumTag::External | EnumTag::Adjacent { .. } | EnumTag::None => return,
+    let tag = match cont.attrs.tag() {
+        TagType::Internal { tag } => tag.as_str(),
+        TagType::External | TagType::Adjacent { .. } | TagType::None => return,
     };
 
-    let diagnose_conflict = || cx.error_spanned_by(
-        cont.original,
-        format!("variant field name `{}` conflicts with internal tag", tag),
-    );
+    let diagnose_conflict = || {
+        cx.error_spanned_by(
+            cont.original,
+            format!("variant field name `{}` conflicts with internal tag", tag),
+        )
+    };
 
     for variant in variants {
         match variant.style {
@@ -278,12 +271,18 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
                     let check_de = !field.attrs.skip_deserializing();
                     let name = field.attrs.name();
                     let ser_name = name.serialize_name();
-                    let de_name = name.deserialize_name();
 
-                    if check_ser && ser_name == tag || check_de && de_name == tag {
+                    if check_ser && ser_name == tag {
                         diagnose_conflict();
                         return;
                     }
+
+                    for de_name in field.attrs.aliases() {
+                        if check_de && de_name == tag {
+                            diagnose_conflict();
+                            return;
+                        }
+                    }
                 }
             }
             Style::Unit | Style::Newtype | Style::Tuple => {}
@@ -294,19 +293,19 @@ 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.
 fn check_adjacent_tag_conflict(cx: &Ctxt, cont: &Container) {
-    let (type_tag, content_tag) = match *cont.attrs.tag() {
-        EnumTag::Adjacent {
-            ref tag,
-            ref content,
-        } => (tag, content),
-        EnumTag::Internal { .. } | EnumTag::External | EnumTag::None => return,
+    let (type_tag, content_tag) = match cont.attrs.tag() {
+        TagType::Adjacent { tag, content } => (tag, content),
+        TagType::Internal { .. } | TagType::External | TagType::None => return,
     };
 
     if type_tag == content_tag {
-        cx.error_spanned_by(cont.original, format!(
-            "enum tags `{}` for type and content conflict with each other",
-            type_tag
-        ));
+        cx.error_spanned_by(
+            cont.original,
+            format!(
+                "enum tags `{}` for type and content conflict with each other",
+                type_tag
+            ),
+        );
     }
 }
 
@@ -323,6 +322,13 @@ fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
         );
     }
 
+    if cont.attrs.type_try_from().is_some() {
+        cx.error_spanned_by(
+            cont.original,
+            "#[serde(transparent)] is not allowed with #[serde(try_from = \"...\")]",
+        );
+    }
+
     if cont.attrs.type_into().is_some() {
         cx.error_spanned_by(
             cont.original,
@@ -330,7 +336,7 @@ fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
         );
     }
 
-    let fields = match cont.data {
+    let fields = match &mut cont.data {
         Data::Enum(_) => {
             cx.error_spanned_by(
                 cont.original,
@@ -345,7 +351,7 @@ fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
             );
             return;
         }
-        Data::Struct(_, ref mut fields) => fields,
+        Data::Struct(_, fields) => fields,
     };
 
     let mut transparent_field = None;
@@ -383,16 +389,16 @@ fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
 }
 
 fn member_message(member: &Member) -> String {
-    match *member {
-        Member::Named(ref ident) => format!("`{}`", ident),
-        Member::Unnamed(ref i) => format!("#{}", i.index),
+    match member {
+        Member::Named(ident) => format!("`{}`", ident),
+        Member::Unnamed(i) => format!("#{}", i.index),
     }
 }
 
 fn allow_transparent(field: &Field, derive: Derive) -> bool {
-    if let Type::Path(ref ty) = *field.ty {
+    if let Type::Path(ty) = ungroup(&field.ty) {
         if let Some(seg) = ty.path.segments.last() {
-            if seg.into_value().ident == "PhantomData" {
+            if seg.ident == "PhantomData" {
                 return false;
             }
         }
@@ -403,3 +409,12 @@ fn allow_transparent(field: &Field, derive: Derive) -> bool {
         Derive::Deserialize => !field.attrs.skip_deserializing() && field.attrs.default().is_none(),
     }
 }
+
+fn check_from_and_try_from(cx: &Ctxt, cont: &mut Container) {
+    if cont.attrs.type_from().is_some() && cont.attrs.type_try_from().is_some() {
+        cx.error_spanned_by(
+            cont.original,
+            "#[serde(from = \"...\")] and #[serde(try_from = \"...\")] conflict with each other",
+        );
+    }
+}

serde_derive/src/internals/ctxt.rs

@@ -38,6 +38,11 @@ impl Ctxt {
             .push(syn::Error::new_spanned(obj.into_token_stream(), msg));
     }
 
+    /// Add one of Syn's parse errors.
+    pub fn syn_error(&self, err: syn::Error) {
+        self.errors.borrow_mut().as_mut().unwrap().push(err);
+    }
+
     /// 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();

serde_derive/src/internals/mod.rs

@@ -6,9 +6,19 @@ pub use self::ctxt::Ctxt;
 
 mod case;
 mod check;
+mod symbol;
+
+use syn::Type;
 
 #[derive(Copy, Clone)]
 pub enum Derive {
     Serialize,
     Deserialize,
 }
+
+pub fn ungroup(mut ty: &Type) -> &Type {
+    while let Type::Group(group) = ty {
+        ty = &group.elem;
+    }
+    ty
+}

serde_derive/src/internals/symbol.rs

@@ -0,0 +1,67 @@
+use std::fmt::{self, Display};
+use syn::{Ident, Path};
+
+#[derive(Copy, Clone)]
+pub struct Symbol(&'static str);
+
+pub const ALIAS: Symbol = Symbol("alias");
+pub const BORROW: Symbol = Symbol("borrow");
+pub const BOUND: Symbol = Symbol("bound");
+pub const CONTENT: Symbol = Symbol("content");
+pub const CRATE: Symbol = Symbol("crate");
+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 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 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 SERDE: Symbol = Symbol("serde");
+pub const SERIALIZE: Symbol = Symbol("serialize");
+pub const SERIALIZE_WITH: Symbol = Symbol("serialize_with");
+pub const SKIP: Symbol = Symbol("skip");
+pub const SKIP_DESERIALIZING: Symbol = Symbol("skip_deserializing");
+pub const SKIP_SERIALIZING: Symbol = Symbol("skip_serializing");
+pub const SKIP_SERIALIZING_IF: Symbol = Symbol("skip_serializing_if");
+pub const TAG: Symbol = Symbol("tag");
+pub const TRANSPARENT: Symbol = Symbol("transparent");
+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");
+
+impl PartialEq<Symbol> for Ident {
+    fn eq(&self, word: &Symbol) -> bool {
+        self == word.0
+    }
+}
+
+impl<'a> PartialEq<Symbol> for &'a Ident {
+    fn eq(&self, word: &Symbol) -> bool {
+        *self == word.0
+    }
+}
+
+impl PartialEq<Symbol> for Path {
+    fn eq(&self, word: &Symbol) -> bool {
+        self.is_ident(word.0)
+    }
+}
+
+impl<'a> PartialEq<Symbol> for &'a Path {
+    fn eq(&self, word: &Symbol) -> bool {
+        self.is_ident(word.0)
+    }
+}
+
+impl Display for Symbol {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(self.0)
+    }
+}

serde_derive/src/lib.rs

@@ -1,8 +1,7 @@
 //! This crate provides Serde's two derive macros.
 //!
-//! ```rust
-//! # #[macro_use]
-//! # extern crate serde_derive;
+//! ```edition2018
+//! # use serde_derive::{Serialize, Deserialize};
 //! #
 //! #[derive(Serialize, Deserialize)]
 //! # struct S;
@@ -14,41 +13,43 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.81")]
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
-// Whitelisted clippy lints
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(
-        cyclomatic_complexity,
-        enum_variant_names,
-        needless_pass_by_value,
-        redundant_field_names,
-        too_many_arguments,
-        used_underscore_binding,
-    )
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.115")]
+#![allow(unknown_lints, bare_trait_objects)]
+#![deny(clippy::all, clippy::pedantic)]
+// Ignored clippy lints
+#![allow(
+    clippy::cognitive_complexity,
+    clippy::enum_variant_names,
+    clippy::match_like_matches_macro,
+    clippy::needless_pass_by_value,
+    clippy::too_many_arguments,
+    clippy::trivially_copy_pass_by_ref,
+    clippy::used_underscore_binding,
+    clippy::wildcard_in_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
 )]
-// Whitelisted clippy_pedantic lints
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(
-        cast_possible_truncation,
-        doc_markdown,
-        enum_glob_use,
-        filter_map,
-        indexing_slicing,
-        items_after_statements,
-        match_same_arms,
-        similar_names,
-        single_match_else,
-        stutter,
-        unseparated_literal_suffix,
-        use_self,
-    )
+// Ignored clippy_pedantic lints
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::checked_conversions,
+    clippy::doc_markdown,
+    clippy::enum_glob_use,
+    clippy::filter_map,
+    clippy::indexing_slicing,
+    clippy::items_after_statements,
+    clippy::match_same_arms,
+    clippy::module_name_repetitions,
+    clippy::must_use_candidate,
+    clippy::option_if_let_else,
+    clippy::similar_names,
+    clippy::single_match_else,
+    clippy::struct_excessive_bools,
+    clippy::too_many_lines,
+    clippy::unseparated_literal_suffix,
+    clippy::use_self,
+    clippy::wildcard_imports
 )]
-// The `quote!` macro requires deep recursion.
-#![recursion_limit = "512"]
 
 #[macro_use]
 extern crate quote;
@@ -69,6 +70,7 @@ mod bound;
 mod fragment;
 
 mod de;
+mod dummy;
 mod pretend;
 mod ser;
 mod try;

serde_derive/src/pretend.rs

@@ -52,8 +52,8 @@ fn pretend_fields_used(cont: &Container) -> TokenStream {
     let type_ident = &cont.ident;
     let (_, ty_generics, _) = cont.generics.split_for_impl();
 
-    let patterns = match cont.data {
-        Data::Enum(ref variants) => variants
+    let patterns = match &cont.data {
+        Data::Enum(variants) => variants
             .iter()
             .filter_map(|variant| match variant.style {
                 Style::Struct => {
@@ -64,7 +64,7 @@ fn pretend_fields_used(cont: &Container) -> TokenStream {
                 _ => None,
             })
             .collect::<Vec<_>>(),
-        Data::Struct(Style::Struct, ref fields) => {
+        Data::Struct(Style::Struct, fields) => {
             let pat = struct_pattern(fields);
             vec![quote!(#type_ident #pat)]
         }
@@ -93,8 +93,8 @@ fn pretend_fields_used(cont: &Container) -> TokenStream {
 //     }
 //
 fn pretend_variants_used(cont: &Container) -> TokenStream {
-    let variants = match cont.data {
-        Data::Enum(ref variants) => variants,
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
         Data::Struct(_, _) => {
             return quote!();
         }

serde_derive/src/ser.rs

@@ -3,11 +3,11 @@ use syn::spanned::Spanned;
 use syn::{self, Ident, Index, Member};
 
 use bound;
+use dummy;
 use fragment::{Fragment, Match, Stmts};
 use internals::ast::{Container, Data, Field, Style, Variant};
 use internals::{attr, Ctxt, Derive};
 use pretend;
-use try;
 
 pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream, Vec<syn::Error>> {
     let ctxt = Ctxt::new();
@@ -16,26 +16,22 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
         None => return Err(ctxt.check().unwrap_err()),
     };
     precondition(&ctxt, &cont);
-    try!(ctxt.check());
+    ctxt.check()?;
 
     let ident = &cont.ident;
     let params = Parameters::new(&cont);
     let (impl_generics, ty_generics, where_clause) = params.generics.split_for_impl();
-    let suffix = ident.to_string().trim_left_matches("r#").to_owned();
-    let dummy_const = Ident::new(
-        &format!("_IMPL_SERIALIZE_FOR_{}", suffix),
-        Span::call_site(),
-    );
     let body = Stmts(serialize_body(&cont, &params));
+    let serde = cont.attrs.serde_path();
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
         let vis = &input.vis;
         let used = pretend::pretend_used(&cont);
         quote! {
             impl #impl_generics #ident #ty_generics #where_clause {
-                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> #serde::export::Result<__S::Ok, __S::Error>
                 where
-                    __S: _serde::Serializer,
+                    __S: #serde::Serializer,
                 {
                     #used
                     #body
@@ -45,10 +41,10 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
     } else {
         quote! {
             #[automatically_derived]
-            impl #impl_generics _serde::Serialize for #ident #ty_generics #where_clause {
-                fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+            impl #impl_generics #serde::Serialize for #ident #ty_generics #where_clause {
+                fn serialize<__S>(&self, __serializer: __S) -> #serde::export::Result<__S::Ok, __S::Error>
                 where
-                    __S: _serde::Serializer,
+                    __S: #serde::Serializer,
                 {
                     #body
                 }
@@ -56,19 +52,12 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
         }
     };
 
-    let try_replacement = try::replacement();
-    let generated = quote! {
-        #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-        const #dummy_const: () = {
-            #[allow(unknown_lints)]
-            #[cfg_attr(feature = "cargo-clippy", allow(useless_attribute))]
-            #[allow(rust_2018_idioms)]
-            extern crate serde as _serde;
-            #try_replacement
-            #impl_block
-        };
-    };
-    Ok(generated)
+    Ok(dummy::wrap_in_const(
+        cont.attrs.custom_serde_path(),
+        "SERIALIZE",
+        ident,
+        impl_block,
+    ))
 }
 
 fn precondition(cx: &Ctxt, cont: &Container) {
@@ -98,6 +87,9 @@ struct Parameters {
 
     /// Type has a `serde(remote = "...")` attribute.
     is_remote: bool,
+
+    /// Type has a repr(packed) attribute.
+    is_packed: bool,
 }
 
 impl Parameters {
@@ -114,20 +106,23 @@ impl Parameters {
             None => cont.ident.clone().into(),
         };
 
+        let is_packed = cont.attrs.is_packed();
+
         let generics = build_generics(cont);
 
         Parameters {
-            self_var: self_var,
-            this: this,
-            generics: generics,
-            is_remote: is_remote,
+            self_var,
+            this,
+            generics,
+            is_remote,
+            is_packed,
         }
     }
 
     /// 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().value().ident.to_string()
+        self.this.segments.last().unwrap().ident.to_string()
     }
 }
 
@@ -175,15 +170,13 @@ fn serialize_body(cont: &Container, params: &Parameters) -> Fragment {
     } else if let Some(type_into) = cont.attrs.type_into() {
         serialize_into(params, type_into)
     } else {
-        match cont.data {
-            Data::Enum(ref variants) => serialize_enum(params, variants, &cont.attrs),
-            Data::Struct(Style::Struct, ref fields) => {
-                serialize_struct(params, fields, &cont.attrs)
-            }
-            Data::Struct(Style::Tuple, ref fields) => {
+        match &cont.data {
+            Data::Enum(variants) => serialize_enum(params, variants, &cont.attrs),
+            Data::Struct(Style::Struct, fields) => serialize_struct(params, fields, &cont.attrs),
+            Data::Struct(Style::Tuple, fields) => {
                 serialize_tuple_struct(params, fields, &cont.attrs)
             }
-            Data::Struct(Style::Newtype, ref fields) => {
+            Data::Struct(Style::Newtype, fields) => {
                 serialize_newtype_struct(params, &fields[0], &cont.attrs)
             }
             Data::Struct(Style::Unit, _) => serialize_unit_struct(&cont.attrs),
@@ -192,8 +185,8 @@ fn serialize_body(cont: &Container, params: &Parameters) -> Fragment {
 }
 
 fn serialize_transparent(cont: &Container, params: &Parameters) -> Fragment {
-    let fields = match cont.data {
-        Data::Struct(_, ref fields) => fields,
+    let fields = match &cont.data {
+        Data::Struct(_, fields) => fields,
         Data::Enum(_) => unreachable!(),
     };
 
@@ -206,7 +199,7 @@ fn serialize_transparent(cont: &Container, params: &Parameters) -> Fragment {
         None => {
             let span = transparent_field.original.span();
             quote_spanned!(span=> _serde::Serialize::serialize)
-        },
+        }
     };
 
     quote_block! {
@@ -270,7 +263,7 @@ fn serialize_tuple_struct(
     let mut serialized_fields = fields
         .iter()
         .enumerate()
-        .filter(|&(_, ref field)| !field.attrs.skip_serializing())
+        .filter(|(_, field)| !field.attrs.skip_serializing())
         .peekable();
 
     let let_mut = mut_if(serialized_fields.peek().is_some());
@@ -306,6 +299,19 @@ fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Contai
     }
 }
 
+fn serialize_struct_tag_field(cattrs: &attr::Container, struct_trait: &StructTrait) -> TokenStream {
+    match cattrs.tag() {
+        attr::TagType::Internal { tag } => {
+            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));
+            }
+        }
+        _ => quote! {},
+    }
+}
+
 fn serialize_struct_as_struct(
     params: &Parameters,
     fields: &[Field],
@@ -316,12 +322,15 @@ fn serialize_struct_as_struct(
 
     let type_name = cattrs.name().serialize_name();
 
+    let tag_field = serialize_struct_tag_field(cattrs, &StructTrait::SerializeStruct);
+    let tag_field_exists = !tag_field.is_empty();
+
     let mut serialized_fields = fields
         .iter()
         .filter(|&field| !field.attrs.skip_serializing())
         .peekable();
 
-    let let_mut = mut_if(serialized_fields.peek().is_some());
+    let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
 
     let len = serialized_fields
         .map(|field| match field.attrs.skip_serializing_if() {
@@ -331,10 +340,14 @@ fn serialize_struct_as_struct(
                 quote!(if #path(#field_expr) { 0 } else { 1 })
             }
         })
-        .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+        .fold(
+            quote!(#tag_field_exists as usize),
+            |sum, expr| quote!(#sum + #expr),
+        );
 
     quote_block! {
         let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(__serializer, #type_name, #len));
+        #tag_field
         #(#serialize_fields)*
         _serde::ser::SerializeStruct::end(__serde_state)
     }
@@ -348,12 +361,15 @@ fn serialize_struct_as_map(
     let serialize_fields =
         serialize_struct_visitor(fields, params, false, &StructTrait::SerializeMap);
 
+    let tag_field = serialize_struct_tag_field(cattrs, &StructTrait::SerializeMap);
+    let tag_field_exists = !tag_field.is_empty();
+
     let mut serialized_fields = fields
         .iter()
         .filter(|&field| !field.attrs.skip_serializing())
         .peekable();
 
-    let let_mut = mut_if(serialized_fields.peek().is_some());
+    let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
 
     let len = if cattrs.has_flatten() {
         quote!(_serde::export::None)
@@ -366,12 +382,16 @@ fn serialize_struct_as_map(
                     quote!(if #path(#field_expr) { 0 } else { 1 })
                 }
             })
-            .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+            .fold(
+                quote!(#tag_field_exists as usize),
+                |sum, expr| quote!(#sum + #expr),
+            );
         quote!(_serde::export::Some(#len))
     };
 
     quote_block! {
         let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(__serializer, #len));
+        #tag_field
         #(#serialize_fields)*
         _serde::ser::SerializeMap::end(__serde_state)
     }
@@ -451,18 +471,17 @@ fn serialize_variant(
             }
         };
 
-        let body = Match(match *cattrs.tag() {
-            attr::EnumTag::External => {
+        let body = Match(match cattrs.tag() {
+            attr::TagType::External => {
                 serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
             }
-            attr::EnumTag::Internal { ref tag } => {
+            attr::TagType::Internal { tag } => {
                 serialize_internally_tagged_variant(params, variant, cattrs, tag)
             }
-            attr::EnumTag::Adjacent {
-                ref tag,
-                ref content,
-            } => serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content),
-            attr::EnumTag::None => serialize_untagged_variant(params, variant, cattrs),
+            attr::TagType::Adjacent { tag, content } => {
+                serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content)
+            }
+            attr::TagType::None => serialize_untagged_variant(params, variant, cattrs),
         });
 
         quote! {
@@ -493,7 +512,7 @@ fn serialize_externally_tagged_variant(
         };
     }
 
-    match variant.style {
+    match effective_style(variant) {
         Style::Unit => {
             quote_expr! {
                 _serde::Serializer::serialize_unit_variant(
@@ -525,17 +544,17 @@ fn serialize_externally_tagged_variant(
         }
         Style::Tuple => serialize_tuple_variant(
             TupleVariant::ExternallyTagged {
-                type_name: type_name,
-                variant_index: variant_index,
-                variant_name: variant_name,
+                type_name,
+                variant_index,
+                variant_name,
             },
             params,
             &variant.fields,
         ),
         Style::Struct => serialize_struct_variant(
             StructVariant::ExternallyTagged {
-                variant_index: variant_index,
-                variant_name: variant_name,
+                variant_index,
+                variant_name,
             },
             params,
             &variant.fields,
@@ -570,7 +589,7 @@ fn serialize_internally_tagged_variant(
         };
     }
 
-    match variant.style {
+    match effective_style(variant) {
         Style::Unit => {
             quote_block! {
                 let mut __struct = try!(_serde::Serializer::serialize_struct(
@@ -601,10 +620,7 @@ fn serialize_internally_tagged_variant(
             }
         }
         Style::Struct => serialize_struct_variant(
-            StructVariant::InternallyTagged {
-                tag: tag,
-                variant_name: variant_name,
-            },
+            StructVariant::InternallyTagged { tag, variant_name },
             params,
             &variant.fields,
             &type_name,
@@ -630,7 +646,7 @@ fn serialize_adjacently_tagged_variant(
             _serde::Serialize::serialize(#ser, __serializer)
         }
     } else {
-        match variant.style {
+        match effective_style(variant) {
             Style::Unit => {
                 return quote_block! {
                     let mut __struct = try!(_serde::Serializer::serialize_struct(
@@ -707,6 +723,8 @@ fn serialize_adjacently_tagged_variant(
             where
                 __S: _serde::Serializer,
             {
+                // Elements that have skip_serializing will be unused.
+                #[allow(unused_variables)]
                 let (#(#fields_ident,)*) = self.data;
                 #inner
             }
@@ -737,7 +755,7 @@ fn serialize_untagged_variant(
         };
     }
 
-    match variant.style {
+    match effective_style(variant) {
         Style::Unit => {
             quote_expr! {
                 _serde::Serializer::serialize_unit(__serializer)
@@ -788,7 +806,7 @@ fn serialize_tuple_variant(
     let mut serialized_fields = fields
         .iter()
         .enumerate()
-        .filter(|&(_, ref field)| !field.attrs.skip_serializing())
+        .filter(|(_, field)| !field.attrs.skip_serializing())
         .peekable();
 
     let let_mut = mut_if(serialized_fields.peek().is_some());
@@ -855,9 +873,9 @@ fn serialize_struct_variant<'a>(
     }
 
     let struct_trait = match context {
-        StructVariant::ExternallyTagged { .. } => (StructTrait::SerializeStructVariant),
+        StructVariant::ExternallyTagged { .. } => StructTrait::SerializeStructVariant,
         StructVariant::InternallyTagged { .. } | StructVariant::Untagged => {
-            (StructTrait::SerializeStruct)
+            StructTrait::SerializeStruct
         }
     };
 
@@ -1023,7 +1041,7 @@ fn serialize_tuple_struct_visitor(
     fields
         .iter()
         .enumerate()
-        .filter(|&(_, ref field)| !field.attrs.skip_serializing())
+        .filter(|(_, field)| !field.attrs.skip_serializing())
         .map(|(i, field)| {
             let mut field_expr = if is_enum {
                 let id = Ident::new(&format!("__field{}", i), Span::call_site());
@@ -1147,9 +1165,9 @@ fn wrap_serialize_variant_with(
         .fields
         .iter()
         .map(|field| {
-            let id = match field.member {
-                Member::Named(ref ident) => ident.clone(),
-                Member::Unnamed(ref member) => {
+            let id = match &field.member {
+                Member::Named(ident) => ident.clone(),
+                Member::Unnamed(member) => {
                     Ident::new(&format!("__field{}", member.index), Span::call_site())
                 }
             };
@@ -1226,9 +1244,19 @@ fn mut_if(is_mut: bool) -> Option<TokenStream> {
 fn get_member(params: &Parameters, field: &Field, member: &Member) -> TokenStream {
     let self_var = &params.self_var;
     match (params.is_remote, field.attrs.getter()) {
-        (false, None) => quote!(&#self_var.#member),
+        (false, None) => {
+            if params.is_packed {
+                quote!(&{#self_var.#member})
+            } else {
+                quote!(&#self_var.#member)
+            }
+        }
         (true, None) => {
-            let inner = quote!(&#self_var.#member);
+            let inner = if params.is_packed {
+                quote!(&{#self_var.#member})
+            } else {
+                quote!(&#self_var.#member)
+            };
             let ty = field.ty;
             quote!(_serde::private::ser::constrain::<#ty>(#inner))
         }
@@ -1242,6 +1270,13 @@ fn get_member(params: &Parameters, field: &Field, member: &Member) -> TokenStrea
     }
 }
 
+fn effective_style(variant: &Variant) -> Style {
+    match variant.style {
+        Style::Newtype if variant.fields[0].attrs.skip_serializing() => Style::Unit,
+        other => other,
+    }
+}
+
 enum StructTrait {
     SerializeMap,
     SerializeStruct,

serde_derive_internals/Cargo.toml

@@ -1,22 +1,22 @@
 [package]
 name = "serde_derive_internals"
-version = "0.24.1" # remember to update html_root_url
+version = "0.25.0" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-license = "MIT/Apache-2.0"
+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"
 keywords = ["serde", "serialization"]
-include = ["Cargo.toml", "lib.rs", "src/**/*.rs", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["lib.rs", "src/**/*.rs", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [lib]
 path = "lib.rs"
 
 [dependencies]
-proc-macro2 = "0.4"
-syn = { version = "0.15", default-features = false, features = ["derive", "parsing", "clone-impls"] }
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "1.0.33", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
 
-[badges]
-travis-ci = { repository = "serde-rs/serde" }
-appveyor = { repository = "serde-rs/serde" }
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

serde_derive_internals/lib.rs

@@ -1,12 +1,15 @@
-#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.24.1")]
+#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.25.0")]
+#![allow(unknown_lints, bare_trait_objects)]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(
     feature = "cargo-clippy",
     allow(
-        cyclomatic_complexity,
-        doc_markdown,
-        match_same_arms,
-        redundant_field_names
+        cognitive_complexity,
+        redundant_field_names,
+        trivially_copy_pass_by_ref,
+        wildcard_in_or_patterns,
+        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+        unnested_or_patterns,
     )
 )]
 
@@ -14,6 +17,7 @@
 extern crate syn;
 
 extern crate proc_macro2;
+extern crate quote;
 
 #[path = "src/mod.rs"]
 mod internals;

serde_test/Cargo.toml

@@ -1,23 +1,22 @@
 [package]
 name = "serde_test"
-version = "1.0.81" # remember to update html_root_url
+version = "1.0.115" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-license = "MIT/Apache-2.0"
+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 = ["Cargo.toml", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+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", features = ["rc"] }
+serde = { version = "1.0", path = "../serde" }
 serde_derive = { version = "1.0", path = "../serde_derive" }
 
-[badges]
-travis-ci = { repository = "serde-rs/serde" }
-appveyor = { repository = "serde-rs/serde" }
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

serde_test/src/assert.rs

@@ -8,16 +8,10 @@ use std::fmt::Debug;
 
 /// Runs both `assert_ser_tokens` and `assert_de_tokens`.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde_derive;
-/// #
-/// # extern crate serde;
-/// # extern crate serde_test;
-/// #
+/// ```edition2018
+/// # use serde::{Serialize, Deserialize};
 /// # use serde_test::{assert_tokens, Token};
 /// #
-/// # fn main() {
 /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
 /// struct S {
 ///     a: u8,
@@ -33,7 +27,6 @@ use std::fmt::Debug;
 ///     Token::U8(0),
 ///     Token::StructEnd,
 /// ]);
-/// # }
 /// ```
 pub fn assert_tokens<'de, T>(value: &T, tokens: &'de [Token])
 where
@@ -45,16 +38,10 @@ where
 
 /// Asserts that `value` serializes to the given `tokens`.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde_derive;
-/// #
-/// # extern crate serde;
-/// # extern crate serde_test;
-/// #
+/// ```edition2018
+/// # use serde::{Serialize, Deserialize};
 /// # use serde_test::{assert_ser_tokens, Token};
 /// #
-/// # fn main() {
 /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
 /// struct S {
 ///     a: u8,
@@ -70,7 +57,6 @@ where
 ///     Token::U8(0),
 ///     Token::StructEnd,
 /// ]);
-/// # }
 /// ```
 pub fn assert_ser_tokens<T>(value: &T, tokens: &[Token])
 where
@@ -90,16 +76,11 @@ where
 /// Asserts that `value` serializes to the given `tokens`, and then yields
 /// `error`.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde_derive;
-/// #
-/// # extern crate serde_test;
-/// #
-/// # fn main() {
+/// ```edition2018
 /// use std::sync::{Arc, Mutex};
 /// use std::thread;
 ///
+/// use serde::Serialize;
 /// use serde_test::{assert_ser_tokens_error, Token};
 ///
 /// #[derive(Serialize)]
@@ -107,26 +88,27 @@ where
 ///     lock: Arc<Mutex<u32>>,
 /// }
 ///
-/// let example = Example { lock: Arc::new(Mutex::new(0)) };
-/// let lock = example.lock.clone();
+/// 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();
+///     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();
+///         // 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);
-/// # }
+///     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);
+/// }
 /// ```
 pub fn assert_ser_tokens_error<T>(value: &T, tokens: &[Token], error: &str)
 where
@@ -145,16 +127,10 @@ where
 
 /// Asserts that the given `tokens` deserialize into `value`.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde_derive;
-/// #
-/// # extern crate serde;
-/// # extern crate serde_test;
-/// #
+/// ```edition2018
+/// # use serde::{Serialize, Deserialize};
 /// # use serde_test::{assert_de_tokens, Token};
 /// #
-/// # fn main() {
 /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
 /// struct S {
 ///     a: u8,
@@ -170,7 +146,6 @@ where
 ///     Token::U8(0),
 ///     Token::StructEnd,
 /// ]);
-/// # }
 /// ```
 pub fn assert_de_tokens<'de, T>(value: &T, tokens: &'de [Token])
 where
@@ -205,16 +180,10 @@ where
 
 /// Asserts that the given `tokens` yield `error` when deserializing.
 ///
-/// ```rust
-/// # #[macro_use]
-/// # extern crate serde_derive;
-/// #
-/// # extern crate serde;
-/// # extern crate serde_test;
-/// #
+/// ```edition2018
+/// # use serde::{Serialize, Deserialize};
 /// # use serde_test::{assert_de_tokens_error, Token};
 /// #
-/// # fn main() {
 /// #[derive(Serialize, Deserialize, PartialEq, Debug)]
 /// #[serde(deny_unknown_fields)]
 /// struct S {
@@ -229,7 +198,6 @@ where
 ///     ],
 ///     "unknown field `x`, expected `a` or `b`",
 /// );
-/// # }
 /// ```
 pub fn assert_de_tokens_error<'de, T>(tokens: &'de [Token], error: &str)
 where

serde_test/src/configure.rs

@@ -14,10 +14,7 @@ pub struct Compact<T: ?Sized>(T);
 /// Trait to determine whether a value is represented in human-readable or
 /// compact form.
 ///
-/// ```
-/// extern crate serde;
-/// extern crate serde_test;
-///
+/// ```edition2018
 /// use serde::{Deserialize, Deserializer, Serialize, Serializer};
 /// use serde_test::{assert_tokens, Configure, Token};
 ///

serde_test/src/de.rs

@@ -89,11 +89,11 @@ impl<'de> Deserializer<'de> {
     where
         V: Visitor<'de>,
     {
-        let value = try!(visitor.visit_seq(DeserializerSeqVisitor {
+        let value = visitor.visit_seq(DeserializerSeqVisitor {
             de: self,
             len: len,
             end: end,
-        },));
+        })?;
         assert_next_token!(self, end);
         Ok(value)
     }
@@ -107,11 +107,11 @@ impl<'de> Deserializer<'de> {
     where
         V: Visitor<'de>,
     {
-        let value = try!(visitor.visit_map(DeserializerMapVisitor {
+        let value = visitor.visit_map(DeserializerMapVisitor {
             de: self,
             len: len,
             end: end,
-        },));
+        })?;
         assert_next_token!(self, end);
         Ok(value)
     }
@@ -456,11 +456,11 @@ impl<'de, 'a> EnumAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
             | Token::TupleVariant { variant: v, .. }
             | Token::StructVariant { variant: v, .. } => {
                 let de = v.into_deserializer();
-                let value = try!(seed.deserialize(de));
+                let value = seed.deserialize(de)?;
                 Ok((value, self))
             }
             _ => {
-                let value = try!(seed.deserialize(&mut *self.de));
+                let value = seed.deserialize(&mut *self.de)?;
                 Ok((value, self))
             }
         }
@@ -613,7 +613,7 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> {
                         len: None,
                         end: Token::TupleVariantEnd,
                     };
-                    try!(seed.deserialize(SeqAccessDeserializer::new(visitor)))
+                    seed.deserialize(SeqAccessDeserializer::new(visitor))?
                 };
                 assert_next_token!(self.de, Token::TupleVariantEnd);
                 Ok(value)
@@ -625,7 +625,7 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> {
                         len: None,
                         end: Token::StructVariantEnd,
                     };
-                    try!(seed.deserialize(MapAccessDeserializer::new(visitor)))
+                    seed.deserialize(MapAccessDeserializer::new(visitor))?
                 };
                 assert_next_token!(self.de, Token::StructVariantEnd);
                 Ok(value)

serde_test/src/lib.rs

@@ -24,19 +24,10 @@
 //!
 //! [`linked-hash-map`]: https://github.com/contain-rs/linked-hash-map
 //!
-//! ```rust
-//! # extern crate serde;
-//! #
-//! # macro_rules! ignore {
-//! #     ($($tt:tt)+) => {}
-//! # }
-//! #
-//! # ignore! {
-//! extern crate linked_hash_map;
+//! ```edition2018
+//! # const IGNORE: &str = stringify! {
 //! use linked_hash_map::LinkedHashMap;
-//! # }
-//!
-//! extern crate serde_test;
+//! # };
 //! use serde_test::{Token, assert_tokens};
 //!
 //! # use std::fmt;
@@ -153,19 +144,20 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.81")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.115")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
-// Whitelisted clippy lints
-#![cfg_attr(feature = "cargo-clippy", allow(float_cmp))]
-// Whitelisted clippy_pedantic 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(
         empty_line_after_outer_attr,
         missing_docs_in_private_items,
+        module_name_repetitions,
+        must_use_candidate,
         redundant_field_names,
-        stutter,
         use_debug,
         use_self
     )

serde_test/src/ser.rs

@@ -427,7 +427,7 @@ impl<'s, 'a> ser::SerializeStruct for &'s mut Serializer<'a> {
     where
         T: Serialize,
     {
-        try!(key.serialize(&mut **self));
+        key.serialize(&mut **self)?;
         value.serialize(&mut **self)
     }
 
@@ -449,7 +449,7 @@ impl<'s, 'a> ser::SerializeStructVariant for Variant<'s, 'a> {
     where
         T: Serialize,
     {
-        try!(key.serialize(&mut *self.ser));
+        key.serialize(&mut *self.ser)?;
         value.serialize(&mut *self.ser)
     }
 

serde_test/src/token.rs

@@ -4,7 +4,7 @@ use std::fmt::{self, Debug, Display};
 pub enum Token {
     /// A serialized `bool`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&true, &[Token::Bool(true)]);
@@ -13,7 +13,7 @@ pub enum Token {
 
     /// A serialized `i8`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0i8, &[Token::I8(0)]);
@@ -22,7 +22,7 @@ pub enum Token {
 
     /// A serialized `i16`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0i16, &[Token::I16(0)]);
@@ -31,7 +31,7 @@ pub enum Token {
 
     /// A serialized `i32`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0i32, &[Token::I32(0)]);
@@ -40,7 +40,7 @@ pub enum Token {
 
     /// A serialized `i64`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0i64, &[Token::I64(0)]);
@@ -49,7 +49,7 @@ pub enum Token {
 
     /// A serialized `u8`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0u8, &[Token::U8(0)]);
@@ -58,7 +58,7 @@ pub enum Token {
 
     /// A serialized `u16`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0u16, &[Token::U16(0)]);
@@ -67,7 +67,7 @@ pub enum Token {
 
     /// A serialized `u32`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0u32, &[Token::U32(0)]);
@@ -76,7 +76,7 @@ pub enum Token {
 
     /// A serialized `u64`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0u64, &[Token::U64(0)]);
@@ -85,7 +85,7 @@ pub enum Token {
 
     /// A serialized `f32`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0f32, &[Token::F32(0.0)]);
@@ -94,7 +94,7 @@ pub enum Token {
 
     /// A serialized `f64`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&0f64, &[Token::F64(0.0)]);
@@ -103,7 +103,7 @@ pub enum Token {
 
     /// A serialized `char`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&'\n', &[Token::Char('\n')]);
@@ -112,7 +112,7 @@ pub enum Token {
 
     /// A serialized `str`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let s = String::from("transient");
@@ -122,7 +122,7 @@ pub enum Token {
 
     /// A borrowed `str`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let s: &str = "borrowed";
@@ -132,7 +132,7 @@ pub enum Token {
 
     /// A serialized `String`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let s = String::from("owned");
@@ -151,7 +151,7 @@ pub enum Token {
 
     /// A serialized `Option<T>` containing none.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let opt = None::<char>;
@@ -163,7 +163,7 @@ pub enum Token {
     ///
     /// The tokens of the value follow after this header.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let opt = Some('c');
@@ -176,7 +176,7 @@ pub enum Token {
 
     /// A serialized `()`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// assert_tokens(&(), &[Token::Unit]);
@@ -185,13 +185,8 @@ pub enum Token {
 
     /// A serialized unit struct of the given name.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -205,13 +200,8 @@ pub enum Token {
 
     /// A unit variant of an enum.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -233,13 +223,8 @@ pub enum Token {
     ///
     /// After this header is the value contained in the newtype struct.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -259,13 +244,8 @@ pub enum Token {
     ///
     /// After this header is the value contained in the newtype variant.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -291,7 +271,7 @@ pub enum Token {
     /// After this header are the elements of the sequence, followed by
     /// `SeqEnd`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let vec = vec!['a', 'b', 'c'];
@@ -312,7 +292,7 @@ pub enum Token {
     ///
     /// After this header are the elements of the tuple, followed by `TupleEnd`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// let tuple = ('a', 100);
@@ -333,13 +313,8 @@ pub enum Token {
     /// After this header are the fields of the tuple struct, followed by
     /// `TupleStructEnd`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -365,13 +340,8 @@ pub enum Token {
     /// After this header are the fields of the tuple variant, followed by
     /// `TupleVariantEnd`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -402,7 +372,7 @@ pub enum Token {
     ///
     /// After this header are the entries of the map, followed by `MapEnd`.
     ///
-    /// ```rust
+    /// ```edition2018
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// use std::collections::BTreeMap;
@@ -429,13 +399,8 @@ pub enum Token {
     ///
     /// After this header are the fields of the struct, followed by `StructEnd`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -466,13 +431,8 @@ pub enum Token {
     /// After this header are the fields of the struct variant, followed by
     /// `StructVariantEnd`.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {
@@ -501,13 +461,8 @@ pub enum Token {
 
     /// The header to an enum of the given name.
     ///
-    /// ```rust
-    /// # #[macro_use]
-    /// # extern crate serde_derive;
-    /// #
-    /// # extern crate serde;
-    /// # extern crate serde_test;
-    /// #
+    /// ```edition2018
+    /// # use serde::{Serialize, Deserialize};
     /// # use serde_test::{assert_tokens, Token};
     /// #
     /// # fn main() {

test_suite/Cargo.toml

@@ -2,17 +2,25 @@
 name = "serde_test_suite"
 version = "0.0.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
+edition = "2018"
 publish = false
+build = "build.rs"
 
 [features]
-unstable = ["serde/unstable", "compiletest_rs"]
+expandtest = []
+unstable = ["serde/unstable"]
+
+[dependencies]
+serde = { path = "../serde" }
+
+[build-dependencies]
+toolchain_find = "0.1"
 
 [dev-dependencies]
 fnv = "1.0"
-rustc-serialize = "0.3.16"
-serde = { path = "../serde", features = ["rc"] }
+macrotest = "=1.0.0"
+rustversion = "1.0"
+serde = { path = "../serde", features = ["rc", "derive"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }
 serde_test = { path = "../serde_test" }
-
-[dependencies]
-compiletest_rs = { version = "0.3", optional = true, features = ["stable"] }
+trybuild = "1.0"

test_suite/build.rs

@@ -0,0 +1,29 @@
+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");
+    }
+}

test_suite/deps/Cargo.toml

@@ -1,11 +0,0 @@
-[package]
-name = "serde_test_suite_deps"
-version = "0.0.0"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-publish = false
-
-[workspace]
-
-[dependencies]
-serde = { path = "../../serde" }
-serde_derive = { path = "../../serde_derive" }

test_suite/deps/src/lib.rs

@@ -1,3 +0,0 @@
-#![feature(/*=============================================]
-#![===  Serde test suite requires a nightly compiler.  ===]
-#![====================================================*/)]

test_suite/no_std/Cargo.toml

@@ -1,11 +1,11 @@
 [package]
 name = "serde_derive_tests_no_std"
 version = "0.0.0"
+edition = "2018"
 publish = false
 
 [dependencies]
 libc = { version = "0.2", default-features = false }
-serde = { path = "../../serde", default-features = false }
-serde_derive = { path = "../../serde_derive" }
+serde = { path = "../../serde", default-features = false, features = ["derive"] }
 
 [workspace]

test_suite/no_std/src/main.rs

@@ -1,8 +1,6 @@
 #![feature(lang_items, start)]
 #![no_std]
 
-extern crate libc;
-
 #[start]
 fn start(_argc: isize, _argv: *const *const u8) -> isize {
     0
@@ -21,8 +19,7 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 
 //////////////////////////////////////////////////////////////////////////////
 
-#[macro_use]
-extern crate serde_derive;
+use serde::{Serialize, Deserialize};
 
 #[derive(Serialize, Deserialize)]
 struct Unit;

test_suite/tests/bytes/mod.rs

@@ -22,7 +22,7 @@ impl<'de> Visitor<'de> for ByteBufVisitor {
         V: SeqAccess<'de>,
     {
         let mut values = Vec::new();
-        while let Some(value) = try!(visitor.next_element()) {
+        while let Some(value) = visitor.next_element()? {
             values.push(value);
         }
         Ok(values)

test_suite/tests/compiletest.rs

@@ -1,15 +1,7 @@
-#![cfg(feature = "unstable")]
-
-extern crate compiletest_rs as compiletest;
-
+#[cfg_attr(target_os = "emscripten", ignore)]
+#[rustversion::attr(not(nightly), ignore)]
 #[test]
 fn ui() {
-    let config = compiletest::Config {
-        mode: compiletest::common::Mode::Ui,
-        src_base: std::path::PathBuf::from("tests/ui"),
-        target_rustcflags: Some("-L deps/target/debug/deps".to_owned()),
-        ..Default::default()
-    };
-
-    compiletest::run_tests(&config);
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/**/*.rs");
 }

test_suite/tests/expand/de_enum.rs

@@ -0,0 +1,13 @@
+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 },
+}

test_suite/tests/expand/default_ty_param.expanded.rs

@@ -0,0 +1,401 @@
+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(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeStruct::serialize_field(
+                &mut __serde_state,
+                "phantom",
+                &self.phantom,
+            ) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            _serde::ser::SerializeStruct::end(__serde_state)
+        }
+    }
+};
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 1",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "phantom" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"phantom" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                where
+                    __D: _serde::Deserializer<'de>,
+                {
+                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
+                }
+            }
+            struct __Visitor<'de, T: AssociatedType<X = i32>> {
+                marker: _serde::export::PhantomData<DefaultTyParam<T>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct DefaultTyParam")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                0usize,
+                                &"struct DefaultTyParam with 1 element",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(DefaultTyParam { phantom: __field0 })
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::MapAccess<'de>,
+                {
+                    let mut __field0: _serde::export::Option<PhantomData<T>> = _serde::export::None;
+                    while let _serde::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if _serde::export::Option::is_some(&__field0) {
+                                    return _serde::export::Err(
+                                        <__A::Error as _serde::de::Error>::duplicate_field(
+                                            "phantom",
+                                        ),
+                                    );
+                                }
+                                __field0 = _serde::export::Some(
+                                    match _serde::de::MapAccess::next_value::<PhantomData<T>>(
+                                        &mut __map,
+                                    ) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    },
+                                );
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    let __field0 = match __field0 {
+                        _serde::export::Some(__field0) => __field0,
+                        _serde::export::None => match _serde::private::de::missing_field("phantom")
+                        {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        },
+                    };
+                    _serde::export::Ok(DefaultTyParam { phantom: __field0 })
+                }
+            }
+            const FIELDS: &'static [&'static str] = &["phantom"];
+            _serde::Deserializer::deserialize_struct(
+                __deserializer,
+                "DefaultTyParam",
+                FIELDS,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<DefaultTyParam<T>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 1",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "phantom" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"phantom" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct DefaultTyParam")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.phantom),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"struct DefaultTyParam with 1 element",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::MapAccess<'de>,
+                {
+                    let mut __field0: bool = false;
+                    while let _serde::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if __field0 {
+                                    return _serde::export::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::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                                __field0 = true;
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    if !__field0 {
+                        self.place.phantom = match _serde::private::de::missing_field("phantom") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        };
+                    };
+                    _serde::export::Ok(())
+                }
+            }
+            const FIELDS: &'static [&'static str] = &["phantom"];
+            _serde::Deserializer::deserialize_struct(
+                __deserializer,
+                "DefaultTyParam",
+                FIELDS,
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/default_ty_param.rs

@@ -0,0 +1,14 @@
+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>,
+}

test_suite/tests/expand/generic_enum.expanded.rs

@@ -0,0 +1,582 @@
+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(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field0,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field1,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "x",
+                        x,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "y",
+                        y,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    _serde::ser::SerializeStructVariant::end(__serde_state)
+                }
+            }
+        }
+    }
+};
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        1u64 => _serde::export::Ok(__Field::__field1),
+                        2u64 => _serde::export::Ok(__Field::__field2),
+                        3u64 => _serde::export::Ok(__Field::__field3),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"variant index 0 <= i < 4",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "Unit" => _serde::export::Ok(__Field::__field0),
+                        "NewType" => _serde::export::Ok(__Field::__field1),
+                        "Seq" => _serde::export::Ok(__Field::__field2),
+                        "Map" => _serde::export::Ok(__Field::__field3),
+                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                            __value, VARIANTS,
+                        )),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"Unit" => _serde::export::Ok(__Field::__field0),
+                        b"NewType" => _serde::export::Ok(__Field::__field1),
+                        b"Seq" => _serde::export::Ok(__Field::__field2),
+                        b"Map" => _serde::export::Ok(__Field::__field3),
+                        _ => {
+                            let __value = &_serde::export::from_utf8_lossy(__value);
+                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                                __value, VARIANTS,
+                            ))
+                        }
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::PhantomData<GenericEnum<T, U>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "enum GenericEnum")
+                }
+                fn visit_enum<__A>(
+                    self,
+                    __data: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::EnumAccess<'de>,
+                {
+                    match match _serde::de::EnumAccess::variant(__data) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        (__Field::__field0, __variant) => {
+                            match _serde::de::VariantAccess::unit_variant(__variant) {
+                                _serde::export::Ok(__val) => __val,
+                                _serde::export::Err(__err) => {
+                                    return _serde::export::Err(__err);
+                                }
+                            };
+                            _serde::export::Ok(GenericEnum::Unit)
+                        }
+                        (__Field::__field1, __variant) => _serde::export::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::export::PhantomData<GenericEnum<T, U>>,
+                                lifetime: _serde::export::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::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "tuple variant GenericEnum::Seq",
+                                    )
+                                }
+                                #[inline]
+                                fn visit_seq<__A>(
+                                    self,
+                                    mut __seq: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::SeqAccess<'de>,
+                                {
+                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
+                                        T,
+                                    >(
+                                        &mut __seq
+                                    ) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: 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::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 1usize , & "tuple variant GenericEnum::Seq with 2 elements" ) ) ;
+                                        }
+                                    };
+                                    _serde::export::Ok(GenericEnum::Seq(__field0, __field1))
+                                }
+                            }
+                            _serde::de::VariantAccess::tuple_variant(
+                                __variant,
+                                2usize,
+                                __Visitor {
+                                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
+                                    lifetime: _serde::export::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::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "field identifier",
+                                    )
+                                }
+                                fn visit_u64<__E>(
+                                    self,
+                                    __value: u64,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        0u64 => _serde::export::Ok(__Field::__field0),
+                                        1u64 => _serde::export::Ok(__Field::__field1),
+                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                                            _serde::de::Unexpected::Unsigned(__value),
+                                            &"field index 0 <= i < 2",
+                                        )),
+                                    }
+                                }
+                                fn visit_str<__E>(
+                                    self,
+                                    __value: &str,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        "x" => _serde::export::Ok(__Field::__field0),
+                                        "y" => _serde::export::Ok(__Field::__field1),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                                fn visit_bytes<__E>(
+                                    self,
+                                    __value: &[u8],
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        b"x" => _serde::export::Ok(__Field::__field0),
+                                        b"y" => _serde::export::Ok(__Field::__field1),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                            }
+                            impl<'de> _serde::Deserialize<'de> for __Field {
+                                #[inline]
+                                fn deserialize<__D>(
+                                    __deserializer: __D,
+                                ) -> _serde::export::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::export::PhantomData<GenericEnum<T, U>>,
+                                lifetime: _serde::export::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::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "struct variant GenericEnum::Map",
+                                    )
+                                }
+                                #[inline]
+                                fn visit_seq<__A>(
+                                    self,
+                                    mut __seq: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::SeqAccess<'de>,
+                                {
+                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
+                                        T,
+                                    >(
+                                        &mut __seq
+                                    ) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: 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::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 1usize , & "struct variant GenericEnum::Map with 2 elements" ) ) ;
+                                        }
+                                    };
+                                    _serde::export::Ok(GenericEnum::Map {
+                                        x: __field0,
+                                        y: __field1,
+                                    })
+                                }
+                                #[inline]
+                                fn visit_map<__A>(
+                                    self,
+                                    mut __map: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::MapAccess<'de>,
+                                {
+                                    let mut __field0: _serde::export::Option<T> =
+                                        _serde::export::None;
+                                    let mut __field1: _serde::export::Option<U> =
+                                        _serde::export::None;
+                                    while let _serde::export::Some(__key) =
+                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
+                                        {
+                                            _serde::export::Ok(__val) => __val,
+                                            _serde::export::Err(__err) => {
+                                                return _serde::export::Err(__err);
+                                            }
+                                        }
+                                    {
+                                        match __key {
+                                            __Field::__field0 => {
+                                                if _serde::export::Option::is_some(&__field0) {
+                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "x" ) ) ;
+                                                }
+                                                __field0 = _serde::export::Some(
+                                                    match _serde::de::MapAccess::next_value::<T>(
+                                                        &mut __map,
+                                                    ) {
+                                                        _serde::export::Ok(__val) => __val,
+                                                        _serde::export::Err(__err) => {
+                                                            return _serde::export::Err(__err);
+                                                        }
+                                                    },
+                                                );
+                                            }
+                                            __Field::__field1 => {
+                                                if _serde::export::Option::is_some(&__field1) {
+                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "y" ) ) ;
+                                                }
+                                                __field1 = _serde::export::Some(
+                                                    match _serde::de::MapAccess::next_value::<U>(
+                                                        &mut __map,
+                                                    ) {
+                                                        _serde::export::Ok(__val) => __val,
+                                                        _serde::export::Err(__err) => {
+                                                            return _serde::export::Err(__err);
+                                                        }
+                                                    },
+                                                );
+                                            }
+                                            _ => {
+                                                let _ = match _serde::de::MapAccess::next_value::<
+                                                    _serde::de::IgnoredAny,
+                                                >(
+                                                    &mut __map
+                                                ) {
+                                                    _serde::export::Ok(__val) => __val,
+                                                    _serde::export::Err(__err) => {
+                                                        return _serde::export::Err(__err);
+                                                    }
+                                                };
+                                            }
+                                        }
+                                    }
+                                    let __field0 = match __field0 {
+                                        _serde::export::Some(__field0) => __field0,
+                                        _serde::export::None => {
+                                            match _serde::private::de::missing_field("x") {
+                                                _serde::export::Ok(__val) => __val,
+                                                _serde::export::Err(__err) => {
+                                                    return _serde::export::Err(__err);
+                                                }
+                                            }
+                                        }
+                                    };
+                                    let __field1 = match __field1 {
+                                        _serde::export::Some(__field1) => __field1,
+                                        _serde::export::None => {
+                                            match _serde::private::de::missing_field("y") {
+                                                _serde::export::Ok(__val) => __val,
+                                                _serde::export::Err(__err) => {
+                                                    return _serde::export::Err(__err);
+                                                }
+                                            }
+                                        }
+                                    };
+                                    _serde::export::Ok(GenericEnum::Map {
+                                        x: __field0,
+                                        y: __field1,
+                                    })
+                                }
+                            }
+                            const FIELDS: &'static [&'static str] = &["x", "y"];
+                            _serde::de::VariantAccess::struct_variant(
+                                __variant,
+                                FIELDS,
+                                __Visitor {
+                                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
+                                    lifetime: _serde::export::PhantomData,
+                                },
+                            )
+                        }
+                    }
+                }
+            }
+            const VARIANTS: &'static [&'static str] = &["Unit", "NewType", "Seq", "Map"];
+            _serde::Deserializer::deserialize_enum(
+                __deserializer,
+                "GenericEnum",
+                VARIANTS,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/generic_enum.rs

@@ -0,0 +1,9 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub enum GenericEnum<T, U> {
+    Unit,
+    NewType(T),
+    Seq(T, U),
+    Map { x: T, y: U },
+}

test_suite/tests/expand/generic_struct.expanded.rs

@@ -0,0 +1,582 @@
+use serde::{Deserialize, Serialize};
+pub struct GenericStruct<T> {
+    x: T,
+}
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "x", &self.x) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            _serde::ser::SerializeStruct::end(__serde_state)
+        }
+    }
+};
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 1",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "x" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"x" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::PhantomData<GenericStruct<T>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct GenericStruct")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
+                    {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                0usize,
+                                &"struct GenericStruct with 1 element",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(GenericStruct { x: __field0 })
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::MapAccess<'de>,
+                {
+                    let mut __field0: _serde::export::Option<T> = _serde::export::None;
+                    while let _serde::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if _serde::export::Option::is_some(&__field0) {
+                                    return _serde::export::Err(
+                                        <__A::Error as _serde::de::Error>::duplicate_field("x"),
+                                    );
+                                }
+                                __field0 = _serde::export::Some(
+                                    match _serde::de::MapAccess::next_value::<T>(&mut __map) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    },
+                                );
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    let __field0 = match __field0 {
+                        _serde::export::Some(__field0) => __field0,
+                        _serde::export::None => match _serde::private::de::missing_field("x") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        },
+                    };
+                    _serde::export::Ok(GenericStruct { x: __field0 })
+                }
+            }
+            const FIELDS: &'static [&'static str] = &["x"];
+            _serde::Deserializer::deserialize_struct(
+                __deserializer,
+                "GenericStruct",
+                FIELDS,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<GenericStruct<T>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 1",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "x" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"x" => _serde::export::Ok(__Field::__field0),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct GenericStruct")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.x),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"struct GenericStruct with 1 element",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::MapAccess<'de>,
+                {
+                    let mut __field0: bool = false;
+                    while let _serde::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if __field0 {
+                                    return _serde::export::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::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                                __field0 = true;
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    if !__field0 {
+                        self.place.x = match _serde::private::de::missing_field("x") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        };
+                    };
+                    _serde::export::Ok(())
+                }
+            }
+            const FIELDS: &'static [&'static str] = &["x"];
+            _serde::Deserializer::deserialize_struct(
+                __deserializer,
+                "GenericStruct",
+                FIELDS,
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};
+pub struct GenericNewTypeStruct<T>(T);
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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(rust_2018_idioms, 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::export::Result<Self, __D::Error>
+        where
+            __D: _serde::Deserializer<'de>,
+        {
+            struct __Visitor<'de, T>
+            where
+                T: _serde::Deserialize<'de>,
+            {
+                marker: _serde::export::PhantomData<GenericNewTypeStruct<T>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(
+                        __formatter,
+                        "tuple struct GenericNewTypeStruct",
+                    )
+                }
+                #[inline]
+                fn visit_newtype_struct<__E>(
+                    self,
+                    __e: __E,
+                ) -> _serde::export::Result<Self::Value, __E::Error>
+                where
+                    __E: _serde::Deserializer<'de>,
+                {
+                    let __field0: T = match <T as _serde::Deserialize>::deserialize(__e) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    _serde::export::Ok(GenericNewTypeStruct(__field0))
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
+                    {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                0usize,
+                                &"tuple struct GenericNewTypeStruct with 1 element",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(GenericNewTypeStruct(__field0))
+                }
+            }
+            _serde::Deserializer::deserialize_newtype_struct(
+                __deserializer,
+                "GenericNewTypeStruct",
+                __Visitor {
+                    marker: _serde::export::PhantomData::<GenericNewTypeStruct<T>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(
+                        __formatter,
+                        "tuple struct GenericNewTypeStruct",
+                    )
+                }
+                #[inline]
+                fn visit_newtype_struct<__E>(
+                    self,
+                    __e: __E,
+                ) -> _serde::export::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::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"tuple struct GenericNewTypeStruct with 1 element",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+            }
+            _serde::Deserializer::deserialize_newtype_struct(
+                __deserializer,
+                "GenericNewTypeStruct",
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/generic_struct.rs

@@ -0,0 +1,9 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub struct GenericStruct<T> {
+    x: T,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct GenericNewTypeStruct<T>(T);

test_suite/tests/expand/generic_tuple_struct.expanded.rs

@@ -0,0 +1,172 @@
+use serde::{Deserialize, Serialize};
+pub struct GenericTupleStruct<T, U>(T, U);
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::PhantomData<GenericTupleStruct<T, U>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(
+                        __formatter,
+                        "tuple struct GenericTupleStruct",
+                    )
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
+                    {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                1usize,
+                                &"tuple struct GenericTupleStruct with 2 elements",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(GenericTupleStruct(__field0, __field1))
+                }
+            }
+            _serde::Deserializer::deserialize_tuple_struct(
+                __deserializer,
+                "GenericTupleStruct",
+                2usize,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<GenericTupleStruct<T, U>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(
+                        __formatter,
+                        "tuple struct GenericTupleStruct",
+                    )
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"tuple struct GenericTupleStruct with 2 elements",
+                        ));
+                    }
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.1),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            1usize,
+                            &"tuple struct GenericTupleStruct with 2 elements",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+            }
+            _serde::Deserializer::deserialize_tuple_struct(
+                __deserializer,
+                "GenericTupleStruct",
+                2usize,
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/generic_tuple_struct.rs

@@ -0,0 +1,4 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Deserialize)]
+pub struct GenericTupleStruct<T, U>(T, U);

test_suite/tests/expand/lifetimes.expanded.rs

@@ -0,0 +1,601 @@
+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(rust_2018_idioms, clippy::useless_attribute)]
+    extern crate serde as _serde;
+    #[automatically_derived]
+    impl<'a> _serde::Serialize for Lifetimes<'a> {
+        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "a",
+                        a,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "a",
+                        a,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    _serde::ser::SerializeStructVariant::end(__serde_state)
+                }
+            }
+        }
+    }
+};
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, 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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        1u64 => _serde::export::Ok(__Field::__field1),
+                        2u64 => _serde::export::Ok(__Field::__field2),
+                        3u64 => _serde::export::Ok(__Field::__field3),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"variant index 0 <= i < 4",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "LifetimeSeq" => _serde::export::Ok(__Field::__field0),
+                        "NoLifetimeSeq" => _serde::export::Ok(__Field::__field1),
+                        "LifetimeMap" => _serde::export::Ok(__Field::__field2),
+                        "NoLifetimeMap" => _serde::export::Ok(__Field::__field3),
+                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                            __value, VARIANTS,
+                        )),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"LifetimeSeq" => _serde::export::Ok(__Field::__field0),
+                        b"NoLifetimeSeq" => _serde::export::Ok(__Field::__field1),
+                        b"LifetimeMap" => _serde::export::Ok(__Field::__field2),
+                        b"NoLifetimeMap" => _serde::export::Ok(__Field::__field3),
+                        _ => {
+                            let __value = &_serde::export::from_utf8_lossy(__value);
+                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                                __value, VARIANTS,
+                            ))
+                        }
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                where
+                    __D: _serde::Deserializer<'de>,
+                {
+                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
+                }
+            }
+            struct __Visitor<'de, 'a> {
+                marker: _serde::export::PhantomData<Lifetimes<'a>>,
+                lifetime: _serde::export::PhantomData<&'de ()>,
+            }
+            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
+                type Value = Lifetimes<'a>;
+                fn expecting(
+                    &self,
+                    __formatter: &mut _serde::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "enum Lifetimes")
+                }
+                fn visit_enum<__A>(
+                    self,
+                    __data: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::EnumAccess<'de>,
+                {
+                    match match _serde::de::EnumAccess::variant(__data) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        (__Field::__field0, __variant) => _serde::export::Result::map(
+                            _serde::de::VariantAccess::newtype_variant::<&'a i32>(__variant),
+                            Lifetimes::LifetimeSeq,
+                        ),
+                        (__Field::__field1, __variant) => _serde::export::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::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "field identifier",
+                                    )
+                                }
+                                fn visit_u64<__E>(
+                                    self,
+                                    __value: u64,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        0u64 => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                                            _serde::de::Unexpected::Unsigned(__value),
+                                            &"field index 0 <= i < 1",
+                                        )),
+                                    }
+                                }
+                                fn visit_str<__E>(
+                                    self,
+                                    __value: &str,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        "a" => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                                fn visit_bytes<__E>(
+                                    self,
+                                    __value: &[u8],
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        b"a" => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                            }
+                            impl<'de> _serde::Deserialize<'de> for __Field {
+                                #[inline]
+                                fn deserialize<__D>(
+                                    __deserializer: __D,
+                                ) -> _serde::export::Result<Self, __D::Error>
+                                where
+                                    __D: _serde::Deserializer<'de>,
+                                {
+                                    _serde::Deserializer::deserialize_identifier(
+                                        __deserializer,
+                                        __FieldVisitor,
+                                    )
+                                }
+                            }
+                            struct __Visitor<'de, 'a> {
+                                marker: _serde::export::PhantomData<Lifetimes<'a>>,
+                                lifetime: _serde::export::PhantomData<&'de ()>,
+                            }
+                            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
+                                type Value = Lifetimes<'a>;
+                                fn expecting(
+                                    &self,
+                                    __formatter: &mut _serde::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "struct variant Lifetimes::LifetimeMap",
+                                    )
+                                }
+                                #[inline]
+                                fn visit_seq<__A>(
+                                    self,
+                                    mut __seq: __A,
+                                ) -> _serde::export::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::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "struct variant Lifetimes::LifetimeMap with 1 element" ) ) ;
+                                        }
+                                    };
+                                    _serde::export::Ok(Lifetimes::LifetimeMap { a: __field0 })
+                                }
+                                #[inline]
+                                fn visit_map<__A>(
+                                    self,
+                                    mut __map: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::MapAccess<'de>,
+                                {
+                                    let mut __field0: _serde::export::Option<&'a i32> =
+                                        _serde::export::None;
+                                    while let _serde::export::Some(__key) =
+                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
+                                        {
+                                            _serde::export::Ok(__val) => __val,
+                                            _serde::export::Err(__err) => {
+                                                return _serde::export::Err(__err);
+                                            }
+                                        }
+                                    {
+                                        match __key {
+                                            __Field::__field0 => {
+                                                if _serde::export::Option::is_some(&__field0) {
+                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "a" ) ) ;
+                                                }
+                                                __field0 = _serde::export::Some(
+                                                    match _serde::de::MapAccess::next_value::<&'a i32>(
+                                                        &mut __map,
+                                                    ) {
+                                                        _serde::export::Ok(__val) => __val,
+                                                        _serde::export::Err(__err) => {
+                                                            return _serde::export::Err(__err);
+                                                        }
+                                                    },
+                                                );
+                                            }
+                                            _ => {
+                                                let _ = match _serde::de::MapAccess::next_value::<
+                                                    _serde::de::IgnoredAny,
+                                                >(
+                                                    &mut __map
+                                                ) {
+                                                    _serde::export::Ok(__val) => __val,
+                                                    _serde::export::Err(__err) => {
+                                                        return _serde::export::Err(__err);
+                                                    }
+                                                };
+                                            }
+                                        }
+                                    }
+                                    let __field0 = match __field0 {
+                                        _serde::export::Some(__field0) => __field0,
+                                        _serde::export::None => {
+                                            match _serde::private::de::missing_field("a") {
+                                                _serde::export::Ok(__val) => __val,
+                                                _serde::export::Err(__err) => {
+                                                    return _serde::export::Err(__err);
+                                                }
+                                            }
+                                        }
+                                    };
+                                    _serde::export::Ok(Lifetimes::LifetimeMap { a: __field0 })
+                                }
+                            }
+                            const FIELDS: &'static [&'static str] = &["a"];
+                            _serde::de::VariantAccess::struct_variant(
+                                __variant,
+                                FIELDS,
+                                __Visitor {
+                                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
+                                    lifetime: _serde::export::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::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "field identifier",
+                                    )
+                                }
+                                fn visit_u64<__E>(
+                                    self,
+                                    __value: u64,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        0u64 => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                                            _serde::de::Unexpected::Unsigned(__value),
+                                            &"field index 0 <= i < 1",
+                                        )),
+                                    }
+                                }
+                                fn visit_str<__E>(
+                                    self,
+                                    __value: &str,
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        "a" => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                                fn visit_bytes<__E>(
+                                    self,
+                                    __value: &[u8],
+                                ) -> _serde::export::Result<Self::Value, __E>
+                                where
+                                    __E: _serde::de::Error,
+                                {
+                                    match __value {
+                                        b"a" => _serde::export::Ok(__Field::__field0),
+                                        _ => _serde::export::Ok(__Field::__ignore),
+                                    }
+                                }
+                            }
+                            impl<'de> _serde::Deserialize<'de> for __Field {
+                                #[inline]
+                                fn deserialize<__D>(
+                                    __deserializer: __D,
+                                ) -> _serde::export::Result<Self, __D::Error>
+                                where
+                                    __D: _serde::Deserializer<'de>,
+                                {
+                                    _serde::Deserializer::deserialize_identifier(
+                                        __deserializer,
+                                        __FieldVisitor,
+                                    )
+                                }
+                            }
+                            struct __Visitor<'de, 'a> {
+                                marker: _serde::export::PhantomData<Lifetimes<'a>>,
+                                lifetime: _serde::export::PhantomData<&'de ()>,
+                            }
+                            impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
+                                type Value = Lifetimes<'a>;
+                                fn expecting(
+                                    &self,
+                                    __formatter: &mut _serde::export::Formatter,
+                                ) -> _serde::export::fmt::Result {
+                                    _serde::export::Formatter::write_str(
+                                        __formatter,
+                                        "struct variant Lifetimes::NoLifetimeMap",
+                                    )
+                                }
+                                #[inline]
+                                fn visit_seq<__A>(
+                                    self,
+                                    mut __seq: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::SeqAccess<'de>,
+                                {
+                                    let __field0 = match match _serde::de::SeqAccess::next_element::<
+                                        i32,
+                                    >(
+                                        &mut __seq
+                                    ) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    } {
+                                        _serde::export::Some(__value) => __value,
+                                        _serde::export::None => {
+                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "struct variant Lifetimes::NoLifetimeMap with 1 element" ) ) ;
+                                        }
+                                    };
+                                    _serde::export::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
+                                }
+                                #[inline]
+                                fn visit_map<__A>(
+                                    self,
+                                    mut __map: __A,
+                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                where
+                                    __A: _serde::de::MapAccess<'de>,
+                                {
+                                    let mut __field0: _serde::export::Option<i32> =
+                                        _serde::export::None;
+                                    while let _serde::export::Some(__key) =
+                                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
+                                        {
+                                            _serde::export::Ok(__val) => __val,
+                                            _serde::export::Err(__err) => {
+                                                return _serde::export::Err(__err);
+                                            }
+                                        }
+                                    {
+                                        match __key {
+                                            __Field::__field0 => {
+                                                if _serde::export::Option::is_some(&__field0) {
+                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "a" ) ) ;
+                                                }
+                                                __field0 = _serde::export::Some(
+                                                    match _serde::de::MapAccess::next_value::<i32>(
+                                                        &mut __map,
+                                                    ) {
+                                                        _serde::export::Ok(__val) => __val,
+                                                        _serde::export::Err(__err) => {
+                                                            return _serde::export::Err(__err);
+                                                        }
+                                                    },
+                                                );
+                                            }
+                                            _ => {
+                                                let _ = match _serde::de::MapAccess::next_value::<
+                                                    _serde::de::IgnoredAny,
+                                                >(
+                                                    &mut __map
+                                                ) {
+                                                    _serde::export::Ok(__val) => __val,
+                                                    _serde::export::Err(__err) => {
+                                                        return _serde::export::Err(__err);
+                                                    }
+                                                };
+                                            }
+                                        }
+                                    }
+                                    let __field0 = match __field0 {
+                                        _serde::export::Some(__field0) => __field0,
+                                        _serde::export::None => {
+                                            match _serde::private::de::missing_field("a") {
+                                                _serde::export::Ok(__val) => __val,
+                                                _serde::export::Err(__err) => {
+                                                    return _serde::export::Err(__err);
+                                                }
+                                            }
+                                        }
+                                    };
+                                    _serde::export::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
+                                }
+                            }
+                            const FIELDS: &'static [&'static str] = &["a"];
+                            _serde::de::VariantAccess::struct_variant(
+                                __variant,
+                                FIELDS,
+                                __Visitor {
+                                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
+                                    lifetime: _serde::export::PhantomData,
+                                },
+                            )
+                        }
+                    }
+                }
+            }
+            const VARIANTS: &'static [&'static str] = &[
+                "LifetimeSeq",
+                "NoLifetimeSeq",
+                "LifetimeMap",
+                "NoLifetimeMap",
+            ];
+            _serde::Deserializer::deserialize_enum(
+                __deserializer,
+                "Lifetimes",
+                VARIANTS,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/lifetimes.rs

@@ -0,0 +1,9 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+enum Lifetimes<'a> {
+    LifetimeSeq(&'a i32),
+    NoLifetimeSeq(i32),
+    LifetimeMap { a: &'a i32 },
+    NoLifetimeMap { a: i32 },
+}

test_suite/tests/expand/named_map.expanded.rs

@@ -0,0 +1,615 @@
+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(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "a", &self.a) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "b", &self.b) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "c", &self.c) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::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(rust_2018_idioms, 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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        1u64 => _serde::export::Ok(__Field::__field1),
+                        2u64 => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 3",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "a" => _serde::export::Ok(__Field::__field0),
+                        "b" => _serde::export::Ok(__Field::__field1),
+                        "c" => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"a" => _serde::export::Ok(__Field::__field0),
+                        b"b" => _serde::export::Ok(__Field::__field1),
+                        b"c" => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::PhantomData<DeNamedMap<A, B, C>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct DeNamedMap")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
+                    {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                2usize,
+                                &"struct DeNamedMap with 3 elements",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(DeNamedMap {
+                        a: __field0,
+                        b: __field1,
+                        c: __field2,
+                    })
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::MapAccess<'de>,
+                {
+                    let mut __field0: _serde::export::Option<A> = _serde::export::None;
+                    let mut __field1: _serde::export::Option<B> = _serde::export::None;
+                    let mut __field2: _serde::export::Option<C> = _serde::export::None;
+                    while let _serde::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if _serde::export::Option::is_some(&__field0) {
+                                    return _serde::export::Err(
+                                        <__A::Error as _serde::de::Error>::duplicate_field("a"),
+                                    );
+                                }
+                                __field0 = _serde::export::Some(
+                                    match _serde::de::MapAccess::next_value::<A>(&mut __map) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    },
+                                );
+                            }
+                            __Field::__field1 => {
+                                if _serde::export::Option::is_some(&__field1) {
+                                    return _serde::export::Err(
+                                        <__A::Error as _serde::de::Error>::duplicate_field("b"),
+                                    );
+                                }
+                                __field1 = _serde::export::Some(
+                                    match _serde::de::MapAccess::next_value::<B>(&mut __map) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    },
+                                );
+                            }
+                            __Field::__field2 => {
+                                if _serde::export::Option::is_some(&__field2) {
+                                    return _serde::export::Err(
+                                        <__A::Error as _serde::de::Error>::duplicate_field("c"),
+                                    );
+                                }
+                                __field2 = _serde::export::Some(
+                                    match _serde::de::MapAccess::next_value::<C>(&mut __map) {
+                                        _serde::export::Ok(__val) => __val,
+                                        _serde::export::Err(__err) => {
+                                            return _serde::export::Err(__err);
+                                        }
+                                    },
+                                );
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    let __field0 = match __field0 {
+                        _serde::export::Some(__field0) => __field0,
+                        _serde::export::None => match _serde::private::de::missing_field("a") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        },
+                    };
+                    let __field1 = match __field1 {
+                        _serde::export::Some(__field1) => __field1,
+                        _serde::export::None => match _serde::private::de::missing_field("b") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        },
+                    };
+                    let __field2 = match __field2 {
+                        _serde::export::Some(__field2) => __field2,
+                        _serde::export::None => match _serde::private::de::missing_field("c") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        },
+                    };
+                    _serde::export::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::export::PhantomData::<DeNamedMap<A, B, C>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        0u64 => _serde::export::Ok(__Field::__field0),
+                        1u64 => _serde::export::Ok(__Field::__field1),
+                        2u64 => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"field index 0 <= i < 3",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        "a" => _serde::export::Ok(__Field::__field0),
+                        "b" => _serde::export::Ok(__Field::__field1),
+                        "c" => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        b"a" => _serde::export::Ok(__Field::__field0),
+                        b"b" => _serde::export::Ok(__Field::__field1),
+                        b"c" => _serde::export::Ok(__Field::__field2),
+                        _ => _serde::export::Ok(__Field::__ignore),
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "struct DeNamedMap")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.a),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"struct DeNamedMap with 3 elements",
+                        ));
+                    }
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.b),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            1usize,
+                            &"struct DeNamedMap with 3 elements",
+                        ));
+                    }
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.c),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            2usize,
+                            &"struct DeNamedMap with 3 elements",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+                #[inline]
+                fn visit_map<__A>(
+                    self,
+                    mut __map: __A,
+                ) -> _serde::export::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::export::Some(__key) =
+                        match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        }
+                    {
+                        match __key {
+                            __Field::__field0 => {
+                                if __field0 {
+                                    return _serde::export::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::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                                __field0 = true;
+                            }
+                            __Field::__field1 => {
+                                if __field1 {
+                                    return _serde::export::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::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                                __field1 = true;
+                            }
+                            __Field::__field2 => {
+                                if __field2 {
+                                    return _serde::export::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::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                                __field2 = true;
+                            }
+                            _ => {
+                                let _ = match _serde::de::MapAccess::next_value::<
+                                    _serde::de::IgnoredAny,
+                                >(&mut __map)
+                                {
+                                    _serde::export::Ok(__val) => __val,
+                                    _serde::export::Err(__err) => {
+                                        return _serde::export::Err(__err);
+                                    }
+                                };
+                            }
+                        }
+                    }
+                    if !__field0 {
+                        self.place.a = match _serde::private::de::missing_field("a") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        };
+                    };
+                    if !__field1 {
+                        self.place.b = match _serde::private::de::missing_field("b") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        };
+                    };
+                    if !__field2 {
+                        self.place.c = match _serde::private::de::missing_field("c") {
+                            _serde::export::Ok(__val) => __val,
+                            _serde::export::Err(__err) => {
+                                return _serde::export::Err(__err);
+                            }
+                        };
+                    };
+                    _serde::export::Ok(())
+                }
+            }
+            const FIELDS: &'static [&'static str] = &["a", "b", "c"];
+            _serde::Deserializer::deserialize_struct(
+                __deserializer,
+                "DeNamedMap",
+                FIELDS,
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/named_map.rs

@@ -0,0 +1,15 @@
+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,
+}

test_suite/tests/expand/named_tuple.expanded.rs

@@ -0,0 +1,250 @@
+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(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.0) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.1) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::Err(__err);
+                }
+            };
+            match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.2) {
+                _serde::export::Ok(__val) => __val,
+                _serde::export::Err(__err) => {
+                    return _serde::export::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(rust_2018_idioms, 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::export::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::export::PhantomData<DeNamedTuple<A, B, C>>,
+                lifetime: _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "tuple struct DeNamedTuple")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
+                    {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        _serde::export::Some(__value) => __value,
+                        _serde::export::None => {
+                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                                2usize,
+                                &"tuple struct DeNamedTuple with 3 elements",
+                            ));
+                        }
+                    };
+                    _serde::export::Ok(DeNamedTuple(__field0, __field1, __field2))
+                }
+            }
+            _serde::Deserializer::deserialize_tuple_struct(
+                __deserializer,
+                "DeNamedTuple",
+                3usize,
+                __Visitor {
+                    marker: _serde::export::PhantomData::<DeNamedTuple<A, B, C>>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+        fn deserialize_in_place<__D>(
+            __deserializer: __D,
+            __place: &mut Self,
+        ) -> _serde::export::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::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "tuple struct DeNamedTuple")
+                }
+                #[inline]
+                fn visit_seq<__A>(
+                    self,
+                    mut __seq: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::SeqAccess<'de>,
+                {
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            0usize,
+                            &"tuple struct DeNamedTuple with 3 elements",
+                        ));
+                    }
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.1),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            1usize,
+                            &"tuple struct DeNamedTuple with 3 elements",
+                        ));
+                    }
+                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                        &mut __seq,
+                        _serde::private::de::InPlaceSeed(&mut self.place.2),
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    } {
+                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                            2usize,
+                            &"tuple struct DeNamedTuple with 3 elements",
+                        ));
+                    }
+                    _serde::export::Ok(())
+                }
+            }
+            _serde::Deserializer::deserialize_tuple_struct(
+                __deserializer,
+                "DeNamedTuple",
+                3usize,
+                __Visitor {
+                    place: __place,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/named_tuple.rs

@@ -0,0 +1,7 @@
+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);

test_suite/tests/expand/named_unit.expanded.rs

@@ -0,0 +1,49 @@
+use serde::{Deserialize, Serialize};
+struct NamedUnit;
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, clippy::useless_attribute)]
+    extern crate serde as _serde;
+    #[automatically_derived]
+    impl _serde::Serialize for NamedUnit {
+        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::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(rust_2018_idioms, clippy::useless_attribute)]
+    extern crate serde as _serde;
+    #[automatically_derived]
+    impl<'de> _serde::Deserialize<'de> for NamedUnit {
+        fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "unit struct NamedUnit")
+                }
+                #[inline]
+                fn visit_unit<__E>(self) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    _serde::export::Ok(NamedUnit)
+                }
+            }
+            _serde::Deserializer::deserialize_unit_struct(__deserializer, "NamedUnit", __Visitor)
+        }
+    }
+};

test_suite/tests/expand/named_unit.rs

@@ -0,0 +1,4 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+struct NamedUnit;

test_suite/tests/expand/ser_enum.expanded.rs

@@ -0,0 +1,268 @@
+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(rust_2018_idioms, 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::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field0,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field1,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field2,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field3,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "a",
+                        a,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "b",
+                        b,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "c",
+                        c,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "d",
+                        d,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field0,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field1,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field2,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeTupleVariant::serialize_field(
+                        &mut __serde_state,
+                        __field3,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::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::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "a",
+                        a,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "b",
+                        b,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "c",
+                        c,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    match _serde::ser::SerializeStructVariant::serialize_field(
+                        &mut __serde_state,
+                        "d",
+                        d,
+                    ) {
+                        _serde::export::Ok(__val) => __val,
+                        _serde::export::Err(__err) => {
+                            return _serde::export::Err(__err);
+                        }
+                    };
+                    _serde::ser::SerializeStructVariant::end(__serde_state)
+                }
+            }
+        }
+    }
+};

test_suite/tests/expand/ser_enum.rs

@@ -0,0 +1,16 @@
+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 },
+}

test_suite/tests/expand/void.expanded.rs

@@ -0,0 +1,124 @@
+use serde::{Deserialize, Serialize};
+enum Void {}
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, clippy::useless_attribute)]
+    extern crate serde as _serde;
+    #[automatically_derived]
+    impl _serde::Serialize for Void {
+        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        where
+            __S: _serde::Serializer,
+        {
+            match *self {}
+        }
+    }
+};
+#[doc(hidden)]
+#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+const _: () = {
+    #[allow(rust_2018_idioms, clippy::useless_attribute)]
+    extern crate serde as _serde;
+    #[automatically_derived]
+    impl<'de> _serde::Deserialize<'de> for Void {
+        fn deserialize<__D>(__deserializer: __D) -> _serde::export::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::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                }
+                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                            _serde::de::Unexpected::Unsigned(__value),
+                            &"variant index 0 <= i < 0",
+                        )),
+                    }
+                }
+                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                            __value, VARIANTS,
+                        )),
+                    }
+                }
+                fn visit_bytes<__E>(
+                    self,
+                    __value: &[u8],
+                ) -> _serde::export::Result<Self::Value, __E>
+                where
+                    __E: _serde::de::Error,
+                {
+                    match __value {
+                        _ => {
+                            let __value = &_serde::export::from_utf8_lossy(__value);
+                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                                __value, VARIANTS,
+                            ))
+                        }
+                    }
+                }
+            }
+            impl<'de> _serde::Deserialize<'de> for __Field {
+                #[inline]
+                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                where
+                    __D: _serde::Deserializer<'de>,
+                {
+                    _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor)
+                }
+            }
+            struct __Visitor<'de> {
+                marker: _serde::export::PhantomData<Void>,
+                lifetime: _serde::export::PhantomData<&'de ()>,
+            }
+            impl<'de> _serde::de::Visitor<'de> for __Visitor<'de> {
+                type Value = Void;
+                fn expecting(
+                    &self,
+                    __formatter: &mut _serde::export::Formatter,
+                ) -> _serde::export::fmt::Result {
+                    _serde::export::Formatter::write_str(__formatter, "enum Void")
+                }
+                fn visit_enum<__A>(
+                    self,
+                    __data: __A,
+                ) -> _serde::export::Result<Self::Value, __A::Error>
+                where
+                    __A: _serde::de::EnumAccess<'de>,
+                {
+                    _serde::export::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::export::PhantomData::<Void>,
+                    lifetime: _serde::export::PhantomData,
+                },
+            )
+        }
+    }
+};

test_suite/tests/expand/void.rs

@@ -0,0 +1,4 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+enum Void {}

test_suite/tests/expandtest.rs

@@ -0,0 +1,8 @@
+#[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");
+}

test_suite/tests/test_annotations.rs

@@ -1,19 +1,14 @@
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(feature = "cargo-clippy", allow(cast_lossless))]
+#![allow(clippy::cast_lossless, clippy::trivially_copy_pass_by_ref)]
 
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-use self::serde::de::{self, MapAccess, Unexpected, Visitor};
-use self::serde::{Deserialize, Deserializer, Serialize, Serializer};
+use serde::de::{self, MapAccess, Unexpected, Visitor};
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
 use std::collections::{BTreeMap, HashMap};
+use std::convert::TryFrom;
 use std::fmt;
 use std::marker::PhantomData;
 
-extern crate serde_test;
-use self::serde_test::{
+use serde_test::{
     assert_de_tokens, assert_de_tokens_error, assert_ser_tokens, assert_ser_tokens_error,
     assert_tokens, Token,
 };
@@ -68,7 +63,7 @@ impl DeserializeWith for i32 {
     where
         D: Deserializer<'de>,
     {
-        if try!(Deserialize::deserialize(de)) {
+        if Deserialize::deserialize(de)? {
             Ok(123)
         } else {
             Ok(2)
@@ -93,6 +88,15 @@ where
     a5: E,
 }
 
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
+struct DefaultTupleStruct<A, B, C>(
+    A,
+    #[serde(default)] B,
+    #[serde(default = "MyDefault::my_default")] C,
+)
+where
+    C: MyDefault;
+
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 struct CollectOther {
     a: u32,
@@ -186,8 +190,37 @@ fn test_default_struct() {
     );
 }
 
+#[test]
+fn test_default_tuple() {
+    assert_de_tokens(
+        &DefaultTupleStruct(1, 2, 3),
+        &[
+            Token::TupleStruct {
+                name: "DefaultTupleStruct",
+                len: 3,
+            },
+            Token::I32(1),
+            Token::I32(2),
+            Token::I32(3),
+            Token::TupleStructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &DefaultTupleStruct(1, 0, 123),
+        &[
+            Token::TupleStruct {
+                name: "DefaultTupleStruct",
+                len: 3,
+            },
+            Token::I32(1),
+            Token::TupleStructEnd,
+        ],
+    );
+}
+
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
-enum DefaultEnum<A, B, C, D, E>
+enum DefaultStructVariant<A, B, C, D, E>
 where
     C: MyDefault,
     E: MyDefault,
@@ -205,10 +238,22 @@ where
     },
 }
 
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
+enum DefaultTupleVariant<A, B, C>
+where
+    C: MyDefault,
+{
+    Tuple(
+        A,
+        #[serde(default)] B,
+        #[serde(default = "MyDefault::my_default")] C,
+    ),
+}
+
 #[test]
-fn test_default_enum() {
+fn test_default_struct_variant() {
     assert_de_tokens(
-        &DefaultEnum::Struct {
+        &DefaultStructVariant::Struct {
             a1: 1,
             a2: 2,
             a3: 3,
@@ -217,7 +262,7 @@ fn test_default_enum() {
         },
         &[
             Token::StructVariant {
-                name: "DefaultEnum",
+                name: "DefaultStructVariant",
                 variant: "Struct",
                 len: 3,
             },
@@ -236,7 +281,7 @@ fn test_default_enum() {
     );
 
     assert_de_tokens(
-        &DefaultEnum::Struct {
+        &DefaultStructVariant::Struct {
             a1: 1,
             a2: 0,
             a3: 123,
@@ -245,7 +290,7 @@ fn test_default_enum() {
         },
         &[
             Token::StructVariant {
-                name: "DefaultEnum",
+                name: "DefaultStructVariant",
                 variant: "Struct",
                 len: 3,
             },
@@ -256,6 +301,37 @@ fn test_default_enum() {
     );
 }
 
+#[test]
+fn test_default_tuple_variant() {
+    assert_de_tokens(
+        &DefaultTupleVariant::Tuple(1, 2, 3),
+        &[
+            Token::TupleVariant {
+                name: "DefaultTupleVariant",
+                variant: "Tuple",
+                len: 3,
+            },
+            Token::I32(1),
+            Token::I32(2),
+            Token::I32(3),
+            Token::TupleVariantEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &DefaultTupleVariant::Tuple(1, 0, 123),
+        &[
+            Token::TupleVariant {
+                name: "DefaultTupleVariant",
+                variant: "Tuple",
+                len: 3,
+            },
+            Token::I32(1),
+            Token::TupleVariantEnd,
+        ],
+    );
+}
+
 // Does not implement std::default::Default.
 #[derive(Debug, PartialEq, Deserialize)]
 struct NoStdDefault(i8);
@@ -441,6 +517,16 @@ struct RenameStructSerializeDeserialize {
     a2: i32,
 }
 
+#[derive(Debug, PartialEq, Deserialize)]
+#[serde(deny_unknown_fields)]
+struct AliasStruct {
+    a1: i32,
+    #[serde(alias = "a3")]
+    a2: i32,
+    #[serde(alias = "a5", rename = "a6")]
+    a4: i32,
+}
+
 #[test]
 fn test_rename_struct() {
     assert_tokens(
@@ -487,6 +573,67 @@ fn test_rename_struct() {
             Token::StructEnd,
         ],
     );
+
+    assert_de_tokens(
+        &AliasStruct {
+            a1: 1,
+            a2: 2,
+            a4: 3,
+        },
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a2"),
+            Token::I32(2),
+            Token::Str("a5"),
+            Token::I32(3),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &AliasStruct {
+            a1: 1,
+            a2: 2,
+            a4: 3,
+        },
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a3"),
+            Token::I32(2),
+            Token::Str("a6"),
+            Token::I32(3),
+            Token::StructEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_unknown_field_rename_struct() {
+    assert_de_tokens_error::<AliasStruct>(
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a3"),
+            Token::I32(2),
+            Token::Str("a4"),
+            Token::I32(3),
+        ],
+        "unknown field `a4`, expected one of `a1`, `a2`, `a6`",
+    );
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -517,6 +664,19 @@ enum RenameEnumSerializeDeserialize<A> {
     },
 }
 
+#[derive(Debug, PartialEq, Deserialize)]
+#[serde(deny_unknown_fields)]
+enum AliasEnum {
+    #[serde(rename = "sailor_moon", alias = "usagi_tsukino")]
+    SailorMoon {
+        a: i8,
+        #[serde(alias = "c")]
+        b: i8,
+        #[serde(alias = "e", rename = "f")]
+        d: i8,
+    },
+}
+
 #[test]
 fn test_rename_enum() {
     assert_tokens(
@@ -603,6 +763,71 @@ fn test_rename_enum() {
             Token::StructVariantEnd,
         ],
     );
+
+    assert_de_tokens(
+        &AliasEnum::SailorMoon { a: 0, b: 1, d: 2 },
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "sailor_moon",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("b"),
+            Token::I8(1),
+            Token::Str("e"),
+            Token::I8(2),
+            Token::StructVariantEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &AliasEnum::SailorMoon { a: 0, b: 1, d: 2 },
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "usagi_tsukino",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("c"),
+            Token::I8(1),
+            Token::Str("f"),
+            Token::I8(2),
+            Token::StructVariantEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_unknown_field_rename_enum() {
+    assert_de_tokens_error::<AliasEnum>(
+        &[Token::StructVariant {
+            name: "AliasEnum",
+            variant: "SailorMoon",
+            len: 3,
+        }],
+        "unknown variant `SailorMoon`, expected `sailor_moon`",
+    );
+
+    assert_de_tokens_error::<AliasEnum>(
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "usagi_tsukino",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("c"),
+            Token::I8(1),
+            Token::Str("d"),
+            Token::I8(2),
+        ],
+        "unknown field `d`, expected one of `a`, `b`, `f`",
+    );
 }
 
 #[derive(Debug, PartialEq, Serialize)]
@@ -1364,14 +1589,35 @@ impl From<Option<u32>> for EnumToU32 {
     }
 }
 
+#[derive(Clone, Deserialize, PartialEq, Debug)]
+#[serde(try_from = "u32")]
+enum TryFromU32 {
+    One,
+    Two,
+}
+
+impl TryFrom<u32> for TryFromU32 {
+    type Error = String;
+
+    fn try_from(value: u32) -> Result<Self, Self::Error> {
+        match value {
+            1 => Ok(TryFromU32::One),
+            2 => Ok(TryFromU32::Two),
+            _ => Err("out of range".to_owned()),
+        }
+    }
+}
+
 #[test]
 fn test_from_into_traits() {
-    assert_ser_tokens::<EnumToU32>(&EnumToU32::One, &[Token::Some, Token::U32(1)]);
-    assert_ser_tokens::<EnumToU32>(&EnumToU32::Nothing, &[Token::None]);
-    assert_de_tokens::<EnumToU32>(&EnumToU32::Two, &[Token::Some, Token::U32(2)]);
-    assert_ser_tokens::<StructFromEnum>(&StructFromEnum(Some(5)), &[Token::None]);
-    assert_ser_tokens::<StructFromEnum>(&StructFromEnum(None), &[Token::None]);
-    assert_de_tokens::<StructFromEnum>(&StructFromEnum(Some(2)), &[Token::Some, Token::U32(2)]);
+    assert_ser_tokens(&EnumToU32::One, &[Token::Some, Token::U32(1)]);
+    assert_ser_tokens(&EnumToU32::Nothing, &[Token::None]);
+    assert_de_tokens(&EnumToU32::Two, &[Token::Some, Token::U32(2)]);
+    assert_ser_tokens(&StructFromEnum(Some(5)), &[Token::None]);
+    assert_ser_tokens(&StructFromEnum(None), &[Token::None]);
+    assert_de_tokens(&StructFromEnum(Some(2)), &[Token::Some, Token::U32(2)]);
+    assert_de_tokens(&TryFromU32::Two, &[Token::U32(2)]);
+    assert_de_tokens_error::<TryFromU32>(&[Token::U32(5)], "out of range");
 }
 
 #[test]
@@ -1721,6 +1967,29 @@ fn test_flatten_map_twice() {
     );
 }
 
+#[test]
+fn test_flatten_unit() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    struct Response<T> {
+        #[serde(flatten)]
+        data: T,
+        status: usize,
+    }
+
+    assert_tokens(
+        &Response {
+            data: (),
+            status: 0,
+        },
+        &[
+            Token::Map { len: None },
+            Token::Str("status"),
+            Token::U64(0),
+            Token::MapEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_flatten_unsupported_type() {
     #[derive(Debug, PartialEq, Serialize, Deserialize)]

test_suite/tests/test_borrow.rs

@@ -1,10 +1,4 @@
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
 use serde::{Deserialize, Deserializer};
-
-extern crate serde_test;
 use serde_test::{assert_de_tokens, assert_de_tokens_error, Token};
 
 use std::borrow::Cow;

test_suite/tests/test_de.rs

@@ -1,28 +1,29 @@
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(feature = "cargo-clippy", allow(decimal_literal_representation))]
+#![allow(clippy::decimal_literal_representation, clippy::unreadable_literal)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
-#[macro_use]
-extern crate serde_derive;
-
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::default::Default;
 use std::ffi::{CStr, CString, OsString};
+use std::fmt::Debug;
 use std::net;
 use std::num::Wrapping;
+use std::ops::Bound;
 use std::path::{Path, PathBuf};
 use std::rc::{Rc, Weak as RcWeak};
+use std::sync::atomic::{
+    AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
+    AtomicUsize, Ordering,
+};
 use std::sync::{Arc, Weak as ArcWeak};
 use std::time::{Duration, UNIX_EPOCH};
 
-extern crate serde;
+#[cfg(target_arch = "x86_64")]
+use std::sync::atomic::{AtomicI64, AtomicU64};
+
+use fnv::FnvHasher;
+use serde::de::DeserializeOwned;
 use serde::{Deserialize, Deserializer};
-
-extern crate fnv;
-use self::fnv::FnvHasher;
-
-extern crate serde_test;
-use self::serde_test::{assert_de_tokens, assert_de_tokens_error, Configure, Token};
+use serde_test::{assert_de_tokens, assert_de_tokens_error, Configure, Token};
 
 #[macro_use]
 mod macros;
@@ -103,6 +104,9 @@ struct StructSkipAllDenyUnknown {
     a: i32,
 }
 
+#[derive(Default, PartialEq, Debug)]
+struct NotDeserializable;
+
 #[derive(PartialEq, Debug, Deserialize)]
 enum Enum {
     #[allow(dead_code)]
@@ -116,6 +120,7 @@ enum Enum {
         b: i32,
         c: i32,
     },
+    SimpleWithSkipped(#[serde(skip_deserializing)] NotDeserializable),
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
@@ -132,6 +137,19 @@ enum EnumOther {
     Other,
 }
 
+#[derive(PartialEq, Debug)]
+struct IgnoredAny;
+
+impl<'de> Deserialize<'de> for IgnoredAny {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        serde::de::IgnoredAny::deserialize(deserializer)?;
+        Ok(IgnoredAny)
+    }
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 macro_rules! declare_tests {
@@ -714,6 +732,11 @@ declare_tests! {
             Token::I32(1),
         ],
     }
+    test_enum_simple_with_skipped {
+        Enum::SimpleWithSkipped(NotDeserializable) => &[
+            Token::UnitVariant { name: "Enum", variant: "SimpleWithSkipped" },
+        ],
+    }
     test_enum_seq {
         Enum::Seq(1, 2, 3) => &[
             Token::TupleVariant { name: "Enum", variant: "Seq", len: 3 },
@@ -845,15 +868,58 @@ declare_tests! {
             Token::SeqEnd,
         ],
     }
+    test_bound {
+        Bound::Unbounded::<()> => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Unbounded"),
+            Token::Unit,
+        ],
+        Bound::Included(0) => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Included"),
+            Token::U8(0),
+        ],
+        Bound::Excluded(0) => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Excluded"),
+            Token::U8(0),
+        ],
+    }
     test_path {
         Path::new("/usr/local/lib") => &[
             Token::BorrowedStr("/usr/local/lib"),
         ],
+        Path::new("/usr/local/lib") => &[
+            Token::BorrowedBytes(b"/usr/local/lib"),
+        ],
     }
     test_path_buf {
+        PathBuf::from("/usr/local/lib") => &[
+            Token::Str("/usr/local/lib"),
+        ],
         PathBuf::from("/usr/local/lib") => &[
             Token::String("/usr/local/lib"),
         ],
+        PathBuf::from("/usr/local/lib") => &[
+            Token::Bytes(b"/usr/local/lib"),
+        ],
+        PathBuf::from("/usr/local/lib") => &[
+            Token::ByteBuf(b"/usr/local/lib"),
+        ],
+    }
+    test_boxed_path {
+        PathBuf::from("/usr/local/lib").into_boxed_path() => &[
+            Token::Str("/usr/local/lib"),
+        ],
+        PathBuf::from("/usr/local/lib").into_boxed_path() => &[
+            Token::String("/usr/local/lib"),
+        ],
+        PathBuf::from("/usr/local/lib").into_boxed_path() => &[
+            Token::Bytes(b"/usr/local/lib"),
+        ],
+        PathBuf::from("/usr/local/lib").into_boxed_path() => &[
+            Token::ByteBuf(b"/usr/local/lib"),
+        ],
     }
     test_cstring {
         CString::new("abc").unwrap() => &[
@@ -920,6 +986,21 @@ declare_tests! {
             Token::SeqEnd,
         ],
     }
+    test_ignored_any {
+        IgnoredAny => &[
+            Token::Str("s"),
+        ],
+        IgnoredAny => &[
+            Token::Seq { len: Some(1) },
+            Token::Bool(true),
+            Token::SeqEnd,
+        ],
+        IgnoredAny => &[
+            Token::Enum { name: "E" },
+            Token::Str("Rust"),
+            Token::Unit,
+        ],
+    }
 }
 
 declare_tests! {
@@ -1103,6 +1184,45 @@ fn test_never_type() {
     );
 }
 
+#[test]
+fn test_atomics() {
+    fn test<L, A, T>(load: L, val: T, token: Token)
+    where
+        L: Fn(&A, Ordering) -> T,
+        A: DeserializeOwned,
+        T: PartialEq + Debug,
+    {
+        let tokens = &[token];
+        let mut de = serde_test::Deserializer::new(tokens);
+        match A::deserialize(&mut de) {
+            Ok(v) => {
+                let loaded = load(&v, Ordering::SeqCst);
+                assert_eq!(val, loaded);
+            }
+            Err(e) => panic!("tokens failed to deserialize: {}", e),
+        };
+        if de.remaining() > 0 {
+            panic!("{} remaining tokens", de.remaining());
+        }
+    }
+
+    test(AtomicBool::load, true, Token::Bool(true));
+    test(AtomicI8::load, -127, Token::I8(-127i8));
+    test(AtomicI16::load, -510, Token::I16(-510i16));
+    test(AtomicI32::load, -131072, Token::I32(-131072i32));
+    test(AtomicIsize::load, -131072isize, Token::I32(-131072));
+    test(AtomicU8::load, 127, Token::U8(127u8));
+    test(AtomicU16::load, 510u16, Token::U16(510u16));
+    test(AtomicU32::load, 131072u32, Token::U32(131072u32));
+    test(AtomicUsize::load, 131072usize, Token::U32(131072));
+
+    #[cfg(target_arch = "x86_64")]
+    {
+        test(AtomicI64::load, -8589934592, Token::I64(-8589934592));
+        test(AtomicU64::load, 8589934592u64, Token::U64(8589934592));
+    }
+}
+
 declare_error_tests! {
     test_unknown_field<StructDenyUnknown> {
         &[
@@ -1132,13 +1252,13 @@ declare_error_tests! {
         &[
             Token::UnitVariant { name: "Enum", variant: "Foo" },
         ],
-        "unknown variant `Foo`, expected one of `Unit`, `Simple`, `Seq`, `Map`",
+        "unknown variant `Foo`, expected one of `Unit`, `Simple`, `Seq`, `Map`, `SimpleWithSkipped`",
     }
     test_enum_skipped_variant<Enum> {
         &[
             Token::UnitVariant { name: "Enum", variant: "Skipped" },
         ],
-        "unknown variant `Skipped`, expected one of `Unit`, `Simple`, `Seq`, `Map`",
+        "unknown variant `Skipped`, expected one of `Unit`, `Simple`, `Seq`, `Map`, `SimpleWithSkipped`",
     }
     test_enum_skip_all<EnumSkipAll> {
         &[
@@ -1169,10 +1289,10 @@ declare_error_tests! {
     test_enum_out_of_range<Enum> {
         &[
             Token::Enum { name: "Enum" },
-            Token::U32(4),
+            Token::U32(5),
             Token::Unit,
         ],
-        "invalid value: integer `4`, expected variant index 0 <= i < 4",
+        "invalid value: integer `5`, expected variant index 0 <= i < 5",
     }
     test_short_tuple<(u8, u8, u8)> {
         &[

test_suite/tests/test_gen.rs

@@ -4,13 +4,14 @@
 
 #![deny(warnings)]
 #![cfg_attr(feature = "unstable", feature(non_ascii_idents))]
+#![allow(
+    unknown_lints,
+    mixed_script_confusables,
+    clippy::trivially_copy_pass_by_ref
+)]
 
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-use self::serde::de::{DeserializeOwned, Deserializer};
-use self::serde::ser::{Serialize, Serializer};
+use serde::de::DeserializeOwned;
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
 use std::borrow::Cow;
 use std::marker::PhantomData;
@@ -384,6 +385,8 @@ fn test_gen() {
     }
 
     mod vis {
+        use serde::{Deserialize, Serialize};
+
         pub struct S;
 
         #[derive(Serialize, Deserialize)]
@@ -523,6 +526,13 @@ fn test_gen() {
     }
     assert::<FlattenWith>();
 
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct FlattenDenyUnknown<T> {
+        #[serde(flatten)]
+        t: T,
+    }
+
     #[derive(Serialize, Deserialize)]
     struct StaticStrStruct<'a> {
         a: &'a str,
@@ -607,6 +617,8 @@ fn test_gen() {
 
     mod restricted {
         mod inner {
+            use serde::{Deserialize, Serialize};
+
             #[derive(Serialize, Deserialize)]
             struct Restricted {
                 pub(super) a: usize,
@@ -664,6 +676,53 @@ fn test_gen() {
         ty: &'a str,
         id: String,
     }
+
+    #[derive(Serialize, Deserialize)]
+    struct FlattenSkipSerializing<T> {
+        #[serde(flatten, skip_serializing)]
+        #[allow(dead_code)]
+        flat: T,
+    }
+
+    #[derive(Serialize, Deserialize)]
+    struct FlattenSkipSerializingIf<T> {
+        #[serde(flatten, skip_serializing_if = "StdOption::is_none")]
+        flat: StdOption<T>,
+    }
+
+    #[derive(Serialize, Deserialize)]
+    struct FlattenSkipDeserializing<T> {
+        #[serde(flatten, skip_deserializing)]
+        flat: T,
+    }
+
+    // https://github.com/serde-rs/serde/issues/1804
+    #[derive(Serialize, Deserialize)]
+    enum Message {
+        #[serde(skip)]
+        #[allow(dead_code)]
+        String(String),
+        #[serde(other)]
+        Unknown,
+    }
+
+    #[derive(Serialize)]
+    #[repr(packed)]
+    struct Packed {
+        x: u8,
+        y: u16,
+    }
+
+    macro_rules! deriving {
+        ($field:ty) => {
+            #[derive(Deserialize)]
+            struct MacroRules<'a> {
+                field: $field,
+            }
+        };
+    }
+
+    deriving!(&'a str);
 }
 
 //////////////////////////////////////////////////////////////////////////

test_suite/tests/test_identifier.rs

@@ -1,7 +1,4 @@
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde_test;
+use serde::Deserialize;
 use serde_test::{assert_de_tokens, Token};
 
 #[test]

test_suite/tests/test_ignored_any.rs

@@ -0,0 +1,104 @@
+use serde::de::value::{Error, MapDeserializer, SeqDeserializer};
+use serde::de::{
+    DeserializeSeed, EnumAccess, IgnoredAny, IntoDeserializer, VariantAccess, Visitor,
+};
+use serde::{forward_to_deserialize_any, Deserialize, Deserializer};
+
+#[derive(PartialEq, Debug, Deserialize)]
+enum Target {
+    Unit,
+    Newtype(i32),
+    Tuple(i32, i32),
+    Struct { a: i32 },
+}
+
+struct Enum(&'static str);
+
+impl<'de> Deserializer<'de> for Enum {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_enum(self)
+    }
+
+    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
+    }
+}
+
+impl<'de> EnumAccess<'de> for Enum {
+    type Error = Error;
+    type Variant = Self;
+
+    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error>
+    where
+        V: DeserializeSeed<'de>,
+    {
+        let v = seed.deserialize(self.0.into_deserializer())?;
+        Ok((v, self))
+    }
+}
+
+impl<'de> VariantAccess<'de> for Enum {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
+    where
+        T: DeserializeSeed<'de>,
+    {
+        seed.deserialize(10i32.into_deserializer())
+    }
+
+    fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        let seq = SeqDeserializer::new(vec![1i32, 2].into_iter());
+        visitor.visit_seq(seq)
+    }
+
+    fn struct_variant<V>(
+        self,
+        _fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        let map = MapDeserializer::new(vec![("a", 10i32)].into_iter());
+        visitor.visit_map(map)
+    }
+}
+
+#[test]
+fn test_deserialize_enum() {
+    // First just make sure the Deserializer impl works
+    assert_eq!(Target::Unit, Target::deserialize(Enum("Unit")).unwrap());
+    assert_eq!(
+        Target::Newtype(10),
+        Target::deserialize(Enum("Newtype")).unwrap()
+    );
+    assert_eq!(
+        Target::Tuple(1, 2),
+        Target::deserialize(Enum("Tuple")).unwrap()
+    );
+    assert_eq!(
+        Target::Struct { a: 10 },
+        Target::deserialize(Enum("Struct")).unwrap()
+    );
+
+    // Now try IgnoredAny
+    IgnoredAny::deserialize(Enum("Unit")).unwrap();
+    IgnoredAny::deserialize(Enum("Newtype")).unwrap();
+    IgnoredAny::deserialize(Enum("Tuple")).unwrap();
+    IgnoredAny::deserialize(Enum("Struct")).unwrap();
+}

test_suite/tests/test_macros.rs

@@ -1,16 +1,10 @@
 #![deny(trivial_numeric_casts)]
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(feature = "cargo-clippy", allow(redundant_field_names))]
-
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_test;
+#![allow(clippy::redundant_field_names)]
 
 mod bytes;
 
-use self::serde_test::{
+use serde::{Deserialize, Serialize};
+use serde_test::{
     assert_de_tokens, assert_de_tokens_error, assert_ser_tokens, assert_tokens, Token,
 };
 
@@ -643,7 +637,10 @@ fn test_untagged_enum() {
         ],
     );
 
+    // Serializes to unit, deserializes from either depending on format's
+    // preference.
     assert_tokens(&Untagged::C, &[Token::Unit]);
+    assert_de_tokens(&Untagged::C, &[Token::None]);
 
     assert_tokens(&Untagged::D(4), &[Token::U8(4)]);
     assert_tokens(&Untagged::E("e".to_owned()), &[Token::Str("e")]);
@@ -658,11 +655,6 @@ fn test_untagged_enum() {
         ],
     );
 
-    assert_de_tokens_error::<Untagged>(
-        &[Token::None],
-        "data did not match any variant of untagged enum Untagged",
-    );
-
     assert_de_tokens_error::<Untagged>(
         &[Token::Tuple { len: 1 }, Token::U8(1), Token::TupleEnd],
         "data did not match any variant of untagged enum Untagged",
@@ -1153,6 +1145,20 @@ fn test_adjacently_tagged_enum() {
         ],
     );
 
+    // optional newtype with no content field
+    assert_de_tokens(
+        &AdjacentlyTagged::Newtype::<Option<u8>>(None),
+        &[
+            Token::Struct {
+                name: "AdjacentlyTagged",
+                len: 1,
+            },
+            Token::Str("t"),
+            Token::Str("Newtype"),
+            Token::StructEnd,
+        ],
+    );
+
     // tuple with tag first
     assert_tokens(
         &AdjacentlyTagged::Tuple::<u8>(1, 1),
@@ -1376,6 +1382,130 @@ fn test_enum_in_internally_tagged_enum() {
     );
 }
 
+#[test]
+fn test_internally_tagged_struct() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "type")]
+    pub struct Struct {
+        a: u8,
+    }
+
+    assert_tokens(
+        &Struct { a: 1 },
+        &[
+            Token::Struct {
+                name: "Struct",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Struct"),
+            Token::Str("a"),
+            Token::U8(1),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Struct { a: 1 },
+        &[
+            Token::Struct {
+                name: "Struct",
+                len: 1,
+            },
+            Token::Str("a"),
+            Token::U8(1),
+            Token::StructEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_internally_tagged_braced_struct_with_zero_fields() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "type")]
+    struct S {}
+
+    assert_tokens(
+        &S {},
+        &[
+            Token::Struct { name: "S", len: 1 },
+            Token::Str("type"),
+            Token::Str("S"),
+            Token::StructEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_internally_tagged_struct_with_flattened_field() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "tag_struct")]
+    pub struct Struct {
+        #[serde(flatten)]
+        pub flat: Enum,
+    }
+
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "tag_enum", content = "content")]
+    pub enum Enum {
+        A(u64),
+    }
+
+    assert_tokens(
+        &Struct { flat: Enum::A(0) },
+        &[
+            Token::Map { len: None },
+            Token::Str("tag_struct"),
+            Token::Str("Struct"),
+            Token::Str("tag_enum"),
+            Token::Str("A"),
+            Token::Str("content"),
+            Token::U64(0),
+            Token::MapEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Struct { flat: Enum::A(0) },
+        &[
+            Token::Map { len: None },
+            Token::Str("tag_enum"),
+            Token::Str("A"),
+            Token::Str("content"),
+            Token::U64(0),
+            Token::MapEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_untagged_enum_with_flattened_integer_key() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(untagged)]
+    pub enum Untagged {
+        Variant {
+            #[serde(flatten)]
+            map: BTreeMap<u64, String>,
+        },
+    }
+
+    assert_tokens(
+        &Untagged::Variant {
+            map: {
+                let mut map = BTreeMap::new();
+                map.insert(100, "BTreeMap".to_owned());
+                map
+            },
+        },
+        &[
+            Token::Map { len: None },
+            Token::U64(100),
+            Token::Str("BTreeMap"),
+            Token::MapEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_enum_in_untagged_enum() {
     #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -1748,3 +1878,31 @@ fn test_internally_tagged_newtype_variant_containing_unit_struct() {
         ],
     );
 }
+
+#[deny(safe_packed_borrows)]
+#[test]
+fn test_packed_struct_can_derive_serialize() {
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(packed, C)]
+    struct PackedC {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(C, packed)]
+    struct CPacked {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(C, packed(2))]
+    struct CPacked2 {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(packed(2), C)]
+    struct Packed2C {
+        t: f32,
+    }
+}

test_suite/tests/test_remote.rs

@@ -1,8 +1,6 @@
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(feature = "cargo-clippy", allow(redundant_field_names))]
+#![allow(clippy::redundant_field_names)]
 
-#[macro_use]
-extern crate serde_derive;
+use serde::{Deserialize, Serialize};
 
 mod remote {
     pub struct Unit;

test_suite/tests/test_roundtrip.rs

@@ -1,5 +1,4 @@
-extern crate serde_test;
-use self::serde_test::{assert_tokens, Configure, Token};
+use serde_test::{assert_tokens, Configure, Token};
 
 use std::net;
 

test_suite/tests/test_ser.rs

@@ -1,27 +1,30 @@
+#![allow(clippy::unreadable_literal)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
-#[macro_use]
-extern crate serde_derive;
-
 use std::cell::RefCell;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::ffi::CString;
 use std::mem;
 use std::net;
 use std::num::Wrapping;
+use std::ops::Bound;
 use std::path::{Path, PathBuf};
 use std::rc::{Rc, Weak as RcWeak};
+use std::sync::atomic::{
+    AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
+    AtomicUsize,
+};
 use std::sync::{Arc, Weak as ArcWeak};
 use std::time::{Duration, UNIX_EPOCH};
 
 #[cfg(unix)]
 use std::str;
+#[cfg(target_arch = "x86_64")]
+use std::sync::atomic::{AtomicI64, AtomicU64};
 
-extern crate serde_test;
-use self::serde_test::{assert_ser_tokens, assert_ser_tokens_error, Configure, Token};
-
-extern crate fnv;
-use self::fnv::FnvHasher;
+use fnv::FnvHasher;
+use serde::Serialize;
+use serde_test::{assert_ser_tokens, assert_ser_tokens_error, Configure, Token};
 
 #[macro_use]
 mod macros;
@@ -41,6 +44,9 @@ struct Struct {
     c: i32,
 }
 
+#[derive(PartialEq, Debug)]
+struct NotSerializable;
+
 #[derive(Serialize, PartialEq, Debug)]
 enum Enum {
     Unit,
@@ -61,6 +67,7 @@ enum Enum {
         _a: i32,
         _b: i32,
     },
+    OneWithSkipped(#[serde(skip_serializing)] NotSerializable),
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -306,8 +313,13 @@ declare_tests! {
         ],
     }
     test_enum {
-        Enum::Unit => &[Token::UnitVariant { name: "Enum", variant: "Unit" }],
-        Enum::One(42) => &[Token::NewtypeVariant { name: "Enum", variant: "One" }, Token::I32(42)],
+        Enum::Unit => &[
+            Token::UnitVariant { name: "Enum", variant: "Unit" },
+        ],
+        Enum::One(42) => &[
+            Token::NewtypeVariant { name: "Enum", variant: "One" },
+            Token::I32(42),
+        ],
         Enum::Seq(1, 2) => &[
             Token::TupleVariant { name: "Enum", variant: "Seq", len: 2 },
                 Token::I32(1),
@@ -323,6 +335,9 @@ declare_tests! {
                 Token::I32(2),
             Token::StructVariantEnd,
         ],
+        Enum::OneWithSkipped(NotSerializable) => &[
+            Token::UnitVariant { name: "Enum", variant: "OneWithSkipped" },
+        ],
     }
     test_box {
         Box::new(0i32) => &[Token::I32(0)],
@@ -380,6 +395,23 @@ declare_tests! {
             Token::StructEnd,
         ],
     }
+    test_bound {
+        Bound::Unbounded::<()> => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Unbounded"),
+            Token::Unit,
+        ],
+        Bound::Included(0u8) => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Included"),
+            Token::U8(0),
+        ],
+        Bound::Excluded(0u8) => &[
+            Token::Enum { name: "Bound" },
+            Token::Str("Excluded"),
+            Token::U8(0),
+        ],
+    }
     test_path {
         Path::new("/usr/local/lib") => &[
             Token::Str("/usr/local/lib"),
@@ -470,6 +502,26 @@ declare_tests! {
             Token::Str("1a"),
         ],
     }
+    test_atomic {
+        AtomicBool::new(false) => &[Token::Bool(false)],
+        AtomicBool::new(true) => &[Token::Bool(true)],
+        AtomicI8::new(63i8) => &[Token::I8(63i8)],
+        AtomicI16::new(-318i16) => &[Token::I16(-318i16)],
+        AtomicI32::new(65792i32) => &[Token::I32(65792i32)],
+        AtomicIsize::new(-65792isize) => &[Token::I64(-65792i64)],
+        AtomicU8::new(192u8) => &[Token::U8(192u8)],
+        AtomicU16::new(510u16) => &[Token::U16(510u16)],
+        AtomicU32::new(131072u32) => &[Token::U32(131072u32)],
+        AtomicUsize::new(655360usize) => &[Token::U64(655360u64)],
+    }
+}
+
+#[cfg(target_arch = "x86_64")]
+declare_tests! {
+    test_atomic64 {
+        AtomicI64::new(-4295032832i64) => &[Token::I64(-4295032832i64)],
+        AtomicU64::new(12884901888u64) => &[Token::U64(12884901888u64)],
+    }
 }
 
 declare_tests! {

test_suite/tests/test_serde_path.rs

@@ -0,0 +1,40 @@
+#[test]
+fn test_gen_custom_serde() {
+    #[derive(serde::Serialize, serde::Deserialize)]
+    #[serde(crate = "fake_serde")]
+    struct Foo;
+
+    // Would be overlapping if serde::Serialize were implemented
+    impl AssertNotSerdeSerialize for Foo {}
+    // Would be overlapping if serde::Deserialize were implemented
+    impl<'a> AssertNotSerdeDeserialize<'a> for Foo {}
+
+    fake_serde::assert::<Foo>();
+}
+
+mod fake_serde {
+    pub use serde::*;
+
+    pub fn assert<T>()
+    where
+        T: Serialize,
+        T: for<'a> Deserialize<'a>,
+    {
+    }
+
+    pub trait Serialize {
+        fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>;
+    }
+
+    pub trait Deserialize<'a>: Sized {
+        fn deserialize<D: Deserializer<'a>>(deserializer: D) -> Result<Self, D::Error>;
+    }
+}
+
+trait AssertNotSerdeSerialize {}
+
+impl<T: serde::Serialize> AssertNotSerdeSerialize for T {}
+
+trait AssertNotSerdeDeserialize<'a> {}
+
+impl<'a, T: serde::Deserialize<'a>> AssertNotSerdeDeserialize<'a> for T {}

test_suite/tests/test_unstable.rs

@@ -1,14 +1,5 @@
 #![deny(warnings)]
 
-#[cfg(feature = "unstable")]
-#[macro_use]
-extern crate serde_derive;
-
-#[cfg(feature = "unstable")]
-extern crate serde;
-#[cfg(feature = "unstable")]
-extern crate serde_test;
-
 // This test target is convoluted with the actual #[test] in a separate file to
 // get it so that the stable compiler does not need to parse the code of the
 // test. If the test were written with #[cfg(feature = "unstable")] #[test]

test_suite/tests/test_value.rs

@@ -1,9 +1,8 @@
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-use serde::de::{value, IntoDeserializer};
-use serde::Deserialize;
+use serde::de::value::{self, MapAccessDeserializer};
+use serde::de::{IntoDeserializer, MapAccess, Visitor};
+use serde::{Deserialize, Deserializer};
+use serde_test::{assert_de_tokens, Token};
+use std::fmt;
 
 #[test]
 fn test_u32_to_enum() {
@@ -36,3 +35,60 @@ fn test_integer128() {
     // i128 to i128
     assert_eq!(1i128, i128::deserialize(de_i128).unwrap());
 }
+
+#[test]
+fn test_map_access_to_enum() {
+    #[derive(PartialEq, Debug)]
+    struct Potential(PotentialKind);
+
+    #[derive(PartialEq, Debug, Deserialize)]
+    enum PotentialKind {
+        Airebo(Airebo),
+    }
+
+    #[derive(PartialEq, Debug, Deserialize)]
+    struct Airebo {
+        lj_sigma: f64,
+    }
+
+    impl<'de> Deserialize<'de> for Potential {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            struct PotentialVisitor;
+
+            impl<'de> Visitor<'de> for PotentialVisitor {
+                type Value = Potential;
+
+                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    write!(formatter, "a map")
+                }
+
+                fn visit_map<A>(self, map: A) -> Result<Self::Value, A::Error>
+                where
+                    A: MapAccess<'de>,
+                {
+                    Deserialize::deserialize(MapAccessDeserializer::new(map)).map(Potential)
+                }
+            }
+
+            deserializer.deserialize_any(PotentialVisitor)
+        }
+    }
+
+    let expected = Potential(PotentialKind::Airebo(Airebo { lj_sigma: 14.0 }));
+
+    assert_de_tokens(
+        &expected,
+        &[
+            Token::Map { len: Some(1) },
+            Token::Str("Airebo"),
+            Token::Map { len: Some(1) },
+            Token::Str("lj_sigma"),
+            Token::F64(14.0),
+            Token::MapEnd,
+            Token::MapEnd,
+        ],
+    );
+}

test_suite/tests/ui/borrow/bad_lifetimes.rs

@@ -1,5 +1,4 @@
-#[macro_use]
-extern crate serde_derive;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize)]
 struct Test<'a> {

test_suite/tests/ui/borrow/bad_lifetimes.stderr

@@ -1,8 +1,5 @@
 error: failed to parse borrowed lifetimes: "zzz"
- --> $DIR/bad_lifetimes.rs:6:22
+ --> $DIR/bad_lifetimes.rs:5:22
   |
-6 |     #[serde(borrow = "zzz")]
+5 |     #[serde(borrow = "zzz")]
   |                      ^^^^^
-
-error: aborting due to previous error
-

test_suite/tests/ui/borrow/duplicate_lifetime.rs

@@ -1,5 +1,4 @@
-#[macro_use]
-extern crate serde_derive;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize)]
 struct Test<'a> {

test_suite/tests/ui/borrow/duplicate_lifetime.stderr

@@ -1,8 +1,5 @@
 error: duplicate borrowed lifetime `'a`
- --> $DIR/duplicate_lifetime.rs:6:22
+ --> $DIR/duplicate_lifetime.rs:5:22
   |
-6 |     #[serde(borrow = "'a + 'a")]
+5 |     #[serde(borrow = "'a + 'a")]
   |                      ^^^^^^^^^
-
-error: aborting due to previous error
-

test_suite/tests/ui/borrow/duplicate_variant.rs

@@ -1,5 +1,4 @@
-#[macro_use]
-extern crate serde_derive;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize)]
 struct Str<'a>(&'a str);