Release 1.0.221

Deprecate serde_if_integer128 macro

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: dtolnay

.github/workflows/ci.yml

@@ -18,16 +18,22 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
       - run: cd test_suite && cargo test --features unstable
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: Cargo.lock
+          path: Cargo.lock
+        continue-on-error: true
 
   windows:
     name: Test suite (windows)
     runs-on: windows-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
       - run: cd test_suite && cargo test --features unstable -- --skip ui --exact
 
@@ -40,15 +46,16 @@ jobs:
         rust: [stable, beta]
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{matrix.rust}}
       - run: cd serde && cargo build --features rc
       - run: cd serde && cargo build --no-default-features
+      - run: cd test_suite/no_std && cargo build
 
   nightly:
-    name: Rust nightly ${{matrix.os == 'windows' && '(windows)' || ''}}
+    name: Rust nightly${{matrix.os == 'windows' && ' (windows)' || ''}}
     runs-on: ${{matrix.os}}-latest
     strategy:
       fail-fast: false
@@ -56,14 +63,14 @@ jobs:
         os: [ubuntu, windows]
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
       - run: cd serde && cargo build
       - run: cd serde && cargo build --no-default-features
       - run: cd serde && cargo build --no-default-features --features alloc
       - run: cd serde && cargo build --no-default-features --features rc,alloc
       - run: cd serde && cargo build --no-default-features --features unstable
-      - run: cd serde && cargo test --features derive,rc,unstable
+      - run: cd serde_core && cargo test --features rc,unstable
       - run: cd test_suite/no_std && cargo build
         if: matrix.os != 'windows'
       - run: cd serde_derive && cargo check --tests
@@ -77,84 +84,68 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [1.19.0, 1.20.0, 1.21.0, 1.25.0, 1.26.0, 1.34.0]
+        rust: [1.56.0, 1.60.0]
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{matrix.rust}}
+      - run: sed -i '/"test_suite"/d' Cargo.toml
       - run: cd serde && cargo build --features rc
       - run: cd serde && cargo build --no-default-features
-      - run: cd serde && cargo build
+      - run: cd serde && cargo build --no-default-features --features alloc
-
-  more:
-    name: Rust ${{matrix.rust}}
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        rust: [1.27.0, 1.28.0]
-    timeout-minutes: 45
-    steps:
-      - uses: actions/checkout@v3
-      - 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 1.56.0
+    name: Rust 1.61.0
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@1.56.0
+      - uses: dtolnay/rust-toolchain@1.61.0
+      - run: |
+          sed -i 's/proc-macro2 = { workspace = true/proc-macro2 = { version = "1"/' serde_derive*/Cargo.toml
+          sed -i 's/quote = { workspace = true/quote = { version = "1"/' serde_derive*/Cargo.toml
+          sed -i 's/syn = { workspace = true/syn = { version = "2"/' serde_derive*/Cargo.toml
       - run: cd serde && cargo check --no-default-features
       - run: cd serde && cargo check
       - run: cd serde_derive && cargo check
-      - run: cd precompiled/serde_derive && cargo check
-
-  alloc:
-    name: Rust 1.36.0
-    runs-on: ubuntu-latest
-    timeout-minutes: 45
-    steps:
-      - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@1.36.0
-      - run: cd serde && cargo build --no-default-features --features alloc
-
-  macos:
-    name: macOS
-    runs-on: macos-latest
-    timeout-minutes: 45
-    steps:
-      - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@stable
-      - run: cd precompiled/serde_derive && cargo check
 
   minimal:
     name: Minimal versions
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
       - run: cargo generate-lockfile -Z minimal-versions
       - run: cargo check --locked --workspace
 
+  doc:
+    name: Documentation
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    env:
+      RUSTDOCFLAGS: -Dwarnings
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: dtolnay/install@cargo-docs-rs
+      - run: cargo docs-rs -p serde
+      - run: cargo docs-rs -p serde_derive
+      - run: cargo docs-rs -p serde_derive_internals
+
   clippy:
     name: Clippy
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@clippy
       - run: cd serde && cargo clippy --features rc,unstable -- -Dclippy::all -Dclippy::pedantic
+      - run: cd serde_core && cargo clippy --features rc,unstable -- -Dclippy::all -Dclippy::pedantic
       - run: cd serde_derive && cargo clippy -- -Dclippy::all -Dclippy::pedantic
       - run: cd serde_derive_internals && cargo clippy -- -Dclippy::all -Dclippy::pedantic
       - run: cd test_suite && cargo clippy --tests --features unstable -- -Dclippy::all -Dclippy::pedantic
@@ -165,10 +156,12 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@miri
+        with:
+          toolchain: nightly-2025-05-16  # https://github.com/rust-lang/miri/issues/4323
       - run: cargo miri setup
-      - run: cd serde && cargo miri test --features derive,rc,unstable
+      - run: cd serde_core && cargo miri test --features rc,unstable
         env:
           MIRIFLAGS: -Zmiri-strict-provenance
       - run: cd test_suite && cargo miri test --features unstable
@@ -181,6 +174,7 @@ jobs:
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
       - uses: dtolnay/install@cargo-outdated
       - run: cargo outdated --workspace --exit-code 1

.gitignore

@@ -1,4 +1,2 @@
-target/
+/target/
-**/*.rs.bk
+/Cargo.lock
-*.sw[po]
-Cargo.lock

Cargo.toml

@@ -1,10 +1,18 @@
 [workspace]
 members = [
     "serde",
+    "serde_core",
     "serde_derive",
     "serde_derive_internals",
     "test_suite",
 ]
+resolver = "2"
 
 [patch.crates-io]
 serde = { path = "serde" }
+serde_core = { path = "serde_core" }
+
+[workspace.dependencies]
+proc-macro2 = { version = "1.0.74", default-features = false }
+quote = { version = "1.0.35", default-features = false }
+syn = { version = "2.0.81", default-features = false }

README.md

@@ -1,13 +1,13 @@
-# Serde   [![Build Status]][actions] [![Latest Version]][crates.io] [![serde: rustc 1.19+]][Rust 1.19] [![serde_derive: rustc 1.56+]][Rust 1.56]
+# Serde   [![Build Status]][actions] [![Latest Version]][crates.io] [![serde msrv]][Rust 1.56] [![serde_derive msrv]][Rust 1.61]
 
 [Build Status]: https://img.shields.io/github/actions/workflow/status/serde-rs/serde/ci.yml?branch=master
 [actions]: https://github.com/serde-rs/serde/actions?query=branch%3Amaster
 [Latest Version]: https://img.shields.io/crates/v/serde.svg
 [crates.io]: https://crates.io/crates/serde
-[serde: rustc 1.19+]: https://img.shields.io/badge/serde-rustc_1.19+-lightgray.svg
+[serde msrv]: https://img.shields.io/crates/msrv/serde.svg?label=serde%20msrv&color=lightgray
-[serde_derive: rustc 1.56+]: https://img.shields.io/badge/serde_derive-rustc_1.56+-lightgray.svg
+[serde_derive msrv]: https://img.shields.io/crates/msrv/serde_derive.svg?label=serde_derive%20msrv&color=lightgray
-[Rust 1.19]: https://blog.rust-lang.org/2017/07/20/Rust-1.19.html
 [Rust 1.56]: https://blog.rust-lang.org/2021/10/21/Rust-1.56.0.html
+[Rust 1.61]: https://blog.rust-lang.org/2022/05/19/Rust-1.61.0.html
 
 **Serde is a framework for *ser*ializing and *de*serializing Rust data structures efficiently and generically.**
 
@@ -15,7 +15,7 @@
 
 You may be looking for:
 
-- [An overview of Serde](https://serde.rs/)
+- [An overview of Serde](https://serde.rs)
 - [Data formats supported by Serde](https://serde.rs/#data-formats)
 - [Setting up `#[derive(Serialize, Deserialize)]`](https://serde.rs/derive.html)
 - [Examples](https://serde.rs/examples.html)
@@ -27,7 +27,7 @@ You may be looking for:
 <details>
 <summary>
 Click to show Cargo.toml.
-<a href="https://play.rust-lang.org/?edition=2018&gist=72755f28f99afc95e01d63174b28c1f5" target="_blank">Run this code in the playground.</a>
+<a href="https://play.rust-lang.org/?edition=2021&gist=72755f28f99afc95e01d63174b28c1f5" target="_blank">Run this code in the playground.</a>
 </summary>
 
 ```toml

crates-io.md

@@ -6,7 +6,7 @@
 
 You may be looking for:
 
-- [An overview of Serde](https://serde.rs/)
+- [An overview of Serde](https://serde.rs)
 - [Data formats supported by Serde](https://serde.rs/#data-formats)
 - [Setting up `#[derive(Serialize, Deserialize)]`](https://serde.rs/derive.html)
 - [Examples](https://serde.rs/examples.html)
@@ -46,8 +46,8 @@ fn main() {
 Serde is one of the most widely used Rust libraries so any place that Rustaceans
 congregate will be able to help you out. For chat, consider trying the
 [#rust-questions] or [#rust-beginners] channels of the unofficial community
-Discord (invite: <https://discord.gg/rust-lang-community>, the [#rust-usage] or
+Discord (invite: <https://discord.gg/rust-lang-community>), the [#rust-usage]
-[#beginners] channels of the official Rust Project Discord (invite:
+or [#beginners] channels of the official Rust Project Discord (invite:
 <https://discord.gg/rust-lang>), or the [#general][zulip] stream in Zulip. For
 asynchronous, consider the [\[rust\] tag on StackOverflow][stackoverflow], the
 [/r/rust] subreddit which has a pinned weekly easy questions post, or the Rust

precompiled/.gitignore

@@ -1 +0,0 @@
-/serde_derive/serde_derive-x86_64-unknown-linux-gnu

precompiled/Cargo.toml

@@ -1,14 +0,0 @@
-[workspace]
-members = ["bin", "proc-macro2"]
-resolver = "2"
-
-[patch.crates-io]
-proc-macro2 = { path = "proc-macro2" }
-
-[profile.precompiled]
-inherits = "release"
-codegen-units = 1
-lto = true
-opt-level = "z"
-panic = "abort"
-strip = true

precompiled/bin/Cargo.toml

@@ -1,17 +0,0 @@
-[package]
-name = "serde_derive"
-version = "1.0.178"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-publish = false
-
-[lib]
-doctest = false
-
-[[bin]]
-name = "serde_derive"
-path = "main.rs"
-
-[dependencies]
-proc-macro2 = "1"
-quote = { version = "1", default-features = false }
-syn = { version = "2.0.25", default-features = false, features = ["clone-impls", "derive", "full", "parsing", "printing"] }

precompiled/bin/build.rs

@@ -1,4 +0,0 @@
-fn main() {
-    println!("cargo:rustc-cfg=precompiled");
-    println!("cargo:rustc-cfg=feature=\"deserialize_in_place\"");
-}

precompiled/bin/main.rs

@@ -1,45 +0,0 @@
-extern crate proc_macro2;
-
-use proc_macro2::watt;
-use proc_macro2::watt::buffer::InputBuffer;
-use std::alloc::{GlobalAlloc, Layout, System};
-use std::io::{self, Read, Write};
-use std::sync::atomic::Ordering;
-
-struct MonotonicAllocator;
-
-#[global_allocator]
-static ALLOCATOR: MonotonicAllocator = MonotonicAllocator;
-
-unsafe impl GlobalAlloc for MonotonicAllocator {
-    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        System.alloc(layout)
-    }
-
-    unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
-        // Leak: this cuts 3% of code size from the precompiled macro binary.
-        // There is no way that serde_derive would fill up all memory on the
-        // host. When the subprocess exits, operating system will clean this up.
-    }
-}
-
-fn main() {
-    let mut buf = Vec::new();
-    io::stdin().read_to_end(&mut buf).unwrap();
-
-    let mut buf = InputBuffer::new(&buf);
-    let derive = match buf.read_u8() {
-        0 => serde_derive::derive_serialize,
-        1 => serde_derive::derive_deserialize,
-        2 => {
-            serde_derive::DESERIALIZE_IN_PLACE.store(true, Ordering::Relaxed);
-            serde_derive::derive_deserialize
-        }
-        _ => unreachable!(),
-    };
-
-    let input = watt::load(&mut buf);
-    let output = derive(input);
-    let bytes = watt::linearize(output);
-    io::stdout().write_all(&bytes).unwrap();
-}

precompiled/bin/src

@@ -1 +0,0 @@
-../../serde_derive/src

precompiled/build.sh

@@ -1,21 +0,0 @@
-#!/bin/bash
-
-cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null
-set -e -x
-
-# TODO: Sanitize host filesystem paths. https://github.com/rust-lang/cargo/issues/12137
-
-cargo +nightly build \
-    --manifest-path bin/Cargo.toml \
-    --bin serde_derive \
-    --profile precompiled \
-    -Z unstable-options \
-    -Z build-std=std,panic_abort \
-    -Z build-std-features=panic_immediate_abort \
-    --target x86_64-unknown-linux-musl \
-    --out-dir serde_derive
-
-rm -f serde_derive/serde_derive-x86_64-unknown-linux-gnu
-mv serde_derive/serde_derive{,-x86_64-unknown-linux-gnu}
-
-#upx --best --lzma serde_derive/serde_derive-x86_64-unknown-linux-gnu

precompiled/proc-macro2/Cargo.toml

@@ -1,8 +0,0 @@
-[package]
-name = "proc-macro2"
-version = "1.0.66"
-edition = "2021"
-publish = false
-
-[dependencies]
-proc-macro2 = { package = "proc-macro2-fallback", version = "1" }

precompiled/proc-macro2/src/lib.rs

@@ -1,815 +0,0 @@
-#[doc(hidden)]
-pub mod watt;
-
-use crate::extra::DelimSpan;
-use crate::watt::Identity;
-use std::cmp::Ordering;
-use std::fmt::{self, Debug, Display};
-use std::hash::{Hash, Hasher};
-use std::ops::RangeBounds;
-use std::str::FromStr;
-
-pub use proc_macro2::{Delimiter, Spacing};
-
-#[derive(Copy, Clone)]
-pub struct Span {
-    lo: u32,
-    hi: u32,
-}
-
-impl Span {
-    pub fn call_site() -> Self {
-        Span { lo: 0, hi: 0 }
-    }
-
-    pub fn join(&self, other: Self) -> Option<Self> {
-        Some(Span {
-            lo: self.lo,
-            hi: other.hi,
-        })
-    }
-}
-
-#[derive(Clone)]
-pub enum TokenTree {
-    Group(Group),
-    Ident(Ident),
-    Punct(Punct),
-    Literal(Literal),
-}
-
-impl TokenTree {
-    pub fn span(&self) -> Span {
-        match self {
-            TokenTree::Group(group) => group.span(),
-            TokenTree::Ident(ident) => ident.span(),
-            TokenTree::Punct(punct) => punct.span(),
-            TokenTree::Literal(literal) => literal.span(),
-        }
-    }
-
-    pub fn set_span(&mut self, span: Span) {
-        match self {
-            TokenTree::Group(group) => group.set_span(span),
-            TokenTree::Ident(ident) => ident.set_span(span),
-            TokenTree::Punct(punct) => punct.set_span(span),
-            TokenTree::Literal(literal) => literal.set_span(span),
-        }
-    }
-}
-
-impl From<Group> for TokenTree {
-    fn from(group: Group) -> Self {
-        TokenTree::Group(group)
-    }
-}
-
-impl From<Ident> for TokenTree {
-    fn from(ident: Ident) -> Self {
-        TokenTree::Ident(ident)
-    }
-}
-
-impl From<Punct> for TokenTree {
-    fn from(punct: Punct) -> Self {
-        TokenTree::Punct(punct)
-    }
-}
-
-impl From<Literal> for TokenTree {
-    fn from(literal: Literal) -> Self {
-        TokenTree::Literal(literal)
-    }
-}
-
-impl Debug for TokenTree {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            TokenTree::Group(group) => Debug::fmt(group, formatter),
-            TokenTree::Ident(ident) => {
-                let mut debug = formatter.debug_struct("Ident");
-                debug.field("sym", &format_args!("{}", ident));
-                debug.finish()
-            }
-            TokenTree::Punct(punct) => Debug::fmt(punct, formatter),
-            TokenTree::Literal(literal) => Debug::fmt(literal, formatter),
-        }
-    }
-}
-
-#[derive(Clone)]
-pub struct Group {
-    delimiter: Delimiter,
-    stream: Vec<TokenTree>,
-    span: Span,
-    span_open: Span,
-    span_close: Span,
-    identity: u32,
-}
-
-impl Group {
-    pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
-        Group {
-            delimiter,
-            stream: stream.content,
-            span: Span::call_site(),
-            span_open: Span::call_site(),
-            span_close: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn stream(&self) -> TokenStream {
-        TokenStream {
-            content: self.stream.clone(),
-        }
-    }
-
-    pub fn delimiter(&self) -> Delimiter {
-        self.delimiter
-    }
-
-    pub fn span(&self) -> Span {
-        self.span
-    }
-
-    pub fn span_open(&self) -> Span {
-        self.span_open
-    }
-
-    pub fn span_close(&self) -> Span {
-        self.span_close
-    }
-
-    pub fn delim_span(&self) -> DelimSpan {
-        DelimSpan {
-            join: self.span,
-            open: self.span_open,
-            close: self.span_close,
-        }
-    }
-
-    pub fn set_span(&mut self, span: Span) {
-        self.span = span;
-        self.identity |= Identity::RESPANNED;
-    }
-}
-
-impl Display for Group {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        let (open, close) = match self.delimiter {
-            Delimiter::Parenthesis => ("(", ")"),
-            Delimiter::Brace => ("{ ", "}"),
-            Delimiter::Bracket => ("[", "]"),
-            Delimiter::None => ("", ""),
-        };
-
-        formatter.write_str(open)?;
-        display_tokens(&self.stream, formatter)?;
-        if self.delimiter == Delimiter::Brace && !self.stream.is_empty() {
-            formatter.write_str(" ")?;
-        }
-        formatter.write_str(close)?;
-
-        Ok(())
-    }
-}
-
-impl Debug for Group {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        let mut debug = formatter.debug_struct("Group");
-        debug.field("delimiter", &self.delimiter);
-        debug.field("stream", &self.stream);
-        debug.finish()
-    }
-}
-
-#[derive(Clone)]
-pub struct Ident {
-    fallback: proc_macro2::Ident,
-    span: Span,
-    identity: u32,
-}
-
-impl Ident {
-    pub fn new(string: &str, span: Span) -> Self {
-        Ident {
-            fallback: proc_macro2::Ident::new(string, proc_macro2::Span::call_site()),
-            span,
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn new_raw(string: &str, span: Span) -> Self {
-        Ident {
-            fallback: proc_macro2::Ident::new_raw(string, proc_macro2::Span::call_site()),
-            span,
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn span(&self) -> Span {
-        self.span
-    }
-
-    pub fn set_span(&mut self, span: Span) {
-        self.span = span;
-        self.identity |= Identity::RESPANNED;
-    }
-}
-
-impl Display for Ident {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Display::fmt(&self.fallback, formatter)
-    }
-}
-
-impl Debug for Ident {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Debug::fmt(&self.fallback, formatter)
-    }
-}
-
-impl Eq for Ident {}
-
-impl PartialEq for Ident {
-    fn eq(&self, other: &Self) -> bool {
-        PartialEq::eq(&self.fallback, &other.fallback)
-    }
-}
-
-impl<T> PartialEq<T> for Ident
-where
-    T: ?Sized + AsRef<str>,
-{
-    fn eq(&self, other: &T) -> bool {
-        PartialEq::eq(&self.fallback, other)
-    }
-}
-
-impl Ord for Ident {
-    fn cmp(&self, other: &Self) -> Ordering {
-        Ord::cmp(&self.fallback, &other.fallback)
-    }
-}
-
-impl PartialOrd for Ident {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        PartialOrd::partial_cmp(&self.fallback, &other.fallback)
-    }
-}
-
-impl Hash for Ident {
-    fn hash<H: Hasher>(&self, hasher: &mut H) {
-        Hash::hash(&self.fallback, hasher);
-    }
-}
-
-#[derive(Clone)]
-pub struct Punct {
-    fallback: proc_macro2::Punct,
-    span: Span,
-    identity: u32,
-}
-
-impl Punct {
-    pub fn new(ch: char, spacing: Spacing) -> Self {
-        Punct {
-            fallback: proc_macro2::Punct::new(ch, spacing),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn as_char(&self) -> char {
-        self.fallback.as_char()
-    }
-
-    pub fn spacing(&self) -> Spacing {
-        self.fallback.spacing()
-    }
-
-    pub fn span(&self) -> Span {
-        self.span
-    }
-
-    pub fn set_span(&mut self, span: Span) {
-        self.span = span;
-        self.identity |= Identity::RESPANNED;
-    }
-}
-
-impl Display for Punct {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Display::fmt(&self.fallback, formatter)
-    }
-}
-
-impl Debug for Punct {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Debug::fmt(&self.fallback, formatter)
-    }
-}
-
-#[derive(Clone)]
-pub struct Literal {
-    fallback: proc_macro2::Literal,
-    span: Span,
-    identity: u32,
-}
-
-impl Literal {
-    pub fn u8_suffixed(n: u8) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u8_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u16_suffixed(n: u16) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u16_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u32_suffixed(n: u32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u32_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u64_suffixed(n: u64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u64_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u128_suffixed(n: u128) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u128_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn usize_suffixed(n: usize) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::usize_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i8_suffixed(n: i8) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i8_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i16_suffixed(n: i16) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i16_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i32_suffixed(n: i32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i32_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i64_suffixed(n: i64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i64_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i128_suffixed(n: i128) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i128_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn isize_suffixed(n: isize) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::isize_suffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u8_unsuffixed(n: u8) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u8_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u16_unsuffixed(n: u16) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u16_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u32_unsuffixed(n: u32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u32_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u64_unsuffixed(n: u64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u64_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn u128_unsuffixed(n: u128) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::u128_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn usize_unsuffixed(n: usize) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::usize_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i8_unsuffixed(n: i8) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i8_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i16_unsuffixed(n: i16) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i16_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i32_unsuffixed(n: i32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i32_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i64_unsuffixed(n: i64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i64_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn i128_unsuffixed(n: i128) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::i128_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn isize_unsuffixed(n: isize) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::isize_unsuffixed(n),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn f64_unsuffixed(f: f64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::f64_unsuffixed(f),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn f64_suffixed(f: f64) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::f64_suffixed(f),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn f32_unsuffixed(f: f32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::f32_unsuffixed(f),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn f32_suffixed(f: f32) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::f32_suffixed(f),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn string(string: &str) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::string(string),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn character(ch: char) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::character(ch),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn byte_string(s: &[u8]) -> Self {
-        Literal {
-            fallback: proc_macro2::Literal::byte_string(s),
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        }
-    }
-
-    pub fn span(&self) -> Span {
-        self.span
-    }
-
-    pub fn set_span(&mut self, span: Span) {
-        self.span = span;
-        self.identity |= Identity::RESPANNED;
-    }
-
-    pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
-        let _ = range;
-        None
-    }
-}
-
-impl FromStr for Literal {
-    type Err = LexError;
-
-    fn from_str(repr: &str) -> Result<Self, Self::Err> {
-        let fallback = match proc_macro2::Literal::from_str(repr) {
-            Ok(literal) => literal,
-            Err(error) => {
-                return Err(LexError {
-                    fallback: error,
-                    span: Span::call_site(),
-                });
-            }
-        };
-        Ok(Literal {
-            fallback,
-            span: Span::call_site(),
-            identity: Identity::NOVEL,
-        })
-    }
-}
-
-impl Display for Literal {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Display::fmt(&self.fallback, formatter)
-    }
-}
-
-impl Debug for Literal {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Debug::fmt(&self.fallback, formatter)
-    }
-}
-
-#[derive(Clone)]
-pub struct TokenStream {
-    content: Vec<TokenTree>,
-}
-
-impl TokenStream {
-    pub fn new() -> Self {
-        TokenStream {
-            content: Vec::new(),
-        }
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.content.is_empty()
-    }
-}
-
-impl IntoIterator for TokenStream {
-    type Item = TokenTree;
-    type IntoIter = token_stream::IntoIter;
-
-    fn into_iter(self) -> Self::IntoIter {
-        token_stream::IntoIter {
-            iter: self.content.into_iter(),
-        }
-    }
-}
-
-impl Extend<TokenStream> for TokenStream {
-    fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
-        self.content.extend(streams.into_iter().flatten());
-    }
-}
-
-impl Extend<TokenTree> for TokenStream {
-    fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, streams: I) {
-        self.content.extend(streams);
-    }
-}
-
-impl FromIterator<TokenStream> for TokenStream {
-    fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
-        let content = streams.into_iter().flatten().collect();
-        TokenStream { content }
-    }
-}
-
-impl FromIterator<TokenTree> for TokenStream {
-    fn from_iter<I: IntoIterator<Item = TokenTree>>(streams: I) -> Self {
-        let content = streams.into_iter().collect();
-        TokenStream { content }
-    }
-}
-
-impl FromStr for TokenStream {
-    type Err = LexError;
-
-    fn from_str(string: &str) -> Result<Self, Self::Err> {
-        let fallback = match proc_macro2::TokenStream::from_str(string) {
-            Ok(token_stream) => token_stream,
-            Err(error) => {
-                return Err(LexError {
-                    fallback: error,
-                    span: Span::call_site(),
-                });
-            }
-        };
-
-        fn convert_token_stream(stream: proc_macro2::TokenStream) -> TokenStream {
-            TokenStream {
-                content: stream.into_iter().map(convert_token_tree).collect(),
-            }
-        }
-
-        fn convert_token_tree(token: proc_macro2::TokenTree) -> TokenTree {
-            match token {
-                proc_macro2::TokenTree::Group(group) => TokenTree::Group(Group::new(
-                    group.delimiter(),
-                    convert_token_stream(group.stream()),
-                )),
-                proc_macro2::TokenTree::Ident(ident) => TokenTree::Ident(Ident {
-                    fallback: ident,
-                    span: Span::call_site(),
-                    identity: Identity::NOVEL,
-                }),
-                proc_macro2::TokenTree::Punct(punct) => TokenTree::Punct(Punct {
-                    fallback: punct,
-                    span: Span::call_site(),
-                    identity: Identity::NOVEL,
-                }),
-                proc_macro2::TokenTree::Literal(literal) => TokenTree::Literal(Literal {
-                    fallback: literal,
-                    span: Span::call_site(),
-                    identity: Identity::NOVEL,
-                }),
-            }
-        }
-
-        Ok(convert_token_stream(fallback))
-    }
-}
-
-fn display_tokens(tokens: &[TokenTree], formatter: &mut fmt::Formatter) -> fmt::Result {
-    let mut joint = false;
-    for (i, token) in tokens.iter().enumerate() {
-        if i != 0 && !joint {
-            write!(formatter, " ")?;
-        }
-        joint = false;
-        match token {
-            TokenTree::Group(group) => Display::fmt(group, formatter),
-            TokenTree::Ident(ident) => Display::fmt(ident, formatter),
-            TokenTree::Punct(punct) => {
-                joint = punct.spacing() == Spacing::Joint;
-                Display::fmt(punct, formatter)
-            }
-            TokenTree::Literal(literal) => Display::fmt(literal, formatter),
-        }?;
-    }
-
-    Ok(())
-}
-
-impl Display for TokenStream {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        display_tokens(&self.content, formatter)
-    }
-}
-
-impl Debug for TokenStream {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        formatter.write_str("TokenStream ")?;
-        formatter.debug_list().entries(&self.content).finish()
-    }
-}
-
-pub struct LexError {
-    fallback: proc_macro2::LexError,
-    span: Span,
-}
-
-impl LexError {
-    pub fn span(&self) -> Span {
-        self.span
-    }
-}
-
-impl Debug for LexError {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        Debug::fmt(&self.fallback, formatter)
-    }
-}
-
-pub mod token_stream {
-    use super::*;
-
-    #[derive(Clone)]
-    pub struct IntoIter {
-        pub(crate) iter: <Vec<TokenTree> as IntoIterator>::IntoIter,
-    }
-
-    impl Iterator for IntoIter {
-        type Item = TokenTree;
-
-        fn next(&mut self) -> Option<Self::Item> {
-            self.iter.next()
-        }
-
-        fn size_hint(&self) -> (usize, Option<usize>) {
-            self.iter.size_hint()
-        }
-    }
-}
-
-pub mod extra {
-    use crate::Span;
-
-    #[derive(Copy, Clone)]
-    pub struct DelimSpan {
-        pub(crate) join: Span,
-        pub(crate) open: Span,
-        pub(crate) close: Span,
-    }
-
-    impl DelimSpan {
-        pub fn join(&self) -> Span {
-            self.join
-        }
-
-        pub fn open(&self) -> Span {
-            self.open
-        }
-
-        pub fn close(&self) -> Span {
-            self.close
-        }
-    }
-}

precompiled/proc-macro2/src/watt/buffer.rs

@@ -1,69 +0,0 @@
-use std::str;
-
-pub struct OutputBuffer {
-    bytes: Vec<u8>,
-}
-
-impl OutputBuffer {
-    pub fn new() -> Self {
-        OutputBuffer { bytes: Vec::new() }
-    }
-
-    pub fn write_u8(&mut self, value: u8) {
-        self.bytes.push(value);
-    }
-
-    pub fn write_u16(&mut self, value: u16) {
-        self.bytes.extend_from_slice(&value.to_le_bytes());
-    }
-
-    pub fn write_u32(&mut self, value: u32) {
-        self.bytes.extend_from_slice(&value.to_le_bytes());
-    }
-
-    pub fn write_str(&mut self, value: &str) {
-        self.bytes.extend_from_slice(value.as_bytes());
-    }
-
-    pub fn into_bytes(self) -> Vec<u8> {
-        self.bytes
-    }
-}
-
-pub struct InputBuffer<'a> {
-    bytes: &'a [u8],
-}
-
-impl<'a> InputBuffer<'a> {
-    pub fn new(bytes: &'a [u8]) -> Self {
-        InputBuffer { bytes }
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.bytes.is_empty()
-    }
-
-    pub fn read_u8(&mut self) -> u8 {
-        let (first, rest) = self.bytes.split_first().unwrap();
-        self.bytes = rest;
-        *first
-    }
-
-    pub fn read_u16(&mut self) -> u16 {
-        let (value, rest) = self.bytes.split_at(2);
-        self.bytes = rest;
-        u16::from_le_bytes([value[0], value[1]])
-    }
-
-    pub fn read_u32(&mut self) -> u32 {
-        let (value, rest) = self.bytes.split_at(4);
-        self.bytes = rest;
-        u32::from_le_bytes([value[0], value[1], value[2], value[3]])
-    }
-
-    pub fn read_str(&mut self, len: usize) -> &'a str {
-        let (string, rest) = self.bytes.split_at(len);
-        self.bytes = rest;
-        str::from_utf8(string).unwrap()
-    }
-}

precompiled/proc-macro2/src/watt/bytecode.rs

@@ -1,17 +0,0 @@
-pub enum Bytecode {}
-
-impl Bytecode {
-    pub const GROUP_PARENTHESIS: u8 = 0;
-    pub const GROUP_BRACE: u8 = 1;
-    pub const GROUP_BRACKET: u8 = 2;
-    pub const GROUP_NONE: u8 = 3;
-    pub const IDENT: u8 = 4;
-    pub const PUNCT_ALONE: u8 = 5;
-    pub const PUNCT_JOINT: u8 = 6;
-    pub const LITERAL: u8 = 7;
-    pub const LOAD_GROUP: u8 = 8;
-    pub const LOAD_IDENT: u8 = 9;
-    pub const LOAD_PUNCT: u8 = 10;
-    pub const LOAD_LITERAL: u8 = 11;
-    pub const SET_SPAN: u8 = 12;
-}

precompiled/proc-macro2/src/watt/mod.rs

@@ -1,205 +0,0 @@
-pub mod buffer;
-pub mod bytecode;
-
-use crate::watt::buffer::{InputBuffer, OutputBuffer};
-use crate::watt::bytecode::Bytecode;
-use crate::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
-use std::str::FromStr;
-
-pub enum Kind {
-    Group(Delimiter),
-    Ident,
-    Punct(Spacing),
-    Literal,
-}
-
-pub enum Identity {}
-
-impl Identity {
-    pub const RESPANNED: u32 = 1 << 31;
-    pub const NOVEL: u32 = u32::MAX;
-}
-
-impl Span {
-    fn is_call_site(&self) -> bool {
-        self.lo == 0 && self.hi == 0
-    }
-}
-
-fn post_increment(counter: &mut u32) -> impl FnMut() -> u32 + '_ {
-    || {
-        let value = *counter;
-        *counter += 1;
-        value
-    }
-}
-
-pub fn load(buf: &mut InputBuffer) -> TokenStream {
-    let mut span_counter = 1;
-    let mut next_span = post_increment(&mut span_counter);
-    let mut next_span = || {
-        let next = next_span();
-        Span { lo: next, hi: next }
-    };
-
-    let [mut group_counter, mut ident_counter, mut punct_counter, mut literal_counter] = [0; 4];
-    let mut next_group = post_increment(&mut group_counter);
-    let mut next_ident = post_increment(&mut ident_counter);
-    let mut next_punct = post_increment(&mut punct_counter);
-    let mut next_literal = post_increment(&mut literal_counter);
-
-    let mut trees = Vec::new();
-    while !buf.is_empty() {
-        match match buf.read_u8() {
-            Bytecode::GROUP_PARENTHESIS => Kind::Group(Delimiter::Parenthesis),
-            Bytecode::GROUP_BRACE => Kind::Group(Delimiter::Brace),
-            Bytecode::GROUP_BRACKET => Kind::Group(Delimiter::Bracket),
-            Bytecode::GROUP_NONE => Kind::Group(Delimiter::None),
-            Bytecode::IDENT => Kind::Ident,
-            Bytecode::PUNCT_ALONE => Kind::Punct(Spacing::Alone),
-            Bytecode::PUNCT_JOINT => Kind::Punct(Spacing::Joint),
-            Bytecode::LITERAL => Kind::Literal,
-            _ => unreachable!(),
-        } {
-            Kind::Group(delimiter) => {
-                let len = buf.read_u32();
-                let stream = trees.drain(trees.len() - len as usize..).collect();
-                trees.push(TokenTree::Group(Group {
-                    delimiter,
-                    stream,
-                    span: next_span(),
-                    span_open: next_span(),
-                    span_close: next_span(),
-                    identity: next_group(),
-                }));
-            }
-            Kind::Ident => {
-                let len = buf.read_u16();
-                let repr = buf.read_str(len as usize);
-                let ident = if let Some(repr) = repr.strip_prefix("r#") {
-                    proc_macro2::Ident::new_raw(repr, proc_macro2::Span::call_site())
-                } else if repr == "$crate" {
-                    proc_macro2::Ident::new("crate", proc_macro2::Span::call_site())
-                } else {
-                    proc_macro2::Ident::new(repr, proc_macro2::Span::call_site())
-                };
-                trees.push(TokenTree::Ident(Ident {
-                    fallback: ident,
-                    span: next_span(),
-                    identity: next_ident(),
-                }));
-            }
-            Kind::Punct(spacing) => {
-                let ch = buf.read_u8();
-                assert!(ch.is_ascii());
-                let punct = proc_macro2::Punct::new(ch as char, spacing);
-                trees.push(TokenTree::Punct(Punct {
-                    fallback: punct,
-                    span: next_span(),
-                    identity: next_punct(),
-                }));
-            }
-            Kind::Literal => {
-                let len = buf.read_u16();
-                let repr = buf.read_str(len as usize);
-                let literal = proc_macro2::Literal::from_str(repr).unwrap();
-                trees.push(TokenTree::Literal(Literal {
-                    fallback: literal,
-                    span: next_span(),
-                    identity: next_literal(),
-                }));
-            }
-        }
-    }
-
-    TokenStream { content: trees }
-}
-
-pub fn linearize(tokens: TokenStream) -> Vec<u8> {
-    let mut buf = OutputBuffer::new();
-    for token in &tokens.content {
-        linearize_token(token, &mut buf);
-    }
-    buf.into_bytes()
-}
-
-fn linearize_token(token: &TokenTree, buf: &mut OutputBuffer) {
-    let needs_span;
-    match token {
-        TokenTree::Group(group) => {
-            if group.identity < Identity::NOVEL {
-                buf.write_u8(Bytecode::LOAD_GROUP);
-                buf.write_u32(group.identity & !Identity::RESPANNED);
-                needs_span = group.identity >= Identity::RESPANNED;
-            } else {
-                let len = group.stream.len();
-                assert!(len <= u32::MAX as usize);
-                for token in &group.stream {
-                    linearize_token(token, buf);
-                }
-                buf.write_u8(match group.delimiter {
-                    Delimiter::Parenthesis => Bytecode::GROUP_PARENTHESIS,
-                    Delimiter::Brace => Bytecode::GROUP_BRACE,
-                    Delimiter::Bracket => Bytecode::GROUP_BRACKET,
-                    Delimiter::None => Bytecode::GROUP_NONE,
-                });
-                buf.write_u32(len as u32);
-                needs_span = !group.span.is_call_site();
-            }
-        }
-        TokenTree::Ident(ident) => {
-            if ident.identity < Identity::NOVEL {
-                buf.write_u8(Bytecode::LOAD_IDENT);
-                buf.write_u32(ident.identity & !Identity::RESPANNED);
-                needs_span = ident.identity >= Identity::RESPANNED;
-            } else {
-                buf.write_u8(Bytecode::IDENT);
-                let repr = ident.to_string();
-                assert!(repr.len() <= u16::MAX as usize);
-                buf.write_u16(repr.len() as u16);
-                buf.write_str(&repr);
-                linearize_span(ident.span, buf);
-                needs_span = false;
-            }
-        }
-        TokenTree::Punct(punct) => {
-            if punct.identity < Identity::NOVEL {
-                buf.write_u8(Bytecode::LOAD_PUNCT);
-                buf.write_u32(punct.identity & !Identity::RESPANNED);
-                needs_span = punct.identity >= Identity::RESPANNED;
-            } else {
-                buf.write_u8(match punct.spacing() {
-                    Spacing::Alone => Bytecode::PUNCT_ALONE,
-                    Spacing::Joint => Bytecode::PUNCT_JOINT,
-                });
-                let ch = punct.as_char();
-                assert!(ch.is_ascii());
-                buf.write_u8(ch as u8);
-                needs_span = !punct.span.is_call_site();
-            }
-        }
-        TokenTree::Literal(literal) => {
-            if literal.identity < Identity::NOVEL {
-                buf.write_u8(Bytecode::LOAD_LITERAL);
-                buf.write_u32(literal.identity & !Identity::RESPANNED);
-                needs_span = literal.identity >= Identity::RESPANNED;
-            } else {
-                buf.write_u8(Bytecode::LITERAL);
-                let repr = literal.to_string();
-                assert!(repr.len() <= u16::MAX as usize);
-                buf.write_u16(repr.len() as u16);
-                buf.write_str(&repr);
-                needs_span = !literal.span.is_call_site();
-            }
-        }
-    }
-    if needs_span {
-        buf.write_u8(Bytecode::SET_SPAN);
-        linearize_span(token.span(), buf);
-    }
-}
-
-fn linearize_span(span: Span, buf: &mut OutputBuffer) {
-    buf.write_u32(span.lo);
-    buf.write_u32(span.hi);
-}

precompiled/serde_derive/Cargo.toml

@@ -1,36 +0,0 @@
-[package]
-name = "serde_derive"
-version = "1.0.178"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-categories = ["no-std", "no-std::no-alloc"]
-description = "Implementation of #[derive(Serialize, Deserialize)]"
-documentation = "https://serde.rs/derive.html"
-edition = "2015"
-homepage = "https://serde.rs"
-include = ["serde_derive-x86_64-unknown-linux-gnu", "src", "LICENSE-APACHE", "LICENSE-MIT"]
-keywords = ["serde", "serialization", "no_std", "derive"]
-license = "MIT OR Apache-2.0"
-readme = "crates-io.md"
-repository = "https://github.com/serde-rs/serde"
-rust-version = "1.56"
-
-[features]
-default = []
-deserialize_in_place = []
-
-[lib]
-proc-macro = true
-
-[target.'cfg(not(all(target_arch = "x86_64", target_os = "linux", target_env = "gnu")))'.dependencies]
-proc-macro2 = "1"
-quote = "1"
-syn = "2.0.25"
-
-[dev-dependencies]
-serde = { version = "1", path = "../../serde" }
-
-[package.metadata.docs.rs]
-targets = ["x86_64-unknown-linux-gnu"]
-rustdoc-args = ["--generate-link-to-definition"]
-
-[workspace]

precompiled/serde_derive/LICENSE-APACHE

@@ -1 +0,0 @@
-../../LICENSE-APACHE

precompiled/serde_derive/LICENSE-MIT

@@ -1 +0,0 @@
-../../LICENSE-MIT

precompiled/serde_derive/README.md

@@ -1 +0,0 @@
-../../README.md

precompiled/serde_derive/crates-io.md

@@ -1 +0,0 @@
-../../crates-io.md

precompiled/serde_derive/src/bound.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/bound.rs

precompiled/serde_derive/src/buffer.rs

@@ -1 +0,0 @@
-../../proc-macro2/src/watt/buffer.rs

precompiled/serde_derive/src/bytecode.rs

@@ -1 +0,0 @@
-../../proc-macro2/src/watt/bytecode.rs

precompiled/serde_derive/src/de.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/de.rs

precompiled/serde_derive/src/dummy.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/dummy.rs

precompiled/serde_derive/src/fragment.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/fragment.rs

precompiled/serde_derive/src/internals

@@ -1 +0,0 @@
-../../../serde_derive/src/internals/

precompiled/serde_derive/src/lib.rs

@@ -1,22 +0,0 @@
-//! This crate provides Serde's two derive macros.
-//!
-//! ```edition2021
-//! # use serde_derive::{Deserialize, Serialize};
-//! #
-//! #[derive(Serialize, Deserialize)]
-//! # struct S;
-//! #
-//! # fn main() {}
-//! ```
-//!
-//! Please refer to [https://serde.rs/derive.html] for how to set this up.
-//!
-//! [https://serde.rs/derive.html]: https://serde.rs/derive.html
-
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.178")]
-
-#[cfg(not(all(target_arch = "x86_64", target_os = "linux", target_env = "gnu")))]
-include!("lib_from_source.rs");
-
-#[cfg(all(target_arch = "x86_64", target_os = "linux", target_env = "gnu"))]
-include!("lib_precompiled.rs");

precompiled/serde_derive/src/lib_from_source.rs

@@ -1,35 +0,0 @@
-extern crate proc_macro;
-extern crate proc_macro2;
-extern crate quote;
-extern crate syn;
-
-#[macro_use]
-mod bound;
-#[macro_use]
-mod fragment;
-
-mod de;
-mod dummy;
-mod internals;
-mod pretend;
-mod ser;
-mod this;
-
-use proc_macro::TokenStream;
-use syn::{parse_macro_input, DeriveInput};
-
-#[proc_macro_derive(Serialize, attributes(serde))]
-pub fn derive_serialize(input: TokenStream) -> TokenStream {
-    let mut input = parse_macro_input!(input as DeriveInput);
-    ser::expand_derive_serialize(&mut input)
-        .unwrap_or_else(syn::Error::into_compile_error)
-        .into()
-}
-
-#[proc_macro_derive(Deserialize, attributes(serde))]
-pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    let mut input = parse_macro_input!(input as DeriveInput);
-    de::expand_derive_deserialize(&mut input)
-        .unwrap_or_else(syn::Error::into_compile_error)
-        .into()
-}

precompiled/serde_derive/src/lib_precompiled.rs

@@ -1,234 +0,0 @@
-extern crate proc_macro;
-
-mod buffer;
-mod bytecode;
-
-use crate::buffer::{InputBuffer, OutputBuffer};
-use crate::bytecode::Bytecode;
-use proc_macro::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
-use std::io::{ErrorKind, Read, Write};
-use std::iter::FromIterator;
-use std::path::Path;
-use std::process::{Command, ExitStatus, Stdio};
-use std::str::FromStr;
-
-#[proc_macro_derive(Serialize, attributes(serde))]
-pub fn derive_serialize(input: TokenStream) -> TokenStream {
-    derive(0, input)
-}
-
-#[proc_macro_derive(Deserialize, attributes(serde))]
-pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    derive(1 + cfg!(feature = "deserialize_in_place") as u8, input)
-}
-
-fn derive(select: u8, input: TokenStream) -> TokenStream {
-    let mut memory = TokenMemory::default();
-    let mut buf = OutputBuffer::new();
-    buf.write_u8(select);
-
-    memory.spans.push(Span::call_site());
-    for token in input {
-        memory.linearize_token(token, &mut buf);
-    }
-
-    let exe_path = Path::new(concat!(
-        env!("CARGO_MANIFEST_DIR"),
-        "/serde_derive-x86_64-unknown-linux-gnu",
-    ));
-    let mut child = match Command::new(exe_path)
-        .stdin(Stdio::piped())
-        .stdout(Stdio::piped())
-        .spawn()
-    {
-        Ok(child) => child,
-        Err(io_error) => {
-            if io_error.kind() == ErrorKind::NotFound {
-                panic!(
-                    "file missing from serde_derive manifest directory during macro expansion: {}",
-                    exe_path.display(),
-                );
-            } else {
-                panic!("failed to spawn process: {}", io_error);
-            }
-        }
-    };
-
-    let mut stdin = child.stdin.take().unwrap();
-    let mut buf = buf.into_bytes();
-    stdin.write_all(&buf).unwrap();
-    drop(stdin);
-
-    let mut stdout = child.stdout.take().unwrap();
-    buf.clear();
-    stdout.read_to_end(&mut buf).unwrap();
-
-    let success = child.wait().as_ref().map_or(true, ExitStatus::success);
-    if !success || buf.is_empty() {
-        panic!();
-    }
-
-    let mut buf = InputBuffer::new(&buf);
-    memory.receive(&mut buf)
-}
-
-#[derive(Default)]
-struct TokenMemory {
-    spans: Vec<Span>,
-    groups: Vec<Group>,
-    idents: Vec<Ident>,
-    puncts: Vec<Punct>,
-    literals: Vec<Literal>,
-}
-
-enum Kind {
-    Group(Delimiter),
-    Ident,
-    Punct(Spacing),
-    Literal,
-}
-
-impl TokenMemory {
-    // Depth-first post-order traversal.
-    fn linearize_token(&mut self, token: TokenTree, buf: &mut OutputBuffer) {
-        match token {
-            TokenTree::Group(group) => {
-                let mut len = 0usize;
-                for token in group.stream() {
-                    self.linearize_token(token, buf);
-                    len += 1;
-                }
-                assert!(len <= u32::MAX as usize);
-                buf.write_u8(match group.delimiter() {
-                    Delimiter::Parenthesis => Bytecode::GROUP_PARENTHESIS,
-                    Delimiter::Brace => Bytecode::GROUP_BRACE,
-                    Delimiter::Bracket => Bytecode::GROUP_BRACKET,
-                    Delimiter::None => Bytecode::GROUP_NONE,
-                });
-                buf.write_u32(len as u32);
-                self.spans
-                    .extend([group.span(), group.span_open(), group.span_close()]);
-                self.groups.push(group);
-            }
-            TokenTree::Ident(ident) => {
-                buf.write_u8(Bytecode::IDENT);
-                let repr = ident.to_string();
-                assert!(repr.len() <= u16::MAX as usize);
-                buf.write_u16(repr.len() as u16);
-                buf.write_str(&repr);
-                self.spans.push(ident.span());
-                self.idents.push(ident);
-            }
-            TokenTree::Punct(punct) => {
-                buf.write_u8(match punct.spacing() {
-                    Spacing::Alone => Bytecode::PUNCT_ALONE,
-                    Spacing::Joint => Bytecode::PUNCT_JOINT,
-                });
-                let ch = punct.as_char();
-                assert!(ch.is_ascii());
-                buf.write_u8(ch as u8);
-                self.spans.push(punct.span());
-                self.puncts.push(punct);
-            }
-            TokenTree::Literal(literal) => {
-                buf.write_u8(Bytecode::LITERAL);
-                let repr = literal.to_string();
-                assert!(repr.len() <= u16::MAX as usize);
-                buf.write_u16(repr.len() as u16);
-                buf.write_str(&repr);
-                self.spans.push(literal.span());
-                self.literals.push(literal);
-            }
-        }
-    }
-
-    fn receive(&self, buf: &mut InputBuffer) -> TokenStream {
-        let mut trees = Vec::new();
-        while !buf.is_empty() {
-            match match buf.read_u8() {
-                Bytecode::GROUP_PARENTHESIS => Kind::Group(Delimiter::Parenthesis),
-                Bytecode::GROUP_BRACE => Kind::Group(Delimiter::Brace),
-                Bytecode::GROUP_BRACKET => Kind::Group(Delimiter::Bracket),
-                Bytecode::GROUP_NONE => Kind::Group(Delimiter::None),
-                Bytecode::IDENT => Kind::Ident,
-                Bytecode::PUNCT_ALONE => Kind::Punct(Spacing::Alone),
-                Bytecode::PUNCT_JOINT => Kind::Punct(Spacing::Joint),
-                Bytecode::LITERAL => Kind::Literal,
-                Bytecode::LOAD_GROUP => {
-                    let identity = buf.read_u32();
-                    let group = self.groups[identity as usize].clone();
-                    trees.push(TokenTree::Group(group));
-                    continue;
-                }
-                Bytecode::LOAD_IDENT => {
-                    let identity = buf.read_u32();
-                    let ident = self.idents[identity as usize].clone();
-                    trees.push(TokenTree::Ident(ident));
-                    continue;
-                }
-                Bytecode::LOAD_PUNCT => {
-                    let identity = buf.read_u32();
-                    let punct = self.puncts[identity as usize].clone();
-                    trees.push(TokenTree::Punct(punct));
-                    continue;
-                }
-                Bytecode::LOAD_LITERAL => {
-                    let identity = buf.read_u32();
-                    let literal = self.literals[identity as usize].clone();
-                    trees.push(TokenTree::Literal(literal));
-                    continue;
-                }
-                Bytecode::SET_SPAN => {
-                    trees.last_mut().unwrap().set_span(self.read_span(buf));
-                    continue;
-                }
-                _ => unreachable!(),
-            } {
-                Kind::Group(delimiter) => {
-                    let len = buf.read_u32();
-                    let stream = trees.drain(trees.len() - len as usize..).collect();
-                    let group = Group::new(delimiter, stream);
-                    trees.push(TokenTree::Group(group));
-                }
-                Kind::Ident => {
-                    let len = buf.read_u16();
-                    let repr = buf.read_str(len as usize);
-                    let span = self.read_span(buf);
-                    let ident = if let Some(repr) = repr.strip_prefix("r#") {
-                        Ident::new_raw(repr, span)
-                    } else {
-                        Ident::new(repr, span)
-                    };
-                    trees.push(TokenTree::Ident(ident));
-                }
-                Kind::Punct(spacing) => {
-                    let ch = buf.read_u8();
-                    assert!(ch.is_ascii());
-                    let punct = Punct::new(ch as char, spacing);
-                    trees.push(TokenTree::Punct(punct));
-                }
-                Kind::Literal => {
-                    let len = buf.read_u16();
-                    let repr = buf.read_str(len as usize);
-                    let literal = Literal::from_str(repr).unwrap();
-                    trees.push(TokenTree::Literal(literal));
-                }
-            }
-        }
-
-        TokenStream::from_iter(trees)
-    }
-
-    fn read_span(&self, buf: &mut InputBuffer) -> Span {
-        let lo = buf.read_u32();
-        let hi = buf.read_u32();
-        let span = self.spans[lo as usize];
-        if lo == hi {
-            span
-        } else {
-            #[cfg(any())] // FIXME
-            return span.join(self.spans[hi as usize]).unwrap_or(span);
-            span
-        }
-    }
-}

precompiled/serde_derive/src/pretend.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/pretend.rs

precompiled/serde_derive/src/ser.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/ser.rs

precompiled/serde_derive/src/this.rs

@@ -1 +0,0 @@
-../../../serde_derive/src/this.rs

serde/Cargo.toml

@@ -1,34 +1,35 @@
 [package]
 name = "serde"
-version = "1.0.178" # remember to update html_root_url and serde_derive dependency
+version = "1.0.221"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
 description = "A generic serialization/deserialization framework"
 documentation = "https://docs.rs/serde"
+edition = "2021"
 homepage = "https://serde.rs"
 keywords = ["serde", "serialization", "no_std"]
 license = "MIT OR Apache-2.0"
 readme = "crates-io.md"
 repository = "https://github.com/serde-rs/serde"
-rust-version = "1.19"
+rust-version = "1.56"
 
 [dependencies]
-serde_derive = { version = "=1.0.178", optional = true, path = "../serde_derive" }
+serde_core = { version = "=1.0.221", path = "../serde_core", default-features = false, features = ["result"] }
-
+serde_derive = { version = "1", optional = true, path = "../serde_derive" }
-[dev-dependencies]
-serde_derive = { version = "1", path = "../serde_derive" }
-
-[lib]
-doc-scrape-examples = false
 
 [package.metadata.playground]
 features = ["derive", "rc"]
 
 [package.metadata.docs.rs]
-features = ["derive"]
+features = ["derive", "rc", "unstable"]
 targets = ["x86_64-unknown-linux-gnu"]
-rustdoc-args = ["--generate-link-to-definition"]
+rustdoc-args = [
+    "--generate-link-to-definition",
+    "--extern-html-root-url=core=https://doc.rust-lang.org",
+    "--extern-html-root-url=alloc=https://doc.rust-lang.org",
+    "--extern-html-root-url=std=https://doc.rust-lang.org",
+]
 
 
 ### FEATURES #################################################################
@@ -41,20 +42,20 @@ derive = ["serde_derive"]
 
 # Provide impls for common standard library types like Vec<T> and HashMap<K, V>.
 # Requires a dependency on the Rust standard library.
-std = []
+std = ["serde_core/std"]
 
 # Provide impls for types that require unstable functionality. For tracking and
 # discussion of unstable functionality please refer to this issue:
 #
 #    https://github.com/serde-rs/serde/issues/812
-unstable = []
+unstable = ["serde_core/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.
-alloc = []
+alloc = ["serde_core/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.
 # Be sure that this is what you want before enabling this feature.
-rc = []
+rc = ["serde_core/rc"]

serde/build.rs

@@ -1,6 +1,6 @@
 use std::env;
 use std::process::Command;
-use std::str::{self, FromStr};
+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
@@ -13,140 +13,23 @@ fn main() {
         None => return,
     };
 
-    let target = env::var("TARGET").unwrap();
+    if minor >= 77 {
-    let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";
+        println!("cargo:rustc-check-cfg=cfg(no_serde_derive)");
-
-    // 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=no_ops_bound");
-        if minor < 17 {
-            println!("cargo:rustc-cfg=no_collections_bound");
-        }
     }
 
-    // core::cmp::Reverse stabilized in Rust 1.19:
+    // Current minimum supported version of serde_derive crate is Rust 1.61.
-    // https://doc.rust-lang.org/stable/core/cmp/struct.Reverse.html
+    if minor < 61 {
-    if minor < 19 {
-        println!("cargo:rustc-cfg=no_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=no_de_boxed_c_str");
-        println!("cargo:rustc-cfg=no_de_boxed_path");
-    }
-
-    // From<Box<T>> for Rc<T> / Arc<T> stabilized in Rust 1.21:
-    // https://doc.rust-lang.org/std/rc/struct.Rc.html#impl-From<Box<T>>
-    // https://doc.rust-lang.org/std/sync/struct.Arc.html#impl-From<Box<T>>
-    if minor < 21 {
-        println!("cargo:rustc-cfg=no_de_rc_dst");
-    }
-
-    // Duration available in core since Rust 1.25:
-    // https://blog.rust-lang.org/2018/03/29/Rust-1.25.html#library-stabilizations
-    if minor < 25 {
-        println!("cargo:rustc-cfg=no_core_duration");
-    }
-
-    // 128-bit integers stabilized in Rust 1.26:
-    // https://blog.rust-lang.org/2018/05/10/Rust-1.26.html
-    //
-    // Disabled on Emscripten targets before Rust 1.40 since
-    // Emscripten did not support 128-bit integers until Rust 1.40
-    // (https://github.com/rust-lang/rust/pull/65251)
-    if minor < 26 || emscripten && minor < 40 {
-        println!("cargo:rustc-cfg=no_integer128");
-    }
-
-    // Inclusive ranges methods stabilized in Rust 1.27:
-    // https://github.com/rust-lang/rust/pull/50758
-    // Also Iterator::try_for_each:
-    // https://blog.rust-lang.org/2018/06/21/Rust-1.27.html#library-stabilizations
-    if minor < 27 {
-        println!("cargo:rustc-cfg=no_range_inclusive");
-        println!("cargo:rustc-cfg=no_iterator_try_fold");
-    }
-
-    // Non-zero integers stabilized in Rust 1.28:
-    // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
-    if minor < 28 {
-        println!("cargo:rustc-cfg=no_num_nonzero");
-    }
-
-    // TryFrom, Atomic types, non-zero signed integers, and SystemTime::checked_add
-    // stabilized in Rust 1.34:
-    // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#tryfrom-and-tryinto
-    // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#library-stabilizations
-    if minor < 34 {
-        println!("cargo:rustc-cfg=no_core_try_from");
-        println!("cargo:rustc-cfg=no_num_nonzero_signed");
-        println!("cargo:rustc-cfg=no_systemtime_checked_add");
-        println!("cargo:rustc-cfg=no_relaxed_trait_bounds");
-    }
-
-    // Current minimum supported version of serde_derive crate is Rust 1.56.
-    if minor < 56 {
         println!("cargo:rustc-cfg=no_serde_derive");
     }
-
-    // Support for #[cfg(target_has_atomic = "...")] stabilized in Rust 1.60.
-    if minor < 60 {
-        println!("cargo:rustc-cfg=no_target_has_atomic");
-        // Allowlist of archs that support std::sync::atomic module. This is
-        // based on rustc's compiler/rustc_target/src/spec/*.rs.
-        let has_atomic64 = target.starts_with("x86_64")
-            || target.starts_with("i686")
-            || target.starts_with("aarch64")
-            || target.starts_with("powerpc64")
-            || target.starts_with("sparc64")
-            || target.starts_with("mips64el")
-            || target.starts_with("riscv64");
-        let has_atomic32 = has_atomic64 || emscripten;
-        if minor < 34 || !has_atomic64 {
-            println!("cargo:rustc-cfg=no_std_atomic64");
-        }
-        if minor < 34 || !has_atomic32 {
-            println!("cargo:rustc-cfg=no_std_atomic");
-        }
-    }
-
-    // Support for core::ffi::CStr and alloc::ffi::CString stabilized in Rust 1.64.
-    // https://blog.rust-lang.org/2022/09/22/Rust-1.64.0.html#c-compatible-ffi-types-in-core-and-alloc
-    if minor < 64 {
-        println!("cargo:rustc-cfg=no_core_cstr");
-    }
 }
 
 fn rustc_minor_version() -> Option<u32> {
-    let rustc = match env::var_os("RUSTC") {
+    let rustc = env::var_os("RUSTC")?;
-        Some(rustc) => rustc,
+    let output = Command::new(rustc).arg("--version").output().ok()?;
-        None => return None,
+    let version = str::from_utf8(&output.stdout).ok()?;
-    };
-
-    let output = match Command::new(rustc).arg("--version").output() {
-        Ok(output) => output,
-        Err(_) => return None,
-    };
-
-    let version = match str::from_utf8(&output.stdout) {
-        Ok(version) => version,
-        Err(_) => return None,
-    };
-
     let mut pieces = version.split('.');
     if pieces.next() != Some("rustc 1") {
         return None;
     }
-
+    pieces.next()?.parse().ok()
-    let next = match pieces.next() {
-        Some(next) => next,
-        None => return None,
-    };
-
-    u32::from_str(next).ok()
 }

serde/src/de/utf8.rs

@@ -1,46 +0,0 @@
-use lib::*;
-
-const TAG_CONT: u8 = 0b1000_0000;
-const TAG_TWO_B: u8 = 0b1100_0000;
-const TAG_THREE_B: u8 = 0b1110_0000;
-const TAG_FOUR_B: u8 = 0b1111_0000;
-const MAX_ONE_B: u32 = 0x80;
-const MAX_TWO_B: u32 = 0x800;
-const MAX_THREE_B: u32 = 0x10000;
-
-#[inline]
-pub fn encode(c: char) -> Encode {
-    let code = c as u32;
-    let mut buf = [0; 4];
-    let pos = if code < MAX_ONE_B {
-        buf[3] = code as u8;
-        3
-    } else if code < MAX_TWO_B {
-        buf[2] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        2
-    } else if code < MAX_THREE_B {
-        buf[1] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        1
-    } else {
-        buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
-        buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT;
-        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
-        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
-        0
-    };
-    Encode { buf, pos }
-}
-
-pub struct Encode {
-    buf: [u8; 4],
-    pos: usize,
-}
-
-impl Encode {
-    pub fn as_str(&self) -> &str {
-        str::from_utf8(&self.buf[self.pos..]).unwrap()
-    }
-}

serde/src/integer128.rs

@@ -1,82 +1,14 @@
-/// Conditional compilation depending on whether Serde is built with support for
-/// 128-bit integers.
-///
-/// Data formats that wish to support Rust compiler versions older than 1.26
-/// (or targets that lack 128-bit integers) may place the i128 / u128 methods
-/// of their Serializer and Deserializer behind this macro.
-///
-/// Data formats that require a minimum Rust compiler version of at least 1.26,
-/// or do not target platforms that lack 128-bit integers, do not need to
-/// bother with this macro and may assume support for 128-bit integers.
-///
-/// ```edition2021
-/// # use serde::__private::doc::Error;
-/// #
-/// # struct MySerializer;
-/// #
-/// use serde::{serde_if_integer128, Serializer};
-///
-/// impl Serializer for MySerializer {
-///     type Ok = ();
-///     type Error = Error;
-///
-///     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
-///         /* ... */
-/// #         unimplemented!()
-///     }
-///
-///     /* ... */
-///
-///     serde_if_integer128! {
-///         fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///
-///         fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///     }
-/// #
-/// #     serde::__serialize_unimplemented! {
-/// #         bool i8 i16 i32 u8 u16 u32 u64 f32 f64 char str bytes none some
-/// #         unit unit_struct unit_variant newtype_struct newtype_variant seq
-/// #         tuple tuple_struct tuple_variant map struct struct_variant
-/// #     }
-/// }
-/// ```
-///
-/// When Serde is built with support for 128-bit integers, this macro expands
-/// transparently into just the input tokens.
-///
-/// ```edition2021
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {
-///         $($tt)*
-///     };
-/// }
-/// ```
-///
-/// When built without support for 128-bit integers, this macro expands to
-/// nothing.
-///
-/// ```edition2021
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {};
-/// }
-/// ```
-#[cfg(not(no_integer128))]
 #[macro_export]
+#[deprecated = "
+This macro has no effect on any version of Serde released in the past 2 years.
+It was used long ago in crates that needed to support Rustc older than 1.26.0,
+or Emscripten targets older than 1.40.0, which did not yet have 128-bit integer
+support. These days Serde requires a Rust compiler newer than that so 128-bit
+integers are always supported.
+"]
+#[doc(hidden)]
 macro_rules! serde_if_integer128 {
     ($($tt:tt)*) => {
         $($tt)*
     };
 }
-
-#[cfg(no_integer128)]
-#[macro_export]
-#[doc(hidden)]
-macro_rules! serde_if_integer128 {
-    ($($tt:tt)*) => {};
-}

serde/src/lib.rs

@@ -9,7 +9,7 @@
 //! these two groups interact with each other, allowing any supported data
 //! structure to be serialized and deserialized using any supported data format.
 //!
-//! See the Serde website <https://serde.rs/> for additional documentation and
+//! See the Serde website <https://serde.rs> for additional documentation and
 //! usage examples.
 //!
 //! ## Design
@@ -63,6 +63,7 @@
 //!   and from DynamoDB.
 //! - [Hjson], a syntax extension to JSON designed around human reading and
 //!   editing. *(deserialization only)*
+//! - [CSV], Comma-separated values is a tabular text file format.
 //!
 //! [JSON]: https://github.com/serde-rs/json
 //! [Postcard]: https://github.com/jamesmunns/postcard
@@ -89,68 +90,76 @@
 //! [DynamoDB Items]: https://docs.rs/serde_dynamo
 //! [rusoto_dynamodb]: https://docs.rs/rusoto_dynamodb
 //! [Hjson]: https://github.com/Canop/deser-hjson
+//! [CSV]: https://docs.rs/csv
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.178")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.221")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
+// Show which crate feature enables conditionally compiled APIs in documentation.
+#![cfg_attr(docsrs, feature(doc_cfg, rustdoc_internals))]
+#![cfg_attr(docsrs, allow(internal_features))]
 // Unstable functionality only if the user asks for it. For tracking and
 // discussion of these features please refer to this issue:
 //
 //    https://github.com/serde-rs/serde/issues/812
-#![cfg_attr(feature = "unstable", feature(error_in_core, never_type))]
+#![cfg_attr(feature = "unstable", feature(never_type))]
-#![allow(unknown_lints, bare_trait_objects, deprecated)]
+#![allow(
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
+    unknown_lints,
+    bare_trait_objects,
+    deprecated,
+    mismatched_lifetime_syntaxes
+)]
 // Ignored clippy and clippy_pedantic lints
-#![cfg_attr(
+#![allow(
-    feature = "cargo-clippy",
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
-    allow(
+    clippy::unnested_or_patterns,
-        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
-        unnested_or_patterns,
+    clippy::semicolon_if_nothing_returned,
-        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
+    // not available in our oldest supported compiler
-        semicolon_if_nothing_returned,
+    clippy::empty_enum,
-        // not available in our oldest supported compiler
+    clippy::type_repetition_in_bounds, // https://github.com/rust-lang/rust-clippy/issues/8772
-        empty_enum,
+    // integer and float ser/de requires these sorts of casts
-        type_repetition_in_bounds, // https://github.com/rust-lang/rust-clippy/issues/8772
+    clippy::cast_possible_truncation,
-        // integer and float ser/de requires these sorts of casts
+    clippy::cast_possible_wrap,
-        cast_possible_truncation,
+    clippy::cast_precision_loss,
-        cast_possible_wrap,
+    clippy::cast_sign_loss,
-        cast_sign_loss,
+    // things are often more readable this way
-        // things are often more readable this way
+    clippy::cast_lossless,
-        cast_lossless,
+    clippy::module_name_repetitions,
-        module_name_repetitions,
+    clippy::single_match_else,
-        option_if_let_else,
+    clippy::type_complexity,
-        single_match_else,
+    clippy::use_self,
-        type_complexity,
+    clippy::zero_prefixed_literal,
-        use_self,
+    // correctly used
-        zero_prefixed_literal,
+    clippy::derive_partial_eq_without_eq,
-        // correctly used
+    clippy::enum_glob_use,
-        derive_partial_eq_without_eq,
+    clippy::explicit_auto_deref,
-        enum_glob_use,
+    clippy::incompatible_msrv,
-        explicit_auto_deref,
+    clippy::let_underscore_untyped,
-        let_underscore_untyped,
+    clippy::map_err_ignore,
-        map_err_ignore,
+    clippy::new_without_default,
-        new_without_default,
+    clippy::result_unit_err,
-        result_unit_err,
+    clippy::wildcard_imports,
-        wildcard_imports,
+    // not practical
-        // not practical
+    clippy::needless_pass_by_value,
-        needless_pass_by_value,
+    clippy::similar_names,
-        similar_names,
+    clippy::too_many_lines,
-        too_many_lines,
+    // preference
-        // preference
+    clippy::doc_markdown,
-        doc_markdown,
+    clippy::elidable_lifetime_names,
-        unseparated_literal_suffix,
+    clippy::needless_lifetimes,
-        // false positive
+    clippy::unseparated_literal_suffix,
-        needless_doctest_main,
+    // false positive
-        // noisy
+    clippy::needless_doctest_main,
-        missing_errors_doc,
+    // noisy
-        must_use_candidate,
+    clippy::missing_errors_doc,
-    )
+    clippy::must_use_candidate,
 )]
 // Restrictions
-#![cfg_attr(feature = "cargo-clippy", deny(question_mark_used))]
+#![deny(clippy::question_mark_used)]
 // Rustc lints.
 #![deny(missing_docs, unused_imports)]
 
@@ -170,21 +179,19 @@ mod lib {
         pub use std::*;
     }
 
-    pub use self::core::{cmp, iter, mem, num, ptr, slice, str};
     pub use self::core::{f32, f64};
-    pub use self::core::{i16, i32, i64, i8, isize};
+    pub use self::core::{ptr, str};
-    pub use self::core::{u16, u32, u64, u8, usize};
 
-    pub use self::core::cell::{Cell, RefCell};
+    #[cfg(any(feature = "std", feature = "alloc"))]
-    pub use self::core::clone::{self, Clone};
+    pub use self::core::slice;
-    pub use self::core::convert::{self, From, Into};
+
-    pub use self::core::default::{self, Default};
+    pub use self::core::clone;
-    pub use self::core::fmt::{self, Debug, Display};
+    pub use self::core::convert;
+    pub use self::core::default;
+    pub use self::core::fmt::{self, Debug, Display, Write as FmtWrite};
     pub use self::core::marker::{self, PhantomData};
-    pub use self::core::num::Wrapping;
+    pub use self::core::option;
-    pub use self::core::ops::{Range, RangeFrom, RangeTo};
+    pub use self::core::result;
-    pub use self::core::option::{self, Option};
-    pub use self::core::result::{self, Result};
 
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::borrow::{Cow, ToOwned};
@@ -205,92 +212,14 @@ mod lib {
     pub use alloc::boxed::Box;
     #[cfg(feature = "std")]
     pub use std::boxed::Box;
-
-    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
-    pub use alloc::rc::{Rc, Weak as RcWeak};
-    #[cfg(all(feature = "rc", feature = "std"))]
-    pub use std::rc::{Rc, Weak as RcWeak};
-
-    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
-    pub use alloc::sync::{Arc, Weak as ArcWeak};
-    #[cfg(all(feature = "rc", feature = "std"))]
-    pub use std::sync::{Arc, Weak as ArcWeak};
-
-    #[cfg(all(feature = "alloc", not(feature = "std")))]
-    pub use alloc::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
-    #[cfg(feature = "std")]
-    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
-
-    #[cfg(all(not(no_core_cstr), not(feature = "std")))]
-    pub use core::ffi::CStr;
-    #[cfg(feature = "std")]
-    pub use std::ffi::CStr;
-
-    #[cfg(all(not(no_core_cstr), feature = "alloc", not(feature = "std")))]
-    pub use alloc::ffi::CString;
-    #[cfg(feature = "std")]
-    pub use std::ffi::CString;
-
-    #[cfg(feature = "std")]
-    pub use std::{error, net};
-
-    #[cfg(feature = "std")]
-    pub use std::collections::{HashMap, HashSet};
-    #[cfg(feature = "std")]
-    pub use std::ffi::{OsStr, OsString};
-    #[cfg(feature = "std")]
-    pub use std::hash::{BuildHasher, Hash};
-    #[cfg(feature = "std")]
-    pub use std::io::Write;
-    #[cfg(feature = "std")]
-    pub use std::path::{Path, PathBuf};
-    #[cfg(feature = "std")]
-    pub use std::sync::{Mutex, RwLock};
-    #[cfg(feature = "std")]
-    pub use std::time::{SystemTime, UNIX_EPOCH};
-
-    #[cfg(all(feature = "std", not(no_collections_bound), no_ops_bound))]
-    pub use std::collections::Bound;
-
-    #[cfg(not(no_core_reverse))]
-    pub use self::core::cmp::Reverse;
-
-    #[cfg(not(no_ops_bound))]
-    pub use self::core::ops::Bound;
-
-    #[cfg(not(no_range_inclusive))]
-    pub use self::core::ops::RangeInclusive;
-
-    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
-    pub use std::sync::atomic::{
-        AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
-        AtomicUsize, Ordering,
-    };
-    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
-    pub use std::sync::atomic::{AtomicI64, AtomicU64};
-
-    #[cfg(all(feature = "std", not(no_target_has_atomic)))]
-    pub use std::sync::atomic::Ordering;
-    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
-    pub use std::sync::atomic::{AtomicBool, AtomicI8, AtomicU8};
-    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "16"))]
-    pub use std::sync::atomic::{AtomicI16, AtomicU16};
-    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "32"))]
-    pub use std::sync::atomic::{AtomicI32, AtomicU32};
-    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "64"))]
-    pub use std::sync::atomic::{AtomicI64, AtomicU64};
-    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
-    pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
-
-    #[cfg(any(feature = "std", not(no_core_duration)))]
-    pub use self::core::time::Duration;
 }
 
 // None of this crate's error handling needs the `From::from` error conversion
 // performed implicitly by the `?` operator or the standard library's `try!`
 // macro. This simplified macro gives a 5.5% improvement in compile time
 // compared to standard `try!`, and 9% improvement compared to `?`.
-macro_rules! try {
+#[cfg(not(no_serde_derive))]
+macro_rules! tri {
     ($expr:expr) => {
         match $expr {
             Ok(val) => val,
@@ -301,36 +230,18 @@ macro_rules! try {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[macro_use]
+pub use serde_core::{
-mod macros;
+    de, forward_to_deserialize_any, ser, Deserialize, Deserializer, Serialize, Serializer,
+};
 
 #[macro_use]
 mod integer128;
 
-pub mod de;
-pub mod ser;
-
-#[doc(inline)]
-pub use de::{Deserialize, Deserializer};
-#[doc(inline)]
-pub use ser::{Serialize, Serializer};
-
 // Used by generated code and doc tests. Not public API.
 #[doc(hidden)]
 #[path = "private/mod.rs"]
 pub mod __private;
 
-#[allow(unused_imports)]
-use self::__private as export;
-#[allow(unused_imports)]
-use self::__private as private;
-
-#[path = "de/seed.rs"]
-mod seed;
-
-#[cfg(not(any(feature = "std", feature = "unstable")))]
-mod std_error;
-
 // Re-export #[derive(Serialize, Deserialize)].
 //
 // The reason re-exporting is not enabled by default is that disabling it would
@@ -341,9 +252,11 @@ extern crate serde_derive;
 
 /// Derive macro available if serde is built with `features = ["derive"]`.
 #[cfg(feature = "serde_derive")]
+#[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
 pub use serde_derive::{Deserialize, Serialize};
 
-#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+#[macro_export]
-mod actually_private {
+#[doc(hidden)]
-    pub struct T;
+macro_rules! __require_serde_not_serde_core {
+    () => {};
 }

serde/src/private/mod.rs

@@ -3,48 +3,16 @@ pub mod de;
 #[cfg(not(no_serde_derive))]
 pub mod ser;
 
-pub mod size_hint;
+pub use crate::lib::clone::Clone;
+pub use crate::lib::convert::{From, Into, TryFrom};
+pub use crate::lib::default::Default;
+pub use crate::lib::fmt::{self, Formatter};
+pub use crate::lib::marker::PhantomData;
+pub use crate::lib::option::Option::{self, None, Some};
+pub use crate::lib::ptr;
+pub use crate::lib::result::Result::{self, Err, Ok};
 
-// FIXME: #[cfg(doctest)] once https://github.com/rust-lang/rust/issues/67295 is fixed.
+pub use serde_core::__private::string::from_utf8_lossy;
-pub mod doc;
-
-pub use lib::clone::Clone;
-pub use lib::convert::{From, Into};
-pub use lib::default::Default;
-pub use lib::fmt::{self, Formatter};
-pub use lib::marker::PhantomData;
-pub use lib::option::Option::{self, None, Some};
-pub use lib::ptr;
-pub use lib::result::Result::{self, Err, Ok};
-
-pub use self::string::from_utf8_lossy;
 
 #[cfg(any(feature = "alloc", feature = "std"))]
-pub use lib::{ToString, Vec};
+pub use crate::lib::{ToString, Vec};
-
-#[cfg(not(no_core_try_from))]
-pub use lib::convert::TryFrom;
-
-mod string {
-    use lib::*;
-
-    #[cfg(any(feature = "std", feature = "alloc"))]
-    pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
-        String::from_utf8_lossy(bytes)
-    }
-
-    // The generated code calls this like:
-    //
-    //     let value = &_serde::__private::from_utf8_lossy(bytes);
-    //     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
-    //
-    // so it is okay for the return type to be different from the std case as long
-    // as the above works.
-    #[cfg(not(any(feature = "std", feature = "alloc")))]
-    pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
-        // Three unicode replacement characters if it fails. They look like a
-        // white-on-black question mark. The user will recognize it as invalid
-        // UTF-8.
-        str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
-    }
-}

serde/src/private/ser.rs

@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;
 
-use ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
+use crate::ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 use self::content::{
@@ -51,11 +51,10 @@ enum Unsupported {
     String,
     ByteArray,
     Optional,
-    #[cfg(any(feature = "std", feature = "alloc"))]
-    UnitStruct,
     Sequence,
     Tuple,
     TupleStruct,
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
     Enum,
 }
 
@@ -69,11 +68,10 @@ impl Display for Unsupported {
             Unsupported::String => formatter.write_str("a string"),
             Unsupported::ByteArray => formatter.write_str("a byte array"),
             Unsupported::Optional => formatter.write_str("an optional"),
-            #[cfg(any(feature = "std", feature = "alloc"))]
-            Unsupported::UnitStruct => formatter.write_str("unit struct"),
             Unsupported::Sequence => formatter.write_str("a sequence"),
             Unsupported::Tuple => formatter.write_str("a tuple"),
             Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
+            #[cfg(not(any(feature = "std", feature = "alloc")))]
             Unsupported::Enum => formatter.write_str("an enum"),
         }
     }
@@ -174,22 +172,22 @@ where
         Err(self.bad_type(Unsupported::Optional))
     }
 
-    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(self.bad_type(Unsupported::Optional))
     }
 
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(1)));
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
         map.end()
     }
 
     fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(1)));
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
         map.end()
     }
 
@@ -199,24 +197,24 @@ where
         _: u32,
         inner_variant: &'static str,
     ) -> Result<Self::Ok, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_entry(inner_variant, &()));
+        tri!(map.serialize_entry(inner_variant, &()));
         map.end()
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         _: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _: &'static str,
         _: u32,
@@ -224,11 +222,11 @@ where
         inner_value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_entry(inner_variant, inner_value));
+        tri!(map.serialize_entry(inner_variant, inner_value));
         map.end()
     }
 
@@ -269,9 +267,9 @@ where
         inner_variant: &'static str,
         len: usize,
     ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_key(inner_variant));
+        tri!(map.serialize_key(inner_variant));
         Ok(SerializeTupleVariantAsMapValue::new(
             map,
             inner_variant,
@@ -280,8 +278,8 @@ where
     }
 
     fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(len.map(|len| len + 1)));
+        let mut map = tri!(self.delegate.serialize_map(len.map(|len| len + 1)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
         Ok(map)
     }
 
@@ -290,8 +288,8 @@ where
         name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeStruct, Self::Error> {
-        let mut state = try!(self.delegate.serialize_struct(name, len + 1));
+        let mut state = tri!(self.delegate.serialize_struct(name, len + 1));
-        try!(state.serialize_field(self.tag, self.variant_name));
+        tri!(state.serialize_field(self.tag, self.variant_name));
         Ok(state)
     }
 
@@ -316,9 +314,9 @@ where
         inner_variant: &'static str,
         len: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        let mut map = try!(self.delegate.serialize_map(Some(2)));
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
-        try!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
-        try!(map.serialize_key(inner_variant));
+        tri!(map.serialize_key(inner_variant));
         Ok(SerializeStructVariantAsMapValue::new(
             map,
             inner_variant,
@@ -327,9 +325,9 @@ where
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         Err(self.bad_type(Unsupported::String))
     }
@@ -337,9 +335,9 @@ where
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 mod content {
-    use lib::*;
+    use crate::lib::*;
 
-    use ser::{self, Serialize, Serializer};
+    use crate::ser::{self, Serialize, Serializer};
 
     pub struct SerializeTupleVariantAsMapValue<M> {
         map: M,
@@ -364,17 +362,17 @@ mod content {
         type Ok = M::Ok;
         type Error = M::Error;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), M::Error>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), M::Error>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
             self.fields.push(value);
             Ok(())
         }
 
         fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self
+            tri!(self
                 .map
                 .serialize_value(&Content::TupleStruct(self.name, self.fields)));
             self.map.end()
@@ -404,21 +402,17 @@ mod content {
         type Ok = M::Ok;
         type Error = M::Error;
 
-        fn serialize_field<T: ?Sized>(
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), M::Error>
-            &mut self,
-            key: &'static str,
-            value: &T,
-        ) -> Result<(), M::Error>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
             self.fields.push((key, value));
             Ok(())
         }
 
         fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self
+            tri!(self
                 .map
                 .serialize_value(&Content::Struct(self.name, self.fields)));
             self.map.end()
@@ -499,50 +493,50 @@ mod content {
                 }
                 Content::Seq(ref elements) => elements.serialize(serializer),
                 Content::Tuple(ref elements) => {
-                    use ser::SerializeTuple;
+                    use crate::ser::SerializeTuple;
-                    let mut tuple = try!(serializer.serialize_tuple(elements.len()));
+                    let mut tuple = tri!(serializer.serialize_tuple(elements.len()));
                     for e in elements {
-                        try!(tuple.serialize_element(e));
+                        tri!(tuple.serialize_element(e));
                     }
                     tuple.end()
                 }
                 Content::TupleStruct(n, ref fields) => {
-                    use ser::SerializeTupleStruct;
+                    use crate::ser::SerializeTupleStruct;
-                    let mut ts = try!(serializer.serialize_tuple_struct(n, fields.len()));
+                    let mut ts = tri!(serializer.serialize_tuple_struct(n, fields.len()));
                     for f in fields {
-                        try!(ts.serialize_field(f));
+                        tri!(ts.serialize_field(f));
                     }
                     ts.end()
                 }
                 Content::TupleVariant(n, i, v, ref fields) => {
-                    use ser::SerializeTupleVariant;
+                    use crate::ser::SerializeTupleVariant;
-                    let mut tv = try!(serializer.serialize_tuple_variant(n, i, v, fields.len()));
+                    let mut tv = tri!(serializer.serialize_tuple_variant(n, i, v, fields.len()));
                     for f in fields {
-                        try!(tv.serialize_field(f));
+                        tri!(tv.serialize_field(f));
                     }
                     tv.end()
                 }
                 Content::Map(ref entries) => {
-                    use ser::SerializeMap;
+                    use crate::ser::SerializeMap;
-                    let mut map = try!(serializer.serialize_map(Some(entries.len())));
+                    let mut map = tri!(serializer.serialize_map(Some(entries.len())));
                     for (k, v) in entries {
-                        try!(map.serialize_entry(k, v));
+                        tri!(map.serialize_entry(k, v));
                     }
                     map.end()
                 }
                 Content::Struct(n, ref fields) => {
-                    use ser::SerializeStruct;
+                    use crate::ser::SerializeStruct;
-                    let mut s = try!(serializer.serialize_struct(n, fields.len()));
+                    let mut s = tri!(serializer.serialize_struct(n, fields.len()));
                     for &(k, ref v) in fields {
-                        try!(s.serialize_field(k, v));
+                        tri!(s.serialize_field(k, v));
                     }
                     s.end()
                 }
                 Content::StructVariant(n, i, v, ref fields) => {
-                    use ser::SerializeStructVariant;
+                    use crate::ser::SerializeStructVariant;
-                    let mut sv = try!(serializer.serialize_struct_variant(n, i, v, fields.len()));
+                    let mut sv = tri!(serializer.serialize_struct_variant(n, i, v, fields.len()));
                     for &(k, ref v) in fields {
-                        try!(sv.serialize_field(k, v));
+                        tri!(sv.serialize_field(k, v));
                     }
                     sv.end()
                 }
@@ -635,11 +629,11 @@ mod content {
             Ok(Content::None)
         }
 
-        fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Content, E>
+        fn serialize_some<T>(self, value: &T) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            Ok(Content::Some(Box::new(try!(value.serialize(self)))))
+            Ok(Content::Some(Box::new(tri!(value.serialize(self)))))
         }
 
         fn serialize_unit(self) -> Result<Content, E> {
@@ -659,21 +653,17 @@ mod content {
             Ok(Content::UnitVariant(name, variant_index, variant))
         }
 
-        fn serialize_newtype_struct<T: ?Sized>(
+        fn serialize_newtype_struct<T>(self, name: &'static str, value: &T) -> Result<Content, E>
-            self,
-            name: &'static str,
-            value: &T,
-        ) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             Ok(Content::NewtypeStruct(
                 name,
-                Box::new(try!(value.serialize(self))),
+                Box::new(tri!(value.serialize(self))),
             ))
         }
 
-        fn serialize_newtype_variant<T: ?Sized>(
+        fn serialize_newtype_variant<T>(
             self,
             name: &'static str,
             variant_index: u32,
@@ -681,13 +671,13 @@ mod content {
             value: &T,
         ) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             Ok(Content::NewtypeVariant(
                 name,
                 variant_index,
                 variant,
-                Box::new(try!(value.serialize(self))),
+                Box::new(tri!(value.serialize(self))),
             ))
         }
 
@@ -782,11 +772,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.elements.push(value);
             Ok(())
         }
@@ -808,11 +798,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.elements.push(value);
             Ok(())
         }
@@ -835,11 +825,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push(value);
             Ok(())
         }
@@ -864,11 +854,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push(value);
             Ok(())
         }
@@ -896,24 +886,24 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), E>
+        fn serialize_key<T>(&mut self, key: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let key = try!(key.serialize(ContentSerializer::<E>::new()));
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
             self.key = Some(key);
             Ok(())
         }
 
-        fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_value<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let key = self
                 .key
                 .take()
                 .expect("serialize_value called before serialize_key");
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.entries.push((key, value));
             Ok(())
         }
@@ -922,13 +912,13 @@ mod content {
             Ok(Content::Map(self.entries))
         }
 
-        fn serialize_entry<K: ?Sized, V: ?Sized>(&mut self, key: &K, value: &V) -> Result<(), E>
+        fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), E>
         where
-            K: Serialize,
+            K: ?Sized + Serialize,
-            V: Serialize,
+            V: ?Sized + Serialize,
         {
-            let key = try!(key.serialize(ContentSerializer::<E>::new()));
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.entries.push((key, value));
             Ok(())
         }
@@ -947,11 +937,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push((key, value));
             Ok(())
         }
@@ -976,11 +966,11 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
-            let value = try!(value.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push((key, value));
             Ok(())
         }
@@ -1025,7 +1015,7 @@ where
     type SerializeTupleStruct = Impossible<Self::Ok, M::Error>;
     type SerializeMap = FlatMapSerializeMap<'a, M>;
     type SerializeStruct = FlatMapSerializeStruct<'a, M>;
-    type SerializeTupleVariant = Impossible<Self::Ok, M::Error>;
+    type SerializeTupleVariant = FlatMapSerializeTupleVariantAsMapValue<'a, M>;
     type SerializeStructVariant = FlatMapSerializeStructVariantAsMapValue<'a, M>;
 
     fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
@@ -1088,9 +1078,9 @@ where
         Ok(())
     }
 
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
@@ -1100,30 +1090,30 @@ where
     }
 
     fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(Self::bad_type(Unsupported::UnitStruct))
+        Ok(())
     }
 
     fn serialize_unit_variant(
         self,
         _: &'static str,
         _: u32,
-        _: &'static str,
+        variant: &'static str,
     ) -> Result<Self::Ok, Self::Error> {
-        Err(Self::bad_type(Unsupported::Enum))
+        self.0.serialize_entry(variant, &())
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         _: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _: &'static str,
         _: u32,
@@ -1131,10 +1121,9 @@ where
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
-        try!(self.0.serialize_key(variant));
+        self.0.serialize_entry(variant, value)
-        self.0.serialize_value(value)
     }
 
     fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
@@ -1157,10 +1146,11 @@ where
         self,
         _: &'static str,
         _: u32,
-        _: &'static str,
+        variant: &'static str,
         _: usize,
     ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        Err(Self::bad_type(Unsupported::Enum))
+        tri!(self.0.serialize_key(variant));
+        Ok(FlatMapSerializeTupleVariantAsMapValue::new(self.0))
     }
 
     fn serialize_map(self, _: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
@@ -1182,7 +1172,7 @@ where
         inner_variant: &'static str,
         _: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        try!(self.0.serialize_key(inner_variant));
+        tri!(self.0.serialize_key(inner_variant));
         Ok(FlatMapSerializeStructVariantAsMapValue::new(
             self.0,
             inner_variant,
@@ -1201,28 +1191,24 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_key(key)
     }
 
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_value(value)
     }
 
-    fn serialize_entry<K: ?Sized, V: ?Sized>(
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
     where
-        K: Serialize,
+        K: ?Sized + Serialize,
-        V: Serialize,
+        V: ?Sized + Serialize,
     {
         self.0.serialize_entry(key, value)
     }
@@ -1243,13 +1229,9 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_entry(key, value)
     }
@@ -1259,6 +1241,52 @@ where
     }
 }
 
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeTupleVariantAsMapValue<'a, M: 'a> {
+    map: &'a mut M,
+    fields: Vec<Content>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    fn new(map: &'a mut M) -> Self {
+        FlatMapSerializeTupleVariantAsMapValue {
+            map,
+            fields: Vec::new(),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeTupleVariant for FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
+    where
+        T: ?Sized + Serialize,
+    {
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+        self.fields.push(value);
+        Ok(())
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        tri!(self.map.serialize_value(&Content::Seq(self.fields)));
+        Ok(())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 #[cfg(any(feature = "std", feature = "alloc"))]
 pub struct FlatMapSerializeStructVariantAsMapValue<'a, M: 'a> {
     map: &'a mut M,
@@ -1288,23 +1316,47 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
-        let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
         self.fields.push((key, value));
         Ok(())
     }
 
     fn end(self) -> Result<(), Self::Error> {
-        try!(self
+        tri!(self
             .map
             .serialize_value(&Content::Struct(self.name, self.fields)));
         Ok(())
     }
 }
+
+pub struct AdjacentlyTaggedEnumVariant {
+    pub enum_name: &'static str,
+    pub variant_index: u32,
+    pub variant_name: &'static str,
+}
+
+impl Serialize for AdjacentlyTaggedEnumVariant {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_unit_variant(self.enum_name, self.variant_index, self.variant_name)
+    }
+}
+
+// Error when Serialize for a non_exhaustive remote enum encounters a variant
+// that is not recognized.
+pub struct CannotSerializeVariant<T>(pub T);
+
+impl<T> Display for CannotSerializeVariant<T>
+where
+    T: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "enum variant cannot be serialized: {:?}", self.0)
+    }
+}

serde_core/Cargo.toml

@@ -0,0 +1,69 @@
+[package]
+name = "serde_core"
+version = "1.0.221"
+authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
+build = "build.rs"
+categories = ["encoding", "no-std", "no-std::no-alloc"]
+description = "Serde traits only, with no support for derive -- use the `serde` crate instead"
+documentation = "https://docs.rs/serde_core"
+edition = "2021"
+homepage = "https://serde.rs"
+keywords = ["serde", "serialization", "no_std"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/serde-rs/serde"
+rust-version = "1.56"
+
+[dev-dependencies]
+serde = { version = "1", path = "../serde" }
+serde_derive = { version = "1", path = "../serde_derive" }
+
+[package.metadata.playground]
+features = ["rc", "result"]
+
+[package.metadata.docs.rs]
+features = ["rc", "result", "unstable"]
+targets = ["x86_64-unknown-linux-gnu"]
+rustdoc-args = [
+    "--generate-link-to-definition",
+    "--extern-html-root-url=core=https://doc.rust-lang.org",
+    "--extern-html-root-url=alloc=https://doc.rust-lang.org",
+    "--extern-html-root-url=std=https://doc.rust-lang.org",
+]
+
+# This cfg cannot be enabled, but it still forces Cargo to keep serde_derive's
+# version in lockstep with serde's, even if someone depends on the two crates
+# separately with serde's "derive" feature disabled. Every serde_derive release
+# is compatible with exactly one serde release because the generated code
+# involves nonpublic APIs which are not bound by semver.
+[target.'cfg(any())'.dependencies]
+serde_derive = { version = "=1.0.221", path = "../serde_derive" }
+
+
+### FEATURES #################################################################
+
+[features]
+default = ["std", "result"]
+
+# Provide impls for common standard library types like Vec<T> and HashMap<K, V>.
+# Requires a dependency on the Rust standard library.
+std = []
+
+# Provide impls for types that require unstable functionality. For tracking and
+# discussion of unstable functionality please refer to this issue:
+#
+#    https://github.com/serde-rs/serde/issues/812
+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.
+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.
+# Be sure that this is what you want before enabling this feature.
+rc = []
+
+# Provide impls for Result<T, E>. Convenient in some contexts but can lead to
+# confusion if ? or unwrap are used incautiously.
+result = []

serde_core/LICENSE-APACHE

@@ -0,0 +1 @@
+../LICENSE-APACHE

serde_core/LICENSE-MIT

@@ -0,0 +1 @@
+../LICENSE-MIT

serde_core/README.md

@@ -0,0 +1,28 @@
+The `serde_core` crate contains Serde's trait definitions with **no support for
+#\[derive()\]**.
+
+In crates that derive an implementation of `Serialize` or `Deserialize`, you
+must depend on the [`serde`] crate, not `serde_core`.
+
+[`serde`]: https://crates.io/crates/serde
+
+In crates that handwrite implementations of Serde traits, or only use them as
+trait bounds, depending on `serde_core` is permitted. But `serde` re-exports all
+of these traits and can be used for this use case too. If in doubt, disregard
+`serde_core` and always use `serde`.
+
+Crates that depend on `serde_core` instead of `serde` are able to compile in
+parallel with `serde_derive` even when `serde`'s "derive" feature is turned on,
+as shown in the following build timings.
+
+<br>
+
+| When `serde_json` depends on `serde` |
+|---|
+| <img src="https://github.com/user-attachments/assets/78dc179c-6ab1-4059-928c-1474b0d9d0bb"> |
+
+<br>
+
+| When `serde_json` depends on `serde_core` |
+|---|
+| <img src="https://github.com/user-attachments/assets/6b6cff5e-3e45-4ac7-9db1-d99ee8b9f5f7"> |

serde_core/build.rs

@@ -0,0 +1,97 @@
+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() {
+    println!("cargo:rerun-if-changed=build.rs");
+
+    let minor = match rustc_minor_version() {
+        Some(minor) => minor,
+        None => return,
+    };
+
+    if minor >= 77 {
+        println!("cargo:rustc-check-cfg=cfg(no_core_cstr)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_error)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_net)");
+        println!("cargo:rustc-check-cfg=cfg(no_core_num_saturating)");
+        println!("cargo:rustc-check-cfg=cfg(no_diagnostic_namespace)");
+        println!("cargo:rustc-check-cfg=cfg(no_serde_derive)");
+        println!("cargo:rustc-check-cfg=cfg(no_std_atomic)");
+        println!("cargo:rustc-check-cfg=cfg(no_std_atomic64)");
+        println!("cargo:rustc-check-cfg=cfg(no_target_has_atomic)");
+    }
+
+    let target = env::var("TARGET").unwrap();
+    let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";
+
+    // Support for #[cfg(target_has_atomic = "...")] stabilized in Rust 1.60.
+    if minor < 60 {
+        println!("cargo:rustc-cfg=no_target_has_atomic");
+        // Allowlist of archs that support std::sync::atomic module. This is
+        // based on rustc's compiler/rustc_target/src/spec/*.rs.
+        let has_atomic64 = target.starts_with("x86_64")
+            || target.starts_with("i686")
+            || target.starts_with("aarch64")
+            || target.starts_with("powerpc64")
+            || target.starts_with("sparc64")
+            || target.starts_with("mips64el")
+            || target.starts_with("riscv64");
+        let has_atomic32 = has_atomic64 || emscripten;
+        if minor < 34 || !has_atomic64 {
+            println!("cargo:rustc-cfg=no_std_atomic64");
+        }
+        if minor < 34 || !has_atomic32 {
+            println!("cargo:rustc-cfg=no_std_atomic");
+        }
+    }
+
+    // Current minimum supported version of serde_derive crate is Rust 1.61.
+    if minor < 61 {
+        println!("cargo:rustc-cfg=no_serde_derive");
+    }
+
+    // Support for core::ffi::CStr and alloc::ffi::CString stabilized in Rust 1.64.
+    // https://blog.rust-lang.org/2022/09/22/Rust-1.64.0.html#c-compatible-ffi-types-in-core-and-alloc
+    if minor < 64 {
+        println!("cargo:rustc-cfg=no_core_cstr");
+    }
+
+    // Support for core::num::Saturating and std::num::Saturating stabilized in Rust 1.74
+    // https://blog.rust-lang.org/2023/11/16/Rust-1.74.0.html#stabilized-apis
+    if minor < 74 {
+        println!("cargo:rustc-cfg=no_core_num_saturating");
+    }
+
+    // Support for core::net stabilized in Rust 1.77.
+    // https://blog.rust-lang.org/2024/03/21/Rust-1.77.0.html
+    if minor < 77 {
+        println!("cargo:rustc-cfg=no_core_net");
+    }
+
+    // Support for the `#[diagnostic]` tool attribute namespace
+    // https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#diagnostic-attributes
+    if minor < 78 {
+        println!("cargo:rustc-cfg=no_diagnostic_namespace");
+    }
+
+    // The Error trait became available in core in 1.81.
+    // https://blog.rust-lang.org/2024/09/05/Rust-1.81.0.html#coreerrorerror
+    if minor < 81 {
+        println!("cargo:rustc-cfg=no_core_error");
+    }
+}
+
+fn rustc_minor_version() -> Option<u32> {
+    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_core/src/de/ignored_any.rs

@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;
 
-use de::{
+use crate::de::{
     Deserialize, Deserializer, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor,
 };
 
@@ -129,12 +129,10 @@ impl<'de> Visitor<'de> for IgnoredAny {
         Ok(IgnoredAny)
     }
 
-    serde_if_integer128! {
+    #[inline]
-        #[inline]
+    fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
-        fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
+        let _ = x;
-            let _ = x;
+        Ok(IgnoredAny)
-            Ok(IgnoredAny)
-        }
     }
 
     #[inline]
@@ -143,12 +141,10 @@ impl<'de> Visitor<'de> for IgnoredAny {
         Ok(IgnoredAny)
     }
 
-    serde_if_integer128! {
+    #[inline]
-        #[inline]
+    fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
-        fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
+        let _ = x;
-            let _ = x;
+        Ok(IgnoredAny)
-            Ok(IgnoredAny)
-        }
     }
 
     #[inline]
@@ -197,7 +193,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
     where
         A: SeqAccess<'de>,
     {
-        while let Some(IgnoredAny) = try!(seq.next_element()) {
+        while let Some(IgnoredAny) = tri!(seq.next_element()) {
             // Gobble
         }
         Ok(IgnoredAny)
@@ -208,7 +204,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
     where
         A: MapAccess<'de>,
     {
-        while let Some((IgnoredAny, IgnoredAny)) = try!(map.next_entry()) {
+        while let Some((IgnoredAny, IgnoredAny)) = tri!(map.next_entry()) {
             // Gobble
         }
         Ok(IgnoredAny)
@@ -227,7 +223,7 @@ impl<'de> Visitor<'de> for IgnoredAny {
     where
         A: EnumAccess<'de>,
     {
-        try!(data.variant::<IgnoredAny>()).1.newtype_variant()
+        tri!(data.variant::<IgnoredAny>()).1.newtype_variant()
     }
 }
 

serde_core/src/de/mod.rs

@@ -64,8 +64,8 @@
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
-//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Rc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
-//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -101,8 +101,8 @@
 //!    - SocketAddrV6
 //!
 //! [Implementing `Deserialize`]: https://serde.rs/impl-deserialize.html
-//! [`Deserialize`]: ../trait.Deserialize.html
+//! [`Deserialize`]: crate::Deserialize
-//! [`Deserializer`]: ../trait.Deserializer.html
+//! [`Deserializer`]: crate::Deserializer
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
 //! [`postcard`]: https://github.com/jamesmunns/postcard
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
@@ -112,29 +112,26 @@
 //! [derive section of the manual]: https://serde.rs/derive.html
 //! [data formats]: https://serde.rs/#data-formats
 
-use lib::*;
+use crate::lib::*;
 
 ////////////////////////////////////////////////////////////////////////////////
 
 pub mod value;
 
-#[cfg(not(no_integer128))]
-mod format;
 mod ignored_any;
 mod impls;
-mod utf8;
 
 pub use self::ignored_any::IgnoredAny;
-
+pub use crate::private::InPlaceSeed;
-#[cfg(all(feature = "unstable", not(feature = "std")))]
+#[cfg(all(not(feature = "std"), no_core_error))]
+#[doc(no_inline)]
+pub use crate::std_error::Error as StdError;
+#[cfg(not(any(feature = "std", no_core_error)))]
 #[doc(no_inline)]
 pub use core::error::Error as StdError;
 #[cfg(feature = "std")]
 #[doc(no_inline)]
 pub use std::error::Error as StdError;
-#[cfg(not(any(feature = "std", feature = "unstable")))]
-#[doc(no_inline)]
-pub use std_error::Error as StdError;
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -160,6 +157,12 @@ macro_rules! declare_error_trait {
         /// type appropriate for a basic JSON data format.
         ///
         /// [example data format]: https://serde.rs/data-format.html
+        #[cfg_attr(
+            not(no_diagnostic_namespace),
+            diagnostic::on_unimplemented(
+                message = "the trait bound `{Self}: serde::de::Error` is not satisfied",
+            )
+        )]
         pub trait Error: Sized $(+ $($supertrait)::+)* {
             /// Raised when there is general error when deserializing a type.
             ///
@@ -208,7 +211,7 @@ macro_rules! declare_error_trait {
             /// containing an integer, the unexpected type is the integer and the
             /// expected type is the string.
             #[cold]
-            fn invalid_type(unexp: Unexpected, exp: &Expected) -> Self {
+            fn invalid_type(unexp: Unexpected, exp: &dyn Expected) -> Self {
                 Error::custom(format_args!("invalid type: {}, expected {}", unexp, exp))
             }
 
@@ -226,7 +229,7 @@ macro_rules! declare_error_trait {
             /// that is not valid UTF-8, the unexpected value is the bytes and the
             /// expected value is a string.
             #[cold]
-            fn invalid_value(unexp: Unexpected, exp: &Expected) -> Self {
+            fn invalid_value(unexp: Unexpected, exp: &dyn Expected) -> Self {
                 Error::custom(format_args!("invalid value: {}, expected {}", unexp, exp))
             }
 
@@ -240,7 +243,7 @@ macro_rules! declare_error_trait {
             /// expected. For example `exp` might say that a tuple of size 6 was
             /// expected.
             #[cold]
-            fn invalid_length(len: usize, exp: &Expected) -> Self {
+            fn invalid_length(len: usize, exp: &dyn Expected) -> Self {
                 Error::custom(format_args!("invalid length {}, expected {}", len, exp))
             }
 
@@ -403,20 +406,20 @@ impl<'a> fmt::Display for Unexpected<'a> {
             Bool(b) => write!(formatter, "boolean `{}`", b),
             Unsigned(i) => write!(formatter, "integer `{}`", i),
             Signed(i) => write!(formatter, "integer `{}`", i),
-            Float(f) => write!(formatter, "floating point `{}`", f),
+            Float(f) => write!(formatter, "floating point `{}`", WithDecimalPoint(f)),
             Char(c) => write!(formatter, "character `{}`", c),
             Str(s) => write!(formatter, "string {:?}", s),
-            Bytes(_) => write!(formatter, "byte array"),
+            Bytes(_) => formatter.write_str("byte array"),
-            Unit => write!(formatter, "unit value"),
+            Unit => formatter.write_str("unit value"),
-            Option => write!(formatter, "Option value"),
+            Option => formatter.write_str("Option value"),
-            NewtypeStruct => write!(formatter, "newtype struct"),
+            NewtypeStruct => formatter.write_str("newtype struct"),
-            Seq => write!(formatter, "sequence"),
+            Seq => formatter.write_str("sequence"),
-            Map => write!(formatter, "map"),
+            Map => formatter.write_str("map"),
-            Enum => write!(formatter, "enum"),
+            Enum => formatter.write_str("enum"),
-            UnitVariant => write!(formatter, "unit variant"),
+            UnitVariant => formatter.write_str("unit variant"),
-            NewtypeVariant => write!(formatter, "newtype variant"),
+            NewtypeVariant => formatter.write_str("newtype variant"),
-            TupleVariant => write!(formatter, "tuple variant"),
+            TupleVariant => formatter.write_str("tuple variant"),
-            StructVariant => write!(formatter, "struct variant"),
+            StructVariant => formatter.write_str("struct variant"),
             Other(other) => formatter.write_str(other),
         }
     }
@@ -473,6 +476,12 @@ impl<'a> fmt::Display for Unexpected<'a> {
 /// ));
 /// # }
 /// ```
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::Expected` is not satisfied",
+    )
+)]
 pub trait Expected {
     /// Format an explanation of what data was being expected. Same signature as
     /// the `Display` and `Debug` traits.
@@ -488,13 +497,13 @@ where
     }
 }
 
-impl<'a> Expected for &'a str {
+impl Expected for &str {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter.write_str(self)
     }
 }
 
-impl<'a> Display for Expected + 'a {
+impl Display for dyn Expected + '_ {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         Expected::fmt(self, formatter)
     }
@@ -533,6 +542,16 @@ impl<'a> Display for Expected + 'a {
 /// deserializer lifetimes] for a more detailed explanation of these lifetimes.
 ///
 /// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        // Prevents `serde_core::de::Deserialize` appearing in the error message
+        // in projects with no direct dependency on serde_core.
+        message = "the trait bound `{Self}: serde::Deserialize<'de>` is not satisfied",
+        note = "for local types consider adding `#[derive(serde::Deserialize)]` to your `{Self}` type",
+        note = "for types from other crates check whether the crate offers a `serde` feature flag",
+    )
+)]
 pub trait Deserialize<'de>: Sized {
     /// Deserialize this value from the given Serde deserializer.
     ///
@@ -569,7 +588,7 @@ pub trait Deserialize<'de>: Sized {
         D: Deserializer<'de>,
     {
         // Default implementation just delegates to `deserialize` impl.
-        *place = try!(Deserialize::deserialize(deserializer));
+        *place = tri!(Deserialize::deserialize(deserializer));
         Ok(())
     }
 }
@@ -605,6 +624,12 @@ pub trait Deserialize<'de>: Sized {
 /// lifetimes].
 ///
 /// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::DeserializeOwned` is not satisfied",
+    )
+)]
 pub trait DeserializeOwned: for<'de> Deserialize<'de> {}
 impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 
@@ -770,6 +795,12 @@ impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {}
 /// #     Ok(())
 /// # }
 /// ```
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::DeserializeSeed<'de>` is not satisfied",
+    )
+)]
 pub trait DeserializeSeed<'de>: Sized {
     /// The type produced by using this seed.
     type Value;
@@ -906,6 +937,12 @@ where
 /// a basic JSON `Deserializer`.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::Deserializer<'de>` is not satisfied",
+    )
+)]
 pub trait Deserializer<'de>: Sized {
     /// The error type that can be returned if some error occurs during
     /// deserialization.
@@ -949,18 +986,15 @@ pub trait Deserializer<'de>: Sized {
     where
         V: Visitor<'de>;
 
-    serde_if_integer128! {
+    /// Hint that the `Deserialize` type is expecting an `i128` value.
-        /// Hint that the `Deserialize` type is expecting an `i128` value.
+    ///
-        ///
+    /// The default behavior unconditionally returns an error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-        /// default behavior unconditionally returns an error.
+    where
-        fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        V: Visitor<'de>,
-        where
+    {
-            V: Visitor<'de>
+        let _ = visitor;
-        {
+        Err(Error::custom("i128 is not supported"))
-            let _ = visitor;
-            Err(Error::custom("i128 is not supported"))
-        }
     }
 
     /// Hint that the `Deserialize` type is expecting a `u8` value.
@@ -983,18 +1017,15 @@ pub trait Deserializer<'de>: Sized {
     where
         V: Visitor<'de>;
 
-    serde_if_integer128! {
+    /// Hint that the `Deserialize` type is expecting an `u128` value.
-        /// Hint that the `Deserialize` type is expecting an `u128` value.
+    ///
-        ///
+    /// The default behavior unconditionally returns an error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-        /// default behavior unconditionally returns an error.
+    where
-        fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        V: Visitor<'de>,
-        where
+    {
-            V: Visitor<'de>
+        let _ = visitor;
-        {
+        Err(Error::custom("u128 is not supported"))
-            let _ = visitor;
-            Err(Error::custom("u128 is not supported"))
-        }
     }
 
     /// Hint that the `Deserialize` type is expecting a `f32` value.
@@ -1227,13 +1258,9 @@ pub trait Deserializer<'de>: Sized {
     // Not public API.
     #[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
     #[doc(hidden)]
-    fn __deserialize_content<V>(
+    fn __deserialize_content_v1<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-        self,
-        _: ::actually_private::T,
-        visitor: V,
-    ) -> Result<::private::de::Content<'de>, Self::Error>
     where
-        V: Visitor<'de, Value = ::private::de::Content<'de>>,
+        V: Visitor<'de, Value = crate::private::Content<'de>>,
     {
         self.deserialize_any(visitor)
     }
@@ -1282,6 +1309,12 @@ pub trait Deserializer<'de>: Sized {
 ///     }
 /// }
 /// ```
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::Visitor<'de>` is not satisfied",
+    )
+)]
 pub trait Visitor<'de>: Sized {
     /// The value produced by this visitor.
     type Value;
@@ -1366,20 +1399,20 @@ pub trait Visitor<'de>: Sized {
         Err(Error::invalid_type(Unexpected::Signed(v), &self))
     }
 
-    serde_if_integer128! {
+    /// The input contains a `i128`.
-        /// The input contains a `i128`.
+    ///
-        ///
+    /// The default implementation fails with a type error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
-        /// default implementation fails with a type error.
+    where
-        fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
+        E: Error,
-        where
+    {
-            E: Error,
+        let mut buf = [0u8; 58];
-        {
+        let mut writer = crate::format::Buf::new(&mut buf);
-            let mut buf = [0u8; 58];
+        fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as i128", v)).unwrap();
-            let mut writer = format::Buf::new(&mut buf);
+        Err(Error::invalid_type(
-            fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as i128", v)).unwrap();
+            Unexpected::Other(writer.as_str()),
-            Err(Error::invalid_type(Unexpected::Other(writer.as_str()), &self))
+            &self,
-        }
+        ))
     }
 
     /// The input contains a `u8`.
@@ -1428,20 +1461,20 @@ pub trait Visitor<'de>: Sized {
         Err(Error::invalid_type(Unexpected::Unsigned(v), &self))
     }
 
-    serde_if_integer128! {
+    /// The input contains a `u128`.
-        /// The input contains a `u128`.
+    ///
-        ///
+    /// The default implementation fails with a type error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
-        /// default implementation fails with a type error.
+    where
-        fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
+        E: Error,
-        where
+    {
-            E: Error,
+        let mut buf = [0u8; 57];
-        {
+        let mut writer = crate::format::Buf::new(&mut buf);
-            let mut buf = [0u8; 57];
+        fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as u128", v)).unwrap();
-            let mut writer = format::Buf::new(&mut buf);
+        Err(Error::invalid_type(
-            fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as u128", v)).unwrap();
+            Unexpected::Other(writer.as_str()),
-            Err(Error::invalid_type(Unexpected::Other(writer.as_str()), &self))
+            &self,
-        }
+        ))
     }
 
     /// The input contains an `f32`.
@@ -1477,7 +1510,7 @@ pub trait Visitor<'de>: Sized {
     where
         E: Error,
     {
-        self.visit_str(utf8::encode(v).as_str())
+        self.visit_str(v.encode_utf8(&mut [0u8; 4]))
     }
 
     /// The input contains a string. The lifetime of the string is ephemeral and
@@ -1532,6 +1565,7 @@ pub trait Visitor<'de>: Sized {
     /// `String`.
     #[inline]
     #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
     where
         E: Error,
@@ -1554,7 +1588,6 @@ pub trait Visitor<'de>: Sized {
     where
         E: Error,
     {
-        let _ = v;
         Err(Error::invalid_type(Unexpected::Bytes(v), &self))
     }
 
@@ -1591,6 +1624,7 @@ pub trait Visitor<'de>: Sized {
     /// The default implementation forwards to `visit_bytes` and then drops the
     /// `Vec<u8>`.
     #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
     where
         E: Error,
@@ -1707,6 +1741,12 @@ pub trait Visitor<'de>: Sized {
 /// implementation of `SeqAccess` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::SeqAccess<'de>` is not satisfied",
+    )
+)]
 pub trait SeqAccess<'de> {
     /// The error type that can be returned if some error occurs during
     /// deserialization.
@@ -1741,9 +1781,9 @@ pub trait SeqAccess<'de> {
     }
 }
 
-impl<'de, 'a, A: ?Sized> SeqAccess<'de> for &'a mut A
+impl<'de, A> SeqAccess<'de> for &mut A
 where
-    A: SeqAccess<'de>,
+    A: ?Sized + SeqAccess<'de>,
 {
     type Error = A::Error;
 
@@ -1789,6 +1829,12 @@ where
 /// implementation of `MapAccess` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::MapAccess<'de>` is not satisfied",
+    )
+)]
 pub trait MapAccess<'de> {
     /// The error type that can be returned if some error occurs during
     /// deserialization.
@@ -1834,9 +1880,9 @@ pub trait MapAccess<'de> {
         K: DeserializeSeed<'de>,
         V: DeserializeSeed<'de>,
     {
-        match try!(self.next_key_seed(kseed)) {
+        match tri!(self.next_key_seed(kseed)) {
             Some(key) => {
-                let value = try!(self.next_value_seed(vseed));
+                let value = tri!(self.next_value_seed(vseed));
                 Ok(Some((key, value)))
             }
             None => Ok(None),
@@ -1894,9 +1940,9 @@ pub trait MapAccess<'de> {
     }
 }
 
-impl<'de, 'a, A: ?Sized> MapAccess<'de> for &'a mut A
+impl<'de, A> MapAccess<'de> for &mut A
 where
-    A: MapAccess<'de>,
+    A: ?Sized + MapAccess<'de>,
 {
     type Error = A::Error;
 
@@ -1981,6 +2027,12 @@ where
 /// implementation of `EnumAccess` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::EnumAccess<'de>` is not satisfied",
+    )
+)]
 pub trait EnumAccess<'de>: Sized {
     /// The error type that can be returned if some error occurs during
     /// deserialization.
@@ -2028,6 +2080,12 @@ pub trait EnumAccess<'de>: Sized {
 /// implementation of `VariantAccess` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::de::VariantAccess<'de>` is not satisfied",
+    )
+)]
 pub trait VariantAccess<'de>: Sized {
     /// The error type that can be returned if some error occurs during
     /// deserialization. Must match the error type of our `EnumAccess`.
@@ -2284,15 +2342,52 @@ impl Display for OneOf {
             1 => write!(formatter, "`{}`", self.names[0]),
             2 => write!(formatter, "`{}` or `{}`", self.names[0], self.names[1]),
             _ => {
-                try!(write!(formatter, "one of "));
+                tri!(formatter.write_str("one of "));
                 for (i, alt) in self.names.iter().enumerate() {
                     if i > 0 {
-                        try!(write!(formatter, ", "));
+                        tri!(formatter.write_str(", "));
                     }
-                    try!(write!(formatter, "`{}`", alt));
+                    tri!(write!(formatter, "`{}`", alt));
                 }
                 Ok(())
             }
         }
     }
 }
+
+struct WithDecimalPoint(f64);
+
+impl Display for WithDecimalPoint {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        struct LookForDecimalPoint<'f, 'a> {
+            formatter: &'f mut fmt::Formatter<'a>,
+            has_decimal_point: bool,
+        }
+
+        impl<'f, 'a> fmt::Write for LookForDecimalPoint<'f, 'a> {
+            fn write_str(&mut self, fragment: &str) -> fmt::Result {
+                self.has_decimal_point |= fragment.contains('.');
+                self.formatter.write_str(fragment)
+            }
+
+            fn write_char(&mut self, ch: char) -> fmt::Result {
+                self.has_decimal_point |= ch == '.';
+                self.formatter.write_char(ch)
+            }
+        }
+
+        if self.0.is_finite() {
+            let mut writer = LookForDecimalPoint {
+                formatter,
+                has_decimal_point: false,
+            };
+            tri!(write!(writer, "{}", self.0));
+            if !writer.has_decimal_point {
+                tri!(formatter.write_str(".0"));
+            }
+        } else {
+            tri!(write!(formatter, "{}", self.0));
+        }
+        Ok(())
+    }
+}

serde_core/src/de/value.rs

@@ -21,12 +21,12 @@
 //! }
 //! ```
 
-use lib::*;
+use crate::lib::*;
 
 use self::private::{First, Second};
-use __private::size_hint;
+use crate::de::{self, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor};
-use de::{self, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor};
+use crate::private::size_hint;
-use ser;
+use crate::ser;
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -113,6 +113,7 @@ impl Debug for Error {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl error::Error for Error {
     fn description(&self) -> &str {
         &self.err
@@ -175,6 +176,17 @@ where
     }
 }
 
+impl<'de, E> IntoDeserializer<'de, E> for UnitDeserializer<E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<E> Debug for UnitDeserializer<E> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter.debug_struct("UnitDeserializer").finish()
@@ -185,12 +197,14 @@ impl<E> Debug for UnitDeserializer<E> {
 
 /// A deserializer that cannot be instantiated.
 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 pub struct NeverDeserializer<E> {
     never: !,
     marker: PhantomData<E>,
 }
 
 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl<'de, E> IntoDeserializer<'de, E> for !
 where
     E: de::Error,
@@ -223,6 +237,18 @@ where
     }
 }
 
+#[cfg(feature = "unstable")]
+impl<'de, E> IntoDeserializer<'de, E> for NeverDeserializer<E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! primitive_deserializer {
@@ -277,6 +303,17 @@ macro_rules! primitive_deserializer {
             }
         }
 
+        impl<'de, E> IntoDeserializer<'de, E> for $name<E>
+        where
+            E: de::Error,
+        {
+            type Deserializer = Self;
+
+            fn into_deserializer(self) -> Self {
+                self
+            }
+        }
+
         impl<E> Debug for $name<E> {
             fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                 formatter
@@ -293,20 +330,17 @@ primitive_deserializer!(i8, "an `i8`.", I8Deserializer, visit_i8);
 primitive_deserializer!(i16, "an `i16`.", I16Deserializer, visit_i16);
 primitive_deserializer!(i32, "an `i32`.", I32Deserializer, visit_i32);
 primitive_deserializer!(i64, "an `i64`.", I64Deserializer, visit_i64);
+primitive_deserializer!(i128, "an `i128`.", I128Deserializer, visit_i128);
 primitive_deserializer!(isize, "an `isize`.", IsizeDeserializer, visit_i64 as i64);
 primitive_deserializer!(u8, "a `u8`.", U8Deserializer, visit_u8);
 primitive_deserializer!(u16, "a `u16`.", U16Deserializer, visit_u16);
 primitive_deserializer!(u64, "a `u64`.", U64Deserializer, visit_u64);
+primitive_deserializer!(u128, "a `u128`.", U128Deserializer, visit_u128);
 primitive_deserializer!(usize, "a `usize`.", UsizeDeserializer, visit_u64 as u64);
 primitive_deserializer!(f32, "an `f32`.", F32Deserializer, visit_f32);
 primitive_deserializer!(f64, "an `f64`.", F64Deserializer, visit_f64);
 primitive_deserializer!(char, "a `char`.", CharDeserializer, visit_char);
 
-serde_if_integer128! {
-    primitive_deserializer!(i128, "an `i128`.", I128Deserializer, visit_i128);
-    primitive_deserializer!(u128, "a `u128`.", U128Deserializer, visit_u128);
-}
-
 /// A deserializer holding a `u32`.
 pub struct U32Deserializer<E> {
     value: u32,
@@ -370,6 +404,17 @@ where
     }
 }
 
+impl<'de, E> IntoDeserializer<'de, E> for U32Deserializer<E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, E> de::EnumAccess<'de> for U32Deserializer<E>
 where
     E: de::Error,
@@ -459,6 +504,17 @@ where
     }
 }
 
+impl<'de, 'a, E> IntoDeserializer<'de, E> for StrDeserializer<'a, E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, 'a, E> de::EnumAccess<'de> for StrDeserializer<'a, E>
 where
     E: de::Error,
@@ -538,6 +594,17 @@ where
     }
 }
 
+impl<'de, E> IntoDeserializer<'de, E> for BorrowedStrDeserializer<'de, E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, E> de::EnumAccess<'de> for BorrowedStrDeserializer<'de, E>
 where
     E: de::Error,
@@ -566,6 +633,7 @@ impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> {
 
 /// A deserializer holding a `String`.
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct StringDeserializer<E> {
     value: String,
     marker: PhantomData<E>,
@@ -582,6 +650,7 @@ impl<E> Clone for StringDeserializer<E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, E> IntoDeserializer<'de, E> for String
 where
     E: de::Error,
@@ -639,6 +708,18 @@ where
     }
 }
 
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'de, E> IntoDeserializer<'de, E> for StringDeserializer<E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'de, E> de::EnumAccess<'de> for StringDeserializer<E>
 where
@@ -669,6 +750,7 @@ impl<E> Debug for StringDeserializer<E> {
 
 /// A deserializer holding a `Cow<str>`.
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct CowStrDeserializer<'a, E> {
     value: Cow<'a, str>,
     marker: PhantomData<E>,
@@ -685,6 +767,7 @@ impl<'a, E> Clone for CowStrDeserializer<'a, E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, 'a, E> IntoDeserializer<'de, E> for Cow<'a, str>
 where
     E: de::Error,
@@ -745,6 +828,18 @@ where
     }
 }
 
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'de, 'a, E> IntoDeserializer<'de, E> for CowStrDeserializer<'a, E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'de, 'a, E> de::EnumAccess<'de> for CowStrDeserializer<'a, E>
 where
@@ -822,6 +917,17 @@ where
     }
 }
 
+impl<'de, 'a, E> IntoDeserializer<'de, E> for BytesDeserializer<'a, E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'a, E> Debug for BytesDeserializer<'a, E> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter
@@ -870,6 +976,17 @@ where
     }
 }
 
+impl<'de, E> IntoDeserializer<'de, E> for BorrowedBytesDeserializer<'de, E>
+where
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, E> Debug for BorrowedBytesDeserializer<'de, E> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter
@@ -937,8 +1054,8 @@ where
     where
         V: de::Visitor<'de>,
     {
-        let v = try!(visitor.visit_seq(&mut self));
+        let v = tri!(visitor.visit_seq(&mut self));
-        try!(self.end());
+        tri!(self.end());
         Ok(v)
     }
 
@@ -949,6 +1066,19 @@ where
     }
 }
 
+impl<'de, I, T, E> IntoDeserializer<'de, E> for SeqDeserializer<I, E>
+where
+    I: Iterator<Item = T>,
+    T: IntoDeserializer<'de, E>,
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, I, T, E> de::SeqAccess<'de> for SeqDeserializer<I, E>
 where
     I: Iterator<Item = T>,
@@ -980,7 +1110,7 @@ struct ExpectedInSeq(usize);
 impl Expected for ExpectedInSeq {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         if self.0 == 1 {
-            write!(formatter, "1 element in sequence")
+            formatter.write_str("1 element in sequence")
         } else {
             write!(formatter, "{} elements in sequence", self.0)
         }
@@ -1003,6 +1133,7 @@ where
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for Vec<T>
 where
     T: IntoDeserializer<'de, E>,
@@ -1016,6 +1147,7 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for BTreeSet<T>
 where
     T: IntoDeserializer<'de, E> + Eq + Ord,
@@ -1029,6 +1161,7 @@ where
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, T, S, E> IntoDeserializer<'de, E> for HashSet<T, S>
 where
     T: IntoDeserializer<'de, E> + Eq + Hash,
@@ -1077,6 +1210,17 @@ where
     }
 }
 
+impl<'de, A> IntoDeserializer<'de, A::Error> for SeqAccessDeserializer<A>
+where
+    A: de::SeqAccess<'de>,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer that iterates over a map.
@@ -1162,8 +1306,8 @@ where
     where
         V: de::Visitor<'de>,
     {
-        let value = try!(visitor.visit_map(&mut self));
+        let value = tri!(visitor.visit_map(&mut self));
-        try!(self.end());
+        tri!(self.end());
         Ok(value)
     }
 
@@ -1171,8 +1315,8 @@ where
     where
         V: de::Visitor<'de>,
     {
-        let value = try!(visitor.visit_seq(&mut self));
+        let value = tri!(visitor.visit_seq(&mut self));
-        try!(self.end());
+        tri!(self.end());
         Ok(value)
     }
 
@@ -1191,6 +1335,21 @@ where
     }
 }
 
+impl<'de, I, E> IntoDeserializer<'de, E> for MapDeserializer<'de, I, E>
+where
+    I: Iterator,
+    I::Item: private::Pair,
+    First<I::Item>: IntoDeserializer<'de, E>,
+    Second<I::Item>: IntoDeserializer<'de, E>,
+    E: de::Error,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, I, E> de::MapAccess<'de> for MapDeserializer<'de, I, E>
 where
     I: Iterator,
@@ -1236,8 +1395,8 @@ where
     {
         match self.next_pair() {
             Some((key, value)) => {
-                let key = try!(kseed.deserialize(key.into_deserializer()));
+                let key = tri!(kseed.deserialize(key.into_deserializer()));
-                let value = try!(vseed.deserialize(value.into_deserializer()));
+                let value = tri!(vseed.deserialize(value.into_deserializer()));
                 Ok(Some((key, value)))
             }
             None => Ok(None),
@@ -1341,7 +1500,7 @@ where
         V: de::Visitor<'de>,
     {
         let mut pair_visitor = PairVisitor(Some(self.0), Some(self.1), PhantomData);
-        let pair = try!(visitor.visit_seq(&mut pair_visitor));
+        let pair = tri!(visitor.visit_seq(&mut pair_visitor));
         if pair_visitor.1.is_none() {
             Ok(pair)
         } else {
@@ -1405,7 +1564,7 @@ struct ExpectedInMap(usize);
 impl Expected for ExpectedInMap {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         if self.0 == 1 {
-            write!(formatter, "1 element in map")
+            formatter.write_str("1 element in map")
         } else {
             write!(formatter, "{} elements in map", self.0)
         }
@@ -1415,6 +1574,7 @@ impl Expected for ExpectedInMap {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V>
 where
     K: IntoDeserializer<'de, E> + Eq + Ord,
@@ -1429,6 +1589,7 @@ where
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, K, V, S, E> IntoDeserializer<'de, E> for HashMap<K, V, S>
 where
     K: IntoDeserializer<'de, E> + Eq + Hash,
@@ -1490,6 +1651,17 @@ where
     }
 }
 
+impl<'de, A> IntoDeserializer<'de, A::Error> for MapAccessDeserializer<A>
+where
+    A: de::MapAccess<'de>,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 impl<'de, A> de::EnumAccess<'de> for MapAccessDeserializer<A>
 where
     A: de::MapAccess<'de>,
@@ -1501,7 +1673,7 @@ where
     where
         T: de::DeserializeSeed<'de>,
     {
-        match try!(self.map.next_key_seed(seed)) {
+        match tri!(self.map.next_key_seed(seed)) {
             Some(key) => Ok((key, private::map_as_enum(self.map))),
             None => Err(de::Error::invalid_type(de::Unexpected::Map, &"enum")),
         }
@@ -1543,12 +1715,25 @@ where
     }
 }
 
+impl<'de, A> IntoDeserializer<'de, A::Error> for EnumAccessDeserializer<A>
+where
+    A: de::EnumAccess<'de>,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 mod private {
-    use lib::*;
+    use crate::lib::*;
 
-    use de::{self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor};
+    use crate::de::{
+        self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor,
+    };
 
     pub struct UnitOnly<E> {
         marker: PhantomData<E>,

serde_core/src/format.rs

@@ -1,5 +1,5 @@
-use lib::fmt::{self, Write};
+use crate::lib::fmt::{self, Write};
-use lib::str;
+use crate::lib::str;
 
 pub(super) struct Buf<'a> {
     bytes: &'a mut [u8],

serde_core/src/lib.rs

@@ -0,0 +1,270 @@
+//! Serde is a framework for ***ser***ializing and ***de***serializing Rust data
+//! structures efficiently and generically.
+//!
+//! The `serde_core` crate contains Serde's trait definitions with **no support
+//! for #\[derive()\]**.
+//!
+//! In crates that derive an implementation of `Serialize` or `Deserialize`, you
+//! must depend on the [`serde`] crate, not `serde_core`.
+//!
+//! [`serde`]: https://crates.io/crates/serde
+//!
+//! In crates that handwrite implementations of Serde traits, or only use them
+//! as trait bounds, depending on `serde_core` is permitted. But `serde`
+//! re-exports all of these traits and can be used for this use case too. If in
+//! doubt, disregard `serde_core` and always use `serde`.
+//!
+//! Crates that depend on `serde_core` instead of `serde` are able to compile in
+//! parallel with `serde_derive` even when `serde`'s "derive" feature is turned on,
+//! as shown in the following build timings.
+//!
+//! <br>
+//!
+//! <table>
+//! <tr><td align="center">When <code>serde_json</code> depends on <code>serde</code></td></tr>
+//! <tr><td><img src="https://github.com/user-attachments/assets/78dc179c-6ab1-4059-928c-1474b0d9d0bb"></td></tr>
+//! </table>
+//!
+//! <br>
+//!
+//! <table>
+//! <tr><td align="center">When <code>serde_json</code> depends on <code>serde_core</code></td></tr>
+//! <tr><td><img src="https://github.com/user-attachments/assets/6b6cff5e-3e45-4ac7-9db1-d99ee8b9f5f7"></td></tr>
+//! </table>
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Serde types in rustdoc of other crates get linked to here.
+#![doc(html_root_url = "https://docs.rs/serde/1.0.221")]
+// Support using Serde without the standard library!
+#![cfg_attr(not(feature = "std"), no_std)]
+// Show which crate feature enables conditionally compiled APIs in documentation.
+#![cfg_attr(docsrs, feature(doc_cfg, rustdoc_internals))]
+#![cfg_attr(docsrs, allow(internal_features))]
+// Unstable functionality only if the user asks for it. For tracking and
+// discussion of these features please refer to this issue:
+//
+//    https://github.com/serde-rs/serde/issues/812
+#![cfg_attr(feature = "unstable", feature(never_type))]
+#![allow(unknown_lints, bare_trait_objects, deprecated)]
+// Ignored clippy and clippy_pedantic lints
+#![allow(
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
+    clippy::semicolon_if_nothing_returned,
+    // not available in our oldest supported compiler
+    clippy::empty_enum,
+    clippy::type_repetition_in_bounds, // https://github.com/rust-lang/rust-clippy/issues/8772
+    // integer and float ser/de requires these sorts of casts
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_precision_loss,
+    clippy::cast_sign_loss,
+    // things are often more readable this way
+    clippy::cast_lossless,
+    clippy::module_name_repetitions,
+    clippy::single_match_else,
+    clippy::type_complexity,
+    clippy::use_self,
+    clippy::zero_prefixed_literal,
+    // correctly used
+    clippy::derive_partial_eq_without_eq,
+    clippy::enum_glob_use,
+    clippy::explicit_auto_deref,
+    clippy::incompatible_msrv,
+    clippy::let_underscore_untyped,
+    clippy::map_err_ignore,
+    clippy::new_without_default,
+    clippy::result_unit_err,
+    clippy::wildcard_imports,
+    // not practical
+    clippy::needless_pass_by_value,
+    clippy::similar_names,
+    clippy::too_many_lines,
+    // preference
+    clippy::doc_markdown,
+    clippy::elidable_lifetime_names,
+    clippy::needless_lifetimes,
+    clippy::unseparated_literal_suffix,
+    // false positive
+    clippy::needless_doctest_main,
+    // noisy
+    clippy::missing_errors_doc,
+    clippy::must_use_candidate,
+)]
+// Restrictions
+#![deny(clippy::question_mark_used)]
+// Rustc lints.
+#![deny(missing_docs, unused_imports)]
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+/// A facade around all the types we need from the `std`, `core`, and `alloc`
+/// crates. This avoids elaborate import wrangling having to happen in every
+/// module.
+mod lib {
+    mod core {
+        #[cfg(not(feature = "std"))]
+        pub use core::*;
+        #[cfg(feature = "std")]
+        pub use std::*;
+    }
+
+    pub use self::core::{f32, f64};
+    pub use self::core::{iter, num, str};
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub use self::core::{cmp, mem};
+
+    pub use self::core::cell::{Cell, RefCell};
+    pub use self::core::cmp::Reverse;
+    pub use self::core::fmt::{self, Debug, Display, Write as FmtWrite};
+    pub use self::core::marker::PhantomData;
+    pub use self::core::num::Wrapping;
+    pub use self::core::ops::{Bound, Range, RangeFrom, RangeInclusive, RangeTo};
+    pub use self::core::result;
+    pub use self::core::time::Duration;
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::borrow::{Cow, ToOwned};
+    #[cfg(feature = "std")]
+    pub use std::borrow::{Cow, ToOwned};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::string::{String, ToString};
+    #[cfg(feature = "std")]
+    pub use std::string::{String, ToString};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::vec::Vec;
+    #[cfg(feature = "std")]
+    pub use std::vec::Vec;
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::boxed::Box;
+    #[cfg(feature = "std")]
+    pub use std::boxed::Box;
+
+    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
+    pub use alloc::rc::{Rc, Weak as RcWeak};
+    #[cfg(all(feature = "rc", feature = "std"))]
+    pub use std::rc::{Rc, Weak as RcWeak};
+
+    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
+    pub use alloc::sync::{Arc, Weak as ArcWeak};
+    #[cfg(all(feature = "rc", feature = "std"))]
+    pub use std::sync::{Arc, Weak as ArcWeak};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+    #[cfg(feature = "std")]
+    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+
+    #[cfg(all(not(no_core_cstr), not(feature = "std")))]
+    pub use self::core::ffi::CStr;
+    #[cfg(feature = "std")]
+    pub use std::ffi::CStr;
+
+    #[cfg(all(not(no_core_cstr), feature = "alloc", not(feature = "std")))]
+    pub use alloc::ffi::CString;
+    #[cfg(feature = "std")]
+    pub use std::ffi::CString;
+
+    #[cfg(all(not(no_core_net), not(feature = "std")))]
+    pub use self::core::net;
+    #[cfg(feature = "std")]
+    pub use std::net;
+
+    #[cfg(feature = "std")]
+    pub use std::error;
+
+    #[cfg(feature = "std")]
+    pub use std::collections::{HashMap, HashSet};
+    #[cfg(feature = "std")]
+    pub use std::ffi::{OsStr, OsString};
+    #[cfg(feature = "std")]
+    pub use std::hash::{BuildHasher, Hash};
+    #[cfg(feature = "std")]
+    pub use std::io::Write;
+    #[cfg(feature = "std")]
+    pub use std::path::{Path, PathBuf};
+    #[cfg(feature = "std")]
+    pub use std::sync::{Mutex, RwLock};
+    #[cfg(feature = "std")]
+    pub use std::time::{SystemTime, UNIX_EPOCH};
+
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
+    pub use std::sync::atomic::{
+        AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
+        AtomicUsize, Ordering,
+    };
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+
+    #[cfg(all(feature = "std", not(no_target_has_atomic)))]
+    pub use std::sync::atomic::Ordering;
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
+    pub use std::sync::atomic::{AtomicBool, AtomicI8, AtomicU8};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "16"))]
+    pub use std::sync::atomic::{AtomicI16, AtomicU16};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "32"))]
+    pub use std::sync::atomic::{AtomicI32, AtomicU32};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "64"))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
+    pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
+
+    #[cfg(not(no_core_num_saturating))]
+    pub use self::core::num::Saturating;
+}
+
+// None of this crate's error handling needs the `From::from` error conversion
+// performed implicitly by the `?` operator or the standard library's `try!`
+// macro. This simplified macro gives a 5.5% improvement in compile time
+// compared to standard `try!`, and 9% improvement compared to `?`.
+macro_rules! tri {
+    ($expr:expr) => {
+        match $expr {
+            Ok(val) => val,
+            Err(err) => return Err(err),
+        }
+    };
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[macro_use]
+mod macros;
+
+pub mod de;
+pub mod ser;
+
+mod format;
+
+#[doc(inline)]
+pub use crate::de::{Deserialize, Deserializer};
+#[doc(inline)]
+pub use crate::ser::{Serialize, Serializer};
+
+// Used by generated code. Not public API.
+#[doc(hidden)]
+#[path = "private/mod.rs"]
+pub mod __private;
+use self::__private as private;
+
+#[cfg(all(not(feature = "std"), no_core_error))]
+mod std_error;
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! __require_serde_not_serde_core {
+    () => {
+        ::core::compile_error!(
+            "Serde derive requires a dependency on the serde crate, not serde_core"
+        );
+    };
+}

serde_core/src/macros.rs

@@ -1,7 +1,6 @@
 // Super explicit first paragraph because this shows up at the top level and
 // trips up people who are just looking for basic Serialize / Deserialize
 // documentation.
-//
 /// Helper macro when implementing the `Deserializer` part of a new data format
 /// for Serde.
 ///
@@ -104,9 +103,9 @@
 /// # }
 /// ```
 ///
-/// [`Deserializer`]: trait.Deserializer.html
+/// [`Deserializer`]: crate::Deserializer
-/// [`Visitor`]: de/trait.Visitor.html
+/// [`Visitor`]: crate::de::Visitor
-/// [`Deserializer::deserialize_any`]: trait.Deserializer.html#tymethod.deserialize_any
+/// [`Deserializer::deserialize_any`]: crate::Deserializer::deserialize_any
 #[macro_export(local_inner_macros)]
 macro_rules! forward_to_deserialize_any {
     (<$visitor:ident: Visitor<$lifetime:tt>> $($func:ident)*) => {
@@ -123,7 +122,7 @@ macro_rules! forward_to_deserialize_any {
 macro_rules! forward_to_deserialize_any_method {
     ($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
         #[inline]
-        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, Self::Error>
+        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, <Self as $crate::de::Deserializer<$l>>::Error>
         where
             $v: $crate::de::Visitor<$l>,
         {
@@ -154,9 +153,7 @@ macro_rules! forward_to_deserialize_any_helper {
         forward_to_deserialize_any_method!{deserialize_i64<$l, $v>()}
     };
     (i128<$l:tt, $v:ident>) => {
-        serde_if_integer128! {
+        forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
-            forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
-        }
     };
     (u8<$l:tt, $v:ident>) => {
         forward_to_deserialize_any_method!{deserialize_u8<$l, $v>()}
@@ -171,9 +168,7 @@ macro_rules! forward_to_deserialize_any_helper {
         forward_to_deserialize_any_method!{deserialize_u64<$l, $v>()}
     };
     (u128<$l:tt, $v:ident>) => {
-        serde_if_integer128! {
+        forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
-            forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
-        }
     };
     (f32<$l:tt, $v:ident>) => {
         forward_to_deserialize_any_method!{deserialize_f32<$l, $v>()}

serde_core/src/private/content.rs

@@ -0,0 +1,264 @@
+use crate::de::{self, Deserialize, Deserializer, EnumAccess, MapAccess, SeqAccess, Visitor};
+use crate::lib::*;
+use crate::private::size_hint;
+
+// Used from generated code to buffer the contents of the Deserializer when
+// deserializing untagged enums and internally tagged enums.
+//
+// Not public API. Use serde-value instead.
+//
+// Obsoleted by format-specific buffer types (https://github.com/serde-rs/serde/pull/2912).
+#[derive(Clone)]
+#[doc(hidden)]
+pub enum Content<'de> {
+    Bool(bool),
+
+    U8(u8),
+    U16(u16),
+    U32(u32),
+    U64(u64),
+
+    I8(i8),
+    I16(i16),
+    I32(i32),
+    I64(i64),
+
+    F32(f32),
+    F64(f64),
+
+    Char(char),
+    String(String),
+    Str(&'de str),
+    ByteBuf(Vec<u8>),
+    Bytes(&'de [u8]),
+
+    None,
+    Some(Box<Content<'de>>),
+
+    Unit,
+    Newtype(Box<Content<'de>>),
+    Seq(Vec<Content<'de>>),
+    Map(Vec<(Content<'de>, Content<'de>)>),
+}
+
+impl<'de> Deserialize<'de> for Content<'de> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        // Untagged and internally tagged enums are only supported in
+        // self-describing formats.
+        let visitor = ContentVisitor { value: PhantomData };
+        deserializer.__deserialize_content_v1(visitor)
+    }
+}
+
+#[doc(hidden)]
+pub struct ContentVisitor<'de> {
+    value: PhantomData<Content<'de>>,
+}
+
+impl<'de> ContentVisitor<'de> {
+    pub fn new() -> Self {
+        ContentVisitor { value: PhantomData }
+    }
+}
+
+impl<'de> Visitor<'de> for ContentVisitor<'de> {
+    type Value = Content<'de>;
+
+    fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str("any value")
+    }
+
+    fn visit_bool<F>(self, value: bool) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::Bool(value))
+    }
+
+    fn visit_i8<F>(self, value: i8) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::I8(value))
+    }
+
+    fn visit_i16<F>(self, value: i16) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::I16(value))
+    }
+
+    fn visit_i32<F>(self, value: i32) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::I32(value))
+    }
+
+    fn visit_i64<F>(self, value: i64) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::I64(value))
+    }
+
+    fn visit_u8<F>(self, value: u8) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::U8(value))
+    }
+
+    fn visit_u16<F>(self, value: u16) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::U16(value))
+    }
+
+    fn visit_u32<F>(self, value: u32) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::U32(value))
+    }
+
+    fn visit_u64<F>(self, value: u64) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::U64(value))
+    }
+
+    fn visit_f32<F>(self, value: f32) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::F32(value))
+    }
+
+    fn visit_f64<F>(self, value: f64) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::F64(value))
+    }
+
+    fn visit_char<F>(self, value: char) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::Char(value))
+    }
+
+    fn visit_str<F>(self, value: &str) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::String(value.into()))
+    }
+
+    fn visit_borrowed_str<F>(self, value: &'de str) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::Str(value))
+    }
+
+    fn visit_string<F>(self, value: String) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::String(value))
+    }
+
+    fn visit_bytes<F>(self, value: &[u8]) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::ByteBuf(value.into()))
+    }
+
+    fn visit_borrowed_bytes<F>(self, value: &'de [u8]) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::Bytes(value))
+    }
+
+    fn visit_byte_buf<F>(self, value: Vec<u8>) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::ByteBuf(value))
+    }
+
+    fn visit_unit<F>(self) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::Unit)
+    }
+
+    fn visit_none<F>(self) -> Result<Self::Value, F>
+    where
+        F: de::Error,
+    {
+        Ok(Content::None)
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let v = tri!(Deserialize::deserialize(deserializer));
+        Ok(Content::Some(Box::new(v)))
+    }
+
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let v = tri!(Deserialize::deserialize(deserializer));
+        Ok(Content::Newtype(Box::new(v)))
+    }
+
+    fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+    where
+        V: SeqAccess<'de>,
+    {
+        let mut vec =
+            Vec::<Content>::with_capacity(size_hint::cautious::<Content>(visitor.size_hint()));
+        while let Some(e) = tri!(visitor.next_element()) {
+            vec.push(e);
+        }
+        Ok(Content::Seq(vec))
+    }
+
+    fn visit_map<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+    where
+        V: MapAccess<'de>,
+    {
+        let mut vec = Vec::<(Content, Content)>::with_capacity(size_hint::cautious::<(
+            Content,
+            Content,
+        )>(visitor.size_hint()));
+        while let Some(kv) = tri!(visitor.next_entry()) {
+            vec.push(kv);
+        }
+        Ok(Content::Map(vec))
+    }
+
+    fn visit_enum<V>(self, _visitor: V) -> Result<Self::Value, V::Error>
+    where
+        V: EnumAccess<'de>,
+    {
+        Err(de::Error::custom(
+            "untagged and internally tagged enums do not support enum input",
+        ))
+    }
+}

serde_core/src/private/doc.rs

@@ -1,8 +1,8 @@
 // Used only by Serde doc tests. Not public API.
 
-use lib::*;
+use crate::lib::*;
 
-use ser;
+use crate::ser;
 
 #[doc(hidden)]
 #[derive(Debug)]
@@ -56,7 +56,10 @@ macro_rules! __serialize_unimplemented {
 #[macro_export]
 macro_rules! __serialize_unimplemented_method {
     ($func:ident $(<$t:ident>)* ($($arg:ty),*) -> $ret:ident) => {
-        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error> {
+        fn $func $(<$t>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error>
+        where
+            $($t: ?Sized + $crate::Serialize,)*
+        {
             unimplemented!()
         }
     };

serde_core/src/private/mod.rs

@@ -0,0 +1,21 @@
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+mod content;
+mod seed;
+
+// FIXME: #[cfg(doctest)] once https://github.com/rust-lang/rust/issues/67295 is fixed.
+#[doc(hidden)]
+pub mod doc;
+
+#[doc(hidden)]
+pub mod size_hint;
+
+#[doc(hidden)]
+pub mod string;
+
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+#[doc(hidden)]
+pub use self::content::{Content, ContentVisitor};
+#[doc(hidden)]
+pub use self::seed::InPlaceSeed;
+#[doc(hidden)]
+pub use crate::lib::result::Result;

serde_core/src/private/seed.rs

@@ -1,4 +1,4 @@
-use de::{Deserialize, DeserializeSeed, Deserializer};
+use crate::de::{Deserialize, DeserializeSeed, Deserializer};
 
 /// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
 ///

serde_core/src/private/size_hint.rs

@@ -1,4 +1,5 @@
-use lib::*;
+#[cfg(any(feature = "std", feature = "alloc"))]
+use crate::lib::*;
 
 pub fn from_bounds<I>(iter: &I) -> Option<usize>
 where

serde_core/src/private/string.rs

@@ -0,0 +1,23 @@
+use crate::lib::*;
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+#[doc(hidden)]
+pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<'_, str> {
+    String::from_utf8_lossy(bytes)
+}
+
+// The generated code calls this like:
+//
+//     let value = &_serde::__private::from_utf8_lossy(bytes);
+//     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+//
+// so it is okay for the return type to be different from the std case as long
+// as the above works.
+#[cfg(not(any(feature = "std", feature = "alloc")))]
+#[doc(hidden)]
+pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
+    // Three unicode replacement characters if it fails. They look like a
+    // white-on-black question mark. The user will recognize it as invalid
+    // UTF-8.
+    str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
+}

serde_core/src/ser/fmt.rs

@@ -1,5 +1,5 @@
-use lib::*;
+use crate::lib::*;
-use ser::{Error, Impossible, Serialize, Serializer};
+use crate::ser::{Error, Impossible, Serialize, Serializer};
 
 impl Error for fmt::Error {
     fn custom<T: Display>(_msg: T) -> Self {
@@ -35,7 +35,7 @@ macro_rules! fmt_primitives {
 ///     }
 /// }
 /// ```
-impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
+impl<'a> Serializer for &mut fmt::Formatter<'a> {
     type Ok = ();
     type Error = fmt::Error;
     type SerializeSeq = Impossible<(), fmt::Error>;
@@ -52,10 +52,12 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         serialize_i16: i16,
         serialize_i32: i32,
         serialize_i64: i64,
+        serialize_i128: i128,
         serialize_u8: u8,
         serialize_u16: u16,
         serialize_u32: u32,
         serialize_u64: u64,
+        serialize_u128: u128,
         serialize_f32: f32,
         serialize_f64: f64,
         serialize_char: char,
@@ -63,13 +65,6 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         serialize_unit_struct: &'static str,
     }
 
-    serde_if_integer128! {
-        fmt_primitives! {
-            serialize_i128: i128,
-            serialize_u128: u128,
-        }
-    }
-
     fn serialize_unit_variant(
         self,
         _name: &'static str,
@@ -79,9 +74,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Display::fmt(variant, self)
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Serialize::serialize(value, self)
     }
@@ -94,9 +89,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    fn serialize_some<T>(self, _value: &T) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(fmt::Error)
     }
@@ -105,7 +100,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _name: &'static str,
         _variant_index: u32,
@@ -113,7 +108,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         _value: &T,
     ) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(fmt::Error)
     }
@@ -166,9 +161,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    fn collect_str<T>(self, value: &T) -> fmt::Result
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         Display::fmt(value, self)
     }

serde_core/src/ser/impls.rs

@@ -1,6 +1,6 @@
-use lib::*;
+use crate::lib::*;
 
-use ser::{Error, Serialize, SerializeTuple, Serializer};
+use crate::ser::{Error, Serialize, SerializeTuple, Serializer};
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -24,20 +24,17 @@ primitive_impl!(i8, serialize_i8);
 primitive_impl!(i16, serialize_i16);
 primitive_impl!(i32, serialize_i32);
 primitive_impl!(i64, serialize_i64);
+primitive_impl!(i128, serialize_i128);
 primitive_impl!(usize, serialize_u64 as u64);
 primitive_impl!(u8, serialize_u8);
 primitive_impl!(u16, serialize_u16);
 primitive_impl!(u32, serialize_u32);
 primitive_impl!(u64, serialize_u64);
+primitive_impl!(u128, serialize_u128);
 primitive_impl!(f32, serialize_f32);
 primitive_impl!(f64, serialize_f64);
 primitive_impl!(char, serialize_char);
 
-serde_if_integer128! {
-    primitive_impl!(i128, serialize_i128);
-    primitive_impl!(u128, serialize_u128);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 
 impl Serialize for str {
@@ -51,6 +48,7 @@ impl Serialize for str {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for String {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -73,6 +71,7 @@ impl<'a> Serialize for fmt::Arguments<'a> {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", not(no_core_cstr)))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for CStr {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -84,6 +83,7 @@ impl Serialize for CStr {
 }
 
 #[cfg(any(feature = "std", all(not(no_core_cstr), feature = "alloc")))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for CString {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -114,7 +114,10 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-impl<T: ?Sized> Serialize for PhantomData<T> {
+impl<T> Serialize for PhantomData<T>
+where
+    T: ?Sized,
+{
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -133,7 +136,7 @@ impl<T> Serialize for [T; 0] {
     where
         S: Serializer,
     {
-        try!(serializer.serialize_tuple(0)).end()
+        tri!(serializer.serialize_tuple(0)).end()
     }
 }
 
@@ -149,9 +152,9 @@ macro_rules! array_impls {
                 where
                     S: Serializer,
                 {
-                    let mut seq = try!(serializer.serialize_tuple($len));
+                    let mut seq = tri!(serializer.serialize_tuple($len));
                     for e in self {
-                        try!(seq.serialize_element(e));
+                        tri!(seq.serialize_element(e));
                     }
                     seq.end()
                 }
@@ -182,9 +185,12 @@ where
     }
 }
 
-#[cfg(all(any(feature = "std", feature = "alloc"), not(no_relaxed_trait_bounds)))]
 macro_rules! seq_impl {
-    ($ty:ident <T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)*>) => {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <T $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
         impl<T $(, $typaram)*> Serialize for $ty<T $(, $typaram)*>
         where
             T: Serialize,
@@ -200,42 +206,41 @@ macro_rules! seq_impl {
     }
 }
 
-#[cfg(all(any(feature = "std", feature = "alloc"), no_relaxed_trait_bounds))]
+seq_impl! {
-macro_rules! seq_impl {
+    #[cfg(any(feature = "std", feature = "alloc"))]
-    ($ty:ident <T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)*>) => {
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
-        impl<T $(, $typaram)*> Serialize for $ty<T $(, $typaram)*>
+    BinaryHeap<T>
-        where
-            T: Serialize $(+ $tbound1 $(+ $tbound2)*)*,
-            $($typaram: $bound,)*
-        {
-            #[inline]
-            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-            where
-                S: Serializer,
-            {
-                serializer.collect_seq(self)
-            }
-        }
-    }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+seq_impl! {
-seq_impl!(BinaryHeap<T: Ord>);
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    BTreeSet<T>
+}
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+seq_impl! {
-seq_impl!(BTreeSet<T: Ord>);
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    HashSet<T, H: BuildHasher>
+}
 
-#[cfg(feature = "std")]
+seq_impl! {
-seq_impl!(HashSet<T: Eq + Hash, H: BuildHasher>);
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    LinkedList<T>
+}
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+seq_impl! {
-seq_impl!(LinkedList<T>);
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    Vec<T>
+}
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+seq_impl! {
-seq_impl!(Vec<T>);
+    #[cfg(any(feature = "std", feature = "alloc"))]
-
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
-#[cfg(any(feature = "std", feature = "alloc"))]
+    VecDeque<T>
-seq_impl!(VecDeque<T>);
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -248,9 +253,9 @@ where
         S: Serializer,
     {
         use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("Range", 2));
+        let mut state = tri!(serializer.serialize_struct("Range", 2));
-        try!(state.serialize_field("start", &self.start));
+        tri!(state.serialize_field("start", &self.start));
-        try!(state.serialize_field("end", &self.end));
+        tri!(state.serialize_field("end", &self.end));
         state.end()
     }
 }
@@ -266,15 +271,14 @@ where
         S: Serializer,
     {
         use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("RangeFrom", 1));
+        let mut state = tri!(serializer.serialize_struct("RangeFrom", 1));
-        try!(state.serialize_field("start", &self.start));
+        tri!(state.serialize_field("start", &self.start));
         state.end()
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(not(no_range_inclusive))]
 impl<Idx> Serialize for RangeInclusive<Idx>
 where
     Idx: Serialize,
@@ -284,9 +288,9 @@ where
         S: Serializer,
     {
         use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("RangeInclusive", 2));
+        let mut state = tri!(serializer.serialize_struct("RangeInclusive", 2));
-        try!(state.serialize_field("start", &self.start()));
+        tri!(state.serialize_field("start", &self.start()));
-        try!(state.serialize_field("end", &self.end()));
+        tri!(state.serialize_field("end", &self.end()));
         state.end()
     }
 }
@@ -302,15 +306,14 @@ where
         S: Serializer,
     {
         use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("RangeTo", 1));
+        let mut state = tri!(serializer.serialize_struct("RangeTo", 1));
-        try!(state.serialize_field("end", &self.end));
+        tri!(state.serialize_field("end", &self.end));
         state.end()
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(any(not(no_ops_bound), all(feature = "std", not(no_collections_bound))))]
 impl<T> Serialize for Bound<T>
 where
     T: Serialize,
@@ -344,6 +347,7 @@ impl Serialize for () {
 }
 
 #[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl Serialize for ! {
     fn serialize<S>(&self, _serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -358,28 +362,46 @@ impl Serialize for ! {
 macro_rules! tuple_impls {
     ($($len:expr => ($($n:tt $name:ident)+))+) => {
         $(
+            #[cfg_attr(docsrs, doc(hidden))]
             impl<$($name),+> Serialize for ($($name,)+)
             where
                 $($name: Serialize,)+
             {
-                #[inline]
+                tuple_impl_body!($len => ($($n)+));
-                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-                where
-                    S: Serializer,
-                {
-                    let mut tuple = try!(serializer.serialize_tuple($len));
-                    $(
-                        try!(tuple.serialize_element(&self.$n));
-                    )+
-                    tuple.end()
-                }
             }
         )+
-    }
+    };
+}
+
+macro_rules! tuple_impl_body {
+    ($len:expr => ($($n:tt)+)) => {
+        #[inline]
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            let mut tuple = tri!(serializer.serialize_tuple($len));
+            $(
+                tri!(tuple.serialize_element(&self.$n));
+            )+
+            tuple.end()
+        }
+    };
+}
+
+#[cfg_attr(docsrs, doc(fake_variadic))]
+#[cfg_attr(
+    docsrs,
+    doc = "This trait is implemented for tuples up to 16 items long."
+)]
+impl<T> Serialize for (T,)
+where
+    T: Serialize,
+{
+    tuple_impl_body!(1 => (0));
 }
 
 tuple_impls! {
-    1 => (0 T0)
     2 => (0 T0 1 T1)
     3 => (0 T0 1 T1 2 T2)
     4 => (0 T0 1 T1 2 T2 3 T3)
@@ -399,9 +421,12 @@ tuple_impls! {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(all(any(feature = "std", feature = "alloc"), not(no_relaxed_trait_bounds)))]
 macro_rules! map_impl {
-    ($ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)*>) => {
+    (
+        $(#[$attr:meta])*
+        $ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)*>
+    ) => {
+        $(#[$attr])*
         impl<K, V $(, $typaram)*> Serialize for $ty<K, V $(, $typaram)*>
         where
             K: Serialize,
@@ -418,40 +443,26 @@ macro_rules! map_impl {
     }
 }
 
-#[cfg(all(any(feature = "std", feature = "alloc"), no_relaxed_trait_bounds))]
+map_impl! {
-macro_rules! map_impl {
+    #[cfg(any(feature = "std", feature = "alloc"))]
-    ($ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)*>) => {
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
-        impl<K, V $(, $typaram)*> Serialize for $ty<K, V $(, $typaram)*>
+    BTreeMap<K: Ord, V>
-        where
-            K: Serialize $(+ $kbound1 $(+ $kbound2)*)*,
-            V: Serialize,
-            $($typaram: $bound,)*
-        {
-            #[inline]
-            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-            where
-                S: Serializer,
-            {
-                serializer.collect_map(self)
-            }
-        }
-    }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+map_impl! {
-map_impl!(BTreeMap<K: Ord, V>);
+    #[cfg(feature = "std")]
-
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-#[cfg(feature = "std")]
+    HashMap<K: Eq + Hash, V, H: BuildHasher>
-map_impl!(HashMap<K: Eq + Hash, V, H: BuildHasher>);
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! deref_impl {
     (
-        $(#[doc = $doc:tt])*
+        $(#[$attr:meta])*
         <$($desc:tt)+
     ) => {
-        $(#[doc = $doc])*
+        $(#[$attr])*
         impl <$($desc)+ {
             #[inline]
             fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -464,13 +475,20 @@ macro_rules! deref_impl {
     };
 }
 
-deref_impl!(<'a, T: ?Sized> Serialize for &'a T where T: Serialize);
+deref_impl! {
-deref_impl!(<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize);
+    <'a, T> Serialize for &'a T where T: ?Sized + Serialize
+}
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+deref_impl! {
-deref_impl!(<T: ?Sized> Serialize for Box<T> where T: Serialize);
+    <'a, T> Serialize for &'a mut T where T: ?Sized + Serialize
+}
+
+deref_impl! {
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    <T> Serialize for Box<T> where T: ?Sized + Serialize
+}
 
-#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 deref_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -480,10 +498,11 @@ deref_impl! {
     /// repeated data.
     ///
     /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
-    <T: ?Sized> Serialize for Rc<T> where T: Serialize
+    #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
+    <T> Serialize for Rc<T> where T: ?Sized + Serialize
 }
 
-#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 deref_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -493,11 +512,16 @@ deref_impl! {
     /// repeated data.
     ///
     /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
-    <T: ?Sized> Serialize for Arc<T> where T: Serialize
+    #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
+    <T> Serialize for Arc<T> where T: ?Sized + Serialize
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+deref_impl! {
-deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned);
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    <'a, T> Serialize for Cow<'a, T> where T: ?Sized + Serialize + ToOwned
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -505,9 +529,13 @@ deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwne
 ///
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-impl<T: ?Sized> Serialize for RcWeak<T>
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
+)]
+impl<T> Serialize for RcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -521,9 +549,13 @@ where
 ///
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-impl<T: ?Sized> Serialize for ArcWeak<T>
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
+)]
+impl<T> Serialize for ArcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -538,7 +570,6 @@ where
 macro_rules! nonzero_integers {
     ($($T:ident,)+) => {
         $(
-            #[cfg(not(no_num_nonzero))]
             impl Serialize for num::$T {
                 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where
@@ -551,34 +582,19 @@ macro_rules! nonzero_integers {
     }
 }
 
-nonzero_integers! {
-    NonZeroU8,
-    NonZeroU16,
-    NonZeroU32,
-    NonZeroU64,
-    NonZeroUsize,
-}
-
-#[cfg(not(no_num_nonzero_signed))]
 nonzero_integers! {
     NonZeroI8,
     NonZeroI16,
     NonZeroI32,
     NonZeroI64,
+    NonZeroI128,
     NonZeroIsize,
-}
+    NonZeroU8,
-
+    NonZeroU16,
-// Currently 128-bit integers do not work on Emscripten targets so we need an
+    NonZeroU32,
-// additional `#[cfg]`
+    NonZeroU64,
-serde_if_integer128! {
+    NonZeroU128,
-    nonzero_integers! {
+    NonZeroUsize,
-        NonZeroU128,
-    }
-
-    #[cfg(not(no_num_nonzero_signed))]
-    nonzero_integers! {
-        NonZeroI128,
-    }
 }
 
 impl<T> Serialize for Cell<T>
@@ -593,9 +609,9 @@ where
     }
 }
 
-impl<T: ?Sized> Serialize for RefCell<T>
+impl<T> Serialize for RefCell<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -609,9 +625,10 @@ where
 }
 
 #[cfg(feature = "std")]
-impl<T: ?Sized> Serialize for Mutex<T>
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl<T> Serialize for Mutex<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -625,9 +642,10 @@ where
 }
 
 #[cfg(feature = "std")]
-impl<T: ?Sized> Serialize for RwLock<T>
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl<T> Serialize for RwLock<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -642,6 +660,8 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(feature = "result")]
+#[cfg_attr(docsrs, doc(cfg(feature = "result")))]
 impl<T, E> Serialize for Result<T, E>
 where
     T: Serialize,
@@ -662,16 +682,15 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(any(feature = "std", not(no_core_duration)))]
 impl Serialize for Duration {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: Serializer,
     {
         use super::SerializeStruct;
-        let mut state = try!(serializer.serialize_struct("Duration", 2));
+        let mut state = tri!(serializer.serialize_struct("Duration", 2));
-        try!(state.serialize_field("secs", &self.as_secs()));
+        tri!(state.serialize_field("secs", &self.as_secs()));
-        try!(state.serialize_field("nanos", &self.subsec_nanos()));
+        tri!(state.serialize_field("nanos", &self.subsec_nanos()));
         state.end()
     }
 }
@@ -679,6 +698,7 @@ impl Serialize for Duration {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for SystemTime {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -689,9 +709,9 @@ impl Serialize for SystemTime {
             Ok(duration_since_epoch) => duration_since_epoch,
             Err(_) => return Err(S::Error::custom("SystemTime must be later than UNIX_EPOCH")),
         };
-        let mut state = try!(serializer.serialize_struct("SystemTime", 2));
+        let mut state = tri!(serializer.serialize_struct("SystemTime", 2));
-        try!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
+        tri!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
-        try!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
+        tri!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
         state.end()
     }
 }
@@ -702,27 +722,17 @@ impl Serialize for SystemTime {
 /// statically known to never have more than a constant `MAX_LEN` bytes.
 ///
 /// Panics if the `Display` impl tries to write more than `MAX_LEN` bytes.
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 macro_rules! serialize_display_bounded_length {
     ($value:expr, $max:expr, $serializer:expr) => {{
         let mut buffer = [0u8; $max];
-        let remaining_len = {
+        let mut writer = crate::format::Buf::new(&mut buffer);
-            let mut remaining = &mut buffer[..];
+        write!(&mut writer, "{}", $value).unwrap();
-            write!(remaining, "{}", $value).unwrap();
+        $serializer.serialize_str(writer.as_str())
-            remaining.len()
-        };
-        let written_len = buffer.len() - remaining_len;
-        let written = &buffer[..written_len];
-
-        // write! only provides fmt::Formatter to Display implementations, which
-        // has methods write_str and write_char but no method to write arbitrary
-        // bytes. Therefore `written` must be valid UTF-8.
-        let written_str = str::from_utf8(written).expect("must be valid UTF-8");
-        $serializer.serialize_str(written_str)
     }};
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::IpAddr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -746,7 +756,7 @@ impl Serialize for net::IpAddr {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 const DEC_DIGITS_LUT: &[u8] = b"\
       0001020304050607080910111213141516171819\
       2021222324252627282930313233343536373839\
@@ -754,7 +764,7 @@ const DEC_DIGITS_LUT: &[u8] = b"\
       6061626364656667686970717273747576777879\
       8081828384858687888990919293949596979899";
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 #[inline]
 fn format_u8(mut n: u8, out: &mut [u8]) -> usize {
     if n >= 100 {
@@ -775,7 +785,7 @@ fn format_u8(mut n: u8, out: &mut [u8]) -> usize {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 #[test]
 fn test_format_u8() {
     let mut i = 0u8;
@@ -792,7 +802,7 @@ fn test_format_u8() {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::Ipv4Addr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -816,7 +826,7 @@ impl Serialize for net::Ipv4Addr {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::Ipv6Addr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -832,7 +842,7 @@ impl Serialize for net::Ipv6Addr {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -856,7 +866,7 @@ impl Serialize for net::SocketAddr {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddrV4 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -872,7 +882,7 @@ impl Serialize for net::SocketAddrV4 {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", not(no_core_net)))]
 impl Serialize for net::SocketAddrV6 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -894,6 +904,7 @@ impl Serialize for net::SocketAddrV6 {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for Path {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -907,6 +918,7 @@ impl Serialize for Path {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for PathBuf {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -917,6 +929,7 @@ impl Serialize for PathBuf {
 }
 
 #[cfg(all(feature = "std", any(unix, windows)))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsStr {
     #[cfg(unix)]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -939,6 +952,7 @@ impl Serialize for OsStr {
 }
 
 #[cfg(all(feature = "std", any(unix, windows)))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsString {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -963,7 +977,20 @@ where
     }
 }
 
-#[cfg(not(no_core_reverse))]
+#[cfg(not(no_core_num_saturating))]
+impl<T> Serialize for Saturating<T>
+where
+    T: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.0.serialize(serializer)
+    }
+}
+
 impl<T> Serialize for Reverse<T>
 where
     T: Serialize,
@@ -984,6 +1011,7 @@ macro_rules! atomic_impl {
     ($($ty:ident $size:expr)*) => {
         $(
             #[cfg(any(no_target_has_atomic, target_has_atomic = $size))]
+            #[cfg_attr(docsrs, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
             impl Serialize for $ty {
                 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where

serde_core/src/ser/impossible.rs

@@ -1,8 +1,8 @@
 //! This module contains `Impossible` serializer and its implementations.
 
-use lib::*;
+use crate::lib::*;
 
-use ser::{
+use crate::ser::{
     self, Serialize, SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant,
     SerializeTuple, SerializeTupleStruct, SerializeTupleVariant,
 };
@@ -17,7 +17,7 @@ use ser::{
 ///
 /// ```edition2021
 /// # use serde::ser::{Serializer, Impossible};
-/// # use serde::__private::doc::Error;
+/// # use serde_core::__private::doc::Error;
 /// #
 /// # struct MySerializer;
 /// #
@@ -41,7 +41,7 @@ use ser::{
 ///     }
 ///
 ///     /* other Serializer methods */
-/// #     serde::__serialize_unimplemented! {
+/// #     serde_core::__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
@@ -49,14 +49,14 @@ use ser::{
 /// }
 /// ```
 ///
-/// [`Serializer`]: trait.Serializer.html
+/// [`Serializer`]: crate::Serializer
-/// [`SerializeSeq`]: trait.SerializeSeq.html
+/// [`SerializeSeq`]: crate::ser::SerializeSeq
-/// [`SerializeTuple`]: trait.SerializeTuple.html
+/// [`SerializeTuple`]: crate::ser::SerializeTuple
-/// [`SerializeTupleStruct`]: trait.SerializeTupleStruct.html
+/// [`SerializeTupleStruct`]: crate::ser::SerializeTupleStruct
-/// [`SerializeTupleVariant`]: trait.SerializeTupleVariant.html
+/// [`SerializeTupleVariant`]: crate::ser::SerializeTupleVariant
-/// [`SerializeMap`]: trait.SerializeMap.html
+/// [`SerializeMap`]: crate::ser::SerializeMap
-/// [`SerializeStruct`]: trait.SerializeStruct.html
+/// [`SerializeStruct`]: crate::ser::SerializeStruct
-/// [`SerializeStructVariant`]: trait.SerializeStructVariant.html
+/// [`SerializeStructVariant`]: crate::ser::SerializeStructVariant
 pub struct Impossible<Ok, Error> {
     void: Void,
     ok: PhantomData<Ok>,
@@ -72,9 +72,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -92,9 +92,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -112,9 +112,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -132,9 +132,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -152,17 +152,17 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         match self.void {}
     }
 
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -180,9 +180,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         let _ = value;
@@ -201,9 +201,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         let _ = value;

serde_core/src/ser/mod.rs

@@ -61,8 +61,8 @@
 //!    - RefCell\<T\>
 //!    - Mutex\<T\>
 //!    - RwLock\<T\>
-//!    - Rc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Rc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
-//!    - Arc\<T\>&emsp;*(if* features = ["rc"] *is enabled)*
+//!    - Arc\<T\>&emsp;*(if* features = \["rc"\] *is enabled)*
 //!  - **Collection types**:
 //!    - BTreeMap\<K, V\>
 //!    - BTreeSet\<T\>
@@ -97,8 +97,8 @@
 //!
 //! [Implementing `Serialize`]: https://serde.rs/impl-serialize.html
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
-//! [`Serialize`]: ../trait.Serialize.html
+//! [`Serialize`]: crate::Serialize
-//! [`Serializer`]: ../trait.Serializer.html
+//! [`Serializer`]: crate::Serializer
 //! [`postcard`]: https://github.com/jamesmunns/postcard
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 //! [`serde_derive`]: https://crates.io/crates/serde_derive
@@ -107,7 +107,7 @@
 //! [derive section of the manual]: https://serde.rs/derive.html
 //! [data formats]: https://serde.rs/#data-formats
 
-use lib::*;
+use crate::lib::*;
 
 mod fmt;
 mod impls;
@@ -115,15 +115,15 @@ mod impossible;
 
 pub use self::impossible::Impossible;
 
-#[cfg(all(feature = "unstable", not(feature = "std")))]
+#[cfg(all(not(feature = "std"), no_core_error))]
+#[doc(no_inline)]
+pub use crate::std_error::Error as StdError;
+#[cfg(not(any(feature = "std", no_core_error)))]
 #[doc(no_inline)]
 pub use core::error::Error as StdError;
 #[cfg(feature = "std")]
 #[doc(no_inline)]
 pub use std::error::Error as StdError;
-#[cfg(not(any(feature = "std", feature = "unstable")))]
-#[doc(no_inline)]
-pub use std_error::Error as StdError;
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -139,6 +139,12 @@ macro_rules! declare_error_trait {
         /// type appropriate for a basic JSON data format.
         ///
         /// [example data format]: https://serde.rs/data-format.html
+        #[cfg_attr(
+            not(no_diagnostic_namespace),
+            diagnostic::on_unimplemented(
+                message = "the trait bound `{Self}: serde::ser::Error` is not satisfied",
+            )
+        )]
         pub trait Error: Sized $(+ $($supertrait)::+)* {
             /// Used when a [`Serialize`] implementation encounters any error
             /// while serializing a type.
@@ -173,8 +179,8 @@ macro_rules! declare_error_trait {
             /// }
             /// ```
             ///
-            /// [`Path`]: https://doc.rust-lang.org/std/path/struct.Path.html
+            /// [`Path`]: std::path::Path
-            /// [`Serialize`]: ../trait.Serialize.html
+            /// [`Serialize`]: crate::Serialize
             fn custom<T>(msg: T) -> Self
             where
                 T: Display;
@@ -215,6 +221,16 @@ declare_error_trait!(Error: Sized + Debug + Display);
 /// [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 /// [`serde_derive`]: https://crates.io/crates/serde_derive
 /// [derive section of the manual]: https://serde.rs/derive.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        // Prevents `serde_core::ser::Serialize` appearing in the error message
+        // in projects with no direct dependency on serde_core.
+        message = "the trait bound `{Self}: serde::Serialize` is not satisfied",
+        note = "for local types consider adding `#[derive(serde::Serialize)]` to your `{Self}` type",
+        note = "for types from other crates check whether the crate offers a `serde` feature flag",
+    )
+)]
 pub trait Serialize {
     /// Serialize this value into the given Serde serializer.
     ///
@@ -330,6 +346,12 @@ pub trait Serialize {
 /// a basic JSON `Serializer`.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::Serializer` is not satisfied",
+    )
+)]
 pub trait Serializer: Sized {
     /// The output type produced by this `Serializer` during successful
     /// serialization. Most serializers that produce text or binary output
@@ -338,7 +360,7 @@ pub trait Serializer: Sized {
     /// in-memory data structures may be simplified by using `Ok` to propagate
     /// the data structure around.
     ///
-    /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+    /// [`io::Write`]: std::io::Write
     type Ok;
 
     /// The error type when some error occurs during serialization.
@@ -391,7 +413,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for bool {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -413,7 +435,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for i8 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -435,7 +457,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for i16 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -457,7 +479,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for i32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -475,7 +497,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for i64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -488,30 +510,27 @@ pub trait Serializer: Sized {
     /// ```
     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>;
 
-    serde_if_integer128! {
+    /// Serialize an `i128` value.
-        /// Serialize an `i128` value.
+    ///
-        ///
+    /// ```edition2021
-        /// ```edition2021
+    /// # use serde::Serializer;
-        /// # use serde::Serializer;
+    /// #
-        /// #
+    /// # serde_core::__private_serialize!();
-        /// # serde::__private_serialize!();
+    /// #
-        /// #
+    /// impl Serialize for i128 {
-        /// impl Serialize for i128 {
+    ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    ///     where
-        ///     where
+    ///         S: Serializer,
-        ///         S: Serializer,
+    ///     {
-        ///     {
+    ///         serializer.serialize_i128(*self)
-        ///         serializer.serialize_i128(*self)
+    ///     }
-        ///     }
+    /// }
-        /// }
+    /// ```
-        /// ```
+    ///
-        ///
+    /// The default behavior unconditionally returns an error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
-        /// default behavior unconditionally returns an error.
+        let _ = v;
-        fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
+        Err(Error::custom("i128 is not supported"))
-            let _ = v;
-            Err(Error::custom("i128 is not supported"))
-        }
     }
 
     /// Serialize a `u8` value.
@@ -523,7 +542,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for u8 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -545,7 +564,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for u16 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -567,7 +586,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for u32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -585,7 +604,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for u64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -598,30 +617,27 @@ pub trait Serializer: Sized {
     /// ```
     fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>;
 
-    serde_if_integer128! {
+    /// Serialize a `u128` value.
-        /// Serialize a `u128` value.
+    ///
-        ///
+    /// ```edition2021
-        /// ```edition2021
+    /// # use serde::Serializer;
-        /// # use serde::Serializer;
+    /// #
-        /// #
+    /// # serde_core::__private_serialize!();
-        /// # serde::__private_serialize!();
+    /// #
-        /// #
+    /// impl Serialize for u128 {
-        /// impl Serialize for u128 {
+    ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    ///     where
-        ///     where
+    ///         S: Serializer,
-        ///         S: Serializer,
+    ///     {
-        ///     {
+    ///         serializer.serialize_u128(*self)
-        ///         serializer.serialize_u128(*self)
+    ///     }
-        ///     }
+    /// }
-        /// }
+    /// ```
-        /// ```
+    ///
-        ///
+    /// The default behavior unconditionally returns an error.
-        /// This method is available only on Rust compiler versions >=1.26. The
+    fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
-        /// default behavior unconditionally returns an error.
+        let _ = v;
-        fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
+        Err(Error::custom("u128 is not supported"))
-            let _ = v;
-            Err(Error::custom("u128 is not supported"))
-        }
     }
 
     /// Serialize an `f32` value.
@@ -633,7 +649,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for f32 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -651,7 +667,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for f64 {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -672,7 +688,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for char {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -690,7 +706,7 @@ pub trait Serializer: Sized {
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for str {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -713,7 +729,7 @@ pub trait Serializer: Sized {
     ///
     /// ```edition2021
     /// # use serde::ser::{Serializer, SerializeSeq};
-    /// # use serde::__private::doc::Error;
+    /// # use serde_core::__private::doc::Error;
     /// #
     /// # struct MySerializer;
     /// #
@@ -729,7 +745,7 @@ pub trait Serializer: Sized {
     ///     seq.end()
     /// }
     /// #
-    /// #     serde::__serialize_unimplemented! {
+    /// #     serde_core::__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
@@ -768,7 +784,7 @@ pub trait Serializer: Sized {
     /// # fn main() {}
     /// ```
     ///
-    /// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
+    /// [`None`]: core::option::Option::None
     fn serialize_none(self) -> Result<Self::Ok, Self::Error>;
 
     /// Serialize a [`Some(T)`] value.
@@ -801,17 +817,17 @@ pub trait Serializer: Sized {
     /// # fn main() {}
     /// ```
     ///
-    /// [`Some(T)`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some
+    /// [`Some(T)`]: core::option::Option::Some
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a `()` value.
     ///
     /// ```edition2021
     /// # use serde::Serializer;
     /// #
-    /// # serde::__private_serialize!();
+    /// # serde_core::__private_serialize!();
     /// #
     /// impl Serialize for () {
     ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -897,13 +913,13 @@ pub trait Serializer: Sized {
     ///     }
     /// }
     /// ```
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         name: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a newtype variant like `E::N` in `enum E { N(u8) }`.
     ///
@@ -931,7 +947,7 @@ pub trait Serializer: Sized {
     ///     }
     /// }
     /// ```
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         name: &'static str,
         variant_index: u32,
@@ -939,7 +955,7 @@ pub trait Serializer: Sized {
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Begin to serialize a variably sized sequence. This call must be
     /// followed by zero or more calls to `serialize_element`, then a call to
@@ -1176,7 +1192,8 @@ pub trait Serializer: Sized {
     /// then a call to `end`.
     ///
     /// The `name` is the name of the struct and the `len` is the number of
-    /// data fields that will be serialized.
+    /// data fields that will be serialized. `len` does not include fields
+    /// which are skipped with [`SerializeStruct::skip_field`].
     ///
     /// ```edition2021
     /// use serde::ser::{Serialize, SerializeStruct, Serializer};
@@ -1213,6 +1230,8 @@ pub trait Serializer: Sized {
     /// The `name` is the name of the enum, the `variant_index` is the index of
     /// this variant within the enum, the `variant` is the name of the variant,
     /// and the `len` is the number of data fields that will be serialized.
+    /// `len` does not include fields which are skipped with
+    /// [`SerializeStructVariant::skip_field`].
     ///
     /// ```edition2021
     /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
@@ -1279,22 +1298,9 @@ pub trait Serializer: Sized {
         I: IntoIterator,
         <I as IntoIterator>::Item: Serialize,
     {
-        let iter = iter.into_iter();
+        let mut iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter)));
+        let mut serializer = tri!(self.serialize_seq(iterator_len_hint(&iter)));
-
+        tri!(iter.try_for_each(|item| serializer.serialize_element(&item)));
-        #[cfg(not(no_iterator_try_fold))]
-        {
-            let mut iter = iter;
-            try!(iter.try_for_each(|item| serializer.serialize_element(&item)));
-        }
-
-        #[cfg(no_iterator_try_fold)]
-        {
-            for item in iter {
-                try!(serializer.serialize_element(&item));
-            }
-        }
-
         serializer.end()
     }
 
@@ -1330,22 +1336,9 @@ pub trait Serializer: Sized {
         V: Serialize,
         I: IntoIterator<Item = (K, V)>,
     {
-        let iter = iter.into_iter();
+        let mut iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter)));
+        let mut serializer = tri!(self.serialize_map(iterator_len_hint(&iter)));
-
+        tri!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value)));
-        #[cfg(not(no_iterator_try_fold))]
-        {
-            let mut iter = iter;
-            try!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value)));
-        }
-
-        #[cfg(no_iterator_try_fold)]
-        {
-            for (key, value) in iter {
-                try!(serializer.serialize_entry(&key, &value));
-            }
-        }
-
         serializer.end()
     }
 
@@ -1375,12 +1368,11 @@ pub trait Serializer: Sized {
     /// }
     /// ```
     ///
-    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    /// [`serialize_str`]: Self::serialize_str
-    /// [`serialize_str`]: #tymethod.serialize_str
     #[cfg(any(feature = "std", feature = "alloc"))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         self.serialize_str(&value.to_string())
     }
@@ -1411,9 +1403,9 @@ pub trait Serializer: Sized {
     /// }
     /// ```
     #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display;
+        T: ?Sized + Display;
 
     /// Determine whether `Serialize` implementations should serialize in
     /// human-readable form.
@@ -1517,6 +1509,12 @@ pub trait Serializer: Sized {
 /// implementation of `SerializeSeq` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeSeq` is not satisfied",
+    )
+)]
 pub trait SerializeSeq {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1525,9 +1523,9 @@ pub trait SerializeSeq {
     type Error: Error;
 
     /// Serialize a sequence element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a sequence.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1617,6 +1615,12 @@ pub trait SerializeSeq {
 /// implementation of `SerializeTuple` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeTuple` is not satisfied",
+    )
+)]
 pub trait SerializeTuple {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1625,9 +1629,9 @@ pub trait SerializeTuple {
     type Error: Error;
 
     /// Serialize a tuple element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1662,6 +1666,12 @@ pub trait SerializeTuple {
 /// implementation of `SerializeTupleStruct` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeTupleStruct` is not satisfied",
+    )
+)]
 pub trait SerializeTupleStruct {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1670,9 +1680,9 @@ pub trait SerializeTupleStruct {
     type Error: Error;
 
     /// Serialize a tuple struct field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple struct.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1720,6 +1730,12 @@ pub trait SerializeTupleStruct {
 /// implementation of `SerializeTupleVariant` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeTupleVariant` is not satisfied",
+    )
+)]
 pub trait SerializeTupleVariant {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1728,9 +1744,9 @@ pub trait SerializeTupleVariant {
     type Error: Error;
 
     /// Serialize a tuple variant field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple variant.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1786,6 +1802,12 @@ pub trait SerializeTupleVariant {
 /// implementation of `SerializeMap` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeMap` is not satisfied",
+    )
+)]
 pub trait SerializeMap {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1799,9 +1821,9 @@ pub trait SerializeMap {
     /// `serialize_entry` instead as it may be implemented more efficiently in
     /// some formats compared to a pair of calls to `serialize_key` and
     /// `serialize_value`.
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a map value.
     ///
@@ -1809,9 +1831,9 @@ pub trait SerializeMap {
     ///
     /// Calling `serialize_value` before `serialize_key` is incorrect and is
     /// allowed to panic or produce bogus results.
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a map entry consisting of a key and a value.
     ///
@@ -1827,19 +1849,15 @@ pub trait SerializeMap {
     /// care about performance or are not able to optimize `serialize_entry` any
     /// better than this.
     ///
-    /// [`Serialize`]: ../trait.Serialize.html
+    /// [`Serialize`]: crate::Serialize
-    /// [`serialize_key`]: #tymethod.serialize_key
+    /// [`serialize_key`]: Self::serialize_key
-    /// [`serialize_value`]: #tymethod.serialize_value
+    /// [`serialize_value`]: Self::serialize_value
-    fn serialize_entry<K: ?Sized, V: ?Sized>(
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
     where
-        K: Serialize,
+        K: ?Sized + Serialize,
-        V: Serialize,
+        V: ?Sized + Serialize,
     {
-        try!(self.serialize_key(key));
+        tri!(self.serialize_key(key));
         self.serialize_value(value)
     }
 
@@ -1880,6 +1898,12 @@ pub trait SerializeMap {
 /// implementation of `SerializeStruct` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeStruct` is not satisfied",
+    )
+)]
 pub trait SerializeStruct {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1888,15 +1912,13 @@ pub trait SerializeStruct {
     type Error: Error;
 
     /// Serialize a struct field.
-    fn serialize_field<T: ?Sized>(
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Indicate that a struct field has been skipped.
+    ///
+    /// The default implementation does nothing.
     #[inline]
     fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
         let _ = key;
@@ -1946,6 +1968,12 @@ pub trait SerializeStruct {
 /// implementation of `SerializeStructVariant` for a basic JSON data format.
 ///
 /// [example data format]: https://serde.rs/data-format.html
+#[cfg_attr(
+    not(no_diagnostic_namespace),
+    diagnostic::on_unimplemented(
+        message = "the trait bound `{Self}: serde::ser::SerializeStructVariant` is not satisfied",
+    )
+)]
 pub trait SerializeStructVariant {
     /// Must match the `Ok` type of our `Serializer`.
     type Ok;
@@ -1954,15 +1982,13 @@ pub trait SerializeStructVariant {
     type Error: Error;
 
     /// Serialize a struct variant field.
-    fn serialize_field<T: ?Sized>(
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Indicate that a struct variant field has been skipped.
+    ///
+    /// The default implementation does nothing.
     #[inline]
     fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
         let _ = key;

serde_core/src/std_error.rs

@@ -1,4 +1,4 @@
-use lib::{Debug, Display};
+use crate::lib::{Debug, Display};
 
 /// Either a re-export of std::error::Error or a new identical trait, depending
 /// on whether Serde's "std" feature is enabled.
@@ -42,7 +42,7 @@ use lib::{Debug, Display};
 /// ```
 pub trait Error: Debug + Display {
     /// The underlying cause of this error, if any.
-    fn source(&self) -> Option<&(Error + 'static)> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
         None
     }
 }

serde_derive/Cargo.toml

@@ -1,16 +1,18 @@
 [package]
 name = "serde_derive"
-version = "1.0.178" # remember to update html_root_url
+version = "1.0.221"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 categories = ["no-std", "no-std::no-alloc"]
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
 documentation = "https://serde.rs/derive.html"
+edition = "2021"
+exclude = ["build.rs"]
 homepage = "https://serde.rs"
 keywords = ["serde", "serialization", "no_std", "derive"]
 license = "MIT OR Apache-2.0"
 readme = "crates-io.md"
 repository = "https://github.com/serde-rs/serde"
-rust-version = "1.56"
+rust-version = "1.61"
 
 [features]
 default = []
@@ -21,13 +23,19 @@ name = "serde_derive"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "1.0"
+proc-macro2 = { workspace = true, features = ["proc-macro"] }
-quote = "1.0"
+quote = { workspace = true, features = ["proc-macro"] }
-syn = "2.0.25"
+syn = { workspace = true, features = ["clone-impls", "derive", "parsing", "printing", "proc-macro"] }
 
 [dev-dependencies]
 serde = { version = "1", path = "../serde" }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
-rustdoc-args = ["--generate-link-to-definition"]
+rustdoc-args = [
+    "--generate-link-to-definition",
+    "--extern-html-root-url=core=https://doc.rust-lang.org",
+    "--extern-html-root-url=alloc=https://doc.rust-lang.org",
+    "--extern-html-root-url=std=https://doc.rust-lang.org",
+    "--extern-html-root-url=proc_macro=https://doc.rust-lang.org",
+]

serde_derive/build.rs

@@ -0,0 +1,8 @@
+fn main() {
+    // Warning: build.rs is not published to crates.io.
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rustc-cfg=check_cfg");
+    println!("cargo:rustc-check-cfg=cfg(check_cfg)");
+    println!("cargo:rustc-check-cfg=cfg(exhaustive)");
+}

serde_derive/src/bound.rs

@@ -144,6 +144,7 @@ pub fn with_bound(
 
         fn visit_type(&mut self, ty: &'ast syn::Type) {
             match ty {
+                #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                 syn::Type::Array(ty) => self.visit_type(&ty.elem),
                 syn::Type::BareFn(ty) => {
                     for arg in &ty.inputs {
@@ -181,7 +182,6 @@ pub fn with_bound(
 
                 syn::Type::Infer(_) | syn::Type::Never(_) | syn::Type::Verbatim(_) => {}
 
-                #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                 _ => {}
             }
         }
@@ -196,16 +196,13 @@ pub fn with_bound(
                 syn::PathArguments::AngleBracketed(arguments) => {
                     for arg in &arguments.args {
                         match arg {
+                            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                             syn::GenericArgument::Type(arg) => self.visit_type(arg),
                             syn::GenericArgument::AssocType(arg) => self.visit_type(&arg.ty),
                             syn::GenericArgument::Lifetime(_)
                             | syn::GenericArgument::Const(_)
                             | syn::GenericArgument::AssocConst(_)
                             | syn::GenericArgument::Constraint(_) => {}
-                            #[cfg_attr(
-                                all(test, exhaustive),
-                                deny(non_exhaustive_omitted_patterns)
-                            )]
                             _ => {}
                         }
                     }
@@ -228,9 +225,11 @@ pub fn with_bound(
 
         fn visit_type_param_bound(&mut self, bound: &'ast syn::TypeParamBound) {
             match bound {
+                #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                 syn::TypeParamBound::Trait(bound) => self.visit_path(&bound.path),
-                syn::TypeParamBound::Lifetime(_) | syn::TypeParamBound::Verbatim(_) => {}
+                syn::TypeParamBound::Lifetime(_)
-                #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
+                | syn::TypeParamBound::PreciseCapture(_)
+                | syn::TypeParamBound::Verbatim(_) => {}
                 _ => {}
             }
         }

serde_derive/src/dummy.rs

@@ -14,9 +14,17 @@ pub fn wrap_in_const(serde_path: Option<&syn::Path>, code: TokenStream) -> Token
 
     quote! {
         #[doc(hidden)]
-        #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
+        #[allow(
+            non_upper_case_globals,
+            unused_attributes,
+            unused_qualifications,
+            clippy::absolute_paths,
+        )]
         const _: () = {
             #use_serde
+
+            _serde::__require_serde_not_serde_core!();
+
             #code
         };
     }

serde_derive/src/internals/ast.rs

@@ -63,7 +63,7 @@ impl<'a> Container<'a> {
         item: &'a syn::DeriveInput,
         derive: Derive,
     ) -> Option<Container<'a>> {
-        let mut attrs = attr::Container::from_ast(cx, item);
+        let attrs = attr::Container::from_ast(cx, item);
 
         let mut data = match &item.data {
             syn::Data::Enum(data) => Data::Enum(enum_from_ast(cx, &data.variants, attrs.default())),
@@ -77,15 +77,11 @@ impl<'a> Container<'a> {
             }
         };
 
-        let mut has_flatten = false;
         match &mut data {
             Data::Enum(variants) => {
                 for variant in variants {
                     variant.attrs.rename_by_rules(attrs.rename_all_rules());
                     for field in &mut variant.fields {
-                        if field.attrs.flatten() {
-                            has_flatten = true;
-                        }
                         field.attrs.rename_by_rules(
                             variant
                                 .attrs
@@ -97,18 +93,11 @@ impl<'a> Container<'a> {
             }
             Data::Struct(_, fields) => {
                 for field in fields {
-                    if field.attrs.flatten() {
-                        has_flatten = true;
-                    }
                     field.attrs.rename_by_rules(attrs.rename_all_rules());
                 }
             }
         }
 
-        if has_flatten {
-            attrs.mark_has_flatten();
-        }
-
         let mut item = Container {
             ident: item.ident.clone(),
             attrs,

serde_derive/src/internals/attr.rs

@@ -1,3 +1,4 @@
+use crate::internals::name::{MultiName, Name};
 use crate::internals::symbol::*;
 use crate::internals::{ungroup, Ctxt};
 use proc_macro2::{Spacing, Span, TokenStream, TokenTree};
@@ -8,6 +9,7 @@ use std::iter::FromIterator;
 use syn::meta::ParseNestedMeta;
 use syn::parse::ParseStream;
 use syn::punctuated::Punctuated;
+use syn::spanned::Spanned;
 use syn::{parse_quote, token, Ident, Lifetime, Token};
 
 // This module handles parsing of `#[serde(...)]` attributes. The entrypoints
@@ -20,7 +22,7 @@ use syn::{parse_quote, token, Ident, Lifetime, Token};
 
 pub use crate::internals::case::RenameRule;
 
-struct Attr<'c, T> {
+pub(crate) struct Attr<'c, T> {
     cx: &'c Ctxt,
     name: Symbol,
     tokens: TokenStream,
@@ -61,7 +63,7 @@ impl<'c, T> Attr<'c, T> {
         }
     }
 
-    fn get(self) -> Option<T> {
+    pub(crate) fn get(self) -> Option<T> {
         self.value
     }
 
@@ -89,7 +91,7 @@ impl<'c> BoolAttr<'c> {
     }
 }
 
-struct VecAttr<'c, T> {
+pub(crate) struct VecAttr<'c, T> {
     cx: &'c Ctxt,
     name: Symbol,
     first_dup_tokens: TokenStream,
@@ -124,78 +126,19 @@ impl<'c, T> VecAttr<'c, T> {
         }
     }
 
-    fn get(self) -> Vec<T> {
+    pub(crate) fn get(self) -> Vec<T> {
         self.values
     }
 }
 
-pub struct Name {
+fn unraw(ident: &Ident) -> Ident {
-    serialize: String,
+    Ident::new(ident.to_string().trim_start_matches("r#"), ident.span())
-    serialize_renamed: bool,
-    deserialize: String,
-    deserialize_renamed: bool,
-    deserialize_aliases: Vec<String>,
-}
-
-fn unraw(ident: &Ident) -> String {
-    ident.to_string().trim_start_matches("r#").to_owned()
-}
-
-impl Name {
-    fn from_attrs(
-        source_name: String,
-        ser_name: Attr<String>,
-        de_name: Attr<String>,
-        de_aliases: Option<VecAttr<String>>,
-    ) -> Name {
-        let deserialize_aliases = match de_aliases {
-            Some(de_aliases) => {
-                let mut alias_list = BTreeSet::new();
-                for alias_name in de_aliases.get() {
-                    alias_list.insert(alias_name);
-                }
-                alias_list.into_iter().collect()
-            }
-            None => Vec::new(),
-        };
-
-        let ser_name = ser_name.get();
-        let ser_renamed = ser_name.is_some();
-        let de_name = de_name.get();
-        let de_renamed = de_name.is_some();
-        Name {
-            serialize: ser_name.unwrap_or_else(|| source_name.clone()),
-            serialize_renamed: ser_renamed,
-            deserialize: de_name.unwrap_or(source_name),
-            deserialize_renamed: de_renamed,
-            deserialize_aliases,
-        }
-    }
-
-    /// Return the container name for the container when serializing.
-    pub fn serialize_name(&self) -> String {
-        self.serialize.clone()
-    }
-
-    /// Return the container name for the container when deserializing.
-    pub fn deserialize_name(&self) -> String {
-        self.deserialize.clone()
-    }
-
-    fn deserialize_aliases(&self) -> Vec<String> {
-        let mut aliases = self.deserialize_aliases.clone();
-        let main_name = self.deserialize_name();
-        if !aliases.contains(&main_name) {
-            aliases.push(main_name);
-        }
-        aliases
-    }
 }
 
 #[derive(Copy, Clone)]
 pub struct RenameAllRules {
-    serialize: RenameRule,
+    pub serialize: RenameRule,
-    deserialize: RenameRule,
+    pub deserialize: RenameRule,
 }
 
 impl RenameAllRules {
@@ -211,7 +154,7 @@ impl RenameAllRules {
 
 /// Represents struct or enum attribute information.
 pub struct Container {
-    name: Name,
+    name: MultiName,
     transparent: bool,
     deny_unknown_fields: bool,
     default: Default,
@@ -225,11 +168,11 @@ pub struct Container {
     type_into: Option<syn::Type>,
     remote: Option<syn::Path>,
     identifier: Identifier,
-    has_flatten: bool,
     serde_path: Option<syn::Path>,
     is_packed: bool,
     /// Error message generated when type can't be deserialized
     expecting: Option<String>,
+    non_exhaustive: bool,
 }
 
 /// Styles of representing an enum.
@@ -315,9 +258,12 @@ impl Container {
         let mut variant_identifier = BoolAttr::none(cx, VARIANT_IDENTIFIER);
         let mut serde_path = Attr::none(cx, CRATE);
         let mut expecting = Attr::none(cx, EXPECTING);
+        let mut non_exhaustive = false;
 
         for attr in &item.attrs {
             if attr.path() != SERDE {
+                non_exhaustive |=
+                    matches!(&attr.meta, syn::Meta::Path(path) if path == NON_EXHAUSTIVE);
                 continue;
             }
 
@@ -332,8 +278,8 @@ impl Container {
                     // #[serde(rename = "foo")]
                     // #[serde(rename(serialize = "foo", deserialize = "bar"))]
                     let (ser, de) = get_renames(cx, RENAME, &meta)?;
-                    ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value));
+                    ser_name.set_opt(&meta.path, ser.as_ref().map(Name::from));
-                    de_name.set_opt(&meta.path, de.as_ref().map(syn::LitStr::value));
+                    de_name.set_opt(&meta.path, de.as_ref().map(Name::from));
                 } else if meta.path == RENAME_ALL {
                     // #[serde(rename_all = "foo")]
                     // #[serde(rename_all(serialize = "foo", deserialize = "bar"))]
@@ -405,20 +351,20 @@ impl Container {
                         if let Some(path) = parse_lit_into_expr_path(cx, DEFAULT, &meta)? {
                             match &item.data {
                                 syn::Data::Struct(syn::DataStruct { fields, .. }) => match fields {
-                                    syn::Fields::Named(_) => {
+                                    syn::Fields::Named(_) | syn::Fields::Unnamed(_) => {
                                         default.set(&meta.path, Default::Path(path));
                                     }
-                                    syn::Fields::Unnamed(_) | syn::Fields::Unit => {
+                                    syn::Fields::Unit => {
-                                        let msg = "#[serde(default = \"...\")] can only be used on structs with named fields";
+                                        let msg = "#[serde(default = \"...\")] can only be used on structs that have fields";
                                         cx.syn_error(meta.error(msg));
                                     }
                                 },
                                 syn::Data::Enum(_) => {
-                                    let msg = "#[serde(default = \"...\")] can only be used on structs with named fields";
+                                    let msg = "#[serde(default = \"...\")] can only be used on structs";
                                     cx.syn_error(meta.error(msg));
                                 }
                                 syn::Data::Union(_) => {
-                                    let msg = "#[serde(default = \"...\")] can only be used on structs with named fields";
+                                    let msg = "#[serde(default = \"...\")] can only be used on structs";
                                     cx.syn_error(meta.error(msg));
                                 }
                             }
@@ -427,20 +373,20 @@ impl Container {
                         // #[serde(default)]
                         match &item.data {
                             syn::Data::Struct(syn::DataStruct { fields, .. }) => match fields {
-                                syn::Fields::Named(_) => {
+                                syn::Fields::Named(_) | syn::Fields::Unnamed(_) => {
                                     default.set(meta.path, Default::Default);
                                 }
-                                syn::Fields::Unnamed(_) | syn::Fields::Unit => {
+                                syn::Fields::Unit => {
-                                    let msg = "#[serde(default)] can only be used on structs with named fields";
+                                    let msg = "#[serde(default)] can only be used on structs that have fields";
                                     cx.error_spanned_by(fields, msg);
                                 }
                             },
                             syn::Data::Enum(_) => {
-                                let msg = "#[serde(default)] can only be used on structs with named fields";
+                                let msg = "#[serde(default)] can only be used on structs";
                                 cx.syn_error(meta.error(msg));
                             }
                             syn::Data::Union(_) => {
-                                let msg = "#[serde(default)] can only be used on structs with named fields";
+                                let msg = "#[serde(default)] can only be used on structs";
                                 cx.syn_error(meta.error(msg));
                             }
                         }
@@ -572,7 +518,7 @@ impl Container {
         }
 
         Container {
-            name: Name::from_attrs(unraw(&item.ident), ser_name, de_name, None),
+            name: MultiName::from_attrs(Name::from(&unraw(&item.ident)), ser_name, de_name, None),
             transparent: transparent.get(),
             deny_unknown_fields: deny_unknown_fields.get(),
             default: default.get().unwrap_or(Default::None),
@@ -592,14 +538,14 @@ impl Container {
             type_into: type_into.get(),
             remote: remote.get(),
             identifier: decide_identifier(cx, item, field_identifier, variant_identifier),
-            has_flatten: false,
             serde_path: serde_path.get(),
             is_packed,
             expecting: expecting.get(),
+            non_exhaustive,
         }
     }
 
-    pub fn name(&self) -> &Name {
+    pub fn name(&self) -> &MultiName {
         &self.name
     }
 
@@ -659,14 +605,6 @@ impl Container {
         self.identifier
     }
 
-    pub fn has_flatten(&self) -> bool {
-        self.has_flatten
-    }
-
-    pub fn mark_has_flatten(&mut self) {
-        self.has_flatten = true;
-    }
-
     pub fn custom_serde_path(&self) -> Option<&syn::Path> {
         self.serde_path.as_ref()
     }
@@ -681,6 +619,10 @@ impl Container {
     pub fn expecting(&self) -> Option<&str> {
         self.expecting.as_ref().map(String::as_ref)
     }
+
+    pub fn non_exhaustive(&self) -> bool {
+        self.non_exhaustive
+    }
 }
 
 fn decide_tag(
@@ -716,7 +658,7 @@ fn decide_tag(
             }
             TagType::Internal { tag }
         }
-        (Some((untagged_tokens, _)), Some((tag_tokens, _)), None) => {
+        (Some((untagged_tokens, ())), Some((tag_tokens, _)), None) => {
             let msg = "enum cannot be both untagged and internally tagged";
             cx.error_spanned_by(untagged_tokens, msg);
             cx.error_spanned_by(tag_tokens, msg);
@@ -727,14 +669,14 @@ fn decide_tag(
             cx.error_spanned_by(content_tokens, msg);
             TagType::External
         }
-        (Some((untagged_tokens, _)), None, Some((content_tokens, _))) => {
+        (Some((untagged_tokens, ())), None, Some((content_tokens, _))) => {
             let msg = "untagged enum cannot have #[serde(content = \"...\")]";
             cx.error_spanned_by(untagged_tokens, msg);
             cx.error_spanned_by(content_tokens, msg);
             TagType::External
         }
         (None, Some((_, tag)), Some((_, content))) => TagType::Adjacent { tag, content },
-        (Some((untagged_tokens, _)), Some((tag_tokens, _)), Some((content_tokens, _))) => {
+        (Some((untagged_tokens, ())), Some((tag_tokens, _)), Some((content_tokens, _))) => {
             let msg = "untagged enum cannot have #[serde(tag = \"...\", content = \"...\")]";
             cx.error_spanned_by(untagged_tokens, msg);
             cx.error_spanned_by(tag_tokens, msg);
@@ -756,7 +698,7 @@ fn decide_identifier(
         variant_identifier.0.get_with_tokens(),
     ) {
         (_, None, None) => Identifier::No,
-        (_, Some((field_identifier_tokens, _)), Some((variant_identifier_tokens, _))) => {
+        (_, Some((field_identifier_tokens, ())), Some((variant_identifier_tokens, ()))) => {
             let msg =
                 "#[serde(field_identifier)] and #[serde(variant_identifier)] cannot both be set";
             cx.error_spanned_by(field_identifier_tokens, msg);
@@ -790,7 +732,7 @@ fn decide_identifier(
 
 /// Represents variant attribute information
 pub struct Variant {
-    name: Name,
+    name: MultiName,
     rename_all_rules: RenameAllRules,
     ser_bound: Option<Vec<syn::WherePredicate>>,
     de_bound: Option<Vec<syn::WherePredicate>>,
@@ -841,15 +783,15 @@ impl Variant {
                     // #[serde(rename = "foo")]
                     // #[serde(rename(serialize = "foo", deserialize = "bar"))]
                     let (ser, de) = get_multiple_renames(cx, &meta)?;
-                    ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value));
+                    ser_name.set_opt(&meta.path, ser.as_ref().map(Name::from));
                     for de_value in de {
-                        de_name.set_if_none(de_value.value());
+                        de_name.set_if_none(Name::from(&de_value));
-                        de_aliases.insert(&meta.path, de_value.value());
+                        de_aliases.insert(&meta.path, Name::from(&de_value));
                     }
                 } else if meta.path == ALIAS {
                     // #[serde(alias = "foo")]
                     if let Some(s) = get_lit_str(cx, ALIAS, &meta)? {
-                        de_aliases.insert(&meta.path, s.value());
+                        de_aliases.insert(&meta.path, Name::from(&s));
                     }
                 } else if meta.path == RENAME_ALL {
                     // #[serde(rename_all = "foo")]
@@ -898,13 +840,13 @@ impl Variant {
                         ser_path
                             .path
                             .segments
-                            .push(Ident::new("serialize", Span::call_site()).into());
+                            .push(Ident::new("serialize", ser_path.span()).into());
                         serialize_with.set(&meta.path, ser_path);
                         let mut de_path = path;
                         de_path
                             .path
                             .segments
-                            .push(Ident::new("deserialize", Span::call_site()).into());
+                            .push(Ident::new("deserialize", de_path.span()).into());
                         deserialize_with.set(&meta.path, de_path);
                     }
                 } else if meta.path == SERIALIZE_WITH {
@@ -956,7 +898,12 @@ impl Variant {
         }
 
         Variant {
-            name: Name::from_attrs(unraw(&variant.ident), ser_name, de_name, Some(de_aliases)),
+            name: MultiName::from_attrs(
+                Name::from(&unraw(&variant.ident)),
+                ser_name,
+                de_name,
+                Some(de_aliases),
+            ),
             rename_all_rules: RenameAllRules {
                 serialize: rename_all_ser_rule.get().unwrap_or(RenameRule::None),
                 deserialize: rename_all_de_rule.get().unwrap_or(RenameRule::None),
@@ -973,21 +920,27 @@ impl Variant {
         }
     }
 
-    pub fn name(&self) -> &Name {
+    pub fn name(&self) -> &MultiName {
         &self.name
     }
 
-    pub fn aliases(&self) -> Vec<String> {
+    pub fn aliases(&self) -> &BTreeSet<Name> {
         self.name.deserialize_aliases()
     }
 
     pub fn rename_by_rules(&mut self, rules: RenameAllRules) {
         if !self.name.serialize_renamed {
-            self.name.serialize = rules.serialize.apply_to_variant(&self.name.serialize);
+            self.name.serialize.value =
+                rules.serialize.apply_to_variant(&self.name.serialize.value);
         }
         if !self.name.deserialize_renamed {
-            self.name.deserialize = rules.deserialize.apply_to_variant(&self.name.deserialize);
+            self.name.deserialize.value = rules
+                .deserialize
+                .apply_to_variant(&self.name.deserialize.value);
         }
+        self.name
+            .deserialize_aliases
+            .insert(self.name.deserialize.clone());
     }
 
     pub fn rename_all_rules(&self) -> RenameAllRules {
@@ -1029,7 +982,7 @@ impl Variant {
 
 /// Represents field attribute information
 pub struct Field {
-    name: Name,
+    name: MultiName,
     skip_serializing: bool,
     skip_deserializing: bool,
     skip_serializing_if: Option<syn::ExprPath>,
@@ -1088,8 +1041,11 @@ impl Field {
         let mut flatten = BoolAttr::none(cx, FLATTEN);
 
         let ident = match &field.ident {
-            Some(ident) => unraw(ident),
+            Some(ident) => Name::from(&unraw(ident)),
-            None => index.to_string(),
+            None => Name {
+                value: index.to_string(),
+                span: Span::call_site(),
+            },
         };
 
         if let Some(borrow_attribute) = attrs.and_then(|variant| variant.borrow.as_ref()) {
@@ -1125,15 +1081,15 @@ impl Field {
                     // #[serde(rename = "foo")]
                     // #[serde(rename(serialize = "foo", deserialize = "bar"))]
                     let (ser, de) = get_multiple_renames(cx, &meta)?;
-                    ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value));
+                    ser_name.set_opt(&meta.path, ser.as_ref().map(Name::from));
                     for de_value in de {
-                        de_name.set_if_none(de_value.value());
+                        de_name.set_if_none(Name::from(&de_value));
-                        de_aliases.insert(&meta.path, de_value.value());
+                        de_aliases.insert(&meta.path, Name::from(&de_value));
                     }
                 } else if meta.path == ALIAS {
                     // #[serde(alias = "foo")]
                     if let Some(s) = get_lit_str(cx, ALIAS, &meta)? {
-                        de_aliases.insert(&meta.path, s.value());
+                        de_aliases.insert(&meta.path, Name::from(&s));
                     }
                 } else if meta.path == DEFAULT {
                     if meta.input.peek(Token![=]) {
@@ -1177,13 +1133,13 @@ impl Field {
                         ser_path
                             .path
                             .segments
-                            .push(Ident::new("serialize", Span::call_site()).into());
+                            .push(Ident::new("serialize", ser_path.span()).into());
                         serialize_with.set(&meta.path, ser_path);
                         let mut de_path = path;
                         de_path
                             .path
                             .segments
-                            .push(Ident::new("deserialize", Span::call_site()).into());
+                            .push(Ident::new("deserialize", de_path.span()).into());
                         deserialize_with.set(&meta.path, de_path);
                     }
                 } else if meta.path == BOUND {
@@ -1296,7 +1252,7 @@ impl Field {
         }
 
         Field {
-            name: Name::from_attrs(ident, ser_name, de_name, Some(de_aliases)),
+            name: MultiName::from_attrs(ident, ser_name, de_name, Some(de_aliases)),
             skip_serializing: skip_serializing.get(),
             skip_deserializing: skip_deserializing.get(),
             skip_serializing_if: skip_serializing_if.get(),
@@ -1312,21 +1268,26 @@ impl Field {
         }
     }
 
-    pub fn name(&self) -> &Name {
+    pub fn name(&self) -> &MultiName {
         &self.name
     }
 
-    pub fn aliases(&self) -> Vec<String> {
+    pub fn aliases(&self) -> &BTreeSet<Name> {
         self.name.deserialize_aliases()
     }
 
     pub fn rename_by_rules(&mut self, rules: RenameAllRules) {
         if !self.name.serialize_renamed {
-            self.name.serialize = rules.serialize.apply_to_field(&self.name.serialize);
+            self.name.serialize.value = rules.serialize.apply_to_field(&self.name.serialize.value);
         }
         if !self.name.deserialize_renamed {
-            self.name.deserialize = rules.deserialize.apply_to_field(&self.name.deserialize);
+            self.name.deserialize.value = rules
+                .deserialize
+                .apply_to_field(&self.name.deserialize.value);
         }
+        self.name
+            .deserialize_aliases
+            .insert(self.name.deserialize.clone());
     }
 
     pub fn skip_serializing(&self) -> bool {
@@ -1772,7 +1733,7 @@ fn is_primitive_path(path: &syn::Path, primitive: &str) -> bool {
 // attribute on the field so there must be at least one borrowable lifetime.
 fn borrowable_lifetimes(
     cx: &Ctxt,
-    name: &str,
+    name: &Name,
     field: &syn::Field,
 ) -> Result<BTreeSet<syn::Lifetime>, ()> {
     let mut lifetimes = BTreeSet::new();
@@ -1788,6 +1749,7 @@ fn borrowable_lifetimes(
 
 fn collect_lifetimes(ty: &syn::Type, out: &mut BTreeSet<syn::Lifetime>) {
     match ty {
+        #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
         syn::Type::Slice(ty) => {
             collect_lifetimes(&ty.elem, out);
         }
@@ -1823,7 +1785,10 @@ fn collect_lifetimes(ty: &syn::Type, out: &mut BTreeSet<syn::Lifetime>) {
                             syn::GenericArgument::AssocType(binding) => {
                                 collect_lifetimes(&binding.ty, out);
                             }
-                            _ => {}
+                            syn::GenericArgument::Const(_)
+                            | syn::GenericArgument::AssocConst(_)
+                            | syn::GenericArgument::Constraint(_)
+                            | _ => {}
                         }
                     }
                 }
@@ -1845,7 +1810,6 @@ fn collect_lifetimes(ty: &syn::Type, out: &mut BTreeSet<syn::Lifetime>) {
         | syn::Type::Infer(_)
         | syn::Type::Verbatim(_) => {}
 
-        #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
         _ => {}
     }
 }

serde_derive/src/internals/check.rs

@@ -1,11 +1,12 @@
 use crate::internals::ast::{Container, Data, Field, Style};
-use crate::internals::attr::{Identifier, TagType};
+use crate::internals::attr::{Default, Identifier, TagType};
 use crate::internals::{ungroup, Ctxt, Derive};
 use syn::{Member, Type};
 
 // Cross-cutting checks that require looking at more than a single attrs object.
 // Simpler checks should happen when parsing and building the attrs.
 pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
+    check_default_on_tuple(cx, cont);
     check_remote_generic(cx, cont);
     check_getter(cx, cont);
     check_flatten(cx, cont);
@@ -17,6 +18,39 @@ pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
     check_from_and_try_from(cx, cont);
 }
 
+// If some field of a tuple struct is marked #[serde(default)] then all fields
+// after it must also be marked with that attribute, or the struct must have a
+// container-level serde(default) attribute. A field's default value is only
+// used for tuple fields if the sequence is exhausted at that point; that means
+// all subsequent fields will fail to deserialize if they don't have their own
+// default.
+fn check_default_on_tuple(cx: &Ctxt, cont: &Container) {
+    if let Default::None = cont.attrs.default() {
+        if let Data::Struct(Style::Tuple, fields) = &cont.data {
+            let mut first_default_index = None;
+            for (i, field) in fields.iter().enumerate() {
+                // Skipped fields automatically get the #[serde(default)]
+                // attribute. We are interested only on non-skipped fields here.
+                if field.attrs.skip_deserializing() {
+                    continue;
+                }
+                if let Default::None = field.attrs.default() {
+                    if let Some(first) = first_default_index {
+                        cx.error_spanned_by(
+                            field.ty,
+                            format!("field must have #[serde(default)] because previous field {} has #[serde(default)]", first),
+                        );
+                    }
+                    continue;
+                }
+                if first_default_index.is_none() {
+                    first_default_index = Some(i);
+                }
+            }
+        }
+    }
+}
+
 // Remote derive definition type must have either all of the generics of the
 // remote type:
 //
@@ -284,6 +318,9 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
     for variant in variants {
         match variant.style {
             Style::Struct => {
+                if variant.attrs.untagged() {
+                    continue;
+                }
                 for field in &variant.fields {
                     let check_ser =
                         !(field.attrs.skip_serializing() || variant.attrs.skip_serializing());
@@ -292,13 +329,13 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
                     let name = field.attrs.name();
                     let ser_name = name.serialize_name();
 
-                    if check_ser && ser_name == tag {
+                    if check_ser && ser_name.value == tag {
                         diagnose_conflict();
                         return;
                     }
 
                     for de_name in field.attrs.aliases() {
-                        if check_de && de_name == tag {
+                        if check_de && de_name.value == tag {
                             diagnose_conflict();
                             return;
                         }

serde_derive/src/internals/mod.rs

@@ -1,5 +1,6 @@
 pub mod ast;
 pub mod attr;
+pub mod name;
 
 mod case;
 mod check;

serde_derive/src/internals/name.rs

@@ -0,0 +1,113 @@
+use crate::internals::attr::{Attr, VecAttr};
+use proc_macro2::{Ident, Span, TokenStream};
+use quote::ToTokens;
+use std::cmp::Ordering;
+use std::collections::BTreeSet;
+use std::fmt::{self, Display};
+use syn::LitStr;
+
+pub struct MultiName {
+    pub(crate) serialize: Name,
+    pub(crate) serialize_renamed: bool,
+    pub(crate) deserialize: Name,
+    pub(crate) deserialize_renamed: bool,
+    pub(crate) deserialize_aliases: BTreeSet<Name>,
+}
+
+impl MultiName {
+    pub(crate) fn from_attrs(
+        source_name: Name,
+        ser_name: Attr<Name>,
+        de_name: Attr<Name>,
+        de_aliases: Option<VecAttr<Name>>,
+    ) -> Self {
+        let mut alias_set = BTreeSet::new();
+        if let Some(de_aliases) = de_aliases {
+            for alias_name in de_aliases.get() {
+                alias_set.insert(alias_name);
+            }
+        }
+
+        let ser_name = ser_name.get();
+        let ser_renamed = ser_name.is_some();
+        let de_name = de_name.get();
+        let de_renamed = de_name.is_some();
+        MultiName {
+            serialize: ser_name.unwrap_or_else(|| source_name.clone()),
+            serialize_renamed: ser_renamed,
+            deserialize: de_name.unwrap_or(source_name),
+            deserialize_renamed: de_renamed,
+            deserialize_aliases: alias_set,
+        }
+    }
+
+    /// Return the container name for the container when serializing.
+    pub fn serialize_name(&self) -> &Name {
+        &self.serialize
+    }
+
+    /// Return the container name for the container when deserializing.
+    pub fn deserialize_name(&self) -> &Name {
+        &self.deserialize
+    }
+
+    pub(crate) fn deserialize_aliases(&self) -> &BTreeSet<Name> {
+        &self.deserialize_aliases
+    }
+}
+
+#[derive(Clone)]
+pub struct Name {
+    pub value: String,
+    pub span: Span,
+}
+
+impl ToTokens for Name {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        LitStr::new(&self.value, self.span).to_tokens(tokens);
+    }
+}
+
+impl Ord for Name {
+    fn cmp(&self, other: &Self) -> Ordering {
+        Ord::cmp(&self.value, &other.value)
+    }
+}
+
+impl PartialOrd for Name {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(Ord::cmp(self, other))
+    }
+}
+
+impl Eq for Name {}
+
+impl PartialEq for Name {
+    fn eq(&self, other: &Self) -> bool {
+        self.value == other.value
+    }
+}
+
+impl From<&Ident> for Name {
+    fn from(ident: &Ident) -> Self {
+        Name {
+            value: ident.to_string(),
+            span: ident.span(),
+        }
+    }
+}
+
+impl From<&LitStr> for Name {
+    fn from(lit: &LitStr) -> Self {
+        Name {
+            value: lit.value(),
+            span: lit.span(),
+        }
+    }
+}
+
+impl Display for Name {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.value, formatter)
+    }
+}

serde_derive/src/internals/receiver.rs

@@ -2,7 +2,6 @@ use crate::internals::respan::respan;
 use proc_macro2::Span;
 use quote::ToTokens;
 use std::mem;
-use syn::punctuated::Punctuated;
 use syn::{
     parse_quote, Data, DeriveInput, Expr, ExprPath, GenericArgument, GenericParam, Generics, Macro,
     Path, PathArguments, QSelf, ReturnType, Token, Type, TypeParamBound, TypePath, WherePredicate,
@@ -49,7 +48,7 @@ impl ReplaceReceiver<'_> {
 
         path.leading_colon = Some(**path.segments.pairs().next().unwrap().punct().unwrap());
 
-        let segments = mem::replace(&mut path.segments, Punctuated::new());
+        let segments = mem::take(&mut path.segments);
         path.segments = segments.into_pairs().skip(1).collect();
     }
 
@@ -84,7 +83,7 @@ impl ReplaceReceiver<'_> {
             self.visit_type_mut_impl(ty);
             return;
         };
-        *ty = self.self_ty(span).into();
+        *ty = Type::Path(self.self_ty(span));
     }
 
     // `Self::Assoc` -> `<Receiver>::Assoc`
@@ -107,6 +106,7 @@ impl ReplaceReceiver<'_> {
 
     fn visit_type_mut_impl(&mut self, ty: &mut Type) {
         match ty {
+            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
             Type::Array(ty) => {
                 self.visit_type_mut(&mut ty.elem);
                 self.visit_expr_mut(&mut ty.len);
@@ -147,7 +147,6 @@ impl ReplaceReceiver<'_> {
 
             Type::Infer(_) | Type::Never(_) | Type::Verbatim(_) => {}
 
-            #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
             _ => {}
         }
     }
@@ -178,13 +177,13 @@ impl ReplaceReceiver<'_> {
             PathArguments::AngleBracketed(arguments) => {
                 for arg in &mut arguments.args {
                     match arg {
+                        #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                         GenericArgument::Type(arg) => self.visit_type_mut(arg),
                         GenericArgument::AssocType(arg) => self.visit_type_mut(&mut arg.ty),
                         GenericArgument::Lifetime(_)
                         | GenericArgument::Const(_)
                         | GenericArgument::AssocConst(_)
                         | GenericArgument::Constraint(_) => {}
-                        #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                         _ => {}
                     }
                 }
@@ -207,9 +206,11 @@ impl ReplaceReceiver<'_> {
 
     fn visit_type_param_bound_mut(&mut self, bound: &mut TypeParamBound) {
         match bound {
+            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
             TypeParamBound::Trait(bound) => self.visit_path_mut(&mut bound.path),
-            TypeParamBound::Lifetime(_) | TypeParamBound::Verbatim(_) => {}
+            TypeParamBound::Lifetime(_)
-            #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
+            | TypeParamBound::PreciseCapture(_)
+            | TypeParamBound::Verbatim(_) => {}
             _ => {}
         }
     }
@@ -228,6 +229,7 @@ impl ReplaceReceiver<'_> {
         if let Some(where_clause) = &mut generics.where_clause {
             for predicate in &mut where_clause.predicates {
                 match predicate {
+                    #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                     WherePredicate::Type(predicate) => {
                         self.visit_type_mut(&mut predicate.bounded_ty);
                         for bound in &mut predicate.bounds {
@@ -235,7 +237,6 @@ impl ReplaceReceiver<'_> {
                         }
                     }
                     WherePredicate::Lifetime(_) => {}
-                    #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
                     _ => {}
                 }
             }

serde_derive/src/internals/symbol.rs

@@ -19,6 +19,7 @@ pub const FLATTEN: Symbol = Symbol("flatten");
 pub const FROM: Symbol = Symbol("from");
 pub const GETTER: Symbol = Symbol("getter");
 pub const INTO: Symbol = Symbol("into");
+pub const NON_EXHAUSTIVE: Symbol = Symbol("non_exhaustive");
 pub const OTHER: Symbol = Symbol("other");
 pub const REMOTE: Symbol = Symbol("remote");
 pub const RENAME: Symbol = Symbol("rename");
@@ -45,7 +46,7 @@ impl PartialEq<Symbol> for Ident {
     }
 }
 
-impl<'a> PartialEq<Symbol> for &'a Ident {
+impl PartialEq<Symbol> for &Ident {
     fn eq(&self, word: &Symbol) -> bool {
         *self == word.0
     }
@@ -57,7 +58,7 @@ impl PartialEq<Symbol> for Path {
     }
 }
 
-impl<'a> PartialEq<Symbol> for &'a Path {
+impl PartialEq<Symbol> for &Path {
     fn eq(&self, word: &Symbol) -> bool {
         self.is_ident(word.0)
     }

serde_derive/src/lib.rs

@@ -13,7 +13,8 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.178")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.221")]
+#![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(
     // clippy false positive: https://github.com/rust-lang/rust-clippy/issues/7054
@@ -26,6 +27,7 @@
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
     clippy::manual_map,
     clippy::match_like_matches_macro,
+    clippy::needless_lifetimes,
     clippy::needless_pass_by_value,
     clippy::too_many_arguments,
     clippy::trivially_copy_pass_by_ref,
@@ -39,6 +41,7 @@
     clippy::cast_possible_truncation,
     clippy::checked_conversions,
     clippy::doc_markdown,
+    clippy::elidable_lifetime_names,
     clippy::enum_glob_use,
     clippy::indexing_slicing,
     clippy::items_after_statements,
@@ -50,33 +53,28 @@
     clippy::match_wildcard_for_single_variants,
     clippy::module_name_repetitions,
     clippy::must_use_candidate,
-    clippy::option_if_let_else,
     clippy::similar_names,
     clippy::single_match_else,
     clippy::struct_excessive_bools,
     clippy::too_many_lines,
+    clippy::uninlined_format_args,
     clippy::unseparated_literal_suffix,
     clippy::unused_self,
     clippy::use_self,
     clippy::wildcard_imports
 )]
 #![cfg_attr(all(test, exhaustive), feature(non_exhaustive_omitted_patterns_lint))]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 extern crate proc_macro2;
 extern crate quote;
 extern crate syn;
 
-#[cfg(not(precompiled))]
 extern crate proc_macro;
-#[cfg(precompiled)]
-extern crate proc_macro2 as proc_macro;
 
 mod internals;
 
 use proc_macro::TokenStream;
-#[cfg(precompiled)]
-use std::sync::atomic::AtomicBool;
-#[cfg(not(precompiled))]
 use syn::parse_macro_input;
 use syn::DeriveInput;
 
@@ -91,20 +89,7 @@ mod pretend;
 mod ser;
 mod this;
 
-#[cfg(precompiled)]
+#[proc_macro_derive(Serialize, attributes(serde))]
-macro_rules! parse_macro_input {
-    ($tokenstream:ident as $ty:ty) => {
-        match syn::parse2::<$ty>($tokenstream) {
-            Ok(data) => data,
-            Err(err) => return err.to_compile_error(),
-        }
-    };
-}
-
-#[cfg(precompiled)]
-pub static DESERIALIZE_IN_PLACE: AtomicBool = AtomicBool::new(false);
-
-#[cfg_attr(not(precompiled), proc_macro_derive(Serialize, attributes(serde)))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     ser::expand_derive_serialize(&mut input)
@@ -112,7 +97,7 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
         .into()
 }
 
-#[cfg_attr(not(precompiled), proc_macro_derive(Deserialize, attributes(serde)))]
+#[proc_macro_derive(Deserialize, attributes(serde))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     de::expand_derive_deserialize(&mut input)

serde_derive/src/pretend.rs

@@ -64,14 +64,14 @@ pub fn pretend_used(cont: &Container, is_packed: bool) -> TokenStream {
 fn pretend_fields_used(cont: &Container, is_packed: bool) -> TokenStream {
     match &cont.data {
         Data::Enum(variants) => pretend_fields_used_enum(cont, variants),
-        Data::Struct(Style::Struct, fields) => {
+        Data::Struct(Style::Struct | Style::Tuple | Style::Newtype, fields) => {
             if is_packed {
                 pretend_fields_used_struct_packed(cont, fields)
             } else {
                 pretend_fields_used_struct(cont, fields)
             }
         }
-        Data::Struct(_, _) => quote!(),
+        Data::Struct(Style::Unit, _) => quote!(),
     }
 }
 
@@ -115,13 +115,13 @@ fn pretend_fields_used_enum(cont: &Container, variants: &[Variant]) -> TokenStre
     let patterns = variants
         .iter()
         .filter_map(|variant| match variant.style {
-            Style::Struct => {
+            Style::Struct | Style::Tuple | Style::Newtype => {
                 let variant_ident = &variant.ident;
                 let members = variant.fields.iter().map(|field| &field.member);
                 let placeholders = (0usize..).map(|i| format_ident!("__v{}", i));
                 Some(quote!(#type_ident::#variant_ident { #(#members: #placeholders),* }))
             }
-            _ => None,
+            Style::Unit => None,
         })
         .collect::<Vec<_>>();
 

serde_derive/src/ser.rs

@@ -1,5 +1,6 @@
 use crate::fragment::{Fragment, Match, Stmts};
 use crate::internals::ast::{Container, Data, Field, Style, Variant};
+use crate::internals::name::Name;
 use crate::internals::{attr, replace_receiver, Ctxt, Derive};
 use crate::{bound, dummy, pretend, this};
 use proc_macro2::{Span, TokenStream};
@@ -28,6 +29,7 @@ pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<Toke
         let vis = &input.vis;
         let used = pretend::pretend_used(&cont, params.is_packed);
         quote! {
+            #[automatically_derived]
             impl #impl_generics #ident #ty_generics #where_clause {
                 #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> #serde::__private::Result<__S::Ok, __S::Error>
                 where
@@ -148,7 +150,7 @@ fn build_generics(cont: &Container) -> syn::Generics {
 }
 
 // Fields with a `skip_serializing` or `serialize_with` attribute, or which
-// belong to a variant with a 'skip_serializing` or `serialize_with` attribute,
+// belong to a variant with a `skip_serializing` or `serialize_with` attribute,
 // are not serialized by us so we do not generate a bound. Fields with a `bound`
 // attribute specify their own bound so we do not generate one. All other fields
 // may need a `T: Serialize` bound where T is the type of the field.
@@ -289,9 +291,18 @@ fn serialize_tuple_struct(
 }
 
 fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
-    assert!(fields.len() as u64 <= u64::from(u32::max_value()));
+    assert!(
+        fields.len() as u64 <= u64::from(u32::MAX),
+        "too many fields in {}: {}, maximum supported count is {}",
+        cattrs.name().serialize_name(),
+        fields.len(),
+        u32::MAX,
+    );
 
-    if cattrs.has_flatten() {
+    let has_non_skipped_flatten = fields
+        .iter()
+        .any(|field| field.attrs.flatten() && !field.attrs.skip_serializing());
+    if has_non_skipped_flatten {
         serialize_struct_as_map(params, fields, cattrs)
     } else {
         serialize_struct_as_struct(params, fields, cattrs)
@@ -370,26 +381,8 @@ fn serialize_struct_as_map(
 
     let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
 
-    let len = if cattrs.has_flatten() {
-        quote!(_serde::__private::None)
-    } else {
-        let len = serialized_fields
-            .map(|field| match field.attrs.skip_serializing_if() {
-                None => quote!(1),
-                Some(path) => {
-                    let field_expr = get_member(params, field, &field.member);
-                    quote!(if #path(#field_expr) { 0 } else { 1 })
-                }
-            })
-            .fold(
-                quote!(#tag_field_exists as usize),
-                |sum, expr| quote!(#sum + #expr),
-            );
-        quote!(_serde::__private::Some(#len))
-    };
-
     quote_block! {
-        let #let_mut __serde_state = _serde::Serializer::serialize_map(__serializer, #len)?;
+        let #let_mut __serde_state = _serde::Serializer::serialize_map(__serializer, _serde::__private::None)?;
         #tag_field
         #(#serialize_fields)*
         _serde::ser::SerializeMap::end(__serde_state)
@@ -397,11 +390,11 @@ fn serialize_struct_as_map(
 }
 
 fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Container) -> Fragment {
-    assert!(variants.len() as u64 <= u64::from(u32::max_value()));
+    assert!(variants.len() as u64 <= u64::from(u32::MAX));
 
     let self_var = &params.self_var;
 
-    let arms: Vec<_> = variants
+    let mut arms: Vec<_> = variants
         .iter()
         .enumerate()
         .map(|(variant_index, variant)| {
@@ -409,6 +402,12 @@ fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Cont
         })
         .collect();
 
+    if cattrs.remote().is_some() && cattrs.non_exhaustive() {
+        arms.push(quote! {
+            ref unrecognized => _serde::__private::Err(_serde::ser::Error::custom(_serde::__private::ser::CannotSerializeVariant(unrecognized))),
+        });
+    }
+
     quote_expr! {
         match *#self_var {
             #(#arms)*
@@ -478,7 +477,14 @@ fn serialize_variant(
                 serialize_internally_tagged_variant(params, variant, cattrs, tag)
             }
             (attr::TagType::Adjacent { tag, content }, false) => {
-                serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content)
+                serialize_adjacently_tagged_variant(
+                    params,
+                    variant,
+                    cattrs,
+                    variant_index,
+                    tag,
+                    content,
+                )
             }
             (attr::TagType::None, _) | (_, true) => {
                 serialize_untagged_variant(params, variant, cattrs)
@@ -559,7 +565,7 @@ fn serialize_externally_tagged_variant(
             },
             params,
             &variant.fields,
-            &type_name,
+            type_name,
         ),
     }
 }
@@ -624,7 +630,7 @@ fn serialize_internally_tagged_variant(
             StructVariant::InternallyTagged { tag, variant_name },
             params,
             &variant.fields,
-            &type_name,
+            type_name,
         ),
         Style::Tuple => unreachable!("checked in serde_derive_internals"),
     }
@@ -634,12 +640,20 @@ fn serialize_adjacently_tagged_variant(
     params: &Parameters,
     variant: &Variant,
     cattrs: &attr::Container,
+    variant_index: u32,
     tag: &str,
     content: &str,
 ) -> Fragment {
     let this_type = &params.this_type;
     let type_name = cattrs.name().serialize_name();
     let variant_name = variant.attrs.name().serialize_name();
+    let serialize_variant = quote! {
+        &_serde::__private::ser::AdjacentlyTaggedEnumVariant {
+            enum_name: #type_name,
+            variant_index: #variant_index,
+            variant_name: #variant_name,
+        }
+    };
 
     let inner = Stmts(if let Some(path) = variant.attrs.serialize_with() {
         let ser = wrap_serialize_variant_with(params, path, variant);
@@ -653,7 +667,7 @@ fn serialize_adjacently_tagged_variant(
                     let mut __struct = _serde::Serializer::serialize_struct(
                         __serializer, #type_name, 1)?;
                     _serde::ser::SerializeStruct::serialize_field(
-                        &mut __struct, #tag, #variant_name)?;
+                        &mut __struct, #tag, #serialize_variant)?;
                     _serde::ser::SerializeStruct::end(__struct)
                 };
             }
@@ -670,7 +684,7 @@ fn serialize_adjacently_tagged_variant(
                     let mut __struct = _serde::Serializer::serialize_struct(
                         __serializer, #type_name, 2)?;
                     _serde::ser::SerializeStruct::serialize_field(
-                        &mut __struct, #tag, #variant_name)?;
+                        &mut __struct, #tag, #serialize_variant)?;
                     #func(
                         &mut __struct, #content, #field_expr)?;
                     _serde::ser::SerializeStruct::end(__struct)
@@ -683,13 +697,13 @@ fn serialize_adjacently_tagged_variant(
                 StructVariant::Untagged,
                 params,
                 &variant.fields,
-                &variant_name,
+                variant_name,
             ),
         }
     });
 
     let fields_ty = variant.fields.iter().map(|f| &f.ty);
-    let fields_ident: &Vec<_> = &match variant.style {
+    let fields_ident: &[_] = &match variant.style {
         Style::Unit => {
             if variant.attrs.serialize_with().is_some() {
                 vec![]
@@ -720,6 +734,7 @@ fn serialize_adjacently_tagged_variant(
             phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
         }
 
+        #[automatically_derived]
         impl #wrapper_impl_generics _serde::Serialize for __AdjacentlyTagged #wrapper_ty_generics #where_clause {
             fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where
@@ -735,7 +750,7 @@ fn serialize_adjacently_tagged_variant(
         let mut __struct = _serde::Serializer::serialize_struct(
             __serializer, #type_name, 2)?;
         _serde::ser::SerializeStruct::serialize_field(
-            &mut __struct, #tag, #variant_name)?;
+            &mut __struct, #tag, #serialize_variant)?;
         _serde::ser::SerializeStruct::serialize_field(
             &mut __struct, #content, &__AdjacentlyTagged {
                 data: (#(#fields_ident,)*),
@@ -779,16 +794,16 @@ fn serialize_untagged_variant(
         Style::Tuple => serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields),
         Style::Struct => {
             let type_name = cattrs.name().serialize_name();
-            serialize_struct_variant(StructVariant::Untagged, params, &variant.fields, &type_name)
+            serialize_struct_variant(StructVariant::Untagged, params, &variant.fields, type_name)
         }
     }
 }
 
-enum TupleVariant {
+enum TupleVariant<'a> {
     ExternallyTagged {
-        type_name: String,
+        type_name: &'a Name,
         variant_index: u32,
-        variant_name: String,
+        variant_name: &'a Name,
     },
     Untagged,
 }
@@ -855,11 +870,11 @@ fn serialize_tuple_variant(
 enum StructVariant<'a> {
     ExternallyTagged {
         variant_index: u32,
-        variant_name: String,
+        variant_name: &'a Name,
     },
     InternallyTagged {
         tag: &'a str,
-        variant_name: String,
+        variant_name: &'a Name,
     },
     Untagged,
 }
@@ -868,7 +883,7 @@ fn serialize_struct_variant(
     context: StructVariant,
     params: &Parameters,
     fields: &[Field],
-    name: &str,
+    name: &Name,
 ) -> Fragment {
     if fields.iter().any(|field| field.attrs.flatten()) {
         return serialize_struct_variant_with_flatten(context, params, fields, name);
@@ -952,7 +967,7 @@ fn serialize_struct_variant_with_flatten(
     context: StructVariant,
     params: &Parameters,
     fields: &[Field],
-    name: &str,
+    name: &Name,
 ) -> Fragment {
     let struct_trait = StructTrait::SerializeMap;
     let serialize_fields = serialize_struct_visitor(fields, params, true, &struct_trait);
@@ -984,6 +999,7 @@ fn serialize_struct_variant_with_flatten(
                     phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
                 }
 
+                #[automatically_derived]
                 impl #wrapper_impl_generics _serde::Serialize for __EnumFlatten #wrapper_ty_generics #where_clause {
                     fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
                     where
@@ -1208,6 +1224,17 @@ fn wrap_serialize_with(
         })
     });
 
+    let self_var = quote!(self);
+    let serializer_var = quote!(__s);
+
+    // If #serialize_with returns wrong type, error will be reported on here.
+    // We attach span of the path to this piece so error will be reported
+    // on the #[serde(with = "...")]
+    //                       ^^^^^
+    let wrapper_serialize = quote_spanned! {serialize_with.span()=>
+        #serialize_with(#(#self_var.values.#field_access, )* #serializer_var)
+    };
+
     quote!({
         #[doc(hidden)]
         struct __SerializeWith #wrapper_impl_generics #where_clause {
@@ -1215,12 +1242,13 @@ fn wrap_serialize_with(
             phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
         }
 
+        #[automatically_derived]
         impl #wrapper_impl_generics _serde::Serialize for __SerializeWith #wrapper_ty_generics #where_clause {
-            fn serialize<__S>(&self, __s: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
+            fn serialize<__S>(&#self_var, #serializer_var: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where
                 __S: _serde::Serializer,
             {
-                #serialize_with(#(self.values.#field_access, )* __s)
+                #wrapper_serialize
             }
         }
 

serde_derive_internals/Cargo.toml

@@ -1,24 +1,31 @@
 [package]
 name = "serde_derive_internals"
-version = "0.28.0" # remember to update html_root_url
+version = "0.29.1"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 description = "AST representation used by Serde derive macros. Unstable."
 documentation = "https://docs.rs/serde_derive_internals"
+edition = "2021"
 exclude = ["build.rs"]
 homepage = "https://serde.rs"
 keywords = ["serde", "serialization"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/serde-rs/serde"
-rust-version = "1.56"
+rust-version = "1.61"
 
 [lib]
 path = "lib.rs"
 
 [dependencies]
-proc-macro2 = "1.0"
+proc-macro2 = { workspace = true }
-quote = "1.0"
+quote = { workspace = true }
-syn = { version = "2.0.25", default-features = false, features = ["clone-impls", "derive", "parsing", "printing"] }
+syn = { workspace = true, features = ["clone-impls", "derive", "parsing", "printing"] }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
-rustdoc-args = ["--generate-link-to-definition"]
+rustdoc-args = [
+    "--generate-link-to-definition",
+    "--extern-html-root-url=core=https://doc.rust-lang.org",
+    "--extern-html-root-url=alloc=https://doc.rust-lang.org",
+    "--extern-html-root-url=std=https://doc.rust-lang.org",
+    "--extern-html-root-url=proc_macro=https://doc.rust-lang.org",
+]

serde_derive_internals/build.rs

@@ -1,9 +1,17 @@
 use std::path::Path;
 
 fn main() {
+    // Warning: build.rs is not published to crates.io.
+
     println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rerun-if-changed=src/mod.rs");
 
+    println!("cargo:rustc-cfg=check_cfg");
+    println!("cargo:rustc-check-cfg=cfg(check_cfg)");
+    println!("cargo:rustc-check-cfg=cfg(exhaustive)");
+    println!("cargo:rustc-check-cfg=cfg(serde_build_from_git)");
+    println!("cargo:rustc-check-cfg=cfg(feature, values(\"deserialize_in_place\"))");
+
     // Sometimes on Windows the git checkout does not correctly wire up the
     // symlink from serde_derive_internals/src to serde_derive/src/internals.
     // When this happens we'll just build based on relative paths within the git

serde_derive_internals/lib.rs

@@ -1,4 +1,5 @@
-#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.28.0")]
+#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.29.1")]
+#![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(
     clippy::cognitive_complexity,
@@ -8,6 +9,7 @@
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
     clippy::manual_map,
     clippy::missing_panics_doc,
+    clippy::needless_lifetimes,
     clippy::redundant_field_names,
     clippy::result_unit_err,
     clippy::should_implement_trait,
@@ -19,6 +21,7 @@
 // Ignored clippy_pedantic lints
 #![allow(
     clippy::doc_markdown,
+    clippy::elidable_lifetime_names,
     clippy::enum_glob_use,
     clippy::items_after_statements,
     clippy::let_underscore_untyped,
@@ -34,9 +37,11 @@
     clippy::single_match_else,
     clippy::struct_excessive_bools,
     clippy::too_many_lines,
+    clippy::uninlined_format_args,
     clippy::unused_self,
     clippy::wildcard_imports
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 extern crate proc_macro2;
 extern crate quote;

test_suite/Cargo.toml

@@ -2,7 +2,7 @@
 name = "serde_test_suite"
 version = "0.0.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
-edition = "2018"
+edition = "2021"
 publish = false
 
 [features]
@@ -13,9 +13,9 @@ serde = { path = "../serde" }
 
 [dev-dependencies]
 automod = "1.0.1"
-fnv = "1.0"
+foldhash = "0.2"
 rustversion = "1.0"
 serde = { path = "../serde", features = ["rc"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }
 serde_test = "1.0.176"
-trybuild = { version = "1.0.66", features = ["diff"] }
+trybuild = { version = "1.0.108", features = ["diff"] }

test_suite/no_std/.gitignore

@@ -0,0 +1,2 @@
+/target/
+/Cargo.lock

test_suite/no_std/Cargo.toml

@@ -2,7 +2,7 @@
 name = "serde_derive_tests_no_std"
 version = "0.0.0"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
-edition = "2018"
+edition = "2021"
 publish = false
 
 [dependencies]
@@ -10,4 +10,10 @@ libc = { version = "0.2", default-features = false }
 serde = { path = "../../serde", default-features = false }
 serde_derive = { path = "../../serde_derive" }
 
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+
 [workspace]

test_suite/no_std/src/main.rs

@@ -1,15 +1,13 @@
-#![feature(lang_items, start)]
 #![no_std]
+#![no_main]
 
-#[start]
+use core::ffi::c_int;
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+
+#[no_mangle]
+extern "C" fn main(_argc: c_int, _argv: *const *const u8) -> c_int {
     0
 }
 
-#[lang = "eh_personality"]
-#[no_mangle]
-pub extern "C" fn rust_eh_personality() {}
-
 #[panic_handler]
 fn panic(_info: &core::panic::PanicInfo) -> ! {
     unsafe {
@@ -22,21 +20,21 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 use serde_derive::{Deserialize, Serialize};
 
 #[derive(Serialize, Deserialize)]
-struct Unit;
+pub struct Unit;
 
 #[derive(Serialize, Deserialize)]
-struct Newtype(u8);
+pub struct Newtype(u8);
 
 #[derive(Serialize, Deserialize)]
-struct Tuple(u8, u8);
+pub struct Tuple(u8, u8);
 
 #[derive(Serialize, Deserialize)]
-struct Struct {
+pub struct Struct {
     f: u8,
 }
 
 #[derive(Serialize, Deserialize)]
-enum Enum {
+pub enum Enum {
     Unit,
     Newtype(u8),
     Tuple(u8, u8),

test_suite/tests/compiletest.rs

@@ -1,6 +1,6 @@
-#[cfg_attr(target_os = "emscripten", ignore)]
+#[cfg_attr(target_os = "emscripten", ignore = "disabled on Emscripten")]
-#[rustversion::attr(not(nightly), ignore)]
+#[rustversion::attr(not(nightly), ignore = "requires nightly")]
-#[cfg_attr(miri, ignore)]
+#[cfg_attr(miri, ignore = "incompatible with miri")]
 #[allow(unused_attributes)]
 #[test]
 fn ui() {

test_suite/tests/macros/mod.rs

@@ -34,9 +34,8 @@ macro_rules! hashset {
         $(set.insert($value);)+
         set
     }};
-    ($hasher:ident @ $($value:expr),+) => {{
+    ($hasher:ty; $($value:expr),+) => {{
-        use std::hash::BuildHasherDefault;
+        let mut set = HashSet::<_, $hasher>::default();
-        let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
         $(set.insert($value);)+
         set
     }};
@@ -51,9 +50,8 @@ macro_rules! hashmap {
         $(map.insert($key, $value);)+
         map
     }};
-    ($hasher:ident @ $($key:expr => $value:expr),+) => {{
+    ($hasher:ty; $($key:expr => $value:expr),+) => {{
-        use std::hash::BuildHasherDefault;
+        let mut map = HashMap::<_, _, $hasher>::default();
-        let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
         $(map.insert($key, $value);)+
         map
     }};

test_suite/tests/regression/issue1904.rs

@@ -0,0 +1,66 @@
+#![allow(dead_code)] // we do not read enum fields
+
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+pub struct Nested;
+
+#[derive(Deserialize)]
+pub enum ExternallyTagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+pub enum ExternallyTagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}
+
+// Internally tagged enums cannot contain tuple variants so not tested here
+
+#[derive(Deserialize)]
+#[serde(tag = "tag", content = "content")]
+pub enum AdjacentlyTagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(tag = "tag", content = "content")]
+pub enum AdjacentlyTagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub enum Untagged1 {
+    Tuple(f64, String),
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub enum Untagged2 {
+    Flatten {
+        #[serde(flatten)]
+        nested: Nested,
+    },
+    Tuple(f64, String),
+}

test_suite/tests/regression/issue2371.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use serde_derive::Deserialize;
 
 #[derive(Deserialize)]
@@ -7,7 +9,9 @@ pub struct Nested;
 pub enum ExternallyTagged {
     Flatten {
         #[serde(flatten)]
+        #[allow(dead_code)]
         nested: Nested,
+        #[allow(dead_code)]
         string: &'static str,
     },
 }
@@ -17,7 +21,9 @@ pub enum ExternallyTagged {
 pub enum InternallyTagged {
     Flatten {
         #[serde(flatten)]
+        #[allow(dead_code)]
         nested: Nested,
+        #[allow(dead_code)]
         string: &'static str,
     },
 }
@@ -27,7 +33,9 @@ pub enum InternallyTagged {
 pub enum AdjacentlyTagged {
     Flatten {
         #[serde(flatten)]
+        #[allow(dead_code)]
         nested: Nested,
+        #[allow(dead_code)]
         string: &'static str,
     },
 }
@@ -37,7 +45,9 @@ pub enum AdjacentlyTagged {
 pub enum UntaggedWorkaround {
     Flatten {
         #[serde(flatten)]
+        #[allow(dead_code)]
         nested: Nested,
+        #[allow(dead_code)]
         string: &'static str,
     },
 }

test_suite/tests/regression/issue2409.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use serde_derive::Deserialize;
 
 macro_rules! bug {

test_suite/tests/regression/issue2415.rs

@@ -2,4 +2,5 @@ use serde_derive::Serialize;
 
 #[derive(Serialize)]
 #[serde()]
+#[allow(dead_code)]
 pub struct S;

test_suite/tests/regression/issue2565.rs

@@ -0,0 +1,48 @@
+use serde_derive::{Deserialize, Serialize};
+use serde_test::{assert_tokens, Token};
+
+#[derive(Serialize, Deserialize, Debug, PartialEq)]
+enum Enum {
+    Simple {
+        a: i32,
+    },
+    Flatten {
+        #[serde(flatten)]
+        flatten: (),
+        a: i32,
+    },
+}
+
+#[test]
+fn simple_variant() {
+    assert_tokens(
+        &Enum::Simple { a: 42 },
+        &[
+            Token::StructVariant {
+                name: "Enum",
+                variant: "Simple",
+                len: 1,
+            },
+            Token::Str("a"),
+            Token::I32(42),
+            Token::StructVariantEnd,
+        ],
+    );
+}
+
+#[test]
+fn flatten_variant() {
+    assert_tokens(
+        &Enum::Flatten { flatten: (), a: 42 },
+        &[
+            Token::NewtypeVariant {
+                name: "Enum",
+                variant: "Flatten",
+            },
+            Token::Map { len: None },
+            Token::Str("a"),
+            Token::I32(42),
+            Token::MapEnd,
+        ],
+    );
+}

test_suite/tests/regression/issue2792.rs

@@ -0,0 +1,18 @@
+#![allow(dead_code)] // we do not read enum fields
+
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
+pub enum A {
+    B {
+        c: String,
+    },
+    D {
+        #[serde(flatten)]
+        e: E,
+    },
+}
+
+#[derive(Deserialize)]
+pub struct E {}

test_suite/tests/regression/issue2844.rs

@@ -0,0 +1,33 @@
+#![allow(clippy::trivially_copy_pass_by_ref, dead_code)]
+
+use serde_derive::{Deserialize, Serialize};
+
+macro_rules! declare_in_macro {
+    ($with:literal) => {
+        #[derive(Serialize, Deserialize)]
+        pub struct S {
+            #[serde(with = $with)]
+            f: i32,
+        }
+    };
+}
+
+declare_in_macro!("with");
+
+mod with {
+    use serde::{Deserializer, Serializer};
+
+    pub fn serialize<S>(_: &i32, _: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        unimplemented!()
+    }
+
+    pub fn deserialize<'de, D>(_: D) -> Result<i32, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        unimplemented!()
+    }
+}

test_suite/tests/regression/issue2846.rs

@@ -0,0 +1,27 @@
+#![allow(clippy::trivially_copy_pass_by_ref, dead_code)]
+
+use serde_derive::Deserialize;
+
+macro_rules! declare_in_macro {
+    ($with:literal) => {
+        #[derive(Deserialize)]
+        pub struct S(
+            #[serde(with = $with)]
+            #[allow(dead_code)]
+            i32,
+        );
+    };
+}
+
+declare_in_macro!("with");
+
+mod with {
+    use serde::Deserializer;
+
+    pub fn deserialize<'de, D>(_: D) -> Result<i32, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        unimplemented!()
+    }
+}