Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

99 files changed, 56416 insertions, 0 deletions

diff --git a/vendor/syn/.cargo-checksum.json b/vendor/syn/.cargo-checksum.json
new file mode 100644
index 0000000..d49c1be
--- /dev/null
+++ b/vendor/syn/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{},"package":"e96b79aaa137db8f61e26363a0c9b47d8b4ec75da28b7d1d614c2303e232408b"}
\ No newline at end of file
diff --git a/vendor/syn/Cargo.toml b/vendor/syn/Cargo.toml
new file mode 100644
index 0000000..92b5f7e
--- /dev/null
+++ b/vendor/syn/Cargo.toml
@@ -0,0 +1,205 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.56"
+name = "syn"
+version = "2.0.38"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
+include = [
+    "/Cargo.toml",
+    "/LICENSE-APACHE",
+    "/LICENSE-MIT",
+    "/README.md",
+    "/src/**",
+    "/tests/**",
+]
+description = "Parser for Rust source code"
+documentation = "https://docs.rs/syn"
+readme = "README.md"
+keywords = [
+    "macros",
+    "syn",
+]
+categories = [
+    "development-tools::procedural-macro-helpers",
+    "parser-implementations",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/dtolnay/syn"
+autotests = false
+autobenches = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = [
+    "--cfg",
+    "doc_cfg",
+    "--generate-link-to-definition",
+]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[package.metadata.playground]
+features = [
+    "full",
+    "visit",
+    "visit-mut",
+    "fold",
+    "extra-traits",
+]
+
+
+
+[dependencies.proc-macro2]
+version = "1.0.67"
+default-features = false
+
+[dependencies.quote]
+version = "1.0.27"
+optional = true
+default-features = false
+
+[dependencies.unicode-ident]
+version = "1"
+
+[dev-dependencies.anyhow]
+version = "1"
+
+[dev-dependencies.automod]
+version = "1"
+
+[dev-dependencies.flate2]
+version = "1"
+
+[dev-dependencies.insta]
+version = "1"
+
+[dev-dependencies.rayon]
+version = "1"
+
+[dev-dependencies.ref-cast]
+version = "1"
+
+[dev-dependencies.regex]
+version = "1"
+
+[dev-dependencies.reqwest]
+version = "0.11"
+features = ["blocking"]
+
+[dev-dependencies.rustversion]
+version = "1"
+
+[dev-dependencies.tar]
+version = "0.4.16"
+
+[dev-dependencies.termcolor]
+version = "1"
+
+[dev-dependencies.walkdir]
+version = "2.3.2"
+
+[features]
+clone-impls = []
+default = [
+    "derive",
+    "parsing",
+    "printing",
+    "clone-impls",
+    "proc-macro",
+]
+derive = []
+extra-traits = []
+fold = []
+full = []
+parsing = []
+printing = ["quote"]
+proc-macro = [
+    "proc-macro2/proc-macro",
+    "quote/proc-macro",
+]
+visit = []
+visit-mut = []
+[[test]]
+name="regression"
+required-features = ["parsing", "full", "extra-traits"]
+[[test]]
+name="test_asyncness"
+required-features = ["full", "derive"]
+[[test]]
+name="test_attribute"
+required-features = ["full", "derive"]
+[[test]]
+name="test_derive_input"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_expr"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_generics"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_grouping"
+required-features = ["full", "derive"]
+[[test]]
+name="test_ident"
+required-features = ["parsing"]
+[[test]]
+name="test_item"
+required-features = ["full", "derive"]
+[[test]]
+name="test_iterators"
+required-features = ["full", "derive"]
+[[test]]
+name="test_lit"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_meta"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_parse_buffer"
+required-features = ["parsing"]
+[[test]]
+name="test_parse_stream"
+required-features = ["parsing"]
+[[test]]
+name="test_path"
+required-features = ["full", "derive"]
+[[test]]
+name="test_pat"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_receiver"
+required-features = ["full", "derive"]
+[[test]]
+name="test_shebang"
+required-features = ["full", "derive"]
+[[test]]
+name="test_should_parse"
+required-features = ["parsing", "full"]
+[[test]]
+name="test_size"
+required-features = ["full"]
+[[test]]
+name="test_stmt"
+required-features = ["full", "derive"]
+[[test]]
+name="test_token_trees"
+required-features = ["full", "derive"]
+[[test]]
+name="test_ty"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="test_visibility"
+required-features = ["full", "extra-traits", "derive"]
+[[test]]
+name="zzz_stable"
diff --git a/vendor/syn/LICENSE-APACHE b/vendor/syn/LICENSE-APACHE
new file mode 100644
index 0000000..1b5ec8b
--- /dev/null
+++ b/vendor/syn/LICENSE-APACHE
@@ -0,0 +1,176 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
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+6. Trademarks. This License does not grant permission to use the trade
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+END OF TERMS AND CONDITIONS
diff --git a/vendor/syn/LICENSE-MIT b/vendor/syn/LICENSE-MIT
new file mode 100644
index 0000000..31aa793
--- /dev/null
+++ b/vendor/syn/LICENSE-MIT
@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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diff --git a/vendor/syn/README.md b/vendor/syn/README.md
new file mode 100644
index 0000000..e8d99ab
--- /dev/null
+++ b/vendor/syn/README.md
@@ -0,0 +1,284 @@
+Parser for Rust source code
+===========================
+
+[<img alt="github" src="https://img.shields.io/badge/github-dtolnay/syn-8da0cb?style=for-the-badge&labelColor=555555&logo=github" height="20">](https://github.com/dtolnay/syn)
+[<img alt="crates.io" src="https://img.shields.io/crates/v/syn.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/syn)
+[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-syn-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs" height="20">](https://docs.rs/syn)
+[<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/dtolnay/syn/ci.yml?branch=master&style=for-the-badge" height="20">](https://github.com/dtolnay/syn/actions?query=branch%3Amaster)
+
+Syn is a parsing library for parsing a stream of Rust tokens into a syntax tree
+of Rust source code.
+
+Currently this library is geared toward use in Rust procedural macros, but
+contains some APIs that may be useful more generally.
+
+- **Data structures** — Syn provides a complete syntax tree that can represent
+  any valid Rust source code. The syntax tree is rooted at [`syn::File`] which
+  represents a full source file, but there are other entry points that may be
+  useful to procedural macros including [`syn::Item`], [`syn::Expr`] and
+  [`syn::Type`].
+
+- **Derives** — Of particular interest to derive macros is [`syn::DeriveInput`]
+  which is any of the three legal input items to a derive macro. An example
+  below shows using this type in a library that can derive implementations of a
+  user-defined trait.
+
+- **Parsing** — Parsing in Syn is built around [parser functions] with the
+  signature `fn(ParseStream) -> Result<T>`. Every syntax tree node defined by
+  Syn is individually parsable and may be used as a building block for custom
+  syntaxes, or you may dream up your own brand new syntax without involving any
+  of our syntax tree types.
+
+- **Location information** — Every token parsed by Syn is associated with a
+  `Span` that tracks line and column information back to the source of that
+  token. These spans allow a procedural macro to display detailed error messages
+  pointing to all the right places in the user's code. There is an example of
+  this below.
+
+- **Feature flags** — Functionality is aggressively feature gated so your
+  procedural macros enable only what they need, and do not pay in compile time
+  for all the rest.
+
+[`syn::File`]: https://docs.rs/syn/2.0/syn/struct.File.html
+[`syn::Item`]: https://docs.rs/syn/2.0/syn/enum.Item.html
+[`syn::Expr`]: https://docs.rs/syn/2.0/syn/enum.Expr.html
+[`syn::Type`]: https://docs.rs/syn/2.0/syn/enum.Type.html
+[`syn::DeriveInput`]: https://docs.rs/syn/2.0/syn/struct.DeriveInput.html
+[parser functions]: https://docs.rs/syn/2.0/syn/parse/index.html
+
+*Version requirement: Syn supports rustc 1.56 and up.*
+
+[*Release notes*](https://github.com/dtolnay/syn/releases)
+
+<br>
+
+## Resources
+
+The best way to learn about procedural macros is by writing some. Consider
+working through [this procedural macro workshop][workshop] to get familiar with
+the different types of procedural macros. The workshop contains relevant links
+into the Syn documentation as you work through each project.
+
+[workshop]: https://github.com/dtolnay/proc-macro-workshop
+
+<br>
+
+## Example of a derive macro
+
+The canonical derive macro using Syn looks like this. We write an ordinary Rust
+function tagged with a `proc_macro_derive` attribute and the name of the trait
+we are deriving. Any time that derive appears in the user's code, the Rust
+compiler passes their data structure as tokens into our macro. We get to execute
+arbitrary Rust code to figure out what to do with those tokens, then hand some
+tokens back to the compiler to compile into the user's crate.
+
+[`TokenStream`]: https://doc.rust-lang.org/proc_macro/struct.TokenStream.html
+
+```toml
+[dependencies]
+syn = "2.0"
+quote = "1.0"
+
+[lib]
+proc-macro = true
+```
+
+```rust
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput};
+
+#[proc_macro_derive(MyMacro)]
+pub fn my_macro(input: TokenStream) -> TokenStream {
+    // Parse the input tokens into a syntax tree
+    let input = parse_macro_input!(input as DeriveInput);
+
+    // Build the output, possibly using quasi-quotation
+    let expanded = quote! {
+        // ...
+    };
+
+    // Hand the output tokens back to the compiler
+    TokenStream::from(expanded)
+}
+```
+
+The [`heapsize`] example directory shows a complete working implementation of a
+derive macro. The example derives a `HeapSize` trait which computes an estimate
+of the amount of heap memory owned by a value.
+
+[`heapsize`]: examples/heapsize
+
+```rust
+pub trait HeapSize {
+    /// Total number of bytes of heap memory owned by `self`.
+    fn heap_size_of_children(&self) -> usize;
+}
+```
+
+The derive macro allows users to write `#[derive(HeapSize)]` on data structures
+in their program.
+
+```rust
+#[derive(HeapSize)]
+struct Demo<'a, T: ?Sized> {
+    a: Box<T>,
+    b: u8,
+    c: &'a str,
+    d: String,
+}
+```
+
+<br>
+
+## Spans and error reporting
+
+The token-based procedural macro API provides great control over where the
+compiler's error messages are displayed in user code. Consider the error the
+user sees if one of their field types does not implement `HeapSize`.
+
+```rust
+#[derive(HeapSize)]
+struct Broken {
+    ok: String,
+    bad: std::thread::Thread,
+}
+```
+
+By tracking span information all the way through the expansion of a procedural
+macro as shown in the `heapsize` example, token-based macros in Syn are able to
+trigger errors that directly pinpoint the source of the problem.
+
+```console
+error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied
+ --> src/main.rs:7:5
+  |
+7 |     bad: std::thread::Thread,
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HeapSize` is not implemented for `std::thread::Thread`
+```
+
+<br>
+
+## Parsing a custom syntax
+
+The [`lazy-static`] example directory shows the implementation of a
+`functionlike!(...)` procedural macro in which the input tokens are parsed using
+Syn's parsing API.
+
+[`lazy-static`]: examples/lazy-static
+
+The example reimplements the popular `lazy_static` crate from crates.io as a
+procedural macro.
+
+```rust
+lazy_static! {
+    static ref USERNAME: Regex = Regex::new("^[a-z0-9_-]{3,16}$").unwrap();
+}
+```
+
+The implementation shows how to trigger custom warnings and error messages on
+the macro input.
+
+```console
+warning: come on, pick a more creative name
+  --> src/main.rs:10:16
+   |
+10 |     static ref FOO: String = "lazy_static".to_owned();
+   |                ^^^
+```
+
+<br>
+
+## Testing
+
+When testing macros, we often care not just that the macro can be used
+successfully but also that when the macro is provided with invalid input it
+produces maximally helpful error messages. Consider using the [`trybuild`] crate
+to write tests for errors that are emitted by your macro or errors detected by
+the Rust compiler in the expanded code following misuse of the macro. Such tests
+help avoid regressions from later refactors that mistakenly make an error no
+longer trigger or be less helpful than it used to be.
+
+[`trybuild`]: https://github.com/dtolnay/trybuild
+
+<br>
+
+## Debugging
+
+When developing a procedural macro it can be helpful to look at what the
+generated code looks like. Use `cargo rustc -- -Zunstable-options
+--pretty=expanded` or the [`cargo expand`] subcommand.
+
+[`cargo expand`]: https://github.com/dtolnay/cargo-expand
+
+To show the expanded code for some crate that uses your procedural macro, run
+`cargo expand` from that crate. To show the expanded code for one of your own
+test cases, run `cargo expand --test the_test_case` where the last argument is
+the name of the test file without the `.rs` extension.
+
+This write-up by Brandon W Maister discusses debugging in more detail:
+[Debugging Rust's new Custom Derive system][debugging].
+
+[debugging]: https://quodlibetor.github.io/posts/debugging-rusts-new-custom-derive-system/
+
+<br>
+
+## Optional features
+
+Syn puts a lot of functionality behind optional features in order to optimize
+compile time for the most common use cases. The following features are
+available.
+
+- **`derive`** *(enabled by default)* — Data structures for representing the
+  possible input to a derive macro, including structs and enums and types.
+- **`full`** — Data structures for representing the syntax tree of all valid
+  Rust source code, including items and expressions.
+- **`parsing`** *(enabled by default)* — Ability to parse input tokens into a
+  syntax tree node of a chosen type.
+- **`printing`** *(enabled by default)* — Ability to print a syntax tree node as
+  tokens of Rust source code.
+- **`visit`** — Trait for traversing a syntax tree.
+- **`visit-mut`** — Trait for traversing and mutating in place a syntax tree.
+- **`fold`** — Trait for transforming an owned syntax tree.
+- **`clone-impls`** *(enabled by default)* — Clone impls for all syntax tree
+  types.
+- **`extra-traits`** — Debug, Eq, PartialEq, Hash impls for all syntax tree
+  types.
+- **`proc-macro`** *(enabled by default)* — Runtime dependency on the dynamic
+  library libproc_macro from rustc toolchain.
+
+<br>
+
+## Proc macro shim
+
+Syn operates on the token representation provided by the [proc-macro2] crate
+from crates.io rather than using the compiler's built in proc-macro crate
+directly. This enables code using Syn to execute outside of the context of a
+procedural macro, such as in unit tests or build.rs, and we avoid needing
+incompatible ecosystems for proc macros vs non-macro use cases.
+
+In general all of your code should be written against proc-macro2 rather than
+proc-macro. The one exception is in the signatures of procedural macro entry
+points, which are required by the language to use `proc_macro::TokenStream`.
+
+The proc-macro2 crate will automatically detect and use the compiler's data
+structures when a procedural macro is active.
+
+[proc-macro2]: https://docs.rs/proc-macro2/1.0/proc_macro2/
+
+<br>
+
+#### License
+
+<sup>
+Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
+2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
+</sup>
+
+<br>
+
+<sub>
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
+be dual licensed as above, without any additional terms or conditions.
+</sub>
diff --git a/vendor/syn/benches/file.rs b/vendor/syn/benches/file.rs
new file mode 100644
index 0000000..b424723
--- /dev/null
+++ b/vendor/syn/benches/file.rs
@@ -0,0 +1,57 @@
+// $ cargo bench --features full,test --bench file
+
+#![feature(rustc_private, test)]
+#![recursion_limit = "1024"]
+#![allow(
+    clippy::items_after_statements,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::missing_panics_doc,
+    clippy::must_use_candidate,
+    clippy::uninlined_format_args
+)]
+
+extern crate test;
+
+#[macro_use]
+#[path = "../tests/macros/mod.rs"]
+mod macros;
+
+#[allow(dead_code)]
+#[path = "../tests/repo/mod.rs"]
+mod repo;
+
+use proc_macro2::{Span, TokenStream};
+use std::fs;
+use std::str::FromStr;
+use syn::parse::{ParseStream, Parser};
+use test::Bencher;
+
+const FILE: &str = "tests/rust/library/core/src/str/mod.rs";
+
+fn get_tokens() -> TokenStream {
+    repo::clone_rust();
+    let content = fs::read_to_string(FILE).unwrap();
+    TokenStream::from_str(&content).unwrap()
+}
+
+#[bench]
+fn baseline(b: &mut Bencher) {
+    let tokens = get_tokens();
+    b.iter(|| drop(tokens.clone()));
+}
+
+#[bench]
+fn create_token_buffer(b: &mut Bencher) {
+    let tokens = get_tokens();
+    fn immediate_fail(_input: ParseStream) -> syn::Result<()> {
+        Err(syn::Error::new(Span::call_site(), ""))
+    }
+    b.iter(|| immediate_fail.parse2(tokens.clone()));
+}
+
+#[bench]
+fn parse_file(b: &mut Bencher) {
+    let tokens = get_tokens();
+    b.iter(|| syn::parse2::<syn::File>(tokens.clone()));
+}
diff --git a/vendor/syn/benches/rust.rs b/vendor/syn/benches/rust.rs
new file mode 100644
index 0000000..6439761
--- /dev/null
+++ b/vendor/syn/benches/rust.rs
@@ -0,0 +1,181 @@
+// $ cargo bench --features full,test --bench rust
+//
+// Syn only, useful for profiling:
+// $ RUSTFLAGS='--cfg syn_only' cargo build --release --features full,test --bench rust
+
+#![cfg_attr(not(syn_only), feature(rustc_private))]
+#![recursion_limit = "1024"]
+#![allow(
+    clippy::cast_lossless,
+    clippy::let_underscore_untyped,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::uninlined_format_args,
+    clippy::unnecessary_wraps
+)]
+
+#[macro_use]
+#[path = "../tests/macros/mod.rs"]
+mod macros;
+
+#[allow(dead_code)]
+#[path = "../tests/repo/mod.rs"]
+mod repo;
+
+use std::fs;
+use std::time::{Duration, Instant};
+
+#[cfg(not(syn_only))]
+mod tokenstream_parse {
+    use proc_macro2::TokenStream;
+    use std::str::FromStr;
+
+    pub fn bench(content: &str) -> Result<(), ()> {
+        TokenStream::from_str(content).map(drop).map_err(drop)
+    }
+}
+
+mod syn_parse {
+    pub fn bench(content: &str) -> Result<(), ()> {
+        syn::parse_file(content).map(drop).map_err(drop)
+    }
+}
+
+#[cfg(not(syn_only))]
+mod librustc_parse {
+    extern crate rustc_data_structures;
+    extern crate rustc_driver;
+    extern crate rustc_error_messages;
+    extern crate rustc_errors;
+    extern crate rustc_parse;
+    extern crate rustc_session;
+    extern crate rustc_span;
+
+    use rustc_data_structures::sync::Lrc;
+    use rustc_error_messages::FluentBundle;
+    use rustc_errors::{emitter::Emitter, translation::Translate, Diagnostic, Handler};
+    use rustc_session::parse::ParseSess;
+    use rustc_span::source_map::{FilePathMapping, SourceMap};
+    use rustc_span::{edition::Edition, FileName};
+
+    pub fn bench(content: &str) -> Result<(), ()> {
+        struct SilentEmitter;
+
+        impl Emitter for SilentEmitter {
+            fn emit_diagnostic(&mut self, _diag: &Diagnostic) {}
+            fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+                None
+            }
+        }
+
+        impl Translate for SilentEmitter {
+            fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+                None
+            }
+            fn fallback_fluent_bundle(&self) -> &FluentBundle {
+                panic!("silent emitter attempted to translate a diagnostic");
+            }
+        }
+
+        rustc_span::create_session_if_not_set_then(Edition::Edition2018, |_| {
+            let cm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let emitter = Box::new(SilentEmitter);
+            let handler = Handler::with_emitter(emitter);
+            let sess = ParseSess::with_span_handler(handler, cm);
+            if let Err(diagnostic) = rustc_parse::parse_crate_from_source_str(
+                FileName::Custom("bench".to_owned()),
+                content.to_owned(),
+                &sess,
+            ) {
+                diagnostic.cancel();
+                return Err(());
+            };
+            Ok(())
+        })
+    }
+}
+
+#[cfg(not(syn_only))]
+mod read_from_disk {
+    pub fn bench(content: &str) -> Result<(), ()> {
+        let _ = content;
+        Ok(())
+    }
+}
+
+fn exec(mut codepath: impl FnMut(&str) -> Result<(), ()>) -> Duration {
+    let begin = Instant::now();
+    let mut success = 0;
+    let mut total = 0;
+
+    ["tests/rust/compiler", "tests/rust/library"]
+        .iter()
+        .flat_map(|dir| {
+            walkdir::WalkDir::new(dir)
+                .into_iter()
+                .filter_entry(repo::base_dir_filter)
+        })
+        .for_each(|entry| {
+            let entry = entry.unwrap();
+            let path = entry.path();
+            if path.is_dir() {
+                return;
+            }
+            let content = fs::read_to_string(path).unwrap();
+            let ok = codepath(&content).is_ok();
+            success += ok as usize;
+            total += 1;
+            if !ok {
+                eprintln!("FAIL {}", path.display());
+            }
+        });
+
+    assert_eq!(success, total);
+    begin.elapsed()
+}
+
+fn main() {
+    repo::clone_rust();
+
+    macro_rules! testcases {
+        ($($(#[$cfg:meta])* $name:ident,)*) => {
+            [
+                $(
+                    $(#[$cfg])*
+                    (stringify!($name), $name::bench as fn(&str) -> Result<(), ()>),
+                )*
+            ]
+        };
+    }
+
+    #[cfg(not(syn_only))]
+    {
+        let mut lines = 0;
+        let mut files = 0;
+        exec(|content| {
+            lines += content.lines().count();
+            files += 1;
+            Ok(())
+        });
+        eprintln!("\n{} lines in {} files", lines, files);
+    }
+
+    for (name, f) in testcases!(
+        #[cfg(not(syn_only))]
+        read_from_disk,
+        #[cfg(not(syn_only))]
+        tokenstream_parse,
+        syn_parse,
+        #[cfg(not(syn_only))]
+        librustc_parse,
+    ) {
+        eprint!("{:20}", format!("{}:", name));
+        let elapsed = exec(f);
+        eprintln!(
+            "elapsed={}.{:03}s",
+            elapsed.as_secs(),
+            elapsed.subsec_millis(),
+        );
+    }
+    eprintln!();
+}
diff --git a/vendor/syn/debian/patches/fix-tests.diff b/vendor/syn/debian/patches/fix-tests.diff
new file mode 100644
index 0000000..e8d86c7
--- /dev/null
+++ b/vendor/syn/debian/patches/fix-tests.diff
@@ -0,0 +1,118 @@
+--- rust-syn-2.0.18.orig/Cargo.toml
++++ rust-syn-2.0.18/Cargo.toml
+@@ -36,6 +36,8 @@ categories = [
+ ]
+ license = "MIT OR Apache-2.0"
+ repository = "https://github.com/dtolnay/syn"
++autotests = false
++autobenches = false
+ 
+ [package.metadata.docs.rs]
+ all-features = true
+@@ -125,3 +127,77 @@ proc-macro = [
+ ]
+ visit = []
+ visit-mut = []
++[[test]]
++name="regression"
++required-features = ["parsing", "full", "extra-traits"]
++[[test]]
++name="test_asyncness"
++required-features = ["full", "derive"]
++[[test]]
++name="test_attribute"
++required-features = ["full", "derive"]
++[[test]]
++name="test_derive_input"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_expr"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_generics"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_grouping"
++required-features = ["full", "derive"]
++[[test]]
++name="test_ident"
++required-features = ["parsing"]
++[[test]]
++name="test_item"
++required-features = ["full", "derive"]
++[[test]]
++name="test_iterators"
++required-features = ["full", "derive"]
++[[test]]
++name="test_lit"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_meta"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_parse_buffer"
++required-features = ["parsing"]
++[[test]]
++name="test_parse_stream"
++required-features = ["parsing"]
++[[test]]
++name="test_path"
++required-features = ["full", "derive"]
++[[test]]
++name="test_pat"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_receiver"
++required-features = ["full", "derive"]
++[[test]]
++name="test_shebang"
++required-features = ["full", "derive"]
++[[test]]
++name="test_should_parse"
++required-features = ["parsing", "full"]
++[[test]]
++name="test_size"
++required-features = ["full"]
++[[test]]
++name="test_stmt"
++required-features = ["full", "derive"]
++[[test]]
++name="test_token_trees"
++required-features = ["full", "derive"]
++[[test]]
++name="test_ty"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="test_visibility"
++required-features = ["full", "extra-traits", "derive"]
++[[test]]
++name="zzz_stable"
+--- rust-syn-2.0.18.orig/tests/repo/mod.rs
++++ rust-syn-2.0.18/tests/repo/mod.rs
+@@ -272,7 +272,7 @@ pub fn edition(path: &Path) -> &'static
+     }
+ }
+ 
+-pub fn clone_rust() {
++/*pub fn clone_rust() {
+     let needs_clone = match fs::read_to_string("tests/rust/COMMIT") {
+         Err(_) => true,
+         Ok(contents) => contents.trim() != REVISION,
+@@ -298,9 +298,9 @@ pub fn clone_rust() {
+     if !missing.is_empty() {
+         panic!("excluded test file does not exist:{}\n", missing);
+     }
+-}
++}*/
+ 
+-fn download_and_unpack() -> Result<()> {
++/*fn download_and_unpack() -> Result<()> {
+     let url = format!(
+         "https://github.com/rust-lang/rust/archive/{}.tar.gz",
+         REVISION
+@@ -329,4 +329,4 @@ fn download_and_unpack() -> Result<()> {
+ 
+     fs::write("tests/rust/COMMIT", REVISION)?;
+     Ok(())
+-}
++}*/
diff --git a/vendor/syn/debian/patches/relax-deps.diff b/vendor/syn/debian/patches/relax-deps.diff
new file mode 100644
index 0000000..03d8912
--- /dev/null
+++ b/vendor/syn/debian/patches/relax-deps.diff
@@ -0,0 +1,39 @@
+--- a/Cargo.toml
++++ b/Cargo.toml
+@@ -18,3 +18,2 @@
+ include = [
+-    "/benches/**",
+     "/Cargo.toml",
+@@ -57,10 +56,0 @@
+-[lib]
+-doc-scrape-examples = false
+-
+-[[bench]]
+-name = "rust"
+-harness = false
+-required-features = [
+-    "full",
+-    "parsing",
+-]
+@@ -70,6 +70,0 @@
+-[[bench]]
+-name = "file"
+-required-features = [
+-    "full",
+-    "parsing",
+-]
+@@ -90,3 +90,3 @@
+ [dependencies.quote]
+-version = "1.0.28"
++version = "1.0.27"
+ optional = true
+@@ -115,5 +97,2 @@
+ 
+-[dev-dependencies.syn-test-suite]
+-version = "0"
+-
+ [dev-dependencies.tar]
+@@ -146,3 +125,2 @@
+ ]
+-test = ["syn-test-suite/all-features"]
+ visit = []
diff --git a/vendor/syn/debian/patches/series b/vendor/syn/debian/patches/series
new file mode 100644
index 0000000..c28cbd3
--- /dev/null
+++ b/vendor/syn/debian/patches/series
@@ -0,0 +1,2 @@
+relax-deps.diff
+fix-tests.diff
diff --git a/vendor/syn/src/attr.rs b/vendor/syn/src/attr.rs
new file mode 100644
index 0000000..34d5515
--- /dev/null
+++ b/vendor/syn/src/attr.rs
@@ -0,0 +1,776 @@
+use super::*;
+use proc_macro2::TokenStream;
+use std::iter;
+use std::slice;
+
+#[cfg(feature = "parsing")]
+use crate::meta::{self, ParseNestedMeta};
+#[cfg(feature = "parsing")]
+use crate::parse::{Parse, ParseStream, Parser, Result};
+
+ast_struct! {
+    /// An attribute, like `#[repr(transparent)]`.
+    ///
+    /// <br>
+    ///
+    /// # Syntax
+    ///
+    /// Rust has six types of attributes.
+    ///
+    /// - Outer attributes like `#[repr(transparent)]`. These appear outside or
+    ///   in front of the item they describe.
+    ///
+    /// - Inner attributes like `#![feature(proc_macro)]`. These appear inside
+    ///   of the item they describe, usually a module.
+    ///
+    /// - Outer one-line doc comments like `/// Example`.
+    ///
+    /// - Inner one-line doc comments like `//! Please file an issue`.
+    ///
+    /// - Outer documentation blocks `/** Example */`.
+    ///
+    /// - Inner documentation blocks `/*! Please file an issue */`.
+    ///
+    /// The `style` field of type `AttrStyle` distinguishes whether an attribute
+    /// is outer or inner.
+    ///
+    /// Every attribute has a `path` that indicates the intended interpretation
+    /// of the rest of the attribute's contents. The path and the optional
+    /// additional contents are represented together in the `meta` field of the
+    /// attribute in three possible varieties:
+    ///
+    /// - Meta::Path &mdash; attributes whose information content conveys just a
+    ///   path, for example the `#[test]` attribute.
+    ///
+    /// - Meta::List &mdash; attributes that carry arbitrary tokens after the
+    ///   path, surrounded by a delimiter (parenthesis, bracket, or brace). For
+    ///   example `#[derive(Copy)]` or `#[precondition(x < 5)]`.
+    ///
+    /// - Meta::NameValue &mdash; attributes with an `=` sign after the path,
+    ///   followed by a Rust expression. For example `#[path =
+    ///   "sys/windows.rs"]`.
+    ///
+    /// All doc comments are represented in the NameValue style with a path of
+    /// "doc", as this is how they are processed by the compiler and by
+    /// `macro_rules!` macros.
+    ///
+    /// ```text
+    /// #[derive(Copy, Clone)]
+    ///   ~~~~~~Path
+    ///   ^^^^^^^^^^^^^^^^^^^Meta::List
+    ///
+    /// #[path = "sys/windows.rs"]
+    ///   ~~~~Path
+    ///   ^^^^^^^^^^^^^^^^^^^^^^^Meta::NameValue
+    ///
+    /// #[test]
+    ///   ^^^^Meta::Path
+    /// ```
+    ///
+    /// <br>
+    ///
+    /// # Parsing from tokens to Attribute
+    ///
+    /// This type does not implement the [`Parse`] trait and thus cannot be
+    /// parsed directly by [`ParseStream::parse`]. Instead use
+    /// [`ParseStream::call`] with one of the two parser functions
+    /// [`Attribute::parse_outer`] or [`Attribute::parse_inner`] depending on
+    /// which you intend to parse.
+    ///
+    /// [`Parse`]: parse::Parse
+    /// [`ParseStream::parse`]: parse::ParseBuffer::parse
+    /// [`ParseStream::call`]: parse::ParseBuffer::call
+    ///
+    /// ```
+    /// use syn::{Attribute, Ident, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // Parses a unit struct with attributes.
+    /// //
+    /// //     #[path = "s.tmpl"]
+    /// //     struct S;
+    /// struct UnitStruct {
+    ///     attrs: Vec<Attribute>,
+    ///     struct_token: Token![struct],
+    ///     name: Ident,
+    ///     semi_token: Token![;],
+    /// }
+    ///
+    /// impl Parse for UnitStruct {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         Ok(UnitStruct {
+    ///             attrs: input.call(Attribute::parse_outer)?,
+    ///             struct_token: input.parse()?,
+    ///             name: input.parse()?,
+    ///             semi_token: input.parse()?,
+    ///         })
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// <p><br></p>
+    ///
+    /// # Parsing from Attribute to structured arguments
+    ///
+    /// The grammar of attributes in Rust is very flexible, which makes the
+    /// syntax tree not that useful on its own. In particular, arguments of the
+    /// `Meta::List` variety of attribute are held in an arbitrary `tokens:
+    /// TokenStream`. Macros are expected to check the `path` of the attribute,
+    /// decide whether they recognize it, and then parse the remaining tokens
+    /// according to whatever grammar they wish to require for that kind of
+    /// attribute. Use [`parse_args()`] to parse those tokens into the expected
+    /// data structure.
+    ///
+    /// [`parse_args()`]: Attribute::parse_args
+    ///
+    /// <p><br></p>
+    ///
+    /// # Doc comments
+    ///
+    /// The compiler transforms doc comments, such as `/// comment` and `/*!
+    /// comment */`, into attributes before macros are expanded. Each comment is
+    /// expanded into an attribute of the form `#[doc = r"comment"]`.
+    ///
+    /// As an example, the following `mod` items are expanded identically:
+    ///
+    /// ```
+    /// # use syn::{ItemMod, parse_quote};
+    /// let doc: ItemMod = parse_quote! {
+    ///     /// Single line doc comments
+    ///     /// We write so many!
+    ///     /**
+    ///      * Multi-line comments...
+    ///      * May span many lines
+    ///      */
+    ///     mod example {
+    ///         //! Of course, they can be inner too
+    ///         /*! And fit in a single line */
+    ///     }
+    /// };
+    /// let attr: ItemMod = parse_quote! {
+    ///     #[doc = r" Single line doc comments"]
+    ///     #[doc = r" We write so many!"]
+    ///     #[doc = r"
+    ///      * Multi-line comments...
+    ///      * May span many lines
+    ///      "]
+    ///     mod example {
+    ///         #![doc = r" Of course, they can be inner too"]
+    ///         #![doc = r" And fit in a single line "]
+    ///     }
+    /// };
+    /// assert_eq!(doc, attr);
+    /// ```
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Attribute {
+        pub pound_token: Token![#],
+        pub style: AttrStyle,
+        pub bracket_token: token::Bracket,
+        pub meta: Meta,
+    }
+}
+
+impl Attribute {
+    /// Returns the path that identifies the interpretation of this attribute.
+    ///
+    /// For example this would return the `test` in `#[test]`, the `derive` in
+    /// `#[derive(Copy)]`, and the `path` in `#[path = "sys/windows.rs"]`.
+    pub fn path(&self) -> &Path {
+        self.meta.path()
+    }
+
+    /// Parse the arguments to the attribute as a syntax tree.
+    ///
+    /// This is similar to pulling out the `TokenStream` from `Meta::List` and
+    /// doing `syn::parse2::<T>(meta_list.tokens)`, except that using
+    /// `parse_args` the error message has a more useful span when `tokens` is
+    /// empty.
+    ///
+    /// The surrounding delimiters are *not* included in the input to the
+    /// parser.
+    ///
+    /// ```text
+    /// #[my_attr(value < 5)]
+    ///           ^^^^^^^^^ what gets parsed
+    /// ```
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{parse_quote, Attribute, Expr};
+    ///
+    /// let attr: Attribute = parse_quote! {
+    ///     #[precondition(value < 5)]
+    /// };
+    ///
+    /// if attr.path().is_ident("precondition") {
+    ///     let precondition: Expr = attr.parse_args()?;
+    ///     // ...
+    /// }
+    /// # anyhow::Ok(())
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_args<T: Parse>(&self) -> Result<T> {
+        self.parse_args_with(T::parse)
+    }
+
+    /// Parse the arguments to the attribute using the given parser.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{parse_quote, Attribute};
+    ///
+    /// let attr: Attribute = parse_quote! {
+    ///     #[inception { #[brrrrrrraaaaawwwwrwrrrmrmrmmrmrmmmmm] }]
+    /// };
+    ///
+    /// let bwom = attr.parse_args_with(Attribute::parse_outer)?;
+    ///
+    /// // Attribute does not have a Parse impl, so we couldn't directly do:
+    /// // let bwom: Attribute = attr.parse_args()?;
+    /// # anyhow::Ok(())
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_args_with<F: Parser>(&self, parser: F) -> Result<F::Output> {
+        match &self.meta {
+            Meta::Path(path) => Err(crate::error::new2(
+                path.segments.first().unwrap().ident.span(),
+                path.segments.last().unwrap().ident.span(),
+                format!(
+                    "expected attribute arguments in parentheses: {}[{}(...)]",
+                    parsing::DisplayAttrStyle(&self.style),
+                    parsing::DisplayPath(path),
+                ),
+            )),
+            Meta::NameValue(meta) => Err(Error::new(
+                meta.eq_token.span,
+                format_args!(
+                    "expected parentheses: {}[{}(...)]",
+                    parsing::DisplayAttrStyle(&self.style),
+                    parsing::DisplayPath(&meta.path),
+                ),
+            )),
+            Meta::List(meta) => meta.parse_args_with(parser),
+        }
+    }
+
+    /// Parse the arguments to the attribute, expecting it to follow the
+    /// conventional structure used by most of Rust's built-in attributes.
+    ///
+    /// The [*Meta Item Attribute Syntax*][syntax] section in the Rust reference
+    /// explains the convention in more detail. Not all attributes follow this
+    /// convention, so [`parse_args()`][Self::parse_args] is available if you
+    /// need to parse arbitrarily goofy attribute syntax.
+    ///
+    /// [syntax]: https://doc.rust-lang.org/reference/attributes.html#meta-item-attribute-syntax
+    ///
+    /// # Example
+    ///
+    /// We'll parse a struct, and then parse some of Rust's `#[repr]` attribute
+    /// syntax.
+    ///
+    /// ```
+    /// use syn::{parenthesized, parse_quote, token, ItemStruct, LitInt};
+    ///
+    /// let input: ItemStruct = parse_quote! {
+    ///     #[repr(C, align(4))]
+    ///     pub struct MyStruct(u16, u32);
+    /// };
+    ///
+    /// let mut repr_c = false;
+    /// let mut repr_transparent = false;
+    /// let mut repr_align = None::<usize>;
+    /// let mut repr_packed = None::<usize>;
+    /// for attr in &input.attrs {
+    ///     if attr.path().is_ident("repr") {
+    ///         attr.parse_nested_meta(|meta| {
+    ///             // #[repr(C)]
+    ///             if meta.path.is_ident("C") {
+    ///                 repr_c = true;
+    ///                 return Ok(());
+    ///             }
+    ///
+    ///             // #[repr(transparent)]
+    ///             if meta.path.is_ident("transparent") {
+    ///                 repr_transparent = true;
+    ///                 return Ok(());
+    ///             }
+    ///
+    ///             // #[repr(align(N))]
+    ///             if meta.path.is_ident("align") {
+    ///                 let content;
+    ///                 parenthesized!(content in meta.input);
+    ///                 let lit: LitInt = content.parse()?;
+    ///                 let n: usize = lit.base10_parse()?;
+    ///                 repr_align = Some(n);
+    ///                 return Ok(());
+    ///             }
+    ///
+    ///             // #[repr(packed)] or #[repr(packed(N))], omitted N means 1
+    ///             if meta.path.is_ident("packed") {
+    ///                 if meta.input.peek(token::Paren) {
+    ///                     let content;
+    ///                     parenthesized!(content in meta.input);
+    ///                     let lit: LitInt = content.parse()?;
+    ///                     let n: usize = lit.base10_parse()?;
+    ///                     repr_packed = Some(n);
+    ///                 } else {
+    ///                     repr_packed = Some(1);
+    ///                 }
+    ///                 return Ok(());
+    ///             }
+    ///
+    ///             Err(meta.error("unrecognized repr"))
+    ///         })?;
+    ///     }
+    /// }
+    /// # anyhow::Ok(())
+    /// ```
+    ///
+    /// # Alternatives
+    ///
+    /// In some cases, for attributes which have nested layers of structured
+    /// content, the following less flexible approach might be more convenient:
+    ///
+    /// ```
+    /// # use syn::{parse_quote, ItemStruct};
+    /// #
+    /// # let input: ItemStruct = parse_quote! {
+    /// #     #[repr(C, align(4))]
+    /// #     pub struct MyStruct(u16, u32);
+    /// # };
+    /// #
+    /// use syn::punctuated::Punctuated;
+    /// use syn::{parenthesized, token, Error, LitInt, Meta, Token};
+    ///
+    /// let mut repr_c = false;
+    /// let mut repr_transparent = false;
+    /// let mut repr_align = None::<usize>;
+    /// let mut repr_packed = None::<usize>;
+    /// for attr in &input.attrs {
+    ///     if attr.path().is_ident("repr") {
+    ///         let nested = attr.parse_args_with(Punctuated::<Meta, Token![,]>::parse_terminated)?;
+    ///         for meta in nested {
+    ///             match meta {
+    ///                 // #[repr(C)]
+    ///                 Meta::Path(path) if path.is_ident("C") => {
+    ///                     repr_c = true;
+    ///                 }
+    ///
+    ///                 // #[repr(align(N))]
+    ///                 Meta::List(meta) if meta.path.is_ident("align") => {
+    ///                     let lit: LitInt = meta.parse_args()?;
+    ///                     let n: usize = lit.base10_parse()?;
+    ///                     repr_align = Some(n);
+    ///                 }
+    ///
+    ///                 /* ... */
+    ///
+    ///                 _ => {
+    ///                     return Err(Error::new_spanned(meta, "unrecognized repr"));
+    ///                 }
+    ///             }
+    ///         }
+    ///     }
+    /// }
+    /// # Ok(())
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_nested_meta(
+        &self,
+        logic: impl FnMut(ParseNestedMeta) -> Result<()>,
+    ) -> Result<()> {
+        self.parse_args_with(meta::parser(logic))
+    }
+
+    /// Parses zero or more outer attributes from the stream.
+    ///
+    /// # Example
+    ///
+    /// See
+    /// [*Parsing from tokens to Attribute*](#parsing-from-tokens-to-attribute).
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_outer(input: ParseStream) -> Result<Vec<Self>> {
+        let mut attrs = Vec::new();
+        while input.peek(Token![#]) {
+            attrs.push(input.call(parsing::single_parse_outer)?);
+        }
+        Ok(attrs)
+    }
+
+    /// Parses zero or more inner attributes from the stream.
+    ///
+    /// # Example
+    ///
+    /// See
+    /// [*Parsing from tokens to Attribute*](#parsing-from-tokens-to-attribute).
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_inner(input: ParseStream) -> Result<Vec<Self>> {
+        let mut attrs = Vec::new();
+        parsing::parse_inner(input, &mut attrs)?;
+        Ok(attrs)
+    }
+}
+
+ast_enum! {
+    /// Distinguishes between attributes that decorate an item and attributes
+    /// that are contained within an item.
+    ///
+    /// # Outer attributes
+    ///
+    /// - `#[repr(transparent)]`
+    /// - `/// # Example`
+    /// - `/** Please file an issue */`
+    ///
+    /// # Inner attributes
+    ///
+    /// - `#![feature(proc_macro)]`
+    /// - `//! # Example`
+    /// - `/*! Please file an issue */`
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum AttrStyle {
+        Outer,
+        Inner(Token![!]),
+    }
+}
+
+ast_enum_of_structs! {
+    /// Content of a compile-time structured attribute.
+    ///
+    /// ## Path
+    ///
+    /// A meta path is like the `test` in `#[test]`.
+    ///
+    /// ## List
+    ///
+    /// A meta list is like the `derive(Copy)` in `#[derive(Copy)]`.
+    ///
+    /// ## NameValue
+    ///
+    /// A name-value meta is like the `path = "..."` in `#[path =
+    /// "sys/windows.rs"]`.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum Meta {
+        Path(Path),
+
+        /// A structured list within an attribute, like `derive(Copy, Clone)`.
+        List(MetaList),
+
+        /// A name-value pair within an attribute, like `feature = "nightly"`.
+        NameValue(MetaNameValue),
+    }
+}
+
+ast_struct! {
+    /// A structured list within an attribute, like `derive(Copy, Clone)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct MetaList {
+        pub path: Path,
+        pub delimiter: MacroDelimiter,
+        pub tokens: TokenStream,
+    }
+}
+
+ast_struct! {
+    /// A name-value pair within an attribute, like `feature = "nightly"`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct MetaNameValue {
+        pub path: Path,
+        pub eq_token: Token![=],
+        pub value: Expr,
+    }
+}
+
+impl Meta {
+    /// Returns the path that begins this structured meta item.
+    ///
+    /// For example this would return the `test` in `#[test]`, the `derive` in
+    /// `#[derive(Copy)]`, and the `path` in `#[path = "sys/windows.rs"]`.
+    pub fn path(&self) -> &Path {
+        match self {
+            Meta::Path(path) => path,
+            Meta::List(meta) => &meta.path,
+            Meta::NameValue(meta) => &meta.path,
+        }
+    }
+
+    /// Error if this is a `Meta::List` or `Meta::NameValue`.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn require_path_only(&self) -> Result<&Path> {
+        let error_span = match self {
+            Meta::Path(path) => return Ok(path),
+            Meta::List(meta) => meta.delimiter.span().open(),
+            Meta::NameValue(meta) => meta.eq_token.span,
+        };
+        Err(Error::new(error_span, "unexpected token in attribute"))
+    }
+
+    /// Error if this is a `Meta::Path` or `Meta::NameValue`.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn require_list(&self) -> Result<&MetaList> {
+        match self {
+            Meta::List(meta) => Ok(meta),
+            Meta::Path(path) => Err(crate::error::new2(
+                path.segments.first().unwrap().ident.span(),
+                path.segments.last().unwrap().ident.span(),
+                format!(
+                    "expected attribute arguments in parentheses: `{}(...)`",
+                    parsing::DisplayPath(path),
+                ),
+            )),
+            Meta::NameValue(meta) => Err(Error::new(meta.eq_token.span, "expected `(`")),
+        }
+    }
+
+    /// Error if this is a `Meta::Path` or `Meta::List`.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn require_name_value(&self) -> Result<&MetaNameValue> {
+        match self {
+            Meta::NameValue(meta) => Ok(meta),
+            Meta::Path(path) => Err(crate::error::new2(
+                path.segments.first().unwrap().ident.span(),
+                path.segments.last().unwrap().ident.span(),
+                format!(
+                    "expected a value for this attribute: `{} = ...`",
+                    parsing::DisplayPath(path),
+                ),
+            )),
+            Meta::List(meta) => Err(Error::new(meta.delimiter.span().open(), "expected `=`")),
+        }
+    }
+}
+
+impl MetaList {
+    /// See [`Attribute::parse_args`].
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_args<T: Parse>(&self) -> Result<T> {
+        self.parse_args_with(T::parse)
+    }
+
+    /// See [`Attribute::parse_args_with`].
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_args_with<F: Parser>(&self, parser: F) -> Result<F::Output> {
+        let scope = self.delimiter.span().close();
+        crate::parse::parse_scoped(parser, scope, self.tokens.clone())
+    }
+
+    /// See [`Attribute::parse_nested_meta`].
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_nested_meta(
+        &self,
+        logic: impl FnMut(ParseNestedMeta) -> Result<()>,
+    ) -> Result<()> {
+        self.parse_args_with(meta::parser(logic))
+    }
+}
+
+pub(crate) trait FilterAttrs<'a> {
+    type Ret: Iterator<Item = &'a Attribute>;
+
+    fn outer(self) -> Self::Ret;
+    fn inner(self) -> Self::Ret;
+}
+
+impl<'a> FilterAttrs<'a> for &'a [Attribute] {
+    type Ret = iter::Filter<slice::Iter<'a, Attribute>, fn(&&Attribute) -> bool>;
+
+    fn outer(self) -> Self::Ret {
+        fn is_outer(attr: &&Attribute) -> bool {
+            match attr.style {
+                AttrStyle::Outer => true,
+                AttrStyle::Inner(_) => false,
+            }
+        }
+        self.iter().filter(is_outer)
+    }
+
+    fn inner(self) -> Self::Ret {
+        fn is_inner(attr: &&Attribute) -> bool {
+            match attr.style {
+                AttrStyle::Inner(_) => true,
+                AttrStyle::Outer => false,
+            }
+        }
+        self.iter().filter(is_inner)
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::discouraged::Speculative;
+    use crate::parse::{Parse, ParseStream, Result};
+    use std::fmt::{self, Display};
+
+    pub(crate) fn parse_inner(input: ParseStream, attrs: &mut Vec<Attribute>) -> Result<()> {
+        while input.peek(Token![#]) && input.peek2(Token![!]) {
+            attrs.push(input.call(parsing::single_parse_inner)?);
+        }
+        Ok(())
+    }
+
+    pub(crate) fn single_parse_inner(input: ParseStream) -> Result<Attribute> {
+        let content;
+        Ok(Attribute {
+            pound_token: input.parse()?,
+            style: AttrStyle::Inner(input.parse()?),
+            bracket_token: bracketed!(content in input),
+            meta: content.parse()?,
+        })
+    }
+
+    pub(crate) fn single_parse_outer(input: ParseStream) -> Result<Attribute> {
+        let content;
+        Ok(Attribute {
+            pound_token: input.parse()?,
+            style: AttrStyle::Outer,
+            bracket_token: bracketed!(content in input),
+            meta: content.parse()?,
+        })
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Meta {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let path = input.call(Path::parse_mod_style)?;
+            parse_meta_after_path(path, input)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for MetaList {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let path = input.call(Path::parse_mod_style)?;
+            parse_meta_list_after_path(path, input)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for MetaNameValue {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let path = input.call(Path::parse_mod_style)?;
+            parse_meta_name_value_after_path(path, input)
+        }
+    }
+
+    pub(crate) fn parse_meta_after_path(path: Path, input: ParseStream) -> Result<Meta> {
+        if input.peek(token::Paren) || input.peek(token::Bracket) || input.peek(token::Brace) {
+            parse_meta_list_after_path(path, input).map(Meta::List)
+        } else if input.peek(Token![=]) {
+            parse_meta_name_value_after_path(path, input).map(Meta::NameValue)
+        } else {
+            Ok(Meta::Path(path))
+        }
+    }
+
+    fn parse_meta_list_after_path(path: Path, input: ParseStream) -> Result<MetaList> {
+        let (delimiter, tokens) = mac::parse_delimiter(input)?;
+        Ok(MetaList {
+            path,
+            delimiter,
+            tokens,
+        })
+    }
+
+    fn parse_meta_name_value_after_path(path: Path, input: ParseStream) -> Result<MetaNameValue> {
+        let eq_token: Token![=] = input.parse()?;
+        let ahead = input.fork();
+        let lit: Option<Lit> = ahead.parse()?;
+        let value = if let (Some(lit), true) = (lit, ahead.is_empty()) {
+            input.advance_to(&ahead);
+            Expr::Lit(ExprLit {
+                attrs: Vec::new(),
+                lit,
+            })
+        } else if input.peek(Token![#]) && input.peek2(token::Bracket) {
+            return Err(input.error("unexpected attribute inside of attribute"));
+        } else {
+            input.parse()?
+        };
+        Ok(MetaNameValue {
+            path,
+            eq_token,
+            value,
+        })
+    }
+
+    pub(super) struct DisplayAttrStyle<'a>(pub &'a AttrStyle);
+
+    impl<'a> Display for DisplayAttrStyle<'a> {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            formatter.write_str(match self.0 {
+                AttrStyle::Outer => "#",
+                AttrStyle::Inner(_) => "#!",
+            })
+        }
+    }
+
+    pub(super) struct DisplayPath<'a>(pub &'a Path);
+
+    impl<'a> Display for DisplayPath<'a> {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            for (i, segment) in self.0.segments.iter().enumerate() {
+                if i > 0 || self.0.leading_colon.is_some() {
+                    formatter.write_str("::")?;
+                }
+                write!(formatter, "{}", segment.ident)?;
+            }
+            Ok(())
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Attribute {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.pound_token.to_tokens(tokens);
+            if let AttrStyle::Inner(b) = &self.style {
+                b.to_tokens(tokens);
+            }
+            self.bracket_token.surround(tokens, |tokens| {
+                self.meta.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for MetaList {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.path.to_tokens(tokens);
+            self.delimiter.surround(tokens, self.tokens.clone());
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for MetaNameValue {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.path.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.value.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/bigint.rs b/vendor/syn/src/bigint.rs
new file mode 100644
index 0000000..66aaa93
--- /dev/null
+++ b/vendor/syn/src/bigint.rs
@@ -0,0 +1,66 @@
+use std::ops::{AddAssign, MulAssign};
+
+// For implementing base10_digits() accessor on LitInt.
+pub(crate) struct BigInt {
+    digits: Vec<u8>,
+}
+
+impl BigInt {
+    pub(crate) fn new() -> Self {
+        BigInt { digits: Vec::new() }
+    }
+
+    pub(crate) fn to_string(&self) -> String {
+        let mut repr = String::with_capacity(self.digits.len());
+
+        let mut has_nonzero = false;
+        for digit in self.digits.iter().rev() {
+            has_nonzero |= *digit != 0;
+            if has_nonzero {
+                repr.push((*digit + b'0') as char);
+            }
+        }
+
+        if repr.is_empty() {
+            repr.push('0');
+        }
+
+        repr
+    }
+
+    fn reserve_two_digits(&mut self) {
+        let len = self.digits.len();
+        let desired =
+            len + !self.digits.ends_with(&[0, 0]) as usize + !self.digits.ends_with(&[0]) as usize;
+        self.digits.resize(desired, 0);
+    }
+}
+
+impl AddAssign<u8> for BigInt {
+    // Assumes increment <16.
+    fn add_assign(&mut self, mut increment: u8) {
+        self.reserve_two_digits();
+
+        let mut i = 0;
+        while increment > 0 {
+            let sum = self.digits[i] + increment;
+            self.digits[i] = sum % 10;
+            increment = sum / 10;
+            i += 1;
+        }
+    }
+}
+
+impl MulAssign<u8> for BigInt {
+    // Assumes base <=16.
+    fn mul_assign(&mut self, base: u8) {
+        self.reserve_two_digits();
+
+        let mut carry = 0;
+        for digit in &mut self.digits {
+            let prod = *digit * base + carry;
+            *digit = prod % 10;
+            carry = prod / 10;
+        }
+    }
+}
diff --git a/vendor/syn/src/buffer.rs b/vendor/syn/src/buffer.rs
new file mode 100644
index 0000000..564ccc7
--- /dev/null
+++ b/vendor/syn/src/buffer.rs
@@ -0,0 +1,433 @@
+//! A stably addressed token buffer supporting efficient traversal based on a
+//! cheaply copyable cursor.
+
+// This module is heavily commented as it contains most of the unsafe code in
+// Syn, and caution should be used when editing it. The public-facing interface
+// is 100% safe but the implementation is fragile internally.
+
+use crate::Lifetime;
+use proc_macro2::extra::DelimSpan;
+use proc_macro2::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
+use std::cmp::Ordering;
+use std::marker::PhantomData;
+
+/// Internal type which is used instead of `TokenTree` to represent a token tree
+/// within a `TokenBuffer`.
+enum Entry {
+    // Mimicking types from proc-macro.
+    // Group entries contain the offset to the matching End entry.
+    Group(Group, usize),
+    Ident(Ident),
+    Punct(Punct),
+    Literal(Literal),
+    // End entries contain the offset (negative) to the start of the buffer.
+    End(isize),
+}
+
+/// A buffer that can be efficiently traversed multiple times, unlike
+/// `TokenStream` which requires a deep copy in order to traverse more than
+/// once.
+pub struct TokenBuffer {
+    // NOTE: Do not implement clone on this - while the current design could be
+    // cloned, other designs which could be desirable may not be cloneable.
+    entries: Box<[Entry]>,
+}
+
+impl TokenBuffer {
+    fn recursive_new(entries: &mut Vec<Entry>, stream: TokenStream) {
+        for tt in stream {
+            match tt {
+                TokenTree::Ident(ident) => entries.push(Entry::Ident(ident)),
+                TokenTree::Punct(punct) => entries.push(Entry::Punct(punct)),
+                TokenTree::Literal(literal) => entries.push(Entry::Literal(literal)),
+                TokenTree::Group(group) => {
+                    let group_start_index = entries.len();
+                    entries.push(Entry::End(0)); // we replace this below
+                    Self::recursive_new(entries, group.stream());
+                    let group_end_index = entries.len();
+                    entries.push(Entry::End(-(group_end_index as isize)));
+                    let group_end_offset = group_end_index - group_start_index;
+                    entries[group_start_index] = Entry::Group(group, group_end_offset);
+                }
+            }
+        }
+    }
+
+    /// Creates a `TokenBuffer` containing all the tokens from the input
+    /// `proc_macro::TokenStream`.
+    #[cfg(feature = "proc-macro")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "proc-macro")))]
+    pub fn new(stream: proc_macro::TokenStream) -> Self {
+        Self::new2(stream.into())
+    }
+
+    /// Creates a `TokenBuffer` containing all the tokens from the input
+    /// `proc_macro2::TokenStream`.
+    pub fn new2(stream: TokenStream) -> Self {
+        let mut entries = Vec::new();
+        Self::recursive_new(&mut entries, stream);
+        entries.push(Entry::End(-(entries.len() as isize)));
+        Self {
+            entries: entries.into_boxed_slice(),
+        }
+    }
+
+    /// Creates a cursor referencing the first token in the buffer and able to
+    /// traverse until the end of the buffer.
+    pub fn begin(&self) -> Cursor {
+        let ptr = self.entries.as_ptr();
+        unsafe { Cursor::create(ptr, ptr.add(self.entries.len() - 1)) }
+    }
+}
+
+/// A cheaply copyable cursor into a `TokenBuffer`.
+///
+/// This cursor holds a shared reference into the immutable data which is used
+/// internally to represent a `TokenStream`, and can be efficiently manipulated
+/// and copied around.
+///
+/// An empty `Cursor` can be created directly, or one may create a `TokenBuffer`
+/// object and get a cursor to its first token with `begin()`.
+pub struct Cursor<'a> {
+    // The current entry which the `Cursor` is pointing at.
+    ptr: *const Entry,
+    // This is the only `Entry::End` object which this cursor is allowed to
+    // point at. All other `End` objects are skipped over in `Cursor::create`.
+    scope: *const Entry,
+    // Cursor is covariant in 'a. This field ensures that our pointers are still
+    // valid.
+    marker: PhantomData<&'a Entry>,
+}
+
+impl<'a> Cursor<'a> {
+    /// Creates a cursor referencing a static empty TokenStream.
+    pub fn empty() -> Self {
+        // It's safe in this situation for us to put an `Entry` object in global
+        // storage, despite it not actually being safe to send across threads
+        // (`Ident` is a reference into a thread-local table). This is because
+        // this entry never includes a `Ident` object.
+        //
+        // This wrapper struct allows us to break the rules and put a `Sync`
+        // object in global storage.
+        struct UnsafeSyncEntry(Entry);
+        unsafe impl Sync for UnsafeSyncEntry {}
+        static EMPTY_ENTRY: UnsafeSyncEntry = UnsafeSyncEntry(Entry::End(0));
+
+        Cursor {
+            ptr: &EMPTY_ENTRY.0,
+            scope: &EMPTY_ENTRY.0,
+            marker: PhantomData,
+        }
+    }
+
+    /// This create method intelligently exits non-explicitly-entered
+    /// `None`-delimited scopes when the cursor reaches the end of them,
+    /// allowing for them to be treated transparently.
+    unsafe fn create(mut ptr: *const Entry, scope: *const Entry) -> Self {
+        // NOTE: If we're looking at a `End`, we want to advance the cursor
+        // past it, unless `ptr == scope`, which means that we're at the edge of
+        // our cursor's scope. We should only have `ptr != scope` at the exit
+        // from None-delimited groups entered with `ignore_none`.
+        while let Entry::End(_) = *ptr {
+            if ptr == scope {
+                break;
+            }
+            ptr = ptr.add(1);
+        }
+
+        Cursor {
+            ptr,
+            scope,
+            marker: PhantomData,
+        }
+    }
+
+    /// Get the current entry.
+    fn entry(self) -> &'a Entry {
+        unsafe { &*self.ptr }
+    }
+
+    /// Bump the cursor to point at the next token after the current one. This
+    /// is undefined behavior if the cursor is currently looking at an
+    /// `Entry::End`.
+    ///
+    /// If the cursor is looking at an `Entry::Group`, the bumped cursor will
+    /// point at the first token in the group (with the same scope end).
+    unsafe fn bump_ignore_group(self) -> Cursor<'a> {
+        Cursor::create(self.ptr.offset(1), self.scope)
+    }
+
+    /// While the cursor is looking at a `None`-delimited group, move it to look
+    /// at the first token inside instead. If the group is empty, this will move
+    /// the cursor past the `None`-delimited group.
+    ///
+    /// WARNING: This mutates its argument.
+    fn ignore_none(&mut self) {
+        while let Entry::Group(group, _) = self.entry() {
+            if group.delimiter() == Delimiter::None {
+                unsafe { *self = self.bump_ignore_group() };
+            } else {
+                break;
+            }
+        }
+    }
+
+    /// Checks whether the cursor is currently pointing at the end of its valid
+    /// scope.
+    pub fn eof(self) -> bool {
+        // We're at eof if we're at the end of our scope.
+        self.ptr == self.scope
+    }
+
+    /// If the cursor is pointing at a `Group` with the given delimiter, returns
+    /// a cursor into that group and one pointing to the next `TokenTree`.
+    pub fn group(mut self, delim: Delimiter) -> Option<(Cursor<'a>, DelimSpan, Cursor<'a>)> {
+        // If we're not trying to enter a none-delimited group, we want to
+        // ignore them. We have to make sure to _not_ ignore them when we want
+        // to enter them, of course. For obvious reasons.
+        if delim != Delimiter::None {
+            self.ignore_none();
+        }
+
+        if let Entry::Group(group, end_offset) = self.entry() {
+            if group.delimiter() == delim {
+                let span = group.delim_span();
+                let end_of_group = unsafe { self.ptr.add(*end_offset) };
+                let inside_of_group = unsafe { Cursor::create(self.ptr.add(1), end_of_group) };
+                let after_group = unsafe { Cursor::create(end_of_group, self.scope) };
+                return Some((inside_of_group, span, after_group));
+            }
+        }
+
+        None
+    }
+
+    pub(crate) fn any_group(self) -> Option<(Cursor<'a>, Delimiter, DelimSpan, Cursor<'a>)> {
+        if let Entry::Group(group, end_offset) = self.entry() {
+            let delimiter = group.delimiter();
+            let span = group.delim_span();
+            let end_of_group = unsafe { self.ptr.add(*end_offset) };
+            let inside_of_group = unsafe { Cursor::create(self.ptr.add(1), end_of_group) };
+            let after_group = unsafe { Cursor::create(end_of_group, self.scope) };
+            return Some((inside_of_group, delimiter, span, after_group));
+        }
+
+        None
+    }
+
+    pub(crate) fn any_group_token(self) -> Option<(Group, Cursor<'a>)> {
+        if let Entry::Group(group, end_offset) = self.entry() {
+            let end_of_group = unsafe { self.ptr.add(*end_offset) };
+            let after_group = unsafe { Cursor::create(end_of_group, self.scope) };
+            return Some((group.clone(), after_group));
+        }
+
+        None
+    }
+
+    /// If the cursor is pointing at a `Ident`, returns it along with a cursor
+    /// pointing at the next `TokenTree`.
+    pub fn ident(mut self) -> Option<(Ident, Cursor<'a>)> {
+        self.ignore_none();
+        match self.entry() {
+            Entry::Ident(ident) => Some((ident.clone(), unsafe { self.bump_ignore_group() })),
+            _ => None,
+        }
+    }
+
+    /// If the cursor is pointing at a `Punct`, returns it along with a cursor
+    /// pointing at the next `TokenTree`.
+    pub fn punct(mut self) -> Option<(Punct, Cursor<'a>)> {
+        self.ignore_none();
+        match self.entry() {
+            Entry::Punct(punct) if punct.as_char() != '\'' => {
+                Some((punct.clone(), unsafe { self.bump_ignore_group() }))
+            }
+            _ => None,
+        }
+    }
+
+    /// If the cursor is pointing at a `Literal`, return it along with a cursor
+    /// pointing at the next `TokenTree`.
+    pub fn literal(mut self) -> Option<(Literal, Cursor<'a>)> {
+        self.ignore_none();
+        match self.entry() {
+            Entry::Literal(literal) => Some((literal.clone(), unsafe { self.bump_ignore_group() })),
+            _ => None,
+        }
+    }
+
+    /// If the cursor is pointing at a `Lifetime`, returns it along with a
+    /// cursor pointing at the next `TokenTree`.
+    pub fn lifetime(mut self) -> Option<(Lifetime, Cursor<'a>)> {
+        self.ignore_none();
+        match self.entry() {
+            Entry::Punct(punct) if punct.as_char() == '\'' && punct.spacing() == Spacing::Joint => {
+                let next = unsafe { self.bump_ignore_group() };
+                let (ident, rest) = next.ident()?;
+                let lifetime = Lifetime {
+                    apostrophe: punct.span(),
+                    ident,
+                };
+                Some((lifetime, rest))
+            }
+            _ => None,
+        }
+    }
+
+    /// Copies all remaining tokens visible from this cursor into a
+    /// `TokenStream`.
+    pub fn token_stream(self) -> TokenStream {
+        let mut tts = Vec::new();
+        let mut cursor = self;
+        while let Some((tt, rest)) = cursor.token_tree() {
+            tts.push(tt);
+            cursor = rest;
+        }
+        tts.into_iter().collect()
+    }
+
+    /// If the cursor is pointing at a `TokenTree`, returns it along with a
+    /// cursor pointing at the next `TokenTree`.
+    ///
+    /// Returns `None` if the cursor has reached the end of its stream.
+    ///
+    /// This method does not treat `None`-delimited groups as transparent, and
+    /// will return a `Group(None, ..)` if the cursor is looking at one.
+    pub fn token_tree(self) -> Option<(TokenTree, Cursor<'a>)> {
+        let (tree, len) = match self.entry() {
+            Entry::Group(group, end_offset) => (group.clone().into(), *end_offset),
+            Entry::Literal(literal) => (literal.clone().into(), 1),
+            Entry::Ident(ident) => (ident.clone().into(), 1),
+            Entry::Punct(punct) => (punct.clone().into(), 1),
+            Entry::End(_) => return None,
+        };
+
+        let rest = unsafe { Cursor::create(self.ptr.add(len), self.scope) };
+        Some((tree, rest))
+    }
+
+    /// Returns the `Span` of the current token, or `Span::call_site()` if this
+    /// cursor points to eof.
+    pub fn span(self) -> Span {
+        match self.entry() {
+            Entry::Group(group, _) => group.span(),
+            Entry::Literal(literal) => literal.span(),
+            Entry::Ident(ident) => ident.span(),
+            Entry::Punct(punct) => punct.span(),
+            Entry::End(_) => Span::call_site(),
+        }
+    }
+
+    /// Returns the `Span` of the token immediately prior to the position of
+    /// this cursor, or of the current token if there is no previous one.
+    #[cfg(any(feature = "full", feature = "derive"))]
+    pub(crate) fn prev_span(mut self) -> Span {
+        if start_of_buffer(self) < self.ptr {
+            self.ptr = unsafe { self.ptr.offset(-1) };
+            if let Entry::End(_) = self.entry() {
+                // Locate the matching Group begin token.
+                let mut depth = 1;
+                loop {
+                    self.ptr = unsafe { self.ptr.offset(-1) };
+                    match self.entry() {
+                        Entry::Group(group, _) => {
+                            depth -= 1;
+                            if depth == 0 {
+                                return group.span();
+                            }
+                        }
+                        Entry::End(_) => depth += 1,
+                        Entry::Literal(_) | Entry::Ident(_) | Entry::Punct(_) => {}
+                    }
+                }
+            }
+        }
+        self.span()
+    }
+
+    /// Skip over the next token without cloning it. Returns `None` if this
+    /// cursor points to eof.
+    ///
+    /// This method treats `'lifetimes` as a single token.
+    pub(crate) fn skip(self) -> Option<Cursor<'a>> {
+        let len = match self.entry() {
+            Entry::End(_) => return None,
+
+            // Treat lifetimes as a single tt for the purposes of 'skip'.
+            Entry::Punct(punct) if punct.as_char() == '\'' && punct.spacing() == Spacing::Joint => {
+                match unsafe { &*self.ptr.add(1) } {
+                    Entry::Ident(_) => 2,
+                    _ => 1,
+                }
+            }
+
+            Entry::Group(_, end_offset) => *end_offset,
+            _ => 1,
+        };
+
+        Some(unsafe { Cursor::create(self.ptr.add(len), self.scope) })
+    }
+}
+
+impl<'a> Copy for Cursor<'a> {}
+
+impl<'a> Clone for Cursor<'a> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<'a> Eq for Cursor<'a> {}
+
+impl<'a> PartialEq for Cursor<'a> {
+    fn eq(&self, other: &Self) -> bool {
+        self.ptr == other.ptr
+    }
+}
+
+impl<'a> PartialOrd for Cursor<'a> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        if same_buffer(*self, *other) {
+            Some(self.ptr.cmp(&other.ptr))
+        } else {
+            None
+        }
+    }
+}
+
+pub(crate) fn same_scope(a: Cursor, b: Cursor) -> bool {
+    a.scope == b.scope
+}
+
+pub(crate) fn same_buffer(a: Cursor, b: Cursor) -> bool {
+    start_of_buffer(a) == start_of_buffer(b)
+}
+
+fn start_of_buffer(cursor: Cursor) -> *const Entry {
+    unsafe {
+        match &*cursor.scope {
+            Entry::End(offset) => cursor.scope.offset(*offset),
+            _ => unreachable!(),
+        }
+    }
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn cmp_assuming_same_buffer(a: Cursor, b: Cursor) -> Ordering {
+    a.ptr.cmp(&b.ptr)
+}
+
+pub(crate) fn open_span_of_group(cursor: Cursor) -> Span {
+    match cursor.entry() {
+        Entry::Group(group, _) => group.span_open(),
+        _ => cursor.span(),
+    }
+}
+
+pub(crate) fn close_span_of_group(cursor: Cursor) -> Span {
+    match cursor.entry() {
+        Entry::Group(group, _) => group.span_close(),
+        _ => cursor.span(),
+    }
+}
diff --git a/vendor/syn/src/custom_keyword.rs b/vendor/syn/src/custom_keyword.rs
new file mode 100644
index 0000000..9f3ad87
--- /dev/null
+++ b/vendor/syn/src/custom_keyword.rs
@@ -0,0 +1,259 @@
+/// Define a type that supports parsing and printing a given identifier as if it
+/// were a keyword.
+///
+/// # Usage
+///
+/// As a convention, it is recommended that this macro be invoked within a
+/// module called `kw` or `keyword` and that the resulting parser be invoked
+/// with a `kw::` or `keyword::` prefix.
+///
+/// ```
+/// mod kw {
+///     syn::custom_keyword!(whatever);
+/// }
+/// ```
+///
+/// The generated syntax tree node supports the following operations just like
+/// any built-in keyword token.
+///
+/// - [Peeking] — `input.peek(kw::whatever)`
+///
+/// - [Parsing] — `input.parse::<kw::whatever>()?`
+///
+/// - [Printing] — `quote!( ... #whatever_token ... )`
+///
+/// - Construction from a [`Span`] — `let whatever_token = kw::whatever(sp)`
+///
+/// - Field access to its span — `let sp = whatever_token.span`
+///
+/// [Peeking]: crate::parse::ParseBuffer::peek
+/// [Parsing]: crate::parse::ParseBuffer::parse
+/// [Printing]: quote::ToTokens
+/// [`Span`]: proc_macro2::Span
+///
+/// # Example
+///
+/// This example parses input that looks like `bool = true` or `str = "value"`.
+/// The key must be either the identifier `bool` or the identifier `str`. If
+/// `bool`, the value may be either `true` or `false`. If `str`, the value may
+/// be any string literal.
+///
+/// The symbols `bool` and `str` are not reserved keywords in Rust so these are
+/// not considered keywords in the `syn::token` module. Like any other
+/// identifier that is not a keyword, these can be declared as custom keywords
+/// by crates that need to use them as such.
+///
+/// ```
+/// use syn::{LitBool, LitStr, Result, Token};
+/// use syn::parse::{Parse, ParseStream};
+///
+/// mod kw {
+///     syn::custom_keyword!(bool);
+///     syn::custom_keyword!(str);
+/// }
+///
+/// enum Argument {
+///     Bool {
+///         bool_token: kw::bool,
+///         eq_token: Token![=],
+///         value: LitBool,
+///     },
+///     Str {
+///         str_token: kw::str,
+///         eq_token: Token![=],
+///         value: LitStr,
+///     },
+/// }
+///
+/// impl Parse for Argument {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let lookahead = input.lookahead1();
+///         if lookahead.peek(kw::bool) {
+///             Ok(Argument::Bool {
+///                 bool_token: input.parse::<kw::bool>()?,
+///                 eq_token: input.parse()?,
+///                 value: input.parse()?,
+///             })
+///         } else if lookahead.peek(kw::str) {
+///             Ok(Argument::Str {
+///                 str_token: input.parse::<kw::str>()?,
+///                 eq_token: input.parse()?,
+///                 value: input.parse()?,
+///             })
+///         } else {
+///             Err(lookahead.error())
+///         }
+///     }
+/// }
+/// ```
+#[macro_export]
+macro_rules! custom_keyword {
+    ($ident:ident) => {
+        #[allow(non_camel_case_types)]
+        pub struct $ident {
+            pub span: $crate::__private::Span,
+        }
+
+        #[doc(hidden)]
+        #[allow(dead_code, non_snake_case)]
+        pub fn $ident<__S: $crate::__private::IntoSpans<$crate::__private::Span>>(
+            span: __S,
+        ) -> $ident {
+            $ident {
+                span: $crate::__private::IntoSpans::into_spans(span),
+            }
+        }
+
+        const _: () = {
+            impl $crate::__private::Default for $ident {
+                fn default() -> Self {
+                    $ident {
+                        span: $crate::__private::Span::call_site(),
+                    }
+                }
+            }
+
+            $crate::impl_parse_for_custom_keyword!($ident);
+            $crate::impl_to_tokens_for_custom_keyword!($ident);
+            $crate::impl_clone_for_custom_keyword!($ident);
+            $crate::impl_extra_traits_for_custom_keyword!($ident);
+        };
+    };
+}
+
+// Not public API.
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_keyword {
+    ($ident:ident) => {
+        // For peek.
+        impl $crate::token::CustomToken for $ident {
+            fn peek(cursor: $crate::buffer::Cursor) -> $crate::__private::bool {
+                if let $crate::__private::Some((ident, _rest)) = cursor.ident() {
+                    ident == $crate::__private::stringify!($ident)
+                } else {
+                    false
+                }
+            }
+
+            fn display() -> &'static $crate::__private::str {
+                $crate::__private::concat!("`", $crate::__private::stringify!($ident), "`")
+            }
+        }
+
+        impl $crate::parse::Parse for $ident {
+            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
+                input.step(|cursor| {
+                    if let $crate::__private::Some((ident, rest)) = cursor.ident() {
+                        if ident == $crate::__private::stringify!($ident) {
+                            return $crate::__private::Ok(($ident { span: ident.span() }, rest));
+                        }
+                    }
+                    $crate::__private::Err(cursor.error($crate::__private::concat!(
+                        "expected `",
+                        $crate::__private::stringify!($ident),
+                        "`",
+                    )))
+                })
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "parsing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::__private::ToTokens for $ident {
+            fn to_tokens(&self, tokens: &mut $crate::__private::TokenStream2) {
+                let ident = $crate::Ident::new($crate::__private::stringify!($ident), self.span);
+                $crate::__private::TokenStreamExt::append(tokens, ident);
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "printing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "clone-impls")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::__private::Copy for $ident {}
+
+        #[allow(clippy::expl_impl_clone_on_copy)]
+        impl $crate::__private::Clone for $ident {
+            fn clone(&self) -> Self {
+                *self
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "clone-impls"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "extra-traits")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::__private::Debug for $ident {
+            fn fmt(&self, f: &mut $crate::__private::Formatter) -> $crate::__private::FmtResult {
+                $crate::__private::Formatter::write_str(
+                    f,
+                    $crate::__private::concat!(
+                        "Keyword [",
+                        $crate::__private::stringify!($ident),
+                        "]",
+                    ),
+                )
+            }
+        }
+
+        impl $crate::__private::Eq for $ident {}
+
+        impl $crate::__private::PartialEq for $ident {
+            fn eq(&self, _other: &Self) -> $crate::__private::bool {
+                true
+            }
+        }
+
+        impl $crate::__private::Hash for $ident {
+            fn hash<__H: $crate::__private::Hasher>(&self, _state: &mut __H) {}
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "extra-traits"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_keyword {
+    ($ident:ident) => {};
+}
diff --git a/vendor/syn/src/custom_punctuation.rs b/vendor/syn/src/custom_punctuation.rs
new file mode 100644
index 0000000..062fe51
--- /dev/null
+++ b/vendor/syn/src/custom_punctuation.rs
@@ -0,0 +1,302 @@
+/// Define a type that supports parsing and printing a multi-character symbol
+/// as if it were a punctuation token.
+///
+/// # Usage
+///
+/// ```
+/// syn::custom_punctuation!(LeftRightArrow, <=>);
+/// ```
+///
+/// The generated syntax tree node supports the following operations just like
+/// any built-in punctuation token.
+///
+/// - [Peeking] — `input.peek(LeftRightArrow)`
+///
+/// - [Parsing] — `input.parse::<LeftRightArrow>()?`
+///
+/// - [Printing] — `quote!( ... #lrarrow ... )`
+///
+/// - Construction from a [`Span`] — `let lrarrow = LeftRightArrow(sp)`
+///
+/// - Construction from multiple [`Span`] — `let lrarrow = LeftRightArrow([sp, sp, sp])`
+///
+/// - Field access to its spans — `let spans = lrarrow.spans`
+///
+/// [Peeking]: crate::parse::ParseBuffer::peek
+/// [Parsing]: crate::parse::ParseBuffer::parse
+/// [Printing]: quote::ToTokens
+/// [`Span`]: proc_macro2::Span
+///
+/// # Example
+///
+/// ```
+/// use proc_macro2::{TokenStream, TokenTree};
+/// use syn::parse::{Parse, ParseStream, Peek, Result};
+/// use syn::punctuated::Punctuated;
+/// use syn::Expr;
+///
+/// syn::custom_punctuation!(PathSeparator, </>);
+///
+/// // expr </> expr </> expr ...
+/// struct PathSegments {
+///     segments: Punctuated<Expr, PathSeparator>,
+/// }
+///
+/// impl Parse for PathSegments {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let mut segments = Punctuated::new();
+///
+///         let first = parse_until(input, PathSeparator)?;
+///         segments.push_value(syn::parse2(first)?);
+///
+///         while input.peek(PathSeparator) {
+///             segments.push_punct(input.parse()?);
+///
+///             let next = parse_until(input, PathSeparator)?;
+///             segments.push_value(syn::parse2(next)?);
+///         }
+///
+///         Ok(PathSegments { segments })
+///     }
+/// }
+///
+/// fn parse_until<E: Peek>(input: ParseStream, end: E) -> Result<TokenStream> {
+///     let mut tokens = TokenStream::new();
+///     while !input.is_empty() && !input.peek(end) {
+///         let next: TokenTree = input.parse()?;
+///         tokens.extend(Some(next));
+///     }
+///     Ok(tokens)
+/// }
+///
+/// fn main() {
+///     let input = r#" a::b </> c::d::e "#;
+///     let _: PathSegments = syn::parse_str(input).unwrap();
+/// }
+/// ```
+#[macro_export]
+macro_rules! custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        pub struct $ident {
+            pub spans: $crate::custom_punctuation_repr!($($tt)+),
+        }
+
+        #[doc(hidden)]
+        #[allow(dead_code, non_snake_case)]
+        pub fn $ident<__S: $crate::__private::IntoSpans<$crate::custom_punctuation_repr!($($tt)+)>>(
+            spans: __S,
+        ) -> $ident {
+            let _validate_len = 0 $(+ $crate::custom_punctuation_len!(strict, $tt))*;
+            $ident {
+                spans: $crate::__private::IntoSpans::into_spans(spans)
+            }
+        }
+
+        const _: () = {
+            impl $crate::__private::Default for $ident {
+                fn default() -> Self {
+                    $ident($crate::__private::Span::call_site())
+                }
+            }
+
+            $crate::impl_parse_for_custom_punctuation!($ident, $($tt)+);
+            $crate::impl_to_tokens_for_custom_punctuation!($ident, $($tt)+);
+            $crate::impl_clone_for_custom_punctuation!($ident, $($tt)+);
+            $crate::impl_extra_traits_for_custom_punctuation!($ident, $($tt)+);
+        };
+    };
+}
+
+// Not public API.
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        impl $crate::token::CustomToken for $ident {
+            fn peek(cursor: $crate::buffer::Cursor) -> $crate::__private::bool {
+                $crate::__private::peek_punct(cursor, $crate::stringify_punct!($($tt)+))
+            }
+
+            fn display() -> &'static $crate::__private::str {
+                $crate::__private::concat!("`", $crate::stringify_punct!($($tt)+), "`")
+            }
+        }
+
+        impl $crate::parse::Parse for $ident {
+            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
+                let spans: $crate::custom_punctuation_repr!($($tt)+) =
+                    $crate::__private::parse_punct(input, $crate::stringify_punct!($($tt)+))?;
+                Ok($ident(spans))
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "parsing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        impl $crate::__private::ToTokens for $ident {
+            fn to_tokens(&self, tokens: &mut $crate::__private::TokenStream2) {
+                $crate::__private::print_punct($crate::stringify_punct!($($tt)+), &self.spans, tokens)
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "printing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "clone-impls")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        impl $crate::__private::Copy for $ident {}
+
+        #[allow(clippy::expl_impl_clone_on_copy)]
+        impl $crate::__private::Clone for $ident {
+            fn clone(&self) -> Self {
+                *self
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "clone-impls"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "extra-traits")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        impl $crate::__private::Debug for $ident {
+            fn fmt(&self, f: &mut $crate::__private::Formatter) -> $crate::__private::FmtResult {
+                $crate::__private::Formatter::write_str(f, $crate::__private::stringify!($ident))
+            }
+        }
+
+        impl $crate::__private::Eq for $ident {}
+
+        impl $crate::__private::PartialEq for $ident {
+            fn eq(&self, _other: &Self) -> $crate::__private::bool {
+                true
+            }
+        }
+
+        impl $crate::__private::Hash for $ident {
+            fn hash<__H: $crate::__private::Hasher>(&self, _state: &mut __H) {}
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "extra-traits"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! custom_punctuation_repr {
+    ($($tt:tt)+) => {
+        [$crate::__private::Span; 0 $(+ $crate::custom_punctuation_len!(lenient, $tt))+]
+    };
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+#[rustfmt::skip]
+macro_rules! custom_punctuation_len {
+    ($mode:ident, +)     => { 1 };
+    ($mode:ident, +=)    => { 2 };
+    ($mode:ident, &)     => { 1 };
+    ($mode:ident, &&)    => { 2 };
+    ($mode:ident, &=)    => { 2 };
+    ($mode:ident, @)     => { 1 };
+    ($mode:ident, !)     => { 1 };
+    ($mode:ident, ^)     => { 1 };
+    ($mode:ident, ^=)    => { 2 };
+    ($mode:ident, :)     => { 1 };
+    ($mode:ident, ::)    => { 2 };
+    ($mode:ident, ,)     => { 1 };
+    ($mode:ident, /)     => { 1 };
+    ($mode:ident, /=)    => { 2 };
+    ($mode:ident, .)     => { 1 };
+    ($mode:ident, ..)    => { 2 };
+    ($mode:ident, ...)   => { 3 };
+    ($mode:ident, ..=)   => { 3 };
+    ($mode:ident, =)     => { 1 };
+    ($mode:ident, ==)    => { 2 };
+    ($mode:ident, >=)    => { 2 };
+    ($mode:ident, >)     => { 1 };
+    ($mode:ident, <=)    => { 2 };
+    ($mode:ident, <)     => { 1 };
+    ($mode:ident, *=)    => { 2 };
+    ($mode:ident, !=)    => { 2 };
+    ($mode:ident, |)     => { 1 };
+    ($mode:ident, |=)    => { 2 };
+    ($mode:ident, ||)    => { 2 };
+    ($mode:ident, #)     => { 1 };
+    ($mode:ident, ?)     => { 1 };
+    ($mode:ident, ->)    => { 2 };
+    ($mode:ident, <-)    => { 2 };
+    ($mode:ident, %)     => { 1 };
+    ($mode:ident, %=)    => { 2 };
+    ($mode:ident, =>)    => { 2 };
+    ($mode:ident, ;)     => { 1 };
+    ($mode:ident, <<)    => { 2 };
+    ($mode:ident, <<=)   => { 3 };
+    ($mode:ident, >>)    => { 2 };
+    ($mode:ident, >>=)   => { 3 };
+    ($mode:ident, *)     => { 1 };
+    ($mode:ident, -)     => { 1 };
+    ($mode:ident, -=)    => { 2 };
+    ($mode:ident, ~)     => { 1 };
+    (lenient, $tt:tt)    => { 0 };
+    (strict, $tt:tt)     => {{ $crate::custom_punctuation_unexpected!($tt); 0 }};
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! custom_punctuation_unexpected {
+    () => {};
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! stringify_punct {
+    ($($tt:tt)+) => {
+        $crate::__private::concat!($($crate::__private::stringify!($tt)),+)
+    };
+}
diff --git a/vendor/syn/src/data.rs b/vendor/syn/src/data.rs
new file mode 100644
index 0000000..431c085
--- /dev/null
+++ b/vendor/syn/src/data.rs
@@ -0,0 +1,316 @@
+use super::*;
+use crate::punctuated::Punctuated;
+
+ast_struct! {
+    /// An enum variant.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Variant {
+        pub attrs: Vec<Attribute>,
+
+        /// Name of the variant.
+        pub ident: Ident,
+
+        /// Content stored in the variant.
+        pub fields: Fields,
+
+        /// Explicit discriminant: `Variant = 1`
+        pub discriminant: Option<(Token![=], Expr)>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// Data stored within an enum variant or struct.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum Fields {
+        /// Named fields of a struct or struct variant such as `Point { x: f64,
+        /// y: f64 }`.
+        Named(FieldsNamed),
+
+        /// Unnamed fields of a tuple struct or tuple variant such as `Some(T)`.
+        Unnamed(FieldsUnnamed),
+
+        /// Unit struct or unit variant such as `None`.
+        Unit,
+    }
+}
+
+ast_struct! {
+    /// Named fields of a struct or struct variant such as `Point { x: f64,
+    /// y: f64 }`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct FieldsNamed {
+        pub brace_token: token::Brace,
+        pub named: Punctuated<Field, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// Unnamed fields of a tuple struct or tuple variant such as `Some(T)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct FieldsUnnamed {
+        pub paren_token: token::Paren,
+        pub unnamed: Punctuated<Field, Token![,]>,
+    }
+}
+
+impl Fields {
+    /// Get an iterator over the borrowed [`Field`] items in this object. This
+    /// iterator can be used to iterate over a named or unnamed struct or
+    /// variant's fields uniformly.
+    pub fn iter(&self) -> punctuated::Iter<Field> {
+        match self {
+            Fields::Unit => crate::punctuated::empty_punctuated_iter(),
+            Fields::Named(f) => f.named.iter(),
+            Fields::Unnamed(f) => f.unnamed.iter(),
+        }
+    }
+
+    /// Get an iterator over the mutably borrowed [`Field`] items in this
+    /// object. This iterator can be used to iterate over a named or unnamed
+    /// struct or variant's fields uniformly.
+    pub fn iter_mut(&mut self) -> punctuated::IterMut<Field> {
+        match self {
+            Fields::Unit => crate::punctuated::empty_punctuated_iter_mut(),
+            Fields::Named(f) => f.named.iter_mut(),
+            Fields::Unnamed(f) => f.unnamed.iter_mut(),
+        }
+    }
+
+    /// Returns the number of fields.
+    pub fn len(&self) -> usize {
+        match self {
+            Fields::Unit => 0,
+            Fields::Named(f) => f.named.len(),
+            Fields::Unnamed(f) => f.unnamed.len(),
+        }
+    }
+
+    /// Returns `true` if there are zero fields.
+    pub fn is_empty(&self) -> bool {
+        match self {
+            Fields::Unit => true,
+            Fields::Named(f) => f.named.is_empty(),
+            Fields::Unnamed(f) => f.unnamed.is_empty(),
+        }
+    }
+}
+
+impl IntoIterator for Fields {
+    type Item = Field;
+    type IntoIter = punctuated::IntoIter<Field>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        match self {
+            Fields::Unit => Punctuated::<Field, ()>::new().into_iter(),
+            Fields::Named(f) => f.named.into_iter(),
+            Fields::Unnamed(f) => f.unnamed.into_iter(),
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a Fields {
+    type Item = &'a Field;
+    type IntoIter = punctuated::Iter<'a, Field>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a mut Fields {
+    type Item = &'a mut Field;
+    type IntoIter = punctuated::IterMut<'a, Field>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter_mut()
+    }
+}
+
+ast_struct! {
+    /// A field of a struct or enum variant.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Field {
+        pub attrs: Vec<Attribute>,
+
+        pub vis: Visibility,
+
+        pub mutability: FieldMutability,
+
+        /// Name of the field, if any.
+        ///
+        /// Fields of tuple structs have no names.
+        pub ident: Option<Ident>,
+
+        pub colon_token: Option<Token![:]>,
+
+        pub ty: Type,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Variant {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let _visibility: Visibility = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let fields = if input.peek(token::Brace) {
+                Fields::Named(input.parse()?)
+            } else if input.peek(token::Paren) {
+                Fields::Unnamed(input.parse()?)
+            } else {
+                Fields::Unit
+            };
+            let discriminant = if input.peek(Token![=]) {
+                let eq_token: Token![=] = input.parse()?;
+                let discriminant: Expr = input.parse()?;
+                Some((eq_token, discriminant))
+            } else {
+                None
+            };
+            Ok(Variant {
+                attrs,
+                ident,
+                fields,
+                discriminant,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for FieldsNamed {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(FieldsNamed {
+                brace_token: braced!(content in input),
+                named: content.parse_terminated(Field::parse_named, Token![,])?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for FieldsUnnamed {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(FieldsUnnamed {
+                paren_token: parenthesized!(content in input),
+                unnamed: content.parse_terminated(Field::parse_unnamed, Token![,])?,
+            })
+        }
+    }
+
+    impl Field {
+        /// Parses a named (braced struct) field.
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn parse_named(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+
+            let unnamed_field = cfg!(feature = "full") && input.peek(Token![_]);
+            let ident = if unnamed_field {
+                input.call(Ident::parse_any)
+            } else {
+                input.parse()
+            }?;
+
+            let colon_token: Token![:] = input.parse()?;
+
+            let ty: Type = if unnamed_field
+                && (input.peek(Token![struct])
+                    || input.peek(Token![union]) && input.peek2(token::Brace))
+            {
+                let begin = input.fork();
+                input.call(Ident::parse_any)?;
+                input.parse::<FieldsNamed>()?;
+                Type::Verbatim(verbatim::between(&begin, input))
+            } else {
+                input.parse()?
+            };
+
+            Ok(Field {
+                attrs,
+                vis,
+                mutability: FieldMutability::None,
+                ident: Some(ident),
+                colon_token: Some(colon_token),
+                ty,
+            })
+        }
+
+        /// Parses an unnamed (tuple struct) field.
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn parse_unnamed(input: ParseStream) -> Result<Self> {
+            Ok(Field {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                mutability: FieldMutability::None,
+                ident: None,
+                colon_token: None,
+                ty: input.parse()?,
+            })
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::print::TokensOrDefault;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Variant {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(&self.attrs);
+            self.ident.to_tokens(tokens);
+            self.fields.to_tokens(tokens);
+            if let Some((eq_token, disc)) = &self.discriminant {
+                eq_token.to_tokens(tokens);
+                disc.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for FieldsNamed {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.brace_token.surround(tokens, |tokens| {
+                self.named.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for FieldsUnnamed {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.paren_token.surround(tokens, |tokens| {
+                self.unnamed.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Field {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(&self.attrs);
+            self.vis.to_tokens(tokens);
+            if let Some(ident) = &self.ident {
+                ident.to_tokens(tokens);
+                TokensOrDefault(&self.colon_token).to_tokens(tokens);
+            }
+            self.ty.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/derive.rs b/vendor/syn/src/derive.rs
new file mode 100644
index 0000000..25fa4c9
--- /dev/null
+++ b/vendor/syn/src/derive.rs
@@ -0,0 +1,245 @@
+use super::*;
+use crate::punctuated::Punctuated;
+
+ast_struct! {
+    /// Data structure sent to a `proc_macro_derive` macro.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+    pub struct DeriveInput {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub ident: Ident,
+        pub generics: Generics,
+        pub data: Data,
+    }
+}
+
+ast_enum! {
+    /// The storage of a struct, enum or union data structure.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+    pub enum Data {
+        Struct(DataStruct),
+        Enum(DataEnum),
+        Union(DataUnion),
+    }
+}
+
+ast_struct! {
+    /// A struct input to a `proc_macro_derive` macro.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+    pub struct DataStruct {
+        pub struct_token: Token![struct],
+        pub fields: Fields,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// An enum input to a `proc_macro_derive` macro.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+    pub struct DataEnum {
+        pub enum_token: Token![enum],
+        pub brace_token: token::Brace,
+        pub variants: Punctuated<Variant, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// An untagged union input to a `proc_macro_derive` macro.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+    pub struct DataUnion {
+        pub union_token: Token![union],
+        pub fields: FieldsNamed,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for DeriveInput {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis = input.parse::<Visibility>()?;
+
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Token![struct]) {
+                let struct_token = input.parse::<Token![struct]>()?;
+                let ident = input.parse::<Ident>()?;
+                let generics = input.parse::<Generics>()?;
+                let (where_clause, fields, semi) = data_struct(input)?;
+                Ok(DeriveInput {
+                    attrs,
+                    vis,
+                    ident,
+                    generics: Generics {
+                        where_clause,
+                        ..generics
+                    },
+                    data: Data::Struct(DataStruct {
+                        struct_token,
+                        fields,
+                        semi_token: semi,
+                    }),
+                })
+            } else if lookahead.peek(Token![enum]) {
+                let enum_token = input.parse::<Token![enum]>()?;
+                let ident = input.parse::<Ident>()?;
+                let generics = input.parse::<Generics>()?;
+                let (where_clause, brace, variants) = data_enum(input)?;
+                Ok(DeriveInput {
+                    attrs,
+                    vis,
+                    ident,
+                    generics: Generics {
+                        where_clause,
+                        ..generics
+                    },
+                    data: Data::Enum(DataEnum {
+                        enum_token,
+                        brace_token: brace,
+                        variants,
+                    }),
+                })
+            } else if lookahead.peek(Token![union]) {
+                let union_token = input.parse::<Token![union]>()?;
+                let ident = input.parse::<Ident>()?;
+                let generics = input.parse::<Generics>()?;
+                let (where_clause, fields) = data_union(input)?;
+                Ok(DeriveInput {
+                    attrs,
+                    vis,
+                    ident,
+                    generics: Generics {
+                        where_clause,
+                        ..generics
+                    },
+                    data: Data::Union(DataUnion {
+                        union_token,
+                        fields,
+                    }),
+                })
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    pub(crate) fn data_struct(
+        input: ParseStream,
+    ) -> Result<(Option<WhereClause>, Fields, Option<Token![;]>)> {
+        let mut lookahead = input.lookahead1();
+        let mut where_clause = None;
+        if lookahead.peek(Token![where]) {
+            where_clause = Some(input.parse()?);
+            lookahead = input.lookahead1();
+        }
+
+        if where_clause.is_none() && lookahead.peek(token::Paren) {
+            let fields = input.parse()?;
+
+            lookahead = input.lookahead1();
+            if lookahead.peek(Token![where]) {
+                where_clause = Some(input.parse()?);
+                lookahead = input.lookahead1();
+            }
+
+            if lookahead.peek(Token![;]) {
+                let semi = input.parse()?;
+                Ok((where_clause, Fields::Unnamed(fields), Some(semi)))
+            } else {
+                Err(lookahead.error())
+            }
+        } else if lookahead.peek(token::Brace) {
+            let fields = input.parse()?;
+            Ok((where_clause, Fields::Named(fields), None))
+        } else if lookahead.peek(Token![;]) {
+            let semi = input.parse()?;
+            Ok((where_clause, Fields::Unit, Some(semi)))
+        } else {
+            Err(lookahead.error())
+        }
+    }
+
+    pub(crate) fn data_enum(
+        input: ParseStream,
+    ) -> Result<(
+        Option<WhereClause>,
+        token::Brace,
+        Punctuated<Variant, Token![,]>,
+    )> {
+        let where_clause = input.parse()?;
+
+        let content;
+        let brace = braced!(content in input);
+        let variants = content.parse_terminated(Variant::parse, Token![,])?;
+
+        Ok((where_clause, brace, variants))
+    }
+
+    pub(crate) fn data_union(input: ParseStream) -> Result<(Option<WhereClause>, FieldsNamed)> {
+        let where_clause = input.parse()?;
+        let fields = input.parse()?;
+        Ok((where_clause, fields))
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use crate::print::TokensOrDefault;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for DeriveInput {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            for attr in self.attrs.outer() {
+                attr.to_tokens(tokens);
+            }
+            self.vis.to_tokens(tokens);
+            match &self.data {
+                Data::Struct(d) => d.struct_token.to_tokens(tokens),
+                Data::Enum(d) => d.enum_token.to_tokens(tokens),
+                Data::Union(d) => d.union_token.to_tokens(tokens),
+            }
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            match &self.data {
+                Data::Struct(data) => match &data.fields {
+                    Fields::Named(fields) => {
+                        self.generics.where_clause.to_tokens(tokens);
+                        fields.to_tokens(tokens);
+                    }
+                    Fields::Unnamed(fields) => {
+                        fields.to_tokens(tokens);
+                        self.generics.where_clause.to_tokens(tokens);
+                        TokensOrDefault(&data.semi_token).to_tokens(tokens);
+                    }
+                    Fields::Unit => {
+                        self.generics.where_clause.to_tokens(tokens);
+                        TokensOrDefault(&data.semi_token).to_tokens(tokens);
+                    }
+                },
+                Data::Enum(data) => {
+                    self.generics.where_clause.to_tokens(tokens);
+                    data.brace_token.surround(tokens, |tokens| {
+                        data.variants.to_tokens(tokens);
+                    });
+                }
+                Data::Union(data) => {
+                    self.generics.where_clause.to_tokens(tokens);
+                    data.fields.to_tokens(tokens);
+                }
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/discouraged.rs b/vendor/syn/src/discouraged.rs
new file mode 100644
index 0000000..fb98d63
--- /dev/null
+++ b/vendor/syn/src/discouraged.rs
@@ -0,0 +1,219 @@
+//! Extensions to the parsing API with niche applicability.
+
+use super::*;
+use proc_macro2::extra::DelimSpan;
+
+/// Extensions to the `ParseStream` API to support speculative parsing.
+pub trait Speculative {
+    /// Advance this parse stream to the position of a forked parse stream.
+    ///
+    /// This is the opposite operation to [`ParseStream::fork`]. You can fork a
+    /// parse stream, perform some speculative parsing, then join the original
+    /// stream to the fork to "commit" the parsing from the fork to the main
+    /// stream.
+    ///
+    /// If you can avoid doing this, you should, as it limits the ability to
+    /// generate useful errors. That said, it is often the only way to parse
+    /// syntax of the form `A* B*` for arbitrary syntax `A` and `B`. The problem
+    /// is that when the fork fails to parse an `A`, it's impossible to tell
+    /// whether that was because of a syntax error and the user meant to provide
+    /// an `A`, or that the `A`s are finished and it's time to start parsing
+    /// `B`s. Use with care.
+    ///
+    /// Also note that if `A` is a subset of `B`, `A* B*` can be parsed by
+    /// parsing `B*` and removing the leading members of `A` from the
+    /// repetition, bypassing the need to involve the downsides associated with
+    /// speculative parsing.
+    ///
+    /// [`ParseStream::fork`]: ParseBuffer::fork
+    ///
+    /// # Example
+    ///
+    /// There has been chatter about the possibility of making the colons in the
+    /// turbofish syntax like `path::to::<T>` no longer required by accepting
+    /// `path::to<T>` in expression position. Specifically, according to [RFC
+    /// 2544], [`PathSegment`] parsing should always try to consume a following
+    /// `<` token as the start of generic arguments, and reset to the `<` if
+    /// that fails (e.g. the token is acting as a less-than operator).
+    ///
+    /// This is the exact kind of parsing behavior which requires the "fork,
+    /// try, commit" behavior that [`ParseStream::fork`] discourages. With
+    /// `advance_to`, we can avoid having to parse the speculatively parsed
+    /// content a second time.
+    ///
+    /// This change in behavior can be implemented in syn by replacing just the
+    /// `Parse` implementation for `PathSegment`:
+    ///
+    /// ```
+    /// # use syn::ext::IdentExt;
+    /// use syn::parse::discouraged::Speculative;
+    /// # use syn::parse::{Parse, ParseStream};
+    /// # use syn::{Ident, PathArguments, Result, Token};
+    ///
+    /// pub struct PathSegment {
+    ///     pub ident: Ident,
+    ///     pub arguments: PathArguments,
+    /// }
+    /// #
+    /// # impl<T> From<T> for PathSegment
+    /// # where
+    /// #     T: Into<Ident>,
+    /// # {
+    /// #     fn from(ident: T) -> Self {
+    /// #         PathSegment {
+    /// #             ident: ident.into(),
+    /// #             arguments: PathArguments::None,
+    /// #         }
+    /// #     }
+    /// # }
+    ///
+    /// impl Parse for PathSegment {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         if input.peek(Token![super])
+    ///             || input.peek(Token![self])
+    ///             || input.peek(Token![Self])
+    ///             || input.peek(Token![crate])
+    ///         {
+    ///             let ident = input.call(Ident::parse_any)?;
+    ///             return Ok(PathSegment::from(ident));
+    ///         }
+    ///
+    ///         let ident = input.parse()?;
+    ///         if input.peek(Token![::]) && input.peek3(Token![<]) {
+    ///             return Ok(PathSegment {
+    ///                 ident,
+    ///                 arguments: PathArguments::AngleBracketed(input.parse()?),
+    ///             });
+    ///         }
+    ///         if input.peek(Token![<]) && !input.peek(Token![<=]) {
+    ///             let fork = input.fork();
+    ///             if let Ok(arguments) = fork.parse() {
+    ///                 input.advance_to(&fork);
+    ///                 return Ok(PathSegment {
+    ///                     ident,
+    ///                     arguments: PathArguments::AngleBracketed(arguments),
+    ///                 });
+    ///             }
+    ///         }
+    ///         Ok(PathSegment::from(ident))
+    ///     }
+    /// }
+    ///
+    /// # syn::parse_str::<PathSegment>("a<b,c>").unwrap();
+    /// ```
+    ///
+    /// # Drawbacks
+    ///
+    /// The main drawback of this style of speculative parsing is in error
+    /// presentation. Even if the lookahead is the "correct" parse, the error
+    /// that is shown is that of the "fallback" parse. To use the same example
+    /// as the turbofish above, take the following unfinished "turbofish":
+    ///
+    /// ```text
+    /// let _ = f<&'a fn(), for<'a> serde::>();
+    /// ```
+    ///
+    /// If this is parsed as generic arguments, we can provide the error message
+    ///
+    /// ```text
+    /// error: expected identifier
+    ///  --> src.rs:L:C
+    ///   |
+    /// L | let _ = f<&'a fn(), for<'a> serde::>();
+    ///   |                                    ^
+    /// ```
+    ///
+    /// but if parsed using the above speculative parsing, it falls back to
+    /// assuming that the `<` is a less-than when it fails to parse the generic
+    /// arguments, and tries to interpret the `&'a` as the start of a labelled
+    /// loop, resulting in the much less helpful error
+    ///
+    /// ```text
+    /// error: expected `:`
+    ///  --> src.rs:L:C
+    ///   |
+    /// L | let _ = f<&'a fn(), for<'a> serde::>();
+    ///   |               ^^
+    /// ```
+    ///
+    /// This can be mitigated with various heuristics (two examples: show both
+    /// forks' parse errors, or show the one that consumed more tokens), but
+    /// when you can control the grammar, sticking to something that can be
+    /// parsed LL(3) and without the LL(*) speculative parsing this makes
+    /// possible, displaying reasonable errors becomes much more simple.
+    ///
+    /// [RFC 2544]: https://github.com/rust-lang/rfcs/pull/2544
+    /// [`PathSegment`]: crate::PathSegment
+    ///
+    /// # Performance
+    ///
+    /// This method performs a cheap fixed amount of work that does not depend
+    /// on how far apart the two streams are positioned.
+    ///
+    /// # Panics
+    ///
+    /// The forked stream in the argument of `advance_to` must have been
+    /// obtained by forking `self`. Attempting to advance to any other stream
+    /// will cause a panic.
+    fn advance_to(&self, fork: &Self);
+}
+
+impl<'a> Speculative for ParseBuffer<'a> {
+    fn advance_to(&self, fork: &Self) {
+        if !crate::buffer::same_scope(self.cursor(), fork.cursor()) {
+            panic!("Fork was not derived from the advancing parse stream");
+        }
+
+        let (self_unexp, self_sp) = inner_unexpected(self);
+        let (fork_unexp, fork_sp) = inner_unexpected(fork);
+        if !Rc::ptr_eq(&self_unexp, &fork_unexp) {
+            match (fork_sp, self_sp) {
+                // Unexpected set on the fork, but not on `self`, copy it over.
+                (Some(span), None) => {
+                    self_unexp.set(Unexpected::Some(span));
+                }
+                // Unexpected unset. Use chain to propagate errors from fork.
+                (None, None) => {
+                    fork_unexp.set(Unexpected::Chain(self_unexp));
+
+                    // Ensure toplevel 'unexpected' tokens from the fork don't
+                    // bubble up the chain by replacing the root `unexpected`
+                    // pointer, only 'unexpected' tokens from existing group
+                    // parsers should bubble.
+                    fork.unexpected
+                        .set(Some(Rc::new(Cell::new(Unexpected::None))));
+                }
+                // Unexpected has been set on `self`. No changes needed.
+                (_, Some(_)) => {}
+            }
+        }
+
+        // See comment on `cell` in the struct definition.
+        self.cell
+            .set(unsafe { mem::transmute::<Cursor, Cursor<'static>>(fork.cursor()) });
+    }
+}
+
+/// Extensions to the `ParseStream` API to support manipulating invisible
+/// delimiters the same as if they were visible.
+pub trait AnyDelimiter {
+    /// Returns the delimiter, the span of the delimiter token, and the nested
+    /// contents for further parsing.
+    fn parse_any_delimiter(&self) -> Result<(Delimiter, DelimSpan, ParseBuffer)>;
+}
+
+impl<'a> AnyDelimiter for ParseBuffer<'a> {
+    fn parse_any_delimiter(&self) -> Result<(Delimiter, DelimSpan, ParseBuffer)> {
+        self.step(|cursor| {
+            if let Some((content, delimiter, span, rest)) = cursor.any_group() {
+                let scope = crate::buffer::close_span_of_group(*cursor);
+                let nested = crate::parse::advance_step_cursor(cursor, content);
+                let unexpected = crate::parse::get_unexpected(self);
+                let content = crate::parse::new_parse_buffer(scope, nested, unexpected);
+                Ok(((delimiter, span, content), rest))
+            } else {
+                Err(cursor.error("expected any delimiter"))
+            }
+        })
+    }
+}
diff --git a/vendor/syn/src/drops.rs b/vendor/syn/src/drops.rs
new file mode 100644
index 0000000..89b42d8
--- /dev/null
+++ b/vendor/syn/src/drops.rs
@@ -0,0 +1,58 @@
+use std::iter;
+use std::mem::ManuallyDrop;
+use std::ops::{Deref, DerefMut};
+use std::option;
+use std::slice;
+
+#[repr(transparent)]
+pub(crate) struct NoDrop<T: ?Sized>(ManuallyDrop<T>);
+
+impl<T> NoDrop<T> {
+    pub(crate) fn new(value: T) -> Self
+    where
+        T: TrivialDrop,
+    {
+        NoDrop(ManuallyDrop::new(value))
+    }
+}
+
+impl<T: ?Sized> Deref for NoDrop<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T: ?Sized> DerefMut for NoDrop<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+pub(crate) trait TrivialDrop {}
+
+impl<T> TrivialDrop for iter::Empty<T> {}
+impl<'a, T> TrivialDrop for slice::Iter<'a, T> {}
+impl<'a, T> TrivialDrop for slice::IterMut<'a, T> {}
+impl<'a, T> TrivialDrop for option::IntoIter<&'a T> {}
+impl<'a, T> TrivialDrop for option::IntoIter<&'a mut T> {}
+
+#[test]
+fn test_needs_drop() {
+    use std::mem::needs_drop;
+
+    struct NeedsDrop;
+
+    impl Drop for NeedsDrop {
+        fn drop(&mut self) {}
+    }
+
+    assert!(needs_drop::<NeedsDrop>());
+
+    // Test each of the types with a handwritten TrivialDrop impl above.
+    assert!(!needs_drop::<iter::Empty<NeedsDrop>>());
+    assert!(!needs_drop::<slice::Iter<NeedsDrop>>());
+    assert!(!needs_drop::<slice::IterMut<NeedsDrop>>());
+    assert!(!needs_drop::<option::IntoIter<&NeedsDrop>>());
+    assert!(!needs_drop::<option::IntoIter<&mut NeedsDrop>>());
+}
diff --git a/vendor/syn/src/error.rs b/vendor/syn/src/error.rs
new file mode 100644
index 0000000..3fe31d5
--- /dev/null
+++ b/vendor/syn/src/error.rs
@@ -0,0 +1,466 @@
+#[cfg(feature = "parsing")]
+use crate::buffer::Cursor;
+use crate::thread::ThreadBound;
+use proc_macro2::{
+    Delimiter, Group, Ident, LexError, Literal, Punct, Spacing, Span, TokenStream, TokenTree,
+};
+#[cfg(feature = "printing")]
+use quote::ToTokens;
+use std::fmt::{self, Debug, Display};
+use std::slice;
+use std::vec;
+
+/// The result of a Syn parser.
+pub type Result<T> = std::result::Result<T, Error>;
+
+/// Error returned when a Syn parser cannot parse the input tokens.
+///
+/// # Error reporting in proc macros
+///
+/// The correct way to report errors back to the compiler from a procedural
+/// macro is by emitting an appropriately spanned invocation of
+/// [`compile_error!`] in the generated code. This produces a better diagnostic
+/// message than simply panicking the macro.
+///
+/// [`compile_error!`]: std::compile_error!
+///
+/// When parsing macro input, the [`parse_macro_input!`] macro handles the
+/// conversion to `compile_error!` automatically.
+///
+/// [`parse_macro_input!`]: crate::parse_macro_input!
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use syn::parse::{Parse, ParseStream, Result};
+/// use syn::{parse_macro_input, ItemFn};
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro_attribute]
+/// # };
+/// pub fn my_attr(args: TokenStream, input: TokenStream) -> TokenStream {
+///     let args = parse_macro_input!(args as MyAttrArgs);
+///     let input = parse_macro_input!(input as ItemFn);
+///
+///     /* ... */
+///     # TokenStream::new()
+/// }
+///
+/// struct MyAttrArgs {
+///     # _k: [(); { stringify! {
+///     ...
+///     # }; 0 }]
+/// }
+///
+/// impl Parse for MyAttrArgs {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         # stringify! {
+///         ...
+///         # };
+///         # unimplemented!()
+///     }
+/// }
+/// ```
+///
+/// For errors that arise later than the initial parsing stage, the
+/// [`.to_compile_error()`] or [`.into_compile_error()`] methods can be used to
+/// perform an explicit conversion to `compile_error!`.
+///
+/// [`.to_compile_error()`]: Error::to_compile_error
+/// [`.into_compile_error()`]: Error::into_compile_error
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// # use proc_macro::TokenStream;
+/// # use syn::{parse_macro_input, DeriveInput};
+/// #
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro_derive(MyDerive)]
+/// # };
+/// pub fn my_derive(input: TokenStream) -> TokenStream {
+///     let input = parse_macro_input!(input as DeriveInput);
+///
+///     // fn(DeriveInput) -> syn::Result<proc_macro2::TokenStream>
+///     expand::my_derive(input)
+///         .unwrap_or_else(syn::Error::into_compile_error)
+///         .into()
+/// }
+/// #
+/// # mod expand {
+/// #     use proc_macro2::TokenStream;
+/// #     use syn::{DeriveInput, Result};
+/// #
+/// #     pub fn my_derive(input: DeriveInput) -> Result<TokenStream> {
+/// #         unimplemented!()
+/// #     }
+/// # }
+/// ```
+pub struct Error {
+    messages: Vec<ErrorMessage>,
+}
+
+struct ErrorMessage {
+    // Span is implemented as an index into a thread-local interner to keep the
+    // size small. It is not safe to access from a different thread. We want
+    // errors to be Send and Sync to play nicely with ecosystem crates for error
+    // handling, so pin the span we're given to its original thread and assume
+    // it is Span::call_site if accessed from any other thread.
+    span: ThreadBound<SpanRange>,
+    message: String,
+}
+
+// Cannot use std::ops::Range<Span> because that does not implement Copy,
+// whereas ThreadBound<T> requires a Copy impl as a way to ensure no Drop impls
+// are involved.
+struct SpanRange {
+    start: Span,
+    end: Span,
+}
+
+#[cfg(test)]
+struct _Test
+where
+    Error: Send + Sync;
+
+impl Error {
+    /// Usually the [`ParseStream::error`] method will be used instead, which
+    /// automatically uses the correct span from the current position of the
+    /// parse stream.
+    ///
+    /// Use `Error::new` when the error needs to be triggered on some span other
+    /// than where the parse stream is currently positioned.
+    ///
+    /// [`ParseStream::error`]: crate::parse::ParseBuffer::error
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{Error, Ident, LitStr, Result, Token};
+    /// use syn::parse::ParseStream;
+    ///
+    /// // Parses input that looks like `name = "string"` where the key must be
+    /// // the identifier `name` and the value may be any string literal.
+    /// // Returns the string literal.
+    /// fn parse_name(input: ParseStream) -> Result<LitStr> {
+    ///     let name_token: Ident = input.parse()?;
+    ///     if name_token != "name" {
+    ///         // Trigger an error not on the current position of the stream,
+    ///         // but on the position of the unexpected identifier.
+    ///         return Err(Error::new(name_token.span(), "expected `name`"));
+    ///     }
+    ///     input.parse::<Token![=]>()?;
+    ///     let s: LitStr = input.parse()?;
+    ///     Ok(s)
+    /// }
+    /// ```
+    pub fn new<T: Display>(span: Span, message: T) -> Self {
+        return new(span, message.to_string());
+
+        fn new(span: Span, message: String) -> Error {
+            Error {
+                messages: vec![ErrorMessage {
+                    span: ThreadBound::new(SpanRange {
+                        start: span,
+                        end: span,
+                    }),
+                    message,
+                }],
+            }
+        }
+    }
+
+    /// Creates an error with the specified message spanning the given syntax
+    /// tree node.
+    ///
+    /// Unlike the `Error::new` constructor, this constructor takes an argument
+    /// `tokens` which is a syntax tree node. This allows the resulting `Error`
+    /// to attempt to span all tokens inside of `tokens`. While you would
+    /// typically be able to use the `Spanned` trait with the above `Error::new`
+    /// constructor, implementation limitations today mean that
+    /// `Error::new_spanned` may provide a higher-quality error message on
+    /// stable Rust.
+    ///
+    /// When in doubt it's recommended to stick to `Error::new` (or
+    /// `ParseStream::error`)!
+    #[cfg(feature = "printing")]
+    pub fn new_spanned<T: ToTokens, U: Display>(tokens: T, message: U) -> Self {
+        return new_spanned(tokens.into_token_stream(), message.to_string());
+
+        fn new_spanned(tokens: TokenStream, message: String) -> Error {
+            let mut iter = tokens.into_iter();
+            let start = iter.next().map_or_else(Span::call_site, |t| t.span());
+            let end = iter.last().map_or(start, |t| t.span());
+            Error {
+                messages: vec![ErrorMessage {
+                    span: ThreadBound::new(SpanRange { start, end }),
+                    message,
+                }],
+            }
+        }
+    }
+
+    /// The source location of the error.
+    ///
+    /// Spans are not thread-safe so this function returns `Span::call_site()`
+    /// if called from a different thread than the one on which the `Error` was
+    /// originally created.
+    pub fn span(&self) -> Span {
+        let SpanRange { start, end } = match self.messages[0].span.get() {
+            Some(span) => *span,
+            None => return Span::call_site(),
+        };
+        start.join(end).unwrap_or(start)
+    }
+
+    /// Render the error as an invocation of [`compile_error!`].
+    ///
+    /// The [`parse_macro_input!`] macro provides a convenient way to invoke
+    /// this method correctly in a procedural macro.
+    ///
+    /// [`compile_error!`]: std::compile_error!
+    /// [`parse_macro_input!`]: crate::parse_macro_input!
+    pub fn to_compile_error(&self) -> TokenStream {
+        self.messages
+            .iter()
+            .map(ErrorMessage::to_compile_error)
+            .collect()
+    }
+
+    /// Render the error as an invocation of [`compile_error!`].
+    ///
+    /// [`compile_error!`]: std::compile_error!
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # extern crate proc_macro;
+    /// #
+    /// use proc_macro::TokenStream;
+    /// use syn::{parse_macro_input, DeriveInput, Error};
+    ///
+    /// # const _: &str = stringify! {
+    /// #[proc_macro_derive(MyTrait)]
+    /// # };
+    /// pub fn derive_my_trait(input: TokenStream) -> TokenStream {
+    ///     let input = parse_macro_input!(input as DeriveInput);
+    ///     my_trait::expand(input)
+    ///         .unwrap_or_else(Error::into_compile_error)
+    ///         .into()
+    /// }
+    ///
+    /// mod my_trait {
+    ///     use proc_macro2::TokenStream;
+    ///     use syn::{DeriveInput, Result};
+    ///
+    ///     pub(crate) fn expand(input: DeriveInput) -> Result<TokenStream> {
+    ///         /* ... */
+    ///         # unimplemented!()
+    ///     }
+    /// }
+    /// ```
+    pub fn into_compile_error(self) -> TokenStream {
+        self.to_compile_error()
+    }
+
+    /// Add another error message to self such that when `to_compile_error()` is
+    /// called, both errors will be emitted together.
+    pub fn combine(&mut self, another: Error) {
+        self.messages.extend(another.messages);
+    }
+}
+
+impl ErrorMessage {
+    fn to_compile_error(&self) -> TokenStream {
+        let (start, end) = match self.span.get() {
+            Some(range) => (range.start, range.end),
+            None => (Span::call_site(), Span::call_site()),
+        };
+
+        // ::core::compile_error!($message)
+        TokenStream::from_iter(vec![
+            TokenTree::Punct({
+                let mut punct = Punct::new(':', Spacing::Joint);
+                punct.set_span(start);
+                punct
+            }),
+            TokenTree::Punct({
+                let mut punct = Punct::new(':', Spacing::Alone);
+                punct.set_span(start);
+                punct
+            }),
+            TokenTree::Ident(Ident::new("core", start)),
+            TokenTree::Punct({
+                let mut punct = Punct::new(':', Spacing::Joint);
+                punct.set_span(start);
+                punct
+            }),
+            TokenTree::Punct({
+                let mut punct = Punct::new(':', Spacing::Alone);
+                punct.set_span(start);
+                punct
+            }),
+            TokenTree::Ident(Ident::new("compile_error", start)),
+            TokenTree::Punct({
+                let mut punct = Punct::new('!', Spacing::Alone);
+                punct.set_span(start);
+                punct
+            }),
+            TokenTree::Group({
+                let mut group = Group::new(Delimiter::Brace, {
+                    TokenStream::from_iter(vec![TokenTree::Literal({
+                        let mut string = Literal::string(&self.message);
+                        string.set_span(end);
+                        string
+                    })])
+                });
+                group.set_span(end);
+                group
+            }),
+        ])
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) fn new_at<T: Display>(scope: Span, cursor: Cursor, message: T) -> Error {
+    if cursor.eof() {
+        Error::new(scope, format!("unexpected end of input, {}", message))
+    } else {
+        let span = crate::buffer::open_span_of_group(cursor);
+        Error::new(span, message)
+    }
+}
+
+#[cfg(all(feature = "parsing", any(feature = "full", feature = "derive")))]
+pub(crate) fn new2<T: Display>(start: Span, end: Span, message: T) -> Error {
+    return new2(start, end, message.to_string());
+
+    fn new2(start: Span, end: Span, message: String) -> Error {
+        Error {
+            messages: vec![ErrorMessage {
+                span: ThreadBound::new(SpanRange { start, end }),
+                message,
+            }],
+        }
+    }
+}
+
+impl Debug for Error {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        if self.messages.len() == 1 {
+            formatter
+                .debug_tuple("Error")
+                .field(&self.messages[0])
+                .finish()
+        } else {
+            formatter
+                .debug_tuple("Error")
+                .field(&self.messages)
+                .finish()
+        }
+    }
+}
+
+impl Debug for ErrorMessage {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.message, formatter)
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(&self.messages[0].message)
+    }
+}
+
+impl Clone for Error {
+    fn clone(&self) -> Self {
+        Error {
+            messages: self.messages.clone(),
+        }
+    }
+}
+
+impl Clone for ErrorMessage {
+    fn clone(&self) -> Self {
+        ErrorMessage {
+            span: self.span,
+            message: self.message.clone(),
+        }
+    }
+}
+
+impl Clone for SpanRange {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl Copy for SpanRange {}
+
+impl std::error::Error for Error {}
+
+impl From<LexError> for Error {
+    fn from(err: LexError) -> Self {
+        Error::new(err.span(), "lex error")
+    }
+}
+
+impl IntoIterator for Error {
+    type Item = Error;
+    type IntoIter = IntoIter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter {
+            messages: self.messages.into_iter(),
+        }
+    }
+}
+
+pub struct IntoIter {
+    messages: vec::IntoIter<ErrorMessage>,
+}
+
+impl Iterator for IntoIter {
+    type Item = Error;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(Error {
+            messages: vec![self.messages.next()?],
+        })
+    }
+}
+
+impl<'a> IntoIterator for &'a Error {
+    type Item = Error;
+    type IntoIter = Iter<'a>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Iter {
+            messages: self.messages.iter(),
+        }
+    }
+}
+
+pub struct Iter<'a> {
+    messages: slice::Iter<'a, ErrorMessage>,
+}
+
+impl<'a> Iterator for Iter<'a> {
+    type Item = Error;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(Error {
+            messages: vec![self.messages.next()?.clone()],
+        })
+    }
+}
+
+impl Extend<Error> for Error {
+    fn extend<T: IntoIterator<Item = Error>>(&mut self, iter: T) {
+        for err in iter {
+            self.combine(err);
+        }
+    }
+}
diff --git a/vendor/syn/src/export.rs b/vendor/syn/src/export.rs
new file mode 100644
index 0000000..febd322
--- /dev/null
+++ b/vendor/syn/src/export.rs
@@ -0,0 +1,69 @@
+#[doc(hidden)]
+pub use std::clone::Clone;
+#[doc(hidden)]
+pub use std::cmp::{Eq, PartialEq};
+#[doc(hidden)]
+pub use std::concat;
+#[doc(hidden)]
+pub use std::default::Default;
+#[doc(hidden)]
+pub use std::fmt::Debug;
+#[doc(hidden)]
+pub use std::hash::{Hash, Hasher};
+#[doc(hidden)]
+pub use std::marker::Copy;
+#[doc(hidden)]
+pub use std::option::Option::{None, Some};
+#[doc(hidden)]
+pub use std::result::Result::{Err, Ok};
+#[doc(hidden)]
+pub use std::stringify;
+
+#[doc(hidden)]
+pub type Formatter<'a> = std::fmt::Formatter<'a>;
+#[doc(hidden)]
+pub type FmtResult = std::fmt::Result;
+
+#[doc(hidden)]
+pub type bool = std::primitive::bool;
+#[doc(hidden)]
+pub type str = std::primitive::str;
+
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+pub use quote;
+
+#[doc(hidden)]
+pub type Span = proc_macro2::Span;
+#[doc(hidden)]
+pub type TokenStream2 = proc_macro2::TokenStream;
+
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+pub use crate::group::{parse_braces, parse_brackets, parse_parens};
+
+#[doc(hidden)]
+pub use crate::span::IntoSpans;
+
+#[cfg(all(feature = "parsing", feature = "printing"))]
+#[doc(hidden)]
+pub use crate::parse_quote::parse as parse_quote;
+
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+pub use crate::token::parsing::{peek_punct, punct as parse_punct};
+
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+pub use crate::token::printing::punct as print_punct;
+
+#[cfg(feature = "proc-macro")]
+#[doc(hidden)]
+pub type TokenStream = proc_macro::TokenStream;
+
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+pub use quote::{ToTokens, TokenStreamExt};
+
+#[doc(hidden)]
+pub struct private(pub(crate) ());
diff --git a/vendor/syn/src/expr.rs b/vendor/syn/src/expr.rs
new file mode 100644
index 0000000..ae72324
--- /dev/null
+++ b/vendor/syn/src/expr.rs
@@ -0,0 +1,3377 @@
+use super::*;
+use crate::punctuated::Punctuated;
+use proc_macro2::{Span, TokenStream};
+#[cfg(feature = "printing")]
+use quote::IdentFragment;
+#[cfg(feature = "printing")]
+use std::fmt::{self, Display};
+use std::hash::{Hash, Hasher};
+#[cfg(feature = "parsing")]
+use std::mem;
+
+ast_enum_of_structs! {
+    /// A Rust expression.
+    ///
+    /// *This type is available only if Syn is built with the `"derive"` or `"full"`
+    /// feature, but most of the variants are not available unless "full" is enabled.*
+    ///
+    /// # Syntax tree enums
+    ///
+    /// This type is a syntax tree enum. In Syn this and other syntax tree enums
+    /// are designed to be traversed using the following rebinding idiom.
+    ///
+    /// ```
+    /// # use syn::Expr;
+    /// #
+    /// # fn example(expr: Expr) {
+    /// # const IGNORE: &str = stringify! {
+    /// let expr: Expr = /* ... */;
+    /// # };
+    /// match expr {
+    ///     Expr::MethodCall(expr) => {
+    ///         /* ... */
+    ///     }
+    ///     Expr::Cast(expr) => {
+    ///         /* ... */
+    ///     }
+    ///     Expr::If(expr) => {
+    ///         /* ... */
+    ///     }
+    ///
+    ///     /* ... */
+    ///     # _ => {}
+    /// # }
+    /// # }
+    /// ```
+    ///
+    /// We begin with a variable `expr` of type `Expr` that has no fields
+    /// (because it is an enum), and by matching on it and rebinding a variable
+    /// with the same name `expr` we effectively imbue our variable with all of
+    /// the data fields provided by the variant that it turned out to be. So for
+    /// example above if we ended up in the `MethodCall` case then we get to use
+    /// `expr.receiver`, `expr.args` etc; if we ended up in the `If` case we get
+    /// to use `expr.cond`, `expr.then_branch`, `expr.else_branch`.
+    ///
+    /// This approach avoids repeating the variant names twice on every line.
+    ///
+    /// ```
+    /// # use syn::{Expr, ExprMethodCall};
+    /// #
+    /// # fn example(expr: Expr) {
+    /// // Repetitive; recommend not doing this.
+    /// match expr {
+    ///     Expr::MethodCall(ExprMethodCall { method, args, .. }) => {
+    /// # }
+    /// # _ => {}
+    /// # }
+    /// # }
+    /// ```
+    ///
+    /// In general, the name to which a syntax tree enum variant is bound should
+    /// be a suitable name for the complete syntax tree enum type.
+    ///
+    /// ```
+    /// # use syn::{Expr, ExprField};
+    /// #
+    /// # fn example(discriminant: ExprField) {
+    /// // Binding is called `base` which is the name I would use if I were
+    /// // assigning `*discriminant.base` without an `if let`.
+    /// if let Expr::Tuple(base) = *discriminant.base {
+    /// # }
+    /// # }
+    /// ```
+    ///
+    /// A sign that you may not be choosing the right variable names is if you
+    /// see names getting repeated in your code, like accessing
+    /// `receiver.receiver` or `pat.pat` or `cond.cond`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum Expr {
+        /// A slice literal expression: `[a, b, c, d]`.
+        Array(ExprArray),
+
+        /// An assignment expression: `a = compute()`.
+        Assign(ExprAssign),
+
+        /// An async block: `async { ... }`.
+        Async(ExprAsync),
+
+        /// An await expression: `fut.await`.
+        Await(ExprAwait),
+
+        /// A binary operation: `a + b`, `a += b`.
+        Binary(ExprBinary),
+
+        /// A blocked scope: `{ ... }`.
+        Block(ExprBlock),
+
+        /// A `break`, with an optional label to break and an optional
+        /// expression.
+        Break(ExprBreak),
+
+        /// A function call expression: `invoke(a, b)`.
+        Call(ExprCall),
+
+        /// A cast expression: `foo as f64`.
+        Cast(ExprCast),
+
+        /// A closure expression: `|a, b| a + b`.
+        Closure(ExprClosure),
+
+        /// A const block: `const { ... }`.
+        Const(ExprConst),
+
+        /// A `continue`, with an optional label.
+        Continue(ExprContinue),
+
+        /// Access of a named struct field (`obj.k`) or unnamed tuple struct
+        /// field (`obj.0`).
+        Field(ExprField),
+
+        /// A for loop: `for pat in expr { ... }`.
+        ForLoop(ExprForLoop),
+
+        /// An expression contained within invisible delimiters.
+        ///
+        /// This variant is important for faithfully representing the precedence
+        /// of expressions and is related to `None`-delimited spans in a
+        /// `TokenStream`.
+        Group(ExprGroup),
+
+        /// An `if` expression with an optional `else` block: `if expr { ... }
+        /// else { ... }`.
+        ///
+        /// The `else` branch expression may only be an `If` or `Block`
+        /// expression, not any of the other types of expression.
+        If(ExprIf),
+
+        /// A square bracketed indexing expression: `vector[2]`.
+        Index(ExprIndex),
+
+        /// The inferred value of a const generic argument, denoted `_`.
+        Infer(ExprInfer),
+
+        /// A `let` guard: `let Some(x) = opt`.
+        Let(ExprLet),
+
+        /// A literal in place of an expression: `1`, `"foo"`.
+        Lit(ExprLit),
+
+        /// Conditionless loop: `loop { ... }`.
+        Loop(ExprLoop),
+
+        /// A macro invocation expression: `format!("{}", q)`.
+        Macro(ExprMacro),
+
+        /// A `match` expression: `match n { Some(n) => {}, None => {} }`.
+        Match(ExprMatch),
+
+        /// A method call expression: `x.foo::<T>(a, b)`.
+        MethodCall(ExprMethodCall),
+
+        /// A parenthesized expression: `(a + b)`.
+        Paren(ExprParen),
+
+        /// A path like `std::mem::replace` possibly containing generic
+        /// parameters and a qualified self-type.
+        ///
+        /// A plain identifier like `x` is a path of length 1.
+        Path(ExprPath),
+
+        /// A range expression: `1..2`, `1..`, `..2`, `1..=2`, `..=2`.
+        Range(ExprRange),
+
+        /// A referencing operation: `&a` or `&mut a`.
+        Reference(ExprReference),
+
+        /// An array literal constructed from one repeated element: `[0u8; N]`.
+        Repeat(ExprRepeat),
+
+        /// A `return`, with an optional value to be returned.
+        Return(ExprReturn),
+
+        /// A struct literal expression: `Point { x: 1, y: 1 }`.
+        ///
+        /// The `rest` provides the value of the remaining fields as in `S { a:
+        /// 1, b: 1, ..rest }`.
+        Struct(ExprStruct),
+
+        /// A try-expression: `expr?`.
+        Try(ExprTry),
+
+        /// A try block: `try { ... }`.
+        TryBlock(ExprTryBlock),
+
+        /// A tuple expression: `(a, b, c, d)`.
+        Tuple(ExprTuple),
+
+        /// A unary operation: `!x`, `*x`.
+        Unary(ExprUnary),
+
+        /// An unsafe block: `unsafe { ... }`.
+        Unsafe(ExprUnsafe),
+
+        /// Tokens in expression position not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        /// A while loop: `while expr { ... }`.
+        While(ExprWhile),
+
+        /// A yield expression: `yield expr`.
+        Yield(ExprYield),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match expr {
+        //         Expr::Array(expr) => {...}
+        //         Expr::Assign(expr) => {...}
+        //         ...
+        //         Expr::Yield(expr) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A slice literal expression: `[a, b, c, d]`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprArray #full {
+        pub attrs: Vec<Attribute>,
+        pub bracket_token: token::Bracket,
+        pub elems: Punctuated<Expr, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// An assignment expression: `a = compute()`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprAssign #full {
+        pub attrs: Vec<Attribute>,
+        pub left: Box<Expr>,
+        pub eq_token: Token![=],
+        pub right: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// An async block: `async { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprAsync #full {
+        pub attrs: Vec<Attribute>,
+        pub async_token: Token![async],
+        pub capture: Option<Token![move]>,
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// An await expression: `fut.await`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprAwait #full {
+        pub attrs: Vec<Attribute>,
+        pub base: Box<Expr>,
+        pub dot_token: Token![.],
+        pub await_token: Token![await],
+    }
+}
+
+ast_struct! {
+    /// A binary operation: `a + b`, `a += b`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprBinary {
+        pub attrs: Vec<Attribute>,
+        pub left: Box<Expr>,
+        pub op: BinOp,
+        pub right: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A blocked scope: `{ ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprBlock #full {
+        pub attrs: Vec<Attribute>,
+        pub label: Option<Label>,
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// A `break`, with an optional label to break and an optional
+    /// expression.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprBreak #full {
+        pub attrs: Vec<Attribute>,
+        pub break_token: Token![break],
+        pub label: Option<Lifetime>,
+        pub expr: Option<Box<Expr>>,
+    }
+}
+
+ast_struct! {
+    /// A function call expression: `invoke(a, b)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprCall {
+        pub attrs: Vec<Attribute>,
+        pub func: Box<Expr>,
+        pub paren_token: token::Paren,
+        pub args: Punctuated<Expr, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A cast expression: `foo as f64`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprCast {
+        pub attrs: Vec<Attribute>,
+        pub expr: Box<Expr>,
+        pub as_token: Token![as],
+        pub ty: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A closure expression: `|a, b| a + b`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprClosure #full {
+        pub attrs: Vec<Attribute>,
+        pub lifetimes: Option<BoundLifetimes>,
+        pub constness: Option<Token![const]>,
+        pub movability: Option<Token![static]>,
+        pub asyncness: Option<Token![async]>,
+        pub capture: Option<Token![move]>,
+        pub or1_token: Token![|],
+        pub inputs: Punctuated<Pat, Token![,]>,
+        pub or2_token: Token![|],
+        pub output: ReturnType,
+        pub body: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A const block: `const { ... }`.
+    pub struct ExprConst #full {
+        pub attrs: Vec<Attribute>,
+        pub const_token: Token![const],
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// A `continue`, with an optional label.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprContinue #full {
+        pub attrs: Vec<Attribute>,
+        pub continue_token: Token![continue],
+        pub label: Option<Lifetime>,
+    }
+}
+
+ast_struct! {
+    /// Access of a named struct field (`obj.k`) or unnamed tuple struct
+    /// field (`obj.0`).
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprField {
+        pub attrs: Vec<Attribute>,
+        pub base: Box<Expr>,
+        pub dot_token: Token![.],
+        pub member: Member,
+    }
+}
+
+ast_struct! {
+    /// A for loop: `for pat in expr { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprForLoop #full {
+        pub attrs: Vec<Attribute>,
+        pub label: Option<Label>,
+        pub for_token: Token![for],
+        pub pat: Box<Pat>,
+        pub in_token: Token![in],
+        pub expr: Box<Expr>,
+        pub body: Block,
+    }
+}
+
+ast_struct! {
+    /// An expression contained within invisible delimiters.
+    ///
+    /// This variant is important for faithfully representing the precedence
+    /// of expressions and is related to `None`-delimited spans in a
+    /// `TokenStream`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprGroup {
+        pub attrs: Vec<Attribute>,
+        pub group_token: token::Group,
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// An `if` expression with an optional `else` block: `if expr { ... }
+    /// else { ... }`.
+    ///
+    /// The `else` branch expression may only be an `If` or `Block`
+    /// expression, not any of the other types of expression.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprIf #full {
+        pub attrs: Vec<Attribute>,
+        pub if_token: Token![if],
+        pub cond: Box<Expr>,
+        pub then_branch: Block,
+        pub else_branch: Option<(Token![else], Box<Expr>)>,
+    }
+}
+
+ast_struct! {
+    /// A square bracketed indexing expression: `vector[2]`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprIndex {
+        pub attrs: Vec<Attribute>,
+        pub expr: Box<Expr>,
+        pub bracket_token: token::Bracket,
+        pub index: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// The inferred value of a const generic argument, denoted `_`.
+    pub struct ExprInfer #full {
+        pub attrs: Vec<Attribute>,
+        pub underscore_token: Token![_],
+    }
+}
+
+ast_struct! {
+    /// A `let` guard: `let Some(x) = opt`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprLet #full {
+        pub attrs: Vec<Attribute>,
+        pub let_token: Token![let],
+        pub pat: Box<Pat>,
+        pub eq_token: Token![=],
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A literal in place of an expression: `1`, `"foo"`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprLit {
+        pub attrs: Vec<Attribute>,
+        pub lit: Lit,
+    }
+}
+
+ast_struct! {
+    /// Conditionless loop: `loop { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprLoop #full {
+        pub attrs: Vec<Attribute>,
+        pub label: Option<Label>,
+        pub loop_token: Token![loop],
+        pub body: Block,
+    }
+}
+
+ast_struct! {
+    /// A macro invocation expression: `format!("{}", q)`.
+    pub struct ExprMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+    }
+}
+
+ast_struct! {
+    /// A `match` expression: `match n { Some(n) => {}, None => {} }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprMatch #full {
+        pub attrs: Vec<Attribute>,
+        pub match_token: Token![match],
+        pub expr: Box<Expr>,
+        pub brace_token: token::Brace,
+        pub arms: Vec<Arm>,
+    }
+}
+
+ast_struct! {
+    /// A method call expression: `x.foo::<T>(a, b)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprMethodCall #full {
+        pub attrs: Vec<Attribute>,
+        pub receiver: Box<Expr>,
+        pub dot_token: Token![.],
+        pub method: Ident,
+        pub turbofish: Option<AngleBracketedGenericArguments>,
+        pub paren_token: token::Paren,
+        pub args: Punctuated<Expr, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A parenthesized expression: `(a + b)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprParen {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A path like `std::mem::replace` possibly containing generic
+    /// parameters and a qualified self-type.
+    ///
+    /// A plain identifier like `x` is a path of length 1.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprPath {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+    }
+}
+
+ast_struct! {
+    /// A range expression: `1..2`, `1..`, `..2`, `1..=2`, `..=2`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprRange #full {
+        pub attrs: Vec<Attribute>,
+        pub start: Option<Box<Expr>>,
+        pub limits: RangeLimits,
+        pub end: Option<Box<Expr>>,
+    }
+}
+
+ast_struct! {
+    /// A referencing operation: `&a` or `&mut a`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprReference #full {
+        pub attrs: Vec<Attribute>,
+        pub and_token: Token![&],
+        pub mutability: Option<Token![mut]>,
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// An array literal constructed from one repeated element: `[0u8; N]`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprRepeat #full {
+        pub attrs: Vec<Attribute>,
+        pub bracket_token: token::Bracket,
+        pub expr: Box<Expr>,
+        pub semi_token: Token![;],
+        pub len: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A `return`, with an optional value to be returned.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprReturn #full {
+        pub attrs: Vec<Attribute>,
+        pub return_token: Token![return],
+        pub expr: Option<Box<Expr>>,
+    }
+}
+
+ast_struct! {
+    /// A struct literal expression: `Point { x: 1, y: 1 }`.
+    ///
+    /// The `rest` provides the value of the remaining fields as in `S { a:
+    /// 1, b: 1, ..rest }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprStruct #full {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+        pub brace_token: token::Brace,
+        pub fields: Punctuated<FieldValue, Token![,]>,
+        pub dot2_token: Option<Token![..]>,
+        pub rest: Option<Box<Expr>>,
+    }
+}
+
+ast_struct! {
+    /// A try-expression: `expr?`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprTry #full {
+        pub attrs: Vec<Attribute>,
+        pub expr: Box<Expr>,
+        pub question_token: Token![?],
+    }
+}
+
+ast_struct! {
+    /// A try block: `try { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprTryBlock #full {
+        pub attrs: Vec<Attribute>,
+        pub try_token: Token![try],
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// A tuple expression: `(a, b, c, d)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprTuple #full {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Expr, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A unary operation: `!x`, `*x`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprUnary {
+        pub attrs: Vec<Attribute>,
+        pub op: UnOp,
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// An unsafe block: `unsafe { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprUnsafe #full {
+        pub attrs: Vec<Attribute>,
+        pub unsafe_token: Token![unsafe],
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// A while loop: `while expr { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprWhile #full {
+        pub attrs: Vec<Attribute>,
+        pub label: Option<Label>,
+        pub while_token: Token![while],
+        pub cond: Box<Expr>,
+        pub body: Block,
+    }
+}
+
+ast_struct! {
+    /// A yield expression: `yield expr`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ExprYield #full {
+        pub attrs: Vec<Attribute>,
+        pub yield_token: Token![yield],
+        pub expr: Option<Box<Expr>>,
+    }
+}
+
+impl Expr {
+    #[cfg(feature = "parsing")]
+    const DUMMY: Self = Expr::Path(ExprPath {
+        attrs: Vec::new(),
+        qself: None,
+        path: Path {
+            leading_colon: None,
+            segments: Punctuated::new(),
+        },
+    });
+
+    #[cfg(all(feature = "parsing", feature = "full"))]
+    pub(crate) fn replace_attrs(&mut self, new: Vec<Attribute>) -> Vec<Attribute> {
+        match self {
+            Expr::Array(ExprArray { attrs, .. })
+            | Expr::Assign(ExprAssign { attrs, .. })
+            | Expr::Async(ExprAsync { attrs, .. })
+            | Expr::Await(ExprAwait { attrs, .. })
+            | Expr::Binary(ExprBinary { attrs, .. })
+            | Expr::Block(ExprBlock { attrs, .. })
+            | Expr::Break(ExprBreak { attrs, .. })
+            | Expr::Call(ExprCall { attrs, .. })
+            | Expr::Cast(ExprCast { attrs, .. })
+            | Expr::Closure(ExprClosure { attrs, .. })
+            | Expr::Const(ExprConst { attrs, .. })
+            | Expr::Continue(ExprContinue { attrs, .. })
+            | Expr::Field(ExprField { attrs, .. })
+            | Expr::ForLoop(ExprForLoop { attrs, .. })
+            | Expr::Group(ExprGroup { attrs, .. })
+            | Expr::If(ExprIf { attrs, .. })
+            | Expr::Index(ExprIndex { attrs, .. })
+            | Expr::Infer(ExprInfer { attrs, .. })
+            | Expr::Let(ExprLet { attrs, .. })
+            | Expr::Lit(ExprLit { attrs, .. })
+            | Expr::Loop(ExprLoop { attrs, .. })
+            | Expr::Macro(ExprMacro { attrs, .. })
+            | Expr::Match(ExprMatch { attrs, .. })
+            | Expr::MethodCall(ExprMethodCall { attrs, .. })
+            | Expr::Paren(ExprParen { attrs, .. })
+            | Expr::Path(ExprPath { attrs, .. })
+            | Expr::Range(ExprRange { attrs, .. })
+            | Expr::Reference(ExprReference { attrs, .. })
+            | Expr::Repeat(ExprRepeat { attrs, .. })
+            | Expr::Return(ExprReturn { attrs, .. })
+            | Expr::Struct(ExprStruct { attrs, .. })
+            | Expr::Try(ExprTry { attrs, .. })
+            | Expr::TryBlock(ExprTryBlock { attrs, .. })
+            | Expr::Tuple(ExprTuple { attrs, .. })
+            | Expr::Unary(ExprUnary { attrs, .. })
+            | Expr::Unsafe(ExprUnsafe { attrs, .. })
+            | Expr::While(ExprWhile { attrs, .. })
+            | Expr::Yield(ExprYield { attrs, .. }) => mem::replace(attrs, new),
+            Expr::Verbatim(_) => Vec::new(),
+        }
+    }
+}
+
+ast_enum! {
+    /// A struct or tuple struct field accessed in a struct literal or field
+    /// expression.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum Member {
+        /// A named field like `self.x`.
+        Named(Ident),
+        /// An unnamed field like `self.0`.
+        Unnamed(Index),
+    }
+}
+
+impl From<Ident> for Member {
+    fn from(ident: Ident) -> Member {
+        Member::Named(ident)
+    }
+}
+
+impl From<Index> for Member {
+    fn from(index: Index) -> Member {
+        Member::Unnamed(index)
+    }
+}
+
+impl From<usize> for Member {
+    fn from(index: usize) -> Member {
+        Member::Unnamed(Index::from(index))
+    }
+}
+
+impl Eq for Member {}
+
+impl PartialEq for Member {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Member::Named(this), Member::Named(other)) => this == other,
+            (Member::Unnamed(this), Member::Unnamed(other)) => this == other,
+            _ => false,
+        }
+    }
+}
+
+impl Hash for Member {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        match self {
+            Member::Named(m) => m.hash(state),
+            Member::Unnamed(m) => m.hash(state),
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+impl IdentFragment for Member {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Member::Named(m) => Display::fmt(m, formatter),
+            Member::Unnamed(m) => Display::fmt(&m.index, formatter),
+        }
+    }
+
+    fn span(&self) -> Option<Span> {
+        match self {
+            Member::Named(m) => Some(m.span()),
+            Member::Unnamed(m) => Some(m.span),
+        }
+    }
+}
+
+ast_struct! {
+    /// The index of an unnamed tuple struct field.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Index {
+        pub index: u32,
+        pub span: Span,
+    }
+}
+
+impl From<usize> for Index {
+    fn from(index: usize) -> Index {
+        assert!(index < u32::max_value() as usize);
+        Index {
+            index: index as u32,
+            span: Span::call_site(),
+        }
+    }
+}
+
+impl Eq for Index {}
+
+impl PartialEq for Index {
+    fn eq(&self, other: &Self) -> bool {
+        self.index == other.index
+    }
+}
+
+impl Hash for Index {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.index.hash(state);
+    }
+}
+
+#[cfg(feature = "printing")]
+impl IdentFragment for Index {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.index, formatter)
+    }
+
+    fn span(&self) -> Option<Span> {
+        Some(self.span)
+    }
+}
+
+#[cfg(feature = "full")]
+ast_struct! {
+    /// A field-value pair in a struct literal.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct FieldValue {
+        pub attrs: Vec<Attribute>,
+        pub member: Member,
+
+        /// The colon in `Struct { x: x }`. If written in shorthand like
+        /// `Struct { x }`, there is no colon.
+        pub colon_token: Option<Token![:]>,
+
+        pub expr: Expr,
+    }
+}
+
+#[cfg(feature = "full")]
+ast_struct! {
+    /// A lifetime labeling a `for`, `while`, or `loop`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Label {
+        pub name: Lifetime,
+        pub colon_token: Token![:],
+    }
+}
+
+#[cfg(feature = "full")]
+ast_struct! {
+    /// One arm of a `match` expression: `0..=10 => { return true; }`.
+    ///
+    /// As in:
+    ///
+    /// ```
+    /// # fn f() -> bool {
+    /// #     let n = 0;
+    /// match n {
+    ///     0..=10 => {
+    ///         return true;
+    ///     }
+    ///     // ...
+    ///     # _ => {}
+    /// }
+    /// #   false
+    /// # }
+    /// ```
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Arm {
+        pub attrs: Vec<Attribute>,
+        pub pat: Pat,
+        pub guard: Option<(Token![if], Box<Expr>)>,
+        pub fat_arrow_token: Token![=>],
+        pub body: Box<Expr>,
+        pub comma: Option<Token![,]>,
+    }
+}
+
+#[cfg(feature = "full")]
+ast_enum! {
+    /// Limit types of a range, inclusive or exclusive.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub enum RangeLimits {
+        /// Inclusive at the beginning, exclusive at the end.
+        HalfOpen(Token![..]),
+        /// Inclusive at the beginning and end.
+        Closed(Token![..=]),
+    }
+}
+
+#[cfg(any(feature = "parsing", feature = "printing"))]
+#[cfg(feature = "full")]
+pub(crate) fn requires_terminator(expr: &Expr) -> bool {
+    // see https://github.com/rust-lang/rust/blob/9a19e7604/compiler/rustc_ast/src/util/classify.rs#L7-L26
+    match expr {
+        Expr::If(_)
+        | Expr::Match(_)
+        | Expr::Block(_) | Expr::Unsafe(_) // both under ExprKind::Block in rustc
+        | Expr::While(_)
+        | Expr::Loop(_)
+        | Expr::ForLoop(_)
+        | Expr::TryBlock(_)
+        | Expr::Const(_) => false,
+        Expr::Array(_)
+        | Expr::Assign(_)
+        | Expr::Async(_)
+        | Expr::Await(_)
+        | Expr::Binary(_)
+        | Expr::Break(_)
+        | Expr::Call(_)
+        | Expr::Cast(_)
+        | Expr::Closure(_)
+        | Expr::Continue(_)
+        | Expr::Field(_)
+        | Expr::Group(_)
+        | Expr::Index(_)
+        | Expr::Infer(_)
+        | Expr::Let(_)
+        | Expr::Lit(_)
+        | Expr::Macro(_)
+        | Expr::MethodCall(_)
+        | Expr::Paren(_)
+        | Expr::Path(_)
+        | Expr::Range(_)
+        | Expr::Reference(_)
+        | Expr::Repeat(_)
+        | Expr::Return(_)
+        | Expr::Struct(_)
+        | Expr::Try(_)
+        | Expr::Tuple(_)
+        | Expr::Unary(_)
+        | Expr::Yield(_)
+        | Expr::Verbatim(_) => true
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::discouraged::Speculative;
+    #[cfg(feature = "full")]
+    use crate::parse::ParseBuffer;
+    use crate::parse::{Parse, ParseStream, Result};
+    use crate::path;
+    use std::cmp::Ordering;
+
+    mod kw {
+        crate::custom_keyword!(builtin);
+        crate::custom_keyword!(raw);
+    }
+
+    // When we're parsing expressions which occur before blocks, like in an if
+    // statement's condition, we cannot parse a struct literal.
+    //
+    // Struct literals are ambiguous in certain positions
+    // https://github.com/rust-lang/rfcs/pull/92
+    #[cfg(feature = "full")]
+    pub(crate) struct AllowStruct(bool);
+
+    enum Precedence {
+        Any,
+        Assign,
+        Range,
+        Or,
+        And,
+        Compare,
+        BitOr,
+        BitXor,
+        BitAnd,
+        Shift,
+        Arithmetic,
+        Term,
+        Cast,
+    }
+
+    impl Precedence {
+        fn of(op: &BinOp) -> Self {
+            match op {
+                BinOp::Add(_) | BinOp::Sub(_) => Precedence::Arithmetic,
+                BinOp::Mul(_) | BinOp::Div(_) | BinOp::Rem(_) => Precedence::Term,
+                BinOp::And(_) => Precedence::And,
+                BinOp::Or(_) => Precedence::Or,
+                BinOp::BitXor(_) => Precedence::BitXor,
+                BinOp::BitAnd(_) => Precedence::BitAnd,
+                BinOp::BitOr(_) => Precedence::BitOr,
+                BinOp::Shl(_) | BinOp::Shr(_) => Precedence::Shift,
+                BinOp::Eq(_)
+                | BinOp::Lt(_)
+                | BinOp::Le(_)
+                | BinOp::Ne(_)
+                | BinOp::Ge(_)
+                | BinOp::Gt(_) => Precedence::Compare,
+                BinOp::AddAssign(_)
+                | BinOp::SubAssign(_)
+                | BinOp::MulAssign(_)
+                | BinOp::DivAssign(_)
+                | BinOp::RemAssign(_)
+                | BinOp::BitXorAssign(_)
+                | BinOp::BitAndAssign(_)
+                | BinOp::BitOrAssign(_)
+                | BinOp::ShlAssign(_)
+                | BinOp::ShrAssign(_) => Precedence::Assign,
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Expr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            ambiguous_expr(
+                input,
+                #[cfg(feature = "full")]
+                AllowStruct(true),
+            )
+        }
+    }
+
+    impl Expr {
+        /// An alternative to the primary `Expr::parse` parser (from the
+        /// [`Parse`] trait) for ambiguous syntactic positions in which a
+        /// trailing brace should not be taken as part of the expression.
+        ///
+        /// Rust grammar has an ambiguity where braces sometimes turn a path
+        /// expression into a struct initialization and sometimes do not. In the
+        /// following code, the expression `S {}` is one expression. Presumably
+        /// there is an empty struct `struct S {}` defined somewhere which it is
+        /// instantiating.
+        ///
+        /// ```
+        /// # struct S;
+        /// # impl std::ops::Deref for S {
+        /// #     type Target = bool;
+        /// #     fn deref(&self) -> &Self::Target {
+        /// #         &true
+        /// #     }
+        /// # }
+        /// let _ = *S {};
+        ///
+        /// // parsed by rustc as: `*(S {})`
+        /// ```
+        ///
+        /// We would want to parse the above using `Expr::parse` after the `=`
+        /// token.
+        ///
+        /// But in the following, `S {}` is *not* a struct init expression.
+        ///
+        /// ```
+        /// # const S: &bool = &true;
+        /// if *S {} {}
+        ///
+        /// // parsed by rustc as:
+        /// //
+        /// //    if (*S) {
+        /// //        /* empty block */
+        /// //    }
+        /// //    {
+        /// //        /* another empty block */
+        /// //    }
+        /// ```
+        ///
+        /// For that reason we would want to parse if-conditions using
+        /// `Expr::parse_without_eager_brace` after the `if` token. Same for
+        /// similar syntactic positions such as the condition expr after a
+        /// `while` token or the expr at the top of a `match`.
+        ///
+        /// The Rust grammar's choices around which way this ambiguity is
+        /// resolved at various syntactic positions is fairly arbitrary. Really
+        /// either parse behavior could work in most positions, and language
+        /// designers just decide each case based on which is more likely to be
+        /// what the programmer had in mind most of the time.
+        ///
+        /// ```
+        /// # struct S;
+        /// # fn doc() -> S {
+        /// if return S {} {}
+        /// # unreachable!()
+        /// # }
+        ///
+        /// // parsed by rustc as:
+        /// //
+        /// //    if (return (S {})) {
+        /// //    }
+        /// //
+        /// // but could equally well have been this other arbitrary choice:
+        /// //
+        /// //    if (return S) {
+        /// //    }
+        /// //    {}
+        /// ```
+        ///
+        /// Note the grammar ambiguity on trailing braces is distinct from
+        /// precedence and is not captured by assigning a precedence level to
+        /// the braced struct init expr in relation to other operators. This can
+        /// be illustrated by `return 0..S {}` vs `match 0..S {}`. The former
+        /// parses as `return (0..(S {}))` implying tighter precedence for
+        /// struct init than `..`, while the latter parses as `match (0..S) {}`
+        /// implying tighter precedence for `..` than struct init, a
+        /// contradiction.
+        #[cfg(feature = "full")]
+        #[cfg_attr(doc_cfg, doc(cfg(all(feature = "full", feature = "parsing"))))]
+        pub fn parse_without_eager_brace(input: ParseStream) -> Result<Expr> {
+            ambiguous_expr(input, AllowStruct(false))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    impl Copy for AllowStruct {}
+
+    #[cfg(feature = "full")]
+    impl Clone for AllowStruct {
+        fn clone(&self) -> Self {
+            *self
+        }
+    }
+
+    impl Copy for Precedence {}
+
+    impl Clone for Precedence {
+        fn clone(&self) -> Self {
+            *self
+        }
+    }
+
+    impl PartialEq for Precedence {
+        fn eq(&self, other: &Self) -> bool {
+            *self as u8 == *other as u8
+        }
+    }
+
+    impl PartialOrd for Precedence {
+        fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+            let this = *self as u8;
+            let other = *other as u8;
+            Some(this.cmp(&other))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn parse_expr(
+        input: ParseStream,
+        mut lhs: Expr,
+        allow_struct: AllowStruct,
+        base: Precedence,
+    ) -> Result<Expr> {
+        loop {
+            let ahead = input.fork();
+            if let Some(op) = match ahead.parse::<BinOp>() {
+                Ok(op) if Precedence::of(&op) >= base => Some(op),
+                _ => None,
+            } {
+                input.advance_to(&ahead);
+                let precedence = Precedence::of(&op);
+                let mut rhs = unary_expr(input, allow_struct)?;
+                loop {
+                    let next = peek_precedence(input);
+                    if next > precedence || next == precedence && precedence == Precedence::Assign {
+                        rhs = parse_expr(input, rhs, allow_struct, next)?;
+                    } else {
+                        break;
+                    }
+                }
+                lhs = Expr::Binary(ExprBinary {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    op,
+                    right: Box::new(rhs),
+                });
+            } else if Precedence::Assign >= base
+                && input.peek(Token![=])
+                && !input.peek(Token![==])
+                && !input.peek(Token![=>])
+            {
+                let eq_token: Token![=] = input.parse()?;
+                let mut rhs = unary_expr(input, allow_struct)?;
+                loop {
+                    let next = peek_precedence(input);
+                    if next >= Precedence::Assign {
+                        rhs = parse_expr(input, rhs, allow_struct, next)?;
+                    } else {
+                        break;
+                    }
+                }
+                lhs = Expr::Assign(ExprAssign {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    eq_token,
+                    right: Box::new(rhs),
+                });
+            } else if Precedence::Range >= base && input.peek(Token![..]) {
+                let limits: RangeLimits = input.parse()?;
+                let rhs = if matches!(limits, RangeLimits::HalfOpen(_))
+                    && (input.is_empty()
+                        || input.peek(Token![,])
+                        || input.peek(Token![;])
+                        || input.peek(Token![.]) && !input.peek(Token![..])
+                        || !allow_struct.0 && input.peek(token::Brace))
+                {
+                    None
+                } else {
+                    let mut rhs = unary_expr(input, allow_struct)?;
+                    loop {
+                        let next = peek_precedence(input);
+                        if next > Precedence::Range {
+                            rhs = parse_expr(input, rhs, allow_struct, next)?;
+                        } else {
+                            break;
+                        }
+                    }
+                    Some(rhs)
+                };
+                lhs = Expr::Range(ExprRange {
+                    attrs: Vec::new(),
+                    start: Some(Box::new(lhs)),
+                    limits,
+                    end: rhs.map(Box::new),
+                });
+            } else if Precedence::Cast >= base && input.peek(Token![as]) {
+                let as_token: Token![as] = input.parse()?;
+                let allow_plus = false;
+                let allow_group_generic = false;
+                let ty = ty::parsing::ambig_ty(input, allow_plus, allow_group_generic)?;
+                check_cast(input)?;
+                lhs = Expr::Cast(ExprCast {
+                    attrs: Vec::new(),
+                    expr: Box::new(lhs),
+                    as_token,
+                    ty: Box::new(ty),
+                });
+            } else {
+                break;
+            }
+        }
+        Ok(lhs)
+    }
+
+    #[cfg(not(feature = "full"))]
+    fn parse_expr(input: ParseStream, mut lhs: Expr, base: Precedence) -> Result<Expr> {
+        loop {
+            let ahead = input.fork();
+            if let Some(op) = match ahead.parse::<BinOp>() {
+                Ok(op) if Precedence::of(&op) >= base => Some(op),
+                _ => None,
+            } {
+                input.advance_to(&ahead);
+                let precedence = Precedence::of(&op);
+                let mut rhs = unary_expr(input)?;
+                loop {
+                    let next = peek_precedence(input);
+                    if next > precedence || next == precedence && precedence == Precedence::Assign {
+                        rhs = parse_expr(input, rhs, next)?;
+                    } else {
+                        break;
+                    }
+                }
+                lhs = Expr::Binary(ExprBinary {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    op,
+                    right: Box::new(rhs),
+                });
+            } else if Precedence::Cast >= base && input.peek(Token![as]) {
+                let as_token: Token![as] = input.parse()?;
+                let allow_plus = false;
+                let allow_group_generic = false;
+                let ty = ty::parsing::ambig_ty(input, allow_plus, allow_group_generic)?;
+                check_cast(input)?;
+                lhs = Expr::Cast(ExprCast {
+                    attrs: Vec::new(),
+                    expr: Box::new(lhs),
+                    as_token,
+                    ty: Box::new(ty),
+                });
+            } else {
+                break;
+            }
+        }
+        Ok(lhs)
+    }
+
+    fn peek_precedence(input: ParseStream) -> Precedence {
+        if let Ok(op) = input.fork().parse() {
+            Precedence::of(&op)
+        } else if input.peek(Token![=]) && !input.peek(Token![=>]) {
+            Precedence::Assign
+        } else if input.peek(Token![..]) {
+            Precedence::Range
+        } else if input.peek(Token![as]) {
+            Precedence::Cast
+        } else {
+            Precedence::Any
+        }
+    }
+
+    // Parse an arbitrary expression.
+    fn ambiguous_expr(
+        input: ParseStream,
+        #[cfg(feature = "full")] allow_struct: AllowStruct,
+    ) -> Result<Expr> {
+        let lhs = unary_expr(
+            input,
+            #[cfg(feature = "full")]
+            allow_struct,
+        )?;
+        parse_expr(
+            input,
+            lhs,
+            #[cfg(feature = "full")]
+            allow_struct,
+            Precedence::Any,
+        )
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_attrs(input: ParseStream) -> Result<Vec<Attribute>> {
+        let mut attrs = Vec::new();
+        loop {
+            if input.peek(token::Group) {
+                let ahead = input.fork();
+                let group = crate::group::parse_group(&ahead)?;
+                if !group.content.peek(Token![#]) || group.content.peek2(Token![!]) {
+                    break;
+                }
+                let attr = group.content.call(attr::parsing::single_parse_outer)?;
+                if !group.content.is_empty() {
+                    break;
+                }
+                attrs.push(attr);
+            } else if input.peek(Token![#]) {
+                attrs.push(input.call(attr::parsing::single_parse_outer)?);
+            } else {
+                break;
+            }
+        }
+        Ok(attrs)
+    }
+
+    // <UnOp> <trailer>
+    // & <trailer>
+    // &mut <trailer>
+    // box <trailer>
+    #[cfg(feature = "full")]
+    fn unary_expr(input: ParseStream, allow_struct: AllowStruct) -> Result<Expr> {
+        let begin = input.fork();
+        let attrs = input.call(expr_attrs)?;
+        if input.peek(Token![&]) {
+            let and_token: Token![&] = input.parse()?;
+            let raw: Option<kw::raw> = if input.peek(kw::raw)
+                && (input.peek2(Token![mut]) || input.peek2(Token![const]))
+            {
+                Some(input.parse()?)
+            } else {
+                None
+            };
+            let mutability: Option<Token![mut]> = input.parse()?;
+            if raw.is_some() && mutability.is_none() {
+                input.parse::<Token![const]>()?;
+            }
+            let expr = Box::new(unary_expr(input, allow_struct)?);
+            if raw.is_some() {
+                Ok(Expr::Verbatim(verbatim::between(&begin, input)))
+            } else {
+                Ok(Expr::Reference(ExprReference {
+                    attrs,
+                    and_token,
+                    mutability,
+                    expr,
+                }))
+            }
+        } else if input.peek(Token![*]) || input.peek(Token![!]) || input.peek(Token![-]) {
+            expr_unary(input, attrs, allow_struct).map(Expr::Unary)
+        } else {
+            trailer_expr(begin, attrs, input, allow_struct)
+        }
+    }
+
+    #[cfg(not(feature = "full"))]
+    fn unary_expr(input: ParseStream) -> Result<Expr> {
+        if input.peek(Token![*]) || input.peek(Token![!]) || input.peek(Token![-]) {
+            Ok(Expr::Unary(ExprUnary {
+                attrs: Vec::new(),
+                op: input.parse()?,
+                expr: Box::new(unary_expr(input)?),
+            }))
+        } else {
+            trailer_expr(input)
+        }
+    }
+
+    // <atom> (..<args>) ...
+    // <atom> . <ident> (..<args>) ...
+    // <atom> . <ident> ...
+    // <atom> . <lit> ...
+    // <atom> [ <expr> ] ...
+    // <atom> ? ...
+    #[cfg(feature = "full")]
+    fn trailer_expr(
+        begin: ParseBuffer,
+        mut attrs: Vec<Attribute>,
+        input: ParseStream,
+        allow_struct: AllowStruct,
+    ) -> Result<Expr> {
+        let atom = atom_expr(input, allow_struct)?;
+        let mut e = trailer_helper(input, atom)?;
+
+        if let Expr::Verbatim(tokens) = &mut e {
+            *tokens = verbatim::between(&begin, input);
+        } else {
+            let inner_attrs = e.replace_attrs(Vec::new());
+            attrs.extend(inner_attrs);
+            e.replace_attrs(attrs);
+        }
+
+        Ok(e)
+    }
+
+    #[cfg(feature = "full")]
+    fn trailer_helper(input: ParseStream, mut e: Expr) -> Result<Expr> {
+        loop {
+            if input.peek(token::Paren) {
+                let content;
+                e = Expr::Call(ExprCall {
+                    attrs: Vec::new(),
+                    func: Box::new(e),
+                    paren_token: parenthesized!(content in input),
+                    args: content.parse_terminated(Expr::parse, Token![,])?,
+                });
+            } else if input.peek(Token![.])
+                && !input.peek(Token![..])
+                && match e {
+                    Expr::Range(_) => false,
+                    _ => true,
+                }
+            {
+                let mut dot_token: Token![.] = input.parse()?;
+
+                let float_token: Option<LitFloat> = input.parse()?;
+                if let Some(float_token) = float_token {
+                    if multi_index(&mut e, &mut dot_token, float_token)? {
+                        continue;
+                    }
+                }
+
+                let await_token: Option<Token![await]> = input.parse()?;
+                if let Some(await_token) = await_token {
+                    e = Expr::Await(ExprAwait {
+                        attrs: Vec::new(),
+                        base: Box::new(e),
+                        dot_token,
+                        await_token,
+                    });
+                    continue;
+                }
+
+                let member: Member = input.parse()?;
+                let turbofish = if member.is_named() && input.peek(Token![::]) {
+                    Some(AngleBracketedGenericArguments::parse_turbofish(input)?)
+                } else {
+                    None
+                };
+
+                if turbofish.is_some() || input.peek(token::Paren) {
+                    if let Member::Named(method) = member {
+                        let content;
+                        e = Expr::MethodCall(ExprMethodCall {
+                            attrs: Vec::new(),
+                            receiver: Box::new(e),
+                            dot_token,
+                            method,
+                            turbofish,
+                            paren_token: parenthesized!(content in input),
+                            args: content.parse_terminated(Expr::parse, Token![,])?,
+                        });
+                        continue;
+                    }
+                }
+
+                e = Expr::Field(ExprField {
+                    attrs: Vec::new(),
+                    base: Box::new(e),
+                    dot_token,
+                    member,
+                });
+            } else if input.peek(token::Bracket) {
+                let content;
+                e = Expr::Index(ExprIndex {
+                    attrs: Vec::new(),
+                    expr: Box::new(e),
+                    bracket_token: bracketed!(content in input),
+                    index: content.parse()?,
+                });
+            } else if input.peek(Token![?]) {
+                e = Expr::Try(ExprTry {
+                    attrs: Vec::new(),
+                    expr: Box::new(e),
+                    question_token: input.parse()?,
+                });
+            } else {
+                break;
+            }
+        }
+        Ok(e)
+    }
+
+    #[cfg(not(feature = "full"))]
+    fn trailer_expr(input: ParseStream) -> Result<Expr> {
+        let mut e = atom_expr(input)?;
+
+        loop {
+            if input.peek(token::Paren) {
+                let content;
+                e = Expr::Call(ExprCall {
+                    attrs: Vec::new(),
+                    func: Box::new(e),
+                    paren_token: parenthesized!(content in input),
+                    args: content.parse_terminated(Expr::parse, Token![,])?,
+                });
+            } else if input.peek(Token![.])
+                && !input.peek(Token![..])
+                && !input.peek2(Token![await])
+            {
+                let mut dot_token: Token![.] = input.parse()?;
+                let float_token: Option<LitFloat> = input.parse()?;
+                if let Some(float_token) = float_token {
+                    if multi_index(&mut e, &mut dot_token, float_token)? {
+                        continue;
+                    }
+                }
+                e = Expr::Field(ExprField {
+                    attrs: Vec::new(),
+                    base: Box::new(e),
+                    dot_token,
+                    member: input.parse()?,
+                });
+            } else if input.peek(token::Bracket) {
+                let content;
+                e = Expr::Index(ExprIndex {
+                    attrs: Vec::new(),
+                    expr: Box::new(e),
+                    bracket_token: bracketed!(content in input),
+                    index: content.parse()?,
+                });
+            } else {
+                break;
+            }
+        }
+
+        Ok(e)
+    }
+
+    // Parse all atomic expressions which don't have to worry about precedence
+    // interactions, as they are fully contained.
+    #[cfg(feature = "full")]
+    fn atom_expr(input: ParseStream, allow_struct: AllowStruct) -> Result<Expr> {
+        if input.peek(token::Group)
+            && !input.peek2(Token![::])
+            && !input.peek2(Token![!])
+            && !input.peek2(token::Brace)
+        {
+            input.call(expr_group).map(Expr::Group)
+        } else if input.peek(Lit) {
+            input.parse().map(Expr::Lit)
+        } else if input.peek(Token![async])
+            && (input.peek2(token::Brace) || input.peek2(Token![move]) && input.peek3(token::Brace))
+        {
+            input.parse().map(Expr::Async)
+        } else if input.peek(Token![try]) && input.peek2(token::Brace) {
+            input.parse().map(Expr::TryBlock)
+        } else if input.peek(Token![|])
+            || input.peek(Token![move])
+            || input.peek(Token![for])
+                && input.peek2(Token![<])
+                && (input.peek3(Lifetime) || input.peek3(Token![>]))
+            || input.peek(Token![const]) && !input.peek2(token::Brace)
+            || input.peek(Token![static])
+            || input.peek(Token![async]) && (input.peek2(Token![|]) || input.peek2(Token![move]))
+        {
+            expr_closure(input, allow_struct).map(Expr::Closure)
+        } else if input.peek(kw::builtin) && input.peek2(Token![#]) {
+            expr_builtin(input)
+        } else if input.peek(Ident)
+            || input.peek(Token![::])
+            || input.peek(Token![<])
+            || input.peek(Token![self])
+            || input.peek(Token![Self])
+            || input.peek(Token![super])
+            || input.peek(Token![crate])
+            || input.peek(Token![try]) && (input.peek2(Token![!]) || input.peek2(Token![::]))
+        {
+            path_or_macro_or_struct(input, allow_struct)
+        } else if input.peek(token::Paren) {
+            paren_or_tuple(input)
+        } else if input.peek(Token![break]) {
+            expr_break(input, allow_struct).map(Expr::Break)
+        } else if input.peek(Token![continue]) {
+            input.parse().map(Expr::Continue)
+        } else if input.peek(Token![return]) {
+            expr_ret(input, allow_struct).map(Expr::Return)
+        } else if input.peek(token::Bracket) {
+            array_or_repeat(input)
+        } else if input.peek(Token![let]) {
+            input.parse().map(Expr::Let)
+        } else if input.peek(Token![if]) {
+            input.parse().map(Expr::If)
+        } else if input.peek(Token![while]) {
+            input.parse().map(Expr::While)
+        } else if input.peek(Token![for]) {
+            input.parse().map(Expr::ForLoop)
+        } else if input.peek(Token![loop]) {
+            input.parse().map(Expr::Loop)
+        } else if input.peek(Token![match]) {
+            input.parse().map(Expr::Match)
+        } else if input.peek(Token![yield]) {
+            input.parse().map(Expr::Yield)
+        } else if input.peek(Token![unsafe]) {
+            input.parse().map(Expr::Unsafe)
+        } else if input.peek(Token![const]) {
+            input.parse().map(Expr::Const)
+        } else if input.peek(token::Brace) {
+            input.parse().map(Expr::Block)
+        } else if input.peek(Token![..]) {
+            expr_range(input, allow_struct).map(Expr::Range)
+        } else if input.peek(Token![_]) {
+            input.parse().map(Expr::Infer)
+        } else if input.peek(Lifetime) {
+            let the_label: Label = input.parse()?;
+            let mut expr = if input.peek(Token![while]) {
+                Expr::While(input.parse()?)
+            } else if input.peek(Token![for]) {
+                Expr::ForLoop(input.parse()?)
+            } else if input.peek(Token![loop]) {
+                Expr::Loop(input.parse()?)
+            } else if input.peek(token::Brace) {
+                Expr::Block(input.parse()?)
+            } else {
+                return Err(input.error("expected loop or block expression"));
+            };
+            match &mut expr {
+                Expr::While(ExprWhile { label, .. })
+                | Expr::ForLoop(ExprForLoop { label, .. })
+                | Expr::Loop(ExprLoop { label, .. })
+                | Expr::Block(ExprBlock { label, .. }) => *label = Some(the_label),
+                _ => unreachable!(),
+            }
+            Ok(expr)
+        } else {
+            Err(input.error("expected an expression"))
+        }
+    }
+
+    #[cfg(not(feature = "full"))]
+    fn atom_expr(input: ParseStream) -> Result<Expr> {
+        if input.peek(token::Group)
+            && !input.peek2(Token![::])
+            && !input.peek2(Token![!])
+            && !input.peek2(token::Brace)
+        {
+            input.call(expr_group).map(Expr::Group)
+        } else if input.peek(Lit) {
+            input.parse().map(Expr::Lit)
+        } else if input.peek(token::Paren) {
+            input.call(expr_paren).map(Expr::Paren)
+        } else if input.peek(Ident)
+            || input.peek(Token![::])
+            || input.peek(Token![<])
+            || input.peek(Token![self])
+            || input.peek(Token![Self])
+            || input.peek(Token![super])
+            || input.peek(Token![crate])
+        {
+            path_or_macro_or_struct(input)
+        } else if input.is_empty() {
+            Err(input.error("expected an expression"))
+        } else {
+            if input.peek(token::Brace) {
+                let scan = input.fork();
+                let content;
+                braced!(content in scan);
+                if content.parse::<Expr>().is_ok() && content.is_empty() {
+                    let expr_block = verbatim::between(input, &scan);
+                    input.advance_to(&scan);
+                    return Ok(Expr::Verbatim(expr_block));
+                }
+            }
+            Err(input.error("unsupported expression; enable syn's features=[\"full\"]"))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_builtin(input: ParseStream) -> Result<Expr> {
+        let begin = input.fork();
+
+        input.parse::<kw::builtin>()?;
+        input.parse::<Token![#]>()?;
+        input.parse::<Ident>()?;
+
+        let args;
+        parenthesized!(args in input);
+        args.parse::<TokenStream>()?;
+
+        Ok(Expr::Verbatim(verbatim::between(&begin, input)))
+    }
+
+    fn path_or_macro_or_struct(
+        input: ParseStream,
+        #[cfg(feature = "full")] allow_struct: AllowStruct,
+    ) -> Result<Expr> {
+        let (qself, path) = path::parsing::qpath(input, true)?;
+
+        if qself.is_none()
+            && input.peek(Token![!])
+            && !input.peek(Token![!=])
+            && path.is_mod_style()
+        {
+            let bang_token: Token![!] = input.parse()?;
+            let (delimiter, tokens) = mac::parse_delimiter(input)?;
+            return Ok(Expr::Macro(ExprMacro {
+                attrs: Vec::new(),
+                mac: Macro {
+                    path,
+                    bang_token,
+                    delimiter,
+                    tokens,
+                },
+            }));
+        }
+
+        #[cfg(feature = "full")]
+        if allow_struct.0 && input.peek(token::Brace) {
+            return expr_struct_helper(input, qself, path).map(Expr::Struct);
+        }
+
+        Ok(Expr::Path(ExprPath {
+            attrs: Vec::new(),
+            qself,
+            path,
+        }))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprMacro {
+                attrs: Vec::new(),
+                mac: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn paren_or_tuple(input: ParseStream) -> Result<Expr> {
+        let content;
+        let paren_token = parenthesized!(content in input);
+        if content.is_empty() {
+            return Ok(Expr::Tuple(ExprTuple {
+                attrs: Vec::new(),
+                paren_token,
+                elems: Punctuated::new(),
+            }));
+        }
+
+        let first: Expr = content.parse()?;
+        if content.is_empty() {
+            return Ok(Expr::Paren(ExprParen {
+                attrs: Vec::new(),
+                paren_token,
+                expr: Box::new(first),
+            }));
+        }
+
+        let mut elems = Punctuated::new();
+        elems.push_value(first);
+        while !content.is_empty() {
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+            if content.is_empty() {
+                break;
+            }
+            let value = content.parse()?;
+            elems.push_value(value);
+        }
+        Ok(Expr::Tuple(ExprTuple {
+            attrs: Vec::new(),
+            paren_token,
+            elems,
+        }))
+    }
+
+    #[cfg(feature = "full")]
+    fn array_or_repeat(input: ParseStream) -> Result<Expr> {
+        let content;
+        let bracket_token = bracketed!(content in input);
+        if content.is_empty() {
+            return Ok(Expr::Array(ExprArray {
+                attrs: Vec::new(),
+                bracket_token,
+                elems: Punctuated::new(),
+            }));
+        }
+
+        let first: Expr = content.parse()?;
+        if content.is_empty() || content.peek(Token![,]) {
+            let mut elems = Punctuated::new();
+            elems.push_value(first);
+            while !content.is_empty() {
+                let punct = content.parse()?;
+                elems.push_punct(punct);
+                if content.is_empty() {
+                    break;
+                }
+                let value = content.parse()?;
+                elems.push_value(value);
+            }
+            Ok(Expr::Array(ExprArray {
+                attrs: Vec::new(),
+                bracket_token,
+                elems,
+            }))
+        } else if content.peek(Token![;]) {
+            let semi_token: Token![;] = content.parse()?;
+            let len: Expr = content.parse()?;
+            Ok(Expr::Repeat(ExprRepeat {
+                attrs: Vec::new(),
+                bracket_token,
+                expr: Box::new(first),
+                semi_token,
+                len: Box::new(len),
+            }))
+        } else {
+            Err(content.error("expected `,` or `;`"))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprArray {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            let bracket_token = bracketed!(content in input);
+            let mut elems = Punctuated::new();
+
+            while !content.is_empty() {
+                let first: Expr = content.parse()?;
+                elems.push_value(first);
+                if content.is_empty() {
+                    break;
+                }
+                let punct = content.parse()?;
+                elems.push_punct(punct);
+            }
+
+            Ok(ExprArray {
+                attrs: Vec::new(),
+                bracket_token,
+                elems,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprRepeat {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(ExprRepeat {
+                bracket_token: bracketed!(content in input),
+                attrs: Vec::new(),
+                expr: content.parse()?,
+                semi_token: content.parse()?,
+                len: content.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    pub(crate) fn expr_early(input: ParseStream) -> Result<Expr> {
+        let mut attrs = input.call(expr_attrs)?;
+        let mut expr = if input.peek(Token![if]) {
+            Expr::If(input.parse()?)
+        } else if input.peek(Token![while]) {
+            Expr::While(input.parse()?)
+        } else if input.peek(Token![for])
+            && !(input.peek2(Token![<]) && (input.peek3(Lifetime) || input.peek3(Token![>])))
+        {
+            Expr::ForLoop(input.parse()?)
+        } else if input.peek(Token![loop]) {
+            Expr::Loop(input.parse()?)
+        } else if input.peek(Token![match]) {
+            Expr::Match(input.parse()?)
+        } else if input.peek(Token![try]) && input.peek2(token::Brace) {
+            Expr::TryBlock(input.parse()?)
+        } else if input.peek(Token![unsafe]) {
+            Expr::Unsafe(input.parse()?)
+        } else if input.peek(Token![const]) && input.peek2(token::Brace) {
+            Expr::Const(input.parse()?)
+        } else if input.peek(token::Brace) {
+            Expr::Block(input.parse()?)
+        } else {
+            let allow_struct = AllowStruct(true);
+            let mut expr = unary_expr(input, allow_struct)?;
+
+            attrs.extend(expr.replace_attrs(Vec::new()));
+            expr.replace_attrs(attrs);
+
+            return parse_expr(input, expr, allow_struct, Precedence::Any);
+        };
+
+        if input.peek(Token![.]) && !input.peek(Token![..]) || input.peek(Token![?]) {
+            expr = trailer_helper(input, expr)?;
+
+            attrs.extend(expr.replace_attrs(Vec::new()));
+            expr.replace_attrs(attrs);
+
+            let allow_struct = AllowStruct(true);
+            return parse_expr(input, expr, allow_struct, Precedence::Any);
+        }
+
+        attrs.extend(expr.replace_attrs(Vec::new()));
+        expr.replace_attrs(attrs);
+        Ok(expr)
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprLit {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprLit {
+                attrs: Vec::new(),
+                lit: input.parse()?,
+            })
+        }
+    }
+
+    fn expr_group(input: ParseStream) -> Result<ExprGroup> {
+        let group = crate::group::parse_group(input)?;
+        Ok(ExprGroup {
+            attrs: Vec::new(),
+            group_token: group.token,
+            expr: group.content.parse()?,
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprParen {
+        fn parse(input: ParseStream) -> Result<Self> {
+            expr_paren(input)
+        }
+    }
+
+    fn expr_paren(input: ParseStream) -> Result<ExprParen> {
+        let content;
+        Ok(ExprParen {
+            attrs: Vec::new(),
+            paren_token: parenthesized!(content in input),
+            expr: content.parse()?,
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprLet {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprLet {
+                attrs: Vec::new(),
+                let_token: input.parse()?,
+                pat: Box::new(Pat::parse_multi_with_leading_vert(input)?),
+                eq_token: input.parse()?,
+                expr: Box::new({
+                    let allow_struct = AllowStruct(false);
+                    let lhs = unary_expr(input, allow_struct)?;
+                    parse_expr(input, lhs, allow_struct, Precedence::Compare)?
+                }),
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprIf {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            Ok(ExprIf {
+                attrs,
+                if_token: input.parse()?,
+                cond: Box::new(input.call(Expr::parse_without_eager_brace)?),
+                then_branch: input.parse()?,
+                else_branch: {
+                    if input.peek(Token![else]) {
+                        Some(input.call(else_block)?)
+                    } else {
+                        None
+                    }
+                },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn else_block(input: ParseStream) -> Result<(Token![else], Box<Expr>)> {
+        let else_token: Token![else] = input.parse()?;
+
+        let lookahead = input.lookahead1();
+        let else_branch = if input.peek(Token![if]) {
+            input.parse().map(Expr::If)?
+        } else if input.peek(token::Brace) {
+            Expr::Block(ExprBlock {
+                attrs: Vec::new(),
+                label: None,
+                block: input.parse()?,
+            })
+        } else {
+            return Err(lookahead.error());
+        };
+
+        Ok((else_token, Box::new(else_branch)))
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprInfer {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprInfer {
+                attrs: input.call(Attribute::parse_outer)?,
+                underscore_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprForLoop {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let label: Option<Label> = input.parse()?;
+            let for_token: Token![for] = input.parse()?;
+
+            let pat = Pat::parse_multi_with_leading_vert(input)?;
+
+            let in_token: Token![in] = input.parse()?;
+            let expr: Expr = input.call(Expr::parse_without_eager_brace)?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprForLoop {
+                attrs,
+                label,
+                for_token,
+                pat: Box::new(pat),
+                in_token,
+                expr: Box::new(expr),
+                body: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprLoop {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let label: Option<Label> = input.parse()?;
+            let loop_token: Token![loop] = input.parse()?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprLoop {
+                attrs,
+                label,
+                loop_token,
+                body: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprMatch {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let match_token: Token![match] = input.parse()?;
+            let expr = Expr::parse_without_eager_brace(input)?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+
+            let mut arms = Vec::new();
+            while !content.is_empty() {
+                arms.push(content.call(Arm::parse)?);
+            }
+
+            Ok(ExprMatch {
+                attrs,
+                match_token,
+                expr: Box::new(expr),
+                brace_token,
+                arms,
+            })
+        }
+    }
+
+    macro_rules! impl_by_parsing_expr {
+        (
+            $(
+                $expr_type:ty, $variant:ident, $msg:expr,
+            )*
+        ) => {
+            $(
+                #[cfg(all(feature = "full", feature = "printing"))]
+                #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+                impl Parse for $expr_type {
+                    fn parse(input: ParseStream) -> Result<Self> {
+                        let mut expr: Expr = input.parse()?;
+                        loop {
+                            match expr {
+                                Expr::$variant(inner) => return Ok(inner),
+                                Expr::Group(next) => expr = *next.expr,
+                                _ => return Err(Error::new_spanned(expr, $msg)),
+                            }
+                        }
+                    }
+                }
+            )*
+        };
+    }
+
+    impl_by_parsing_expr! {
+        ExprAssign, Assign, "expected assignment expression",
+        ExprAwait, Await, "expected await expression",
+        ExprBinary, Binary, "expected binary operation",
+        ExprCall, Call, "expected function call expression",
+        ExprCast, Cast, "expected cast expression",
+        ExprField, Field, "expected struct field access",
+        ExprIndex, Index, "expected indexing expression",
+        ExprMethodCall, MethodCall, "expected method call expression",
+        ExprRange, Range, "expected range expression",
+        ExprTry, Try, "expected try expression",
+        ExprTuple, Tuple, "expected tuple expression",
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprUnary {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = Vec::new();
+            let allow_struct = AllowStruct(true);
+            expr_unary(input, attrs, allow_struct)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_unary(
+        input: ParseStream,
+        attrs: Vec<Attribute>,
+        allow_struct: AllowStruct,
+    ) -> Result<ExprUnary> {
+        Ok(ExprUnary {
+            attrs,
+            op: input.parse()?,
+            expr: Box::new(unary_expr(input, allow_struct)?),
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprClosure {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            expr_closure(input, allow_struct)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprReference {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            Ok(ExprReference {
+                attrs: Vec::new(),
+                and_token: input.parse()?,
+                mutability: input.parse()?,
+                expr: Box::new(unary_expr(input, allow_struct)?),
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprBreak {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            expr_break(input, allow_struct)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprReturn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            expr_ret(input, allow_struct)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprTryBlock {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprTryBlock {
+                attrs: Vec::new(),
+                try_token: input.parse()?,
+                block: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprYield {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprYield {
+                attrs: Vec::new(),
+                yield_token: input.parse()?,
+                expr: {
+                    if !input.is_empty() && !input.peek(Token![,]) && !input.peek(Token![;]) {
+                        Some(input.parse()?)
+                    } else {
+                        None
+                    }
+                },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_closure(input: ParseStream, allow_struct: AllowStruct) -> Result<ExprClosure> {
+        let lifetimes: Option<BoundLifetimes> = input.parse()?;
+        let constness: Option<Token![const]> = input.parse()?;
+        let movability: Option<Token![static]> = input.parse()?;
+        let asyncness: Option<Token![async]> = input.parse()?;
+        let capture: Option<Token![move]> = input.parse()?;
+        let or1_token: Token![|] = input.parse()?;
+
+        let mut inputs = Punctuated::new();
+        loop {
+            if input.peek(Token![|]) {
+                break;
+            }
+            let value = closure_arg(input)?;
+            inputs.push_value(value);
+            if input.peek(Token![|]) {
+                break;
+            }
+            let punct: Token![,] = input.parse()?;
+            inputs.push_punct(punct);
+        }
+
+        let or2_token: Token![|] = input.parse()?;
+
+        let (output, body) = if input.peek(Token![->]) {
+            let arrow_token: Token![->] = input.parse()?;
+            let ty: Type = input.parse()?;
+            let body: Block = input.parse()?;
+            let output = ReturnType::Type(arrow_token, Box::new(ty));
+            let block = Expr::Block(ExprBlock {
+                attrs: Vec::new(),
+                label: None,
+                block: body,
+            });
+            (output, block)
+        } else {
+            let body = ambiguous_expr(input, allow_struct)?;
+            (ReturnType::Default, body)
+        };
+
+        Ok(ExprClosure {
+            attrs: Vec::new(),
+            lifetimes,
+            constness,
+            movability,
+            asyncness,
+            capture,
+            or1_token,
+            inputs,
+            or2_token,
+            output,
+            body: Box::new(body),
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprAsync {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprAsync {
+                attrs: Vec::new(),
+                async_token: input.parse()?,
+                capture: input.parse()?,
+                block: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn closure_arg(input: ParseStream) -> Result<Pat> {
+        let attrs = input.call(Attribute::parse_outer)?;
+        let mut pat = Pat::parse_single(input)?;
+
+        if input.peek(Token![:]) {
+            Ok(Pat::Type(PatType {
+                attrs,
+                pat: Box::new(pat),
+                colon_token: input.parse()?,
+                ty: input.parse()?,
+            }))
+        } else {
+            match &mut pat {
+                Pat::Const(pat) => pat.attrs = attrs,
+                Pat::Ident(pat) => pat.attrs = attrs,
+                Pat::Lit(pat) => pat.attrs = attrs,
+                Pat::Macro(pat) => pat.attrs = attrs,
+                Pat::Or(pat) => pat.attrs = attrs,
+                Pat::Paren(pat) => pat.attrs = attrs,
+                Pat::Path(pat) => pat.attrs = attrs,
+                Pat::Range(pat) => pat.attrs = attrs,
+                Pat::Reference(pat) => pat.attrs = attrs,
+                Pat::Rest(pat) => pat.attrs = attrs,
+                Pat::Slice(pat) => pat.attrs = attrs,
+                Pat::Struct(pat) => pat.attrs = attrs,
+                Pat::Tuple(pat) => pat.attrs = attrs,
+                Pat::TupleStruct(pat) => pat.attrs = attrs,
+                Pat::Type(_) => unreachable!(),
+                Pat::Verbatim(_) => {}
+                Pat::Wild(pat) => pat.attrs = attrs,
+            }
+            Ok(pat)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprWhile {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let label: Option<Label> = input.parse()?;
+            let while_token: Token![while] = input.parse()?;
+            let cond = Expr::parse_without_eager_brace(input)?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprWhile {
+                attrs,
+                label,
+                while_token,
+                cond: Box::new(cond),
+                body: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprConst {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let const_token: Token![const] = input.parse()?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            let inner_attrs = content.call(Attribute::parse_inner)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprConst {
+                attrs: inner_attrs,
+                const_token,
+                block: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Label {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(Label {
+                name: input.parse()?,
+                colon_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Option<Label> {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Lifetime) {
+                input.parse().map(Some)
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprContinue {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprContinue {
+                attrs: Vec::new(),
+                continue_token: input.parse()?,
+                label: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_break(input: ParseStream, allow_struct: AllowStruct) -> Result<ExprBreak> {
+        Ok(ExprBreak {
+            attrs: Vec::new(),
+            break_token: input.parse()?,
+            label: input.parse()?,
+            expr: {
+                if input.is_empty()
+                    || input.peek(Token![,])
+                    || input.peek(Token![;])
+                    || !allow_struct.0 && input.peek(token::Brace)
+                {
+                    None
+                } else {
+                    let expr = ambiguous_expr(input, allow_struct)?;
+                    Some(Box::new(expr))
+                }
+            },
+        })
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_ret(input: ParseStream, allow_struct: AllowStruct) -> Result<ExprReturn> {
+        Ok(ExprReturn {
+            attrs: Vec::new(),
+            return_token: input.parse()?,
+            expr: {
+                if input.is_empty() || input.peek(Token![,]) || input.peek(Token![;]) {
+                    None
+                } else {
+                    // NOTE: return is greedy and eats blocks after it even when in a
+                    // position where structs are not allowed, such as in if statement
+                    // conditions. For example:
+                    //
+                    // if return { println!("A") } {} // Prints "A"
+                    let expr = ambiguous_expr(input, allow_struct)?;
+                    Some(Box::new(expr))
+                }
+            },
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for FieldValue {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let member: Member = input.parse()?;
+            let (colon_token, value) = if input.peek(Token![:]) || !member.is_named() {
+                let colon_token: Token![:] = input.parse()?;
+                let value: Expr = input.parse()?;
+                (Some(colon_token), value)
+            } else if let Member::Named(ident) = &member {
+                let value = Expr::Path(ExprPath {
+                    attrs: Vec::new(),
+                    qself: None,
+                    path: Path::from(ident.clone()),
+                });
+                (None, value)
+            } else {
+                unreachable!()
+            };
+
+            Ok(FieldValue {
+                attrs,
+                member,
+                colon_token,
+                expr: value,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprStruct {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let (qself, path) = path::parsing::qpath(input, true)?;
+            expr_struct_helper(input, qself, path)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_struct_helper(
+        input: ParseStream,
+        qself: Option<QSelf>,
+        path: Path,
+    ) -> Result<ExprStruct> {
+        let content;
+        let brace_token = braced!(content in input);
+
+        let mut fields = Punctuated::new();
+        while !content.is_empty() {
+            if content.peek(Token![..]) {
+                return Ok(ExprStruct {
+                    attrs: Vec::new(),
+                    qself,
+                    path,
+                    brace_token,
+                    fields,
+                    dot2_token: Some(content.parse()?),
+                    rest: if content.is_empty() {
+                        None
+                    } else {
+                        Some(Box::new(content.parse()?))
+                    },
+                });
+            }
+
+            fields.push(content.parse()?);
+            if content.is_empty() {
+                break;
+            }
+            let punct: Token![,] = content.parse()?;
+            fields.push_punct(punct);
+        }
+
+        Ok(ExprStruct {
+            attrs: Vec::new(),
+            qself,
+            path,
+            brace_token,
+            fields,
+            dot2_token: None,
+            rest: None,
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprUnsafe {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let unsafe_token: Token![unsafe] = input.parse()?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            let inner_attrs = content.call(Attribute::parse_inner)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprUnsafe {
+                attrs: inner_attrs,
+                unsafe_token,
+                block: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprBlock {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let label: Option<Label> = input.parse()?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+            let stmts = content.call(Block::parse_within)?;
+
+            Ok(ExprBlock {
+                attrs,
+                label,
+                block: Block { brace_token, stmts },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_range(input: ParseStream, allow_struct: AllowStruct) -> Result<ExprRange> {
+        let limits: RangeLimits = input.parse()?;
+        let end = if matches!(limits, RangeLimits::HalfOpen(_))
+            && (input.is_empty()
+                || input.peek(Token![,])
+                || input.peek(Token![;])
+                || input.peek(Token![.]) && !input.peek(Token![..])
+                || !allow_struct.0 && input.peek(token::Brace))
+        {
+            None
+        } else {
+            let to = ambiguous_expr(input, allow_struct)?;
+            Some(Box::new(to))
+        };
+        Ok(ExprRange {
+            attrs: Vec::new(),
+            start: None,
+            limits,
+            end,
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for RangeLimits {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let lookahead = input.lookahead1();
+            let dot_dot = lookahead.peek(Token![..]);
+            let dot_dot_eq = dot_dot && lookahead.peek(Token![..=]);
+            let dot_dot_dot = dot_dot && input.peek(Token![...]);
+            if dot_dot_eq {
+                input.parse().map(RangeLimits::Closed)
+            } else if dot_dot && !dot_dot_dot {
+                input.parse().map(RangeLimits::HalfOpen)
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    #[cfg(feature = "full")]
+    impl RangeLimits {
+        pub(crate) fn parse_obsolete(input: ParseStream) -> Result<Self> {
+            let lookahead = input.lookahead1();
+            let dot_dot = lookahead.peek(Token![..]);
+            let dot_dot_eq = dot_dot && lookahead.peek(Token![..=]);
+            let dot_dot_dot = dot_dot && input.peek(Token![...]);
+            if dot_dot_eq {
+                input.parse().map(RangeLimits::Closed)
+            } else if dot_dot_dot {
+                let dot3: Token![...] = input.parse()?;
+                Ok(RangeLimits::Closed(Token![..=](dot3.spans)))
+            } else if dot_dot {
+                input.parse().map(RangeLimits::HalfOpen)
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprPath {
+        fn parse(input: ParseStream) -> Result<Self> {
+            #[cfg(not(feature = "full"))]
+            let attrs = Vec::new();
+            #[cfg(feature = "full")]
+            let attrs = input.call(Attribute::parse_outer)?;
+
+            let (qself, path) = path::parsing::qpath(input, true)?;
+
+            Ok(ExprPath { attrs, qself, path })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Member {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Ident) {
+                input.parse().map(Member::Named)
+            } else if input.peek(LitInt) {
+                input.parse().map(Member::Unnamed)
+            } else {
+                Err(input.error("expected identifier or integer"))
+            }
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Arm {
+        fn parse(input: ParseStream) -> Result<Arm> {
+            let requires_comma;
+            Ok(Arm {
+                attrs: input.call(Attribute::parse_outer)?,
+                pat: Pat::parse_multi_with_leading_vert(input)?,
+                guard: {
+                    if input.peek(Token![if]) {
+                        let if_token: Token![if] = input.parse()?;
+                        let guard: Expr = input.parse()?;
+                        Some((if_token, Box::new(guard)))
+                    } else {
+                        None
+                    }
+                },
+                fat_arrow_token: input.parse()?,
+                body: {
+                    let body = input.call(expr_early)?;
+                    requires_comma = requires_terminator(&body);
+                    Box::new(body)
+                },
+                comma: {
+                    if requires_comma && !input.is_empty() {
+                        Some(input.parse()?)
+                    } else {
+                        input.parse()?
+                    }
+                },
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Index {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let lit: LitInt = input.parse()?;
+            if lit.suffix().is_empty() {
+                Ok(Index {
+                    index: lit
+                        .base10_digits()
+                        .parse()
+                        .map_err(|err| Error::new(lit.span(), err))?,
+                    span: lit.span(),
+                })
+            } else {
+                Err(Error::new(lit.span(), "expected unsuffixed integer"))
+            }
+        }
+    }
+
+    fn multi_index(e: &mut Expr, dot_token: &mut Token![.], float: LitFloat) -> Result<bool> {
+        let float_token = float.token();
+        let float_span = float_token.span();
+        let mut float_repr = float_token.to_string();
+        let trailing_dot = float_repr.ends_with('.');
+        if trailing_dot {
+            float_repr.truncate(float_repr.len() - 1);
+        }
+
+        let mut offset = 0;
+        for part in float_repr.split('.') {
+            let mut index: Index =
+                crate::parse_str(part).map_err(|err| Error::new(float_span, err))?;
+            let part_end = offset + part.len();
+            index.span = float_token.subspan(offset..part_end).unwrap_or(float_span);
+
+            let base = mem::replace(e, Expr::DUMMY);
+            *e = Expr::Field(ExprField {
+                attrs: Vec::new(),
+                base: Box::new(base),
+                dot_token: Token![.](dot_token.span),
+                member: Member::Unnamed(index),
+            });
+
+            let dot_span = float_token
+                .subspan(part_end..part_end + 1)
+                .unwrap_or(float_span);
+            *dot_token = Token![.](dot_span);
+            offset = part_end + 1;
+        }
+
+        Ok(!trailing_dot)
+    }
+
+    #[cfg(feature = "full")]
+    impl Member {
+        fn is_named(&self) -> bool {
+            match self {
+                Member::Named(_) => true,
+                Member::Unnamed(_) => false,
+            }
+        }
+    }
+
+    fn check_cast(input: ParseStream) -> Result<()> {
+        let kind = if input.peek(Token![.]) && !input.peek(Token![..]) {
+            if input.peek2(Token![await]) {
+                "`.await`"
+            } else if input.peek2(Ident) && (input.peek3(token::Paren) || input.peek3(Token![::])) {
+                "a method call"
+            } else {
+                "a field access"
+            }
+        } else if input.peek(Token![?]) {
+            "`?`"
+        } else if input.peek(token::Bracket) {
+            "indexing"
+        } else if input.peek(token::Paren) {
+            "a function call"
+        } else {
+            return Ok(());
+        };
+        let msg = format!("casts cannot be followed by {}", kind);
+        Err(input.error(msg))
+    }
+}
+
+#[cfg(feature = "printing")]
+pub(crate) mod printing {
+    use super::*;
+    #[cfg(feature = "full")]
+    use crate::attr::FilterAttrs;
+    use proc_macro2::{Literal, TokenStream};
+    use quote::{ToTokens, TokenStreamExt};
+
+    // If the given expression is a bare `ExprStruct`, wraps it in parenthesis
+    // before appending it to `TokenStream`.
+    #[cfg(feature = "full")]
+    fn wrap_bare_struct(tokens: &mut TokenStream, e: &Expr) {
+        if let Expr::Struct(_) = *e {
+            token::Paren::default().surround(tokens, |tokens| {
+                e.to_tokens(tokens);
+            });
+        } else {
+            e.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    pub(crate) fn outer_attrs_to_tokens(attrs: &[Attribute], tokens: &mut TokenStream) {
+        tokens.append_all(attrs.outer());
+    }
+
+    #[cfg(feature = "full")]
+    fn inner_attrs_to_tokens(attrs: &[Attribute], tokens: &mut TokenStream) {
+        tokens.append_all(attrs.inner());
+    }
+
+    #[cfg(not(feature = "full"))]
+    pub(crate) fn outer_attrs_to_tokens(_attrs: &[Attribute], _tokens: &mut TokenStream) {}
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprArray {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.bracket_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprAssign {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.left.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.right.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprAsync {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.async_token.to_tokens(tokens);
+            self.capture.to_tokens(tokens);
+            self.block.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprAwait {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.base.to_tokens(tokens);
+            self.dot_token.to_tokens(tokens);
+            self.await_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprBinary {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.left.to_tokens(tokens);
+            self.op.to_tokens(tokens);
+            self.right.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprBlock {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.label.to_tokens(tokens);
+            self.block.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.block.stmts);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprBreak {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.break_token.to_tokens(tokens);
+            self.label.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprCall {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.func.to_tokens(tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.args.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprCast {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.expr.to_tokens(tokens);
+            self.as_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprClosure {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.lifetimes.to_tokens(tokens);
+            self.constness.to_tokens(tokens);
+            self.movability.to_tokens(tokens);
+            self.asyncness.to_tokens(tokens);
+            self.capture.to_tokens(tokens);
+            self.or1_token.to_tokens(tokens);
+            self.inputs.to_tokens(tokens);
+            self.or2_token.to_tokens(tokens);
+            self.output.to_tokens(tokens);
+            self.body.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprConst {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.const_token.to_tokens(tokens);
+            self.block.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.block.stmts);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprContinue {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.continue_token.to_tokens(tokens);
+            self.label.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprField {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.base.to_tokens(tokens);
+            self.dot_token.to_tokens(tokens);
+            self.member.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprForLoop {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.label.to_tokens(tokens);
+            self.for_token.to_tokens(tokens);
+            self.pat.to_tokens(tokens);
+            self.in_token.to_tokens(tokens);
+            wrap_bare_struct(tokens, &self.expr);
+            self.body.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.body.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprGroup {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.group_token.surround(tokens, |tokens| {
+                self.expr.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprIf {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.if_token.to_tokens(tokens);
+            wrap_bare_struct(tokens, &self.cond);
+            self.then_branch.to_tokens(tokens);
+            if let Some((else_token, else_)) = &self.else_branch {
+                else_token.to_tokens(tokens);
+                // If we are not one of the valid expressions to exist in an else
+                // clause, wrap ourselves in a block.
+                match **else_ {
+                    Expr::If(_) | Expr::Block(_) => else_.to_tokens(tokens),
+                    _ => token::Brace::default().surround(tokens, |tokens| else_.to_tokens(tokens)),
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprIndex {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.expr.to_tokens(tokens);
+            self.bracket_token.surround(tokens, |tokens| {
+                self.index.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprInfer {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.underscore_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprLet {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.let_token.to_tokens(tokens);
+            self.pat.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            wrap_bare_struct(tokens, &self.expr);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprLit {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.lit.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprLoop {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.label.to_tokens(tokens);
+            self.loop_token.to_tokens(tokens);
+            self.body.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.body.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.mac.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprMatch {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.match_token.to_tokens(tokens);
+            wrap_bare_struct(tokens, &self.expr);
+            self.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                for (i, arm) in self.arms.iter().enumerate() {
+                    arm.to_tokens(tokens);
+                    // Ensure that we have a comma after a non-block arm, except
+                    // for the last one.
+                    let is_last = i == self.arms.len() - 1;
+                    if !is_last && requires_terminator(&arm.body) && arm.comma.is_none() {
+                        <Token![,]>::default().to_tokens(tokens);
+                    }
+                }
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprMethodCall {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.receiver.to_tokens(tokens);
+            self.dot_token.to_tokens(tokens);
+            self.method.to_tokens(tokens);
+            self.turbofish.to_tokens(tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.args.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprParen {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.expr.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprPath {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            path::printing::print_path(tokens, &self.qself, &self.path);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprRange {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.start.to_tokens(tokens);
+            self.limits.to_tokens(tokens);
+            self.end.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprReference {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.and_token.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprRepeat {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.bracket_token.surround(tokens, |tokens| {
+                self.expr.to_tokens(tokens);
+                self.semi_token.to_tokens(tokens);
+                self.len.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprReturn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.return_token.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            path::printing::print_path(tokens, &self.qself, &self.path);
+            self.brace_token.surround(tokens, |tokens| {
+                self.fields.to_tokens(tokens);
+                if let Some(dot2_token) = &self.dot2_token {
+                    dot2_token.to_tokens(tokens);
+                } else if self.rest.is_some() {
+                    Token![..](Span::call_site()).to_tokens(tokens);
+                }
+                self.rest.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprTry {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.expr.to_tokens(tokens);
+            self.question_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprTryBlock {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.try_token.to_tokens(tokens);
+            self.block.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprTuple {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+                // If we only have one argument, we need a trailing comma to
+                // distinguish ExprTuple from ExprParen.
+                if self.elems.len() == 1 && !self.elems.trailing_punct() {
+                    <Token![,]>::default().to_tokens(tokens);
+                }
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprUnary {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.op.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprUnsafe {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.unsafe_token.to_tokens(tokens);
+            self.block.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.block.stmts);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprWhile {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.label.to_tokens(tokens);
+            self.while_token.to_tokens(tokens);
+            wrap_bare_struct(tokens, &self.cond);
+            self.body.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.body.stmts);
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprYield {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.yield_token.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Arm {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(&self.attrs);
+            self.pat.to_tokens(tokens);
+            if let Some((if_token, guard)) = &self.guard {
+                if_token.to_tokens(tokens);
+                guard.to_tokens(tokens);
+            }
+            self.fat_arrow_token.to_tokens(tokens);
+            self.body.to_tokens(tokens);
+            self.comma.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for FieldValue {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+            self.member.to_tokens(tokens);
+            if let Some(colon_token) = &self.colon_token {
+                colon_token.to_tokens(tokens);
+                self.expr.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Index {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            let mut lit = Literal::i64_unsuffixed(i64::from(self.index));
+            lit.set_span(self.span);
+            tokens.append(lit);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Label {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.name.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Member {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                Member::Named(ident) => ident.to_tokens(tokens),
+                Member::Unnamed(index) => index.to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for RangeLimits {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                RangeLimits::HalfOpen(t) => t.to_tokens(tokens),
+                RangeLimits::Closed(t) => t.to_tokens(tokens),
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/ext.rs b/vendor/syn/src/ext.rs
new file mode 100644
index 0000000..9ee5672
--- /dev/null
+++ b/vendor/syn/src/ext.rs
@@ -0,0 +1,135 @@
+//! Extension traits to provide parsing methods on foreign types.
+
+use crate::buffer::Cursor;
+use crate::parse::Peek;
+use crate::parse::{ParseStream, Result};
+use crate::sealed::lookahead;
+use crate::token::CustomToken;
+use proc_macro2::Ident;
+
+/// Additional methods for `Ident` not provided by proc-macro2 or libproc_macro.
+///
+/// This trait is sealed and cannot be implemented for types outside of Syn. It
+/// is implemented only for `proc_macro2::Ident`.
+pub trait IdentExt: Sized + private::Sealed {
+    /// Parses any identifier including keywords.
+    ///
+    /// This is useful when parsing macro input which allows Rust keywords as
+    /// identifiers.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{Error, Ident, Result, Token};
+    /// use syn::ext::IdentExt;
+    /// use syn::parse::ParseStream;
+    ///
+    /// mod kw {
+    ///     syn::custom_keyword!(name);
+    /// }
+    ///
+    /// // Parses input that looks like `name = NAME` where `NAME` can be
+    /// // any identifier.
+    /// //
+    /// // Examples:
+    /// //
+    /// //     name = anything
+    /// //     name = impl
+    /// fn parse_dsl(input: ParseStream) -> Result<Ident> {
+    ///     input.parse::<kw::name>()?;
+    ///     input.parse::<Token![=]>()?;
+    ///     let name = input.call(Ident::parse_any)?;
+    ///     Ok(name)
+    /// }
+    /// ```
+    fn parse_any(input: ParseStream) -> Result<Self>;
+
+    /// Peeks any identifier including keywords. Usage:
+    /// `input.peek(Ident::peek_any)`
+    ///
+    /// This is different from `input.peek(Ident)` which only returns true in
+    /// the case of an ident which is not a Rust keyword.
+    #[allow(non_upper_case_globals)]
+    const peek_any: private::PeekFn = private::PeekFn;
+
+    /// Strips the raw marker `r#`, if any, from the beginning of an ident.
+    ///
+    ///   - unraw(`x`) = `x`
+    ///   - unraw(`move`) = `move`
+    ///   - unraw(`r#move`) = `move`
+    ///
+    /// # Example
+    ///
+    /// In the case of interop with other languages like Python that have a
+    /// different set of keywords than Rust, we might come across macro input
+    /// that involves raw identifiers to refer to ordinary variables in the
+    /// other language with a name that happens to be a Rust keyword.
+    ///
+    /// The function below appends an identifier from the caller's input onto a
+    /// fixed prefix. Without using `unraw()`, this would tend to produce
+    /// invalid identifiers like `__pyo3_get_r#move`.
+    ///
+    /// ```
+    /// use proc_macro2::Span;
+    /// use syn::Ident;
+    /// use syn::ext::IdentExt;
+    ///
+    /// fn ident_for_getter(variable: &Ident) -> Ident {
+    ///     let getter = format!("__pyo3_get_{}", variable.unraw());
+    ///     Ident::new(&getter, Span::call_site())
+    /// }
+    /// ```
+    fn unraw(&self) -> Ident;
+}
+
+impl IdentExt for Ident {
+    fn parse_any(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| match cursor.ident() {
+            Some((ident, rest)) => Ok((ident, rest)),
+            None => Err(cursor.error("expected ident")),
+        })
+    }
+
+    fn unraw(&self) -> Ident {
+        let string = self.to_string();
+        if let Some(string) = string.strip_prefix("r#") {
+            Ident::new(string, self.span())
+        } else {
+            self.clone()
+        }
+    }
+}
+
+impl Peek for private::PeekFn {
+    type Token = private::IdentAny;
+}
+
+impl CustomToken for private::IdentAny {
+    fn peek(cursor: Cursor) -> bool {
+        cursor.ident().is_some()
+    }
+
+    fn display() -> &'static str {
+        "identifier"
+    }
+}
+
+impl lookahead::Sealed for private::PeekFn {}
+
+mod private {
+    use proc_macro2::Ident;
+
+    pub trait Sealed {}
+
+    impl Sealed for Ident {}
+
+    pub struct PeekFn;
+    pub struct IdentAny;
+
+    impl Copy for PeekFn {}
+    impl Clone for PeekFn {
+        fn clone(&self) -> Self {
+            *self
+        }
+    }
+}
diff --git a/vendor/syn/src/file.rs b/vendor/syn/src/file.rs
new file mode 100644
index 0000000..2d9f298
--- /dev/null
+++ b/vendor/syn/src/file.rs
@@ -0,0 +1,125 @@
+use super::*;
+
+ast_struct! {
+    /// A complete file of Rust source code.
+    ///
+    /// Typically `File` objects are created with [`parse_file`].
+    ///
+    /// # Example
+    ///
+    /// Parse a Rust source file into a `syn::File` and print out a debug
+    /// representation of the syntax tree.
+    ///
+    /// ```
+    /// use std::env;
+    /// use std::fs::File;
+    /// use std::io::Read;
+    /// use std::process;
+    ///
+    /// fn main() {
+    /// # }
+    /// #
+    /// # fn fake_main() {
+    ///     let mut args = env::args();
+    ///     let _ = args.next(); // executable name
+    ///
+    ///     let filename = match (args.next(), args.next()) {
+    ///         (Some(filename), None) => filename,
+    ///         _ => {
+    ///             eprintln!("Usage: dump-syntax path/to/filename.rs");
+    ///             process::exit(1);
+    ///         }
+    ///     };
+    ///
+    ///     let mut file = File::open(&filename).expect("Unable to open file");
+    ///
+    ///     let mut src = String::new();
+    ///     file.read_to_string(&mut src).expect("Unable to read file");
+    ///
+    ///     let syntax = syn::parse_file(&src).expect("Unable to parse file");
+    ///
+    ///     // Debug impl is available if Syn is built with "extra-traits" feature.
+    ///     println!("{:#?}", syntax);
+    /// }
+    /// ```
+    ///
+    /// Running with its own source code as input, this program prints output
+    /// that begins with:
+    ///
+    /// ```text
+    /// File {
+    ///     shebang: None,
+    ///     attrs: [],
+    ///     items: [
+    ///         Use(
+    ///             ItemUse {
+    ///                 attrs: [],
+    ///                 vis: Inherited,
+    ///                 use_token: Use,
+    ///                 leading_colon: None,
+    ///                 tree: Path(
+    ///                     UsePath {
+    ///                         ident: Ident(
+    ///                             std,
+    ///                         ),
+    ///                         colon2_token: Colon2,
+    ///                         tree: Name(
+    ///                             UseName {
+    ///                                 ident: Ident(
+    ///                                     env,
+    ///                                 ),
+    ///                             },
+    ///                         ),
+    ///                     },
+    ///                 ),
+    ///                 semi_token: Semi,
+    ///             },
+    ///         ),
+    /// ...
+    /// ```
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct File {
+        pub shebang: Option<String>,
+        pub attrs: Vec<Attribute>,
+        pub items: Vec<Item>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for File {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(File {
+                shebang: None,
+                attrs: input.call(Attribute::parse_inner)?,
+                items: {
+                    let mut items = Vec::new();
+                    while !input.is_empty() {
+                        items.push(input.parse()?);
+                    }
+                    items
+                },
+            })
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for File {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.inner());
+            tokens.append_all(&self.items);
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/clone.rs b/vendor/syn/src/gen/clone.rs
new file mode 100644
index 0000000..d275f51
--- /dev/null
+++ b/vendor/syn/src/gen/clone.rs
@@ -0,0 +1,2184 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#![allow(clippy::clone_on_copy, clippy::expl_impl_clone_on_copy)]
+use crate::*;
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Abi {
+    fn clone(&self) -> Self {
+        Abi {
+            extern_token: self.extern_token.clone(),
+            name: self.name.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for AngleBracketedGenericArguments {
+    fn clone(&self) -> Self {
+        AngleBracketedGenericArguments {
+            colon2_token: self.colon2_token.clone(),
+            lt_token: self.lt_token.clone(),
+            args: self.args.clone(),
+            gt_token: self.gt_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Arm {
+    fn clone(&self) -> Self {
+        Arm {
+            attrs: self.attrs.clone(),
+            pat: self.pat.clone(),
+            guard: self.guard.clone(),
+            fat_arrow_token: self.fat_arrow_token.clone(),
+            body: self.body.clone(),
+            comma: self.comma.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for AssocConst {
+    fn clone(&self) -> Self {
+        AssocConst {
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            eq_token: self.eq_token.clone(),
+            value: self.value.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for AssocType {
+    fn clone(&self) -> Self {
+        AssocType {
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            eq_token: self.eq_token.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for AttrStyle {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for AttrStyle {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Attribute {
+    fn clone(&self) -> Self {
+        Attribute {
+            pound_token: self.pound_token.clone(),
+            style: self.style.clone(),
+            bracket_token: self.bracket_token.clone(),
+            meta: self.meta.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for BareFnArg {
+    fn clone(&self) -> Self {
+        BareFnArg {
+            attrs: self.attrs.clone(),
+            name: self.name.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for BareVariadic {
+    fn clone(&self) -> Self {
+        BareVariadic {
+            attrs: self.attrs.clone(),
+            name: self.name.clone(),
+            dots: self.dots.clone(),
+            comma: self.comma.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for BinOp {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for BinOp {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Block {
+    fn clone(&self) -> Self {
+        Block {
+            brace_token: self.brace_token.clone(),
+            stmts: self.stmts.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for BoundLifetimes {
+    fn clone(&self) -> Self {
+        BoundLifetimes {
+            for_token: self.for_token.clone(),
+            lt_token: self.lt_token.clone(),
+            lifetimes: self.lifetimes.clone(),
+            gt_token: self.gt_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ConstParam {
+    fn clone(&self) -> Self {
+        ConstParam {
+            attrs: self.attrs.clone(),
+            const_token: self.const_token.clone(),
+            ident: self.ident.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            eq_token: self.eq_token.clone(),
+            default: self.default.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Constraint {
+    fn clone(&self) -> Self {
+        Constraint {
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Data {
+    fn clone(&self) -> Self {
+        match self {
+            Data::Struct(v0) => Data::Struct(v0.clone()),
+            Data::Enum(v0) => Data::Enum(v0.clone()),
+            Data::Union(v0) => Data::Union(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for DataEnum {
+    fn clone(&self) -> Self {
+        DataEnum {
+            enum_token: self.enum_token.clone(),
+            brace_token: self.brace_token.clone(),
+            variants: self.variants.clone(),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for DataStruct {
+    fn clone(&self) -> Self {
+        DataStruct {
+            struct_token: self.struct_token.clone(),
+            fields: self.fields.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for DataUnion {
+    fn clone(&self) -> Self {
+        DataUnion {
+            union_token: self.union_token.clone(),
+            fields: self.fields.clone(),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for DeriveInput {
+    fn clone(&self) -> Self {
+        DeriveInput {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            data: self.data.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Expr {
+    fn clone(&self) -> Self {
+        match self {
+            #[cfg(feature = "full")]
+            Expr::Array(v0) => Expr::Array(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Assign(v0) => Expr::Assign(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Async(v0) => Expr::Async(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Await(v0) => Expr::Await(v0.clone()),
+            Expr::Binary(v0) => Expr::Binary(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Block(v0) => Expr::Block(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Break(v0) => Expr::Break(v0.clone()),
+            Expr::Call(v0) => Expr::Call(v0.clone()),
+            Expr::Cast(v0) => Expr::Cast(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Closure(v0) => Expr::Closure(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Const(v0) => Expr::Const(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Continue(v0) => Expr::Continue(v0.clone()),
+            Expr::Field(v0) => Expr::Field(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::ForLoop(v0) => Expr::ForLoop(v0.clone()),
+            Expr::Group(v0) => Expr::Group(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::If(v0) => Expr::If(v0.clone()),
+            Expr::Index(v0) => Expr::Index(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Infer(v0) => Expr::Infer(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Let(v0) => Expr::Let(v0.clone()),
+            Expr::Lit(v0) => Expr::Lit(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Loop(v0) => Expr::Loop(v0.clone()),
+            Expr::Macro(v0) => Expr::Macro(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Match(v0) => Expr::Match(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::MethodCall(v0) => Expr::MethodCall(v0.clone()),
+            Expr::Paren(v0) => Expr::Paren(v0.clone()),
+            Expr::Path(v0) => Expr::Path(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Range(v0) => Expr::Range(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Reference(v0) => Expr::Reference(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Repeat(v0) => Expr::Repeat(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Return(v0) => Expr::Return(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Struct(v0) => Expr::Struct(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Try(v0) => Expr::Try(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::TryBlock(v0) => Expr::TryBlock(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Tuple(v0) => Expr::Tuple(v0.clone()),
+            Expr::Unary(v0) => Expr::Unary(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Unsafe(v0) => Expr::Unsafe(v0.clone()),
+            Expr::Verbatim(v0) => Expr::Verbatim(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::While(v0) => Expr::While(v0.clone()),
+            #[cfg(feature = "full")]
+            Expr::Yield(v0) => Expr::Yield(v0.clone()),
+            #[cfg(not(feature = "full"))]
+            _ => unreachable!(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprArray {
+    fn clone(&self) -> Self {
+        ExprArray {
+            attrs: self.attrs.clone(),
+            bracket_token: self.bracket_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprAssign {
+    fn clone(&self) -> Self {
+        ExprAssign {
+            attrs: self.attrs.clone(),
+            left: self.left.clone(),
+            eq_token: self.eq_token.clone(),
+            right: self.right.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprAsync {
+    fn clone(&self) -> Self {
+        ExprAsync {
+            attrs: self.attrs.clone(),
+            async_token: self.async_token.clone(),
+            capture: self.capture.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprAwait {
+    fn clone(&self) -> Self {
+        ExprAwait {
+            attrs: self.attrs.clone(),
+            base: self.base.clone(),
+            dot_token: self.dot_token.clone(),
+            await_token: self.await_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprBinary {
+    fn clone(&self) -> Self {
+        ExprBinary {
+            attrs: self.attrs.clone(),
+            left: self.left.clone(),
+            op: self.op.clone(),
+            right: self.right.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprBlock {
+    fn clone(&self) -> Self {
+        ExprBlock {
+            attrs: self.attrs.clone(),
+            label: self.label.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprBreak {
+    fn clone(&self) -> Self {
+        ExprBreak {
+            attrs: self.attrs.clone(),
+            break_token: self.break_token.clone(),
+            label: self.label.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprCall {
+    fn clone(&self) -> Self {
+        ExprCall {
+            attrs: self.attrs.clone(),
+            func: self.func.clone(),
+            paren_token: self.paren_token.clone(),
+            args: self.args.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprCast {
+    fn clone(&self) -> Self {
+        ExprCast {
+            attrs: self.attrs.clone(),
+            expr: self.expr.clone(),
+            as_token: self.as_token.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprClosure {
+    fn clone(&self) -> Self {
+        ExprClosure {
+            attrs: self.attrs.clone(),
+            lifetimes: self.lifetimes.clone(),
+            constness: self.constness.clone(),
+            movability: self.movability.clone(),
+            asyncness: self.asyncness.clone(),
+            capture: self.capture.clone(),
+            or1_token: self.or1_token.clone(),
+            inputs: self.inputs.clone(),
+            or2_token: self.or2_token.clone(),
+            output: self.output.clone(),
+            body: self.body.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprConst {
+    fn clone(&self) -> Self {
+        ExprConst {
+            attrs: self.attrs.clone(),
+            const_token: self.const_token.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprContinue {
+    fn clone(&self) -> Self {
+        ExprContinue {
+            attrs: self.attrs.clone(),
+            continue_token: self.continue_token.clone(),
+            label: self.label.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprField {
+    fn clone(&self) -> Self {
+        ExprField {
+            attrs: self.attrs.clone(),
+            base: self.base.clone(),
+            dot_token: self.dot_token.clone(),
+            member: self.member.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprForLoop {
+    fn clone(&self) -> Self {
+        ExprForLoop {
+            attrs: self.attrs.clone(),
+            label: self.label.clone(),
+            for_token: self.for_token.clone(),
+            pat: self.pat.clone(),
+            in_token: self.in_token.clone(),
+            expr: self.expr.clone(),
+            body: self.body.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprGroup {
+    fn clone(&self) -> Self {
+        ExprGroup {
+            attrs: self.attrs.clone(),
+            group_token: self.group_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprIf {
+    fn clone(&self) -> Self {
+        ExprIf {
+            attrs: self.attrs.clone(),
+            if_token: self.if_token.clone(),
+            cond: self.cond.clone(),
+            then_branch: self.then_branch.clone(),
+            else_branch: self.else_branch.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprIndex {
+    fn clone(&self) -> Self {
+        ExprIndex {
+            attrs: self.attrs.clone(),
+            expr: self.expr.clone(),
+            bracket_token: self.bracket_token.clone(),
+            index: self.index.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprInfer {
+    fn clone(&self) -> Self {
+        ExprInfer {
+            attrs: self.attrs.clone(),
+            underscore_token: self.underscore_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprLet {
+    fn clone(&self) -> Self {
+        ExprLet {
+            attrs: self.attrs.clone(),
+            let_token: self.let_token.clone(),
+            pat: self.pat.clone(),
+            eq_token: self.eq_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprLit {
+    fn clone(&self) -> Self {
+        ExprLit {
+            attrs: self.attrs.clone(),
+            lit: self.lit.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprLoop {
+    fn clone(&self) -> Self {
+        ExprLoop {
+            attrs: self.attrs.clone(),
+            label: self.label.clone(),
+            loop_token: self.loop_token.clone(),
+            body: self.body.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprMacro {
+    fn clone(&self) -> Self {
+        ExprMacro {
+            attrs: self.attrs.clone(),
+            mac: self.mac.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprMatch {
+    fn clone(&self) -> Self {
+        ExprMatch {
+            attrs: self.attrs.clone(),
+            match_token: self.match_token.clone(),
+            expr: self.expr.clone(),
+            brace_token: self.brace_token.clone(),
+            arms: self.arms.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprMethodCall {
+    fn clone(&self) -> Self {
+        ExprMethodCall {
+            attrs: self.attrs.clone(),
+            receiver: self.receiver.clone(),
+            dot_token: self.dot_token.clone(),
+            method: self.method.clone(),
+            turbofish: self.turbofish.clone(),
+            paren_token: self.paren_token.clone(),
+            args: self.args.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprParen {
+    fn clone(&self) -> Self {
+        ExprParen {
+            attrs: self.attrs.clone(),
+            paren_token: self.paren_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprPath {
+    fn clone(&self) -> Self {
+        ExprPath {
+            attrs: self.attrs.clone(),
+            qself: self.qself.clone(),
+            path: self.path.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprRange {
+    fn clone(&self) -> Self {
+        ExprRange {
+            attrs: self.attrs.clone(),
+            start: self.start.clone(),
+            limits: self.limits.clone(),
+            end: self.end.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprReference {
+    fn clone(&self) -> Self {
+        ExprReference {
+            attrs: self.attrs.clone(),
+            and_token: self.and_token.clone(),
+            mutability: self.mutability.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprRepeat {
+    fn clone(&self) -> Self {
+        ExprRepeat {
+            attrs: self.attrs.clone(),
+            bracket_token: self.bracket_token.clone(),
+            expr: self.expr.clone(),
+            semi_token: self.semi_token.clone(),
+            len: self.len.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprReturn {
+    fn clone(&self) -> Self {
+        ExprReturn {
+            attrs: self.attrs.clone(),
+            return_token: self.return_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprStruct {
+    fn clone(&self) -> Self {
+        ExprStruct {
+            attrs: self.attrs.clone(),
+            qself: self.qself.clone(),
+            path: self.path.clone(),
+            brace_token: self.brace_token.clone(),
+            fields: self.fields.clone(),
+            dot2_token: self.dot2_token.clone(),
+            rest: self.rest.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprTry {
+    fn clone(&self) -> Self {
+        ExprTry {
+            attrs: self.attrs.clone(),
+            expr: self.expr.clone(),
+            question_token: self.question_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprTryBlock {
+    fn clone(&self) -> Self {
+        ExprTryBlock {
+            attrs: self.attrs.clone(),
+            try_token: self.try_token.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprTuple {
+    fn clone(&self) -> Self {
+        ExprTuple {
+            attrs: self.attrs.clone(),
+            paren_token: self.paren_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprUnary {
+    fn clone(&self) -> Self {
+        ExprUnary {
+            attrs: self.attrs.clone(),
+            op: self.op.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprUnsafe {
+    fn clone(&self) -> Self {
+        ExprUnsafe {
+            attrs: self.attrs.clone(),
+            unsafe_token: self.unsafe_token.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprWhile {
+    fn clone(&self) -> Self {
+        ExprWhile {
+            attrs: self.attrs.clone(),
+            label: self.label.clone(),
+            while_token: self.while_token.clone(),
+            cond: self.cond.clone(),
+            body: self.body.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ExprYield {
+    fn clone(&self) -> Self {
+        ExprYield {
+            attrs: self.attrs.clone(),
+            yield_token: self.yield_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Field {
+    fn clone(&self) -> Self {
+        Field {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            mutability: self.mutability.clone(),
+            ident: self.ident.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FieldMutability {
+    fn clone(&self) -> Self {
+        match self {
+            FieldMutability::None => FieldMutability::None,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FieldPat {
+    fn clone(&self) -> Self {
+        FieldPat {
+            attrs: self.attrs.clone(),
+            member: self.member.clone(),
+            colon_token: self.colon_token.clone(),
+            pat: self.pat.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FieldValue {
+    fn clone(&self) -> Self {
+        FieldValue {
+            attrs: self.attrs.clone(),
+            member: self.member.clone(),
+            colon_token: self.colon_token.clone(),
+            expr: self.expr.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Fields {
+    fn clone(&self) -> Self {
+        match self {
+            Fields::Named(v0) => Fields::Named(v0.clone()),
+            Fields::Unnamed(v0) => Fields::Unnamed(v0.clone()),
+            Fields::Unit => Fields::Unit,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FieldsNamed {
+    fn clone(&self) -> Self {
+        FieldsNamed {
+            brace_token: self.brace_token.clone(),
+            named: self.named.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FieldsUnnamed {
+    fn clone(&self) -> Self {
+        FieldsUnnamed {
+            paren_token: self.paren_token.clone(),
+            unnamed: self.unnamed.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for File {
+    fn clone(&self) -> Self {
+        File {
+            shebang: self.shebang.clone(),
+            attrs: self.attrs.clone(),
+            items: self.items.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for FnArg {
+    fn clone(&self) -> Self {
+        match self {
+            FnArg::Receiver(v0) => FnArg::Receiver(v0.clone()),
+            FnArg::Typed(v0) => FnArg::Typed(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ForeignItem {
+    fn clone(&self) -> Self {
+        match self {
+            ForeignItem::Fn(v0) => ForeignItem::Fn(v0.clone()),
+            ForeignItem::Static(v0) => ForeignItem::Static(v0.clone()),
+            ForeignItem::Type(v0) => ForeignItem::Type(v0.clone()),
+            ForeignItem::Macro(v0) => ForeignItem::Macro(v0.clone()),
+            ForeignItem::Verbatim(v0) => ForeignItem::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ForeignItemFn {
+    fn clone(&self) -> Self {
+        ForeignItemFn {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            sig: self.sig.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ForeignItemMacro {
+    fn clone(&self) -> Self {
+        ForeignItemMacro {
+            attrs: self.attrs.clone(),
+            mac: self.mac.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ForeignItemStatic {
+    fn clone(&self) -> Self {
+        ForeignItemStatic {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            static_token: self.static_token.clone(),
+            mutability: self.mutability.clone(),
+            ident: self.ident.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ForeignItemType {
+    fn clone(&self) -> Self {
+        ForeignItemType {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            type_token: self.type_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for GenericArgument {
+    fn clone(&self) -> Self {
+        match self {
+            GenericArgument::Lifetime(v0) => GenericArgument::Lifetime(v0.clone()),
+            GenericArgument::Type(v0) => GenericArgument::Type(v0.clone()),
+            GenericArgument::Const(v0) => GenericArgument::Const(v0.clone()),
+            GenericArgument::AssocType(v0) => GenericArgument::AssocType(v0.clone()),
+            GenericArgument::AssocConst(v0) => GenericArgument::AssocConst(v0.clone()),
+            GenericArgument::Constraint(v0) => GenericArgument::Constraint(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for GenericParam {
+    fn clone(&self) -> Self {
+        match self {
+            GenericParam::Lifetime(v0) => GenericParam::Lifetime(v0.clone()),
+            GenericParam::Type(v0) => GenericParam::Type(v0.clone()),
+            GenericParam::Const(v0) => GenericParam::Const(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Generics {
+    fn clone(&self) -> Self {
+        Generics {
+            lt_token: self.lt_token.clone(),
+            params: self.params.clone(),
+            gt_token: self.gt_token.clone(),
+            where_clause: self.where_clause.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplItem {
+    fn clone(&self) -> Self {
+        match self {
+            ImplItem::Const(v0) => ImplItem::Const(v0.clone()),
+            ImplItem::Fn(v0) => ImplItem::Fn(v0.clone()),
+            ImplItem::Type(v0) => ImplItem::Type(v0.clone()),
+            ImplItem::Macro(v0) => ImplItem::Macro(v0.clone()),
+            ImplItem::Verbatim(v0) => ImplItem::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplItemConst {
+    fn clone(&self) -> Self {
+        ImplItemConst {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            defaultness: self.defaultness.clone(),
+            const_token: self.const_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            eq_token: self.eq_token.clone(),
+            expr: self.expr.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplItemFn {
+    fn clone(&self) -> Self {
+        ImplItemFn {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            defaultness: self.defaultness.clone(),
+            sig: self.sig.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplItemMacro {
+    fn clone(&self) -> Self {
+        ImplItemMacro {
+            attrs: self.attrs.clone(),
+            mac: self.mac.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplItemType {
+    fn clone(&self) -> Self {
+        ImplItemType {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            defaultness: self.defaultness.clone(),
+            type_token: self.type_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            eq_token: self.eq_token.clone(),
+            ty: self.ty.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ImplRestriction {
+    fn clone(&self) -> Self {
+        match *self {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Index {
+    fn clone(&self) -> Self {
+        Index {
+            index: self.index.clone(),
+            span: self.span.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Item {
+    fn clone(&self) -> Self {
+        match self {
+            Item::Const(v0) => Item::Const(v0.clone()),
+            Item::Enum(v0) => Item::Enum(v0.clone()),
+            Item::ExternCrate(v0) => Item::ExternCrate(v0.clone()),
+            Item::Fn(v0) => Item::Fn(v0.clone()),
+            Item::ForeignMod(v0) => Item::ForeignMod(v0.clone()),
+            Item::Impl(v0) => Item::Impl(v0.clone()),
+            Item::Macro(v0) => Item::Macro(v0.clone()),
+            Item::Mod(v0) => Item::Mod(v0.clone()),
+            Item::Static(v0) => Item::Static(v0.clone()),
+            Item::Struct(v0) => Item::Struct(v0.clone()),
+            Item::Trait(v0) => Item::Trait(v0.clone()),
+            Item::TraitAlias(v0) => Item::TraitAlias(v0.clone()),
+            Item::Type(v0) => Item::Type(v0.clone()),
+            Item::Union(v0) => Item::Union(v0.clone()),
+            Item::Use(v0) => Item::Use(v0.clone()),
+            Item::Verbatim(v0) => Item::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemConst {
+    fn clone(&self) -> Self {
+        ItemConst {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            const_token: self.const_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            eq_token: self.eq_token.clone(),
+            expr: self.expr.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemEnum {
+    fn clone(&self) -> Self {
+        ItemEnum {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            enum_token: self.enum_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            brace_token: self.brace_token.clone(),
+            variants: self.variants.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemExternCrate {
+    fn clone(&self) -> Self {
+        ItemExternCrate {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            extern_token: self.extern_token.clone(),
+            crate_token: self.crate_token.clone(),
+            ident: self.ident.clone(),
+            rename: self.rename.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemFn {
+    fn clone(&self) -> Self {
+        ItemFn {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            sig: self.sig.clone(),
+            block: self.block.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemForeignMod {
+    fn clone(&self) -> Self {
+        ItemForeignMod {
+            attrs: self.attrs.clone(),
+            unsafety: self.unsafety.clone(),
+            abi: self.abi.clone(),
+            brace_token: self.brace_token.clone(),
+            items: self.items.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemImpl {
+    fn clone(&self) -> Self {
+        ItemImpl {
+            attrs: self.attrs.clone(),
+            defaultness: self.defaultness.clone(),
+            unsafety: self.unsafety.clone(),
+            impl_token: self.impl_token.clone(),
+            generics: self.generics.clone(),
+            trait_: self.trait_.clone(),
+            self_ty: self.self_ty.clone(),
+            brace_token: self.brace_token.clone(),
+            items: self.items.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemMacro {
+    fn clone(&self) -> Self {
+        ItemMacro {
+            attrs: self.attrs.clone(),
+            ident: self.ident.clone(),
+            mac: self.mac.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemMod {
+    fn clone(&self) -> Self {
+        ItemMod {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            unsafety: self.unsafety.clone(),
+            mod_token: self.mod_token.clone(),
+            ident: self.ident.clone(),
+            content: self.content.clone(),
+            semi: self.semi.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemStatic {
+    fn clone(&self) -> Self {
+        ItemStatic {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            static_token: self.static_token.clone(),
+            mutability: self.mutability.clone(),
+            ident: self.ident.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            eq_token: self.eq_token.clone(),
+            expr: self.expr.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemStruct {
+    fn clone(&self) -> Self {
+        ItemStruct {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            struct_token: self.struct_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            fields: self.fields.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemTrait {
+    fn clone(&self) -> Self {
+        ItemTrait {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            unsafety: self.unsafety.clone(),
+            auto_token: self.auto_token.clone(),
+            restriction: self.restriction.clone(),
+            trait_token: self.trait_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            supertraits: self.supertraits.clone(),
+            brace_token: self.brace_token.clone(),
+            items: self.items.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemTraitAlias {
+    fn clone(&self) -> Self {
+        ItemTraitAlias {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            trait_token: self.trait_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            eq_token: self.eq_token.clone(),
+            bounds: self.bounds.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemType {
+    fn clone(&self) -> Self {
+        ItemType {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            type_token: self.type_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            eq_token: self.eq_token.clone(),
+            ty: self.ty.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemUnion {
+    fn clone(&self) -> Self {
+        ItemUnion {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            union_token: self.union_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            fields: self.fields.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ItemUse {
+    fn clone(&self) -> Self {
+        ItemUse {
+            attrs: self.attrs.clone(),
+            vis: self.vis.clone(),
+            use_token: self.use_token.clone(),
+            leading_colon: self.leading_colon.clone(),
+            tree: self.tree.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Label {
+    fn clone(&self) -> Self {
+        Label {
+            name: self.name.clone(),
+            colon_token: self.colon_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LifetimeParam {
+    fn clone(&self) -> Self {
+        LifetimeParam {
+            attrs: self.attrs.clone(),
+            lifetime: self.lifetime.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Lit {
+    fn clone(&self) -> Self {
+        match self {
+            Lit::Str(v0) => Lit::Str(v0.clone()),
+            Lit::ByteStr(v0) => Lit::ByteStr(v0.clone()),
+            Lit::Byte(v0) => Lit::Byte(v0.clone()),
+            Lit::Char(v0) => Lit::Char(v0.clone()),
+            Lit::Int(v0) => Lit::Int(v0.clone()),
+            Lit::Float(v0) => Lit::Float(v0.clone()),
+            Lit::Bool(v0) => Lit::Bool(v0.clone()),
+            Lit::Verbatim(v0) => Lit::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LitBool {
+    fn clone(&self) -> Self {
+        LitBool {
+            value: self.value.clone(),
+            span: self.span.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Local {
+    fn clone(&self) -> Self {
+        Local {
+            attrs: self.attrs.clone(),
+            let_token: self.let_token.clone(),
+            pat: self.pat.clone(),
+            init: self.init.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LocalInit {
+    fn clone(&self) -> Self {
+        LocalInit {
+            eq_token: self.eq_token.clone(),
+            expr: self.expr.clone(),
+            diverge: self.diverge.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Macro {
+    fn clone(&self) -> Self {
+        Macro {
+            path: self.path.clone(),
+            bang_token: self.bang_token.clone(),
+            delimiter: self.delimiter.clone(),
+            tokens: self.tokens.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for MacroDelimiter {
+    fn clone(&self) -> Self {
+        match self {
+            MacroDelimiter::Paren(v0) => MacroDelimiter::Paren(v0.clone()),
+            MacroDelimiter::Brace(v0) => MacroDelimiter::Brace(v0.clone()),
+            MacroDelimiter::Bracket(v0) => MacroDelimiter::Bracket(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Member {
+    fn clone(&self) -> Self {
+        match self {
+            Member::Named(v0) => Member::Named(v0.clone()),
+            Member::Unnamed(v0) => Member::Unnamed(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Meta {
+    fn clone(&self) -> Self {
+        match self {
+            Meta::Path(v0) => Meta::Path(v0.clone()),
+            Meta::List(v0) => Meta::List(v0.clone()),
+            Meta::NameValue(v0) => Meta::NameValue(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for MetaList {
+    fn clone(&self) -> Self {
+        MetaList {
+            path: self.path.clone(),
+            delimiter: self.delimiter.clone(),
+            tokens: self.tokens.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for MetaNameValue {
+    fn clone(&self) -> Self {
+        MetaNameValue {
+            path: self.path.clone(),
+            eq_token: self.eq_token.clone(),
+            value: self.value.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ParenthesizedGenericArguments {
+    fn clone(&self) -> Self {
+        ParenthesizedGenericArguments {
+            paren_token: self.paren_token.clone(),
+            inputs: self.inputs.clone(),
+            output: self.output.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Pat {
+    fn clone(&self) -> Self {
+        match self {
+            Pat::Const(v0) => Pat::Const(v0.clone()),
+            Pat::Ident(v0) => Pat::Ident(v0.clone()),
+            Pat::Lit(v0) => Pat::Lit(v0.clone()),
+            Pat::Macro(v0) => Pat::Macro(v0.clone()),
+            Pat::Or(v0) => Pat::Or(v0.clone()),
+            Pat::Paren(v0) => Pat::Paren(v0.clone()),
+            Pat::Path(v0) => Pat::Path(v0.clone()),
+            Pat::Range(v0) => Pat::Range(v0.clone()),
+            Pat::Reference(v0) => Pat::Reference(v0.clone()),
+            Pat::Rest(v0) => Pat::Rest(v0.clone()),
+            Pat::Slice(v0) => Pat::Slice(v0.clone()),
+            Pat::Struct(v0) => Pat::Struct(v0.clone()),
+            Pat::Tuple(v0) => Pat::Tuple(v0.clone()),
+            Pat::TupleStruct(v0) => Pat::TupleStruct(v0.clone()),
+            Pat::Type(v0) => Pat::Type(v0.clone()),
+            Pat::Verbatim(v0) => Pat::Verbatim(v0.clone()),
+            Pat::Wild(v0) => Pat::Wild(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatIdent {
+    fn clone(&self) -> Self {
+        PatIdent {
+            attrs: self.attrs.clone(),
+            by_ref: self.by_ref.clone(),
+            mutability: self.mutability.clone(),
+            ident: self.ident.clone(),
+            subpat: self.subpat.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatOr {
+    fn clone(&self) -> Self {
+        PatOr {
+            attrs: self.attrs.clone(),
+            leading_vert: self.leading_vert.clone(),
+            cases: self.cases.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatParen {
+    fn clone(&self) -> Self {
+        PatParen {
+            attrs: self.attrs.clone(),
+            paren_token: self.paren_token.clone(),
+            pat: self.pat.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatReference {
+    fn clone(&self) -> Self {
+        PatReference {
+            attrs: self.attrs.clone(),
+            and_token: self.and_token.clone(),
+            mutability: self.mutability.clone(),
+            pat: self.pat.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatRest {
+    fn clone(&self) -> Self {
+        PatRest {
+            attrs: self.attrs.clone(),
+            dot2_token: self.dot2_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatSlice {
+    fn clone(&self) -> Self {
+        PatSlice {
+            attrs: self.attrs.clone(),
+            bracket_token: self.bracket_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatStruct {
+    fn clone(&self) -> Self {
+        PatStruct {
+            attrs: self.attrs.clone(),
+            qself: self.qself.clone(),
+            path: self.path.clone(),
+            brace_token: self.brace_token.clone(),
+            fields: self.fields.clone(),
+            rest: self.rest.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatTuple {
+    fn clone(&self) -> Self {
+        PatTuple {
+            attrs: self.attrs.clone(),
+            paren_token: self.paren_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatTupleStruct {
+    fn clone(&self) -> Self {
+        PatTupleStruct {
+            attrs: self.attrs.clone(),
+            qself: self.qself.clone(),
+            path: self.path.clone(),
+            paren_token: self.paren_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatType {
+    fn clone(&self) -> Self {
+        PatType {
+            attrs: self.attrs.clone(),
+            pat: self.pat.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PatWild {
+    fn clone(&self) -> Self {
+        PatWild {
+            attrs: self.attrs.clone(),
+            underscore_token: self.underscore_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Path {
+    fn clone(&self) -> Self {
+        Path {
+            leading_colon: self.leading_colon.clone(),
+            segments: self.segments.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PathArguments {
+    fn clone(&self) -> Self {
+        match self {
+            PathArguments::None => PathArguments::None,
+            PathArguments::AngleBracketed(v0) => {
+                PathArguments::AngleBracketed(v0.clone())
+            }
+            PathArguments::Parenthesized(v0) => PathArguments::Parenthesized(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PathSegment {
+    fn clone(&self) -> Self {
+        PathSegment {
+            ident: self.ident.clone(),
+            arguments: self.arguments.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PredicateLifetime {
+    fn clone(&self) -> Self {
+        PredicateLifetime {
+            lifetime: self.lifetime.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for PredicateType {
+    fn clone(&self) -> Self {
+        PredicateType {
+            lifetimes: self.lifetimes.clone(),
+            bounded_ty: self.bounded_ty.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for QSelf {
+    fn clone(&self) -> Self {
+        QSelf {
+            lt_token: self.lt_token.clone(),
+            ty: self.ty.clone(),
+            position: self.position.clone(),
+            as_token: self.as_token.clone(),
+            gt_token: self.gt_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for RangeLimits {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for RangeLimits {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Receiver {
+    fn clone(&self) -> Self {
+        Receiver {
+            attrs: self.attrs.clone(),
+            reference: self.reference.clone(),
+            mutability: self.mutability.clone(),
+            self_token: self.self_token.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for ReturnType {
+    fn clone(&self) -> Self {
+        match self {
+            ReturnType::Default => ReturnType::Default,
+            ReturnType::Type(v0, v1) => ReturnType::Type(v0.clone(), v1.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Signature {
+    fn clone(&self) -> Self {
+        Signature {
+            constness: self.constness.clone(),
+            asyncness: self.asyncness.clone(),
+            unsafety: self.unsafety.clone(),
+            abi: self.abi.clone(),
+            fn_token: self.fn_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            paren_token: self.paren_token.clone(),
+            inputs: self.inputs.clone(),
+            variadic: self.variadic.clone(),
+            output: self.output.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for StaticMutability {
+    fn clone(&self) -> Self {
+        match self {
+            StaticMutability::Mut(v0) => StaticMutability::Mut(v0.clone()),
+            StaticMutability::None => StaticMutability::None,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Stmt {
+    fn clone(&self) -> Self {
+        match self {
+            Stmt::Local(v0) => Stmt::Local(v0.clone()),
+            Stmt::Item(v0) => Stmt::Item(v0.clone()),
+            Stmt::Expr(v0, v1) => Stmt::Expr(v0.clone(), v1.clone()),
+            Stmt::Macro(v0) => Stmt::Macro(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for StmtMacro {
+    fn clone(&self) -> Self {
+        StmtMacro {
+            attrs: self.attrs.clone(),
+            mac: self.mac.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitBound {
+    fn clone(&self) -> Self {
+        TraitBound {
+            paren_token: self.paren_token.clone(),
+            modifier: self.modifier.clone(),
+            lifetimes: self.lifetimes.clone(),
+            path: self.path.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for TraitBoundModifier {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitBoundModifier {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitItem {
+    fn clone(&self) -> Self {
+        match self {
+            TraitItem::Const(v0) => TraitItem::Const(v0.clone()),
+            TraitItem::Fn(v0) => TraitItem::Fn(v0.clone()),
+            TraitItem::Type(v0) => TraitItem::Type(v0.clone()),
+            TraitItem::Macro(v0) => TraitItem::Macro(v0.clone()),
+            TraitItem::Verbatim(v0) => TraitItem::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitItemConst {
+    fn clone(&self) -> Self {
+        TraitItemConst {
+            attrs: self.attrs.clone(),
+            const_token: self.const_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            ty: self.ty.clone(),
+            default: self.default.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitItemFn {
+    fn clone(&self) -> Self {
+        TraitItemFn {
+            attrs: self.attrs.clone(),
+            sig: self.sig.clone(),
+            default: self.default.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitItemMacro {
+    fn clone(&self) -> Self {
+        TraitItemMacro {
+            attrs: self.attrs.clone(),
+            mac: self.mac.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TraitItemType {
+    fn clone(&self) -> Self {
+        TraitItemType {
+            attrs: self.attrs.clone(),
+            type_token: self.type_token.clone(),
+            ident: self.ident.clone(),
+            generics: self.generics.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+            default: self.default.clone(),
+            semi_token: self.semi_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Type {
+    fn clone(&self) -> Self {
+        match self {
+            Type::Array(v0) => Type::Array(v0.clone()),
+            Type::BareFn(v0) => Type::BareFn(v0.clone()),
+            Type::Group(v0) => Type::Group(v0.clone()),
+            Type::ImplTrait(v0) => Type::ImplTrait(v0.clone()),
+            Type::Infer(v0) => Type::Infer(v0.clone()),
+            Type::Macro(v0) => Type::Macro(v0.clone()),
+            Type::Never(v0) => Type::Never(v0.clone()),
+            Type::Paren(v0) => Type::Paren(v0.clone()),
+            Type::Path(v0) => Type::Path(v0.clone()),
+            Type::Ptr(v0) => Type::Ptr(v0.clone()),
+            Type::Reference(v0) => Type::Reference(v0.clone()),
+            Type::Slice(v0) => Type::Slice(v0.clone()),
+            Type::TraitObject(v0) => Type::TraitObject(v0.clone()),
+            Type::Tuple(v0) => Type::Tuple(v0.clone()),
+            Type::Verbatim(v0) => Type::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeArray {
+    fn clone(&self) -> Self {
+        TypeArray {
+            bracket_token: self.bracket_token.clone(),
+            elem: self.elem.clone(),
+            semi_token: self.semi_token.clone(),
+            len: self.len.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeBareFn {
+    fn clone(&self) -> Self {
+        TypeBareFn {
+            lifetimes: self.lifetimes.clone(),
+            unsafety: self.unsafety.clone(),
+            abi: self.abi.clone(),
+            fn_token: self.fn_token.clone(),
+            paren_token: self.paren_token.clone(),
+            inputs: self.inputs.clone(),
+            variadic: self.variadic.clone(),
+            output: self.output.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeGroup {
+    fn clone(&self) -> Self {
+        TypeGroup {
+            group_token: self.group_token.clone(),
+            elem: self.elem.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeImplTrait {
+    fn clone(&self) -> Self {
+        TypeImplTrait {
+            impl_token: self.impl_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeInfer {
+    fn clone(&self) -> Self {
+        TypeInfer {
+            underscore_token: self.underscore_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeMacro {
+    fn clone(&self) -> Self {
+        TypeMacro { mac: self.mac.clone() }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeNever {
+    fn clone(&self) -> Self {
+        TypeNever {
+            bang_token: self.bang_token.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeParam {
+    fn clone(&self) -> Self {
+        TypeParam {
+            attrs: self.attrs.clone(),
+            ident: self.ident.clone(),
+            colon_token: self.colon_token.clone(),
+            bounds: self.bounds.clone(),
+            eq_token: self.eq_token.clone(),
+            default: self.default.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeParamBound {
+    fn clone(&self) -> Self {
+        match self {
+            TypeParamBound::Trait(v0) => TypeParamBound::Trait(v0.clone()),
+            TypeParamBound::Lifetime(v0) => TypeParamBound::Lifetime(v0.clone()),
+            TypeParamBound::Verbatim(v0) => TypeParamBound::Verbatim(v0.clone()),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeParen {
+    fn clone(&self) -> Self {
+        TypeParen {
+            paren_token: self.paren_token.clone(),
+            elem: self.elem.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypePath {
+    fn clone(&self) -> Self {
+        TypePath {
+            qself: self.qself.clone(),
+            path: self.path.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypePtr {
+    fn clone(&self) -> Self {
+        TypePtr {
+            star_token: self.star_token.clone(),
+            const_token: self.const_token.clone(),
+            mutability: self.mutability.clone(),
+            elem: self.elem.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeReference {
+    fn clone(&self) -> Self {
+        TypeReference {
+            and_token: self.and_token.clone(),
+            lifetime: self.lifetime.clone(),
+            mutability: self.mutability.clone(),
+            elem: self.elem.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeSlice {
+    fn clone(&self) -> Self {
+        TypeSlice {
+            bracket_token: self.bracket_token.clone(),
+            elem: self.elem.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeTraitObject {
+    fn clone(&self) -> Self {
+        TypeTraitObject {
+            dyn_token: self.dyn_token.clone(),
+            bounds: self.bounds.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for TypeTuple {
+    fn clone(&self) -> Self {
+        TypeTuple {
+            paren_token: self.paren_token.clone(),
+            elems: self.elems.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for UnOp {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UnOp {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UseGlob {
+    fn clone(&self) -> Self {
+        UseGlob {
+            star_token: self.star_token.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UseGroup {
+    fn clone(&self) -> Self {
+        UseGroup {
+            brace_token: self.brace_token.clone(),
+            items: self.items.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UseName {
+    fn clone(&self) -> Self {
+        UseName {
+            ident: self.ident.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UsePath {
+    fn clone(&self) -> Self {
+        UsePath {
+            ident: self.ident.clone(),
+            colon2_token: self.colon2_token.clone(),
+            tree: self.tree.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UseRename {
+    fn clone(&self) -> Self {
+        UseRename {
+            ident: self.ident.clone(),
+            as_token: self.as_token.clone(),
+            rename: self.rename.clone(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for UseTree {
+    fn clone(&self) -> Self {
+        match self {
+            UseTree::Path(v0) => UseTree::Path(v0.clone()),
+            UseTree::Name(v0) => UseTree::Name(v0.clone()),
+            UseTree::Rename(v0) => UseTree::Rename(v0.clone()),
+            UseTree::Glob(v0) => UseTree::Glob(v0.clone()),
+            UseTree::Group(v0) => UseTree::Group(v0.clone()),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Variadic {
+    fn clone(&self) -> Self {
+        Variadic {
+            attrs: self.attrs.clone(),
+            pat: self.pat.clone(),
+            dots: self.dots.clone(),
+            comma: self.comma.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Variant {
+    fn clone(&self) -> Self {
+        Variant {
+            attrs: self.attrs.clone(),
+            ident: self.ident.clone(),
+            fields: self.fields.clone(),
+            discriminant: self.discriminant.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for VisRestricted {
+    fn clone(&self) -> Self {
+        VisRestricted {
+            pub_token: self.pub_token.clone(),
+            paren_token: self.paren_token.clone(),
+            in_token: self.in_token.clone(),
+            path: self.path.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Visibility {
+    fn clone(&self) -> Self {
+        match self {
+            Visibility::Public(v0) => Visibility::Public(v0.clone()),
+            Visibility::Restricted(v0) => Visibility::Restricted(v0.clone()),
+            Visibility::Inherited => Visibility::Inherited,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for WhereClause {
+    fn clone(&self) -> Self {
+        WhereClause {
+            where_token: self.where_token.clone(),
+            predicates: self.predicates.clone(),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for WherePredicate {
+    fn clone(&self) -> Self {
+        match self {
+            WherePredicate::Lifetime(v0) => WherePredicate::Lifetime(v0.clone()),
+            WherePredicate::Type(v0) => WherePredicate::Type(v0.clone()),
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/debug.rs b/vendor/syn/src/gen/debug.rs
new file mode 100644
index 0000000..837fe99
--- /dev/null
+++ b/vendor/syn/src/gen/debug.rs
@@ -0,0 +1,3055 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+use crate::*;
+use std::fmt::{self, Debug};
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Abi {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Abi");
+        formatter.field("extern_token", &self.extern_token);
+        formatter.field("name", &self.name);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for AngleBracketedGenericArguments {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl AngleBracketedGenericArguments {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("colon2_token", &self.colon2_token);
+                formatter.field("lt_token", &self.lt_token);
+                formatter.field("args", &self.args);
+                formatter.field("gt_token", &self.gt_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "AngleBracketedGenericArguments")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Arm {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Arm");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("pat", &self.pat);
+        formatter.field("guard", &self.guard);
+        formatter.field("fat_arrow_token", &self.fat_arrow_token);
+        formatter.field("body", &self.body);
+        formatter.field("comma", &self.comma);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for AssocConst {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("AssocConst");
+        formatter.field("ident", &self.ident);
+        formatter.field("generics", &self.generics);
+        formatter.field("eq_token", &self.eq_token);
+        formatter.field("value", &self.value);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for AssocType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("AssocType");
+        formatter.field("ident", &self.ident);
+        formatter.field("generics", &self.generics);
+        formatter.field("eq_token", &self.eq_token);
+        formatter.field("ty", &self.ty);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for AttrStyle {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("AttrStyle::")?;
+        match self {
+            AttrStyle::Outer => formatter.write_str("Outer"),
+            AttrStyle::Inner(v0) => {
+                let mut formatter = formatter.debug_tuple("Inner");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Attribute {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Attribute");
+        formatter.field("pound_token", &self.pound_token);
+        formatter.field("style", &self.style);
+        formatter.field("bracket_token", &self.bracket_token);
+        formatter.field("meta", &self.meta);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for BareFnArg {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BareFnArg");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("name", &self.name);
+        formatter.field("ty", &self.ty);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for BareVariadic {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BareVariadic");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("name", &self.name);
+        formatter.field("dots", &self.dots);
+        formatter.field("comma", &self.comma);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for BinOp {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("BinOp::")?;
+        match self {
+            BinOp::Add(v0) => {
+                let mut formatter = formatter.debug_tuple("Add");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Sub(v0) => {
+                let mut formatter = formatter.debug_tuple("Sub");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Mul(v0) => {
+                let mut formatter = formatter.debug_tuple("Mul");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Div(v0) => {
+                let mut formatter = formatter.debug_tuple("Div");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Rem(v0) => {
+                let mut formatter = formatter.debug_tuple("Rem");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::And(v0) => {
+                let mut formatter = formatter.debug_tuple("And");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Or(v0) => {
+                let mut formatter = formatter.debug_tuple("Or");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitXor(v0) => {
+                let mut formatter = formatter.debug_tuple("BitXor");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitAnd(v0) => {
+                let mut formatter = formatter.debug_tuple("BitAnd");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitOr(v0) => {
+                let mut formatter = formatter.debug_tuple("BitOr");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Shl(v0) => {
+                let mut formatter = formatter.debug_tuple("Shl");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Shr(v0) => {
+                let mut formatter = formatter.debug_tuple("Shr");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Eq(v0) => {
+                let mut formatter = formatter.debug_tuple("Eq");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Lt(v0) => {
+                let mut formatter = formatter.debug_tuple("Lt");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Le(v0) => {
+                let mut formatter = formatter.debug_tuple("Le");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Ne(v0) => {
+                let mut formatter = formatter.debug_tuple("Ne");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Ge(v0) => {
+                let mut formatter = formatter.debug_tuple("Ge");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::Gt(v0) => {
+                let mut formatter = formatter.debug_tuple("Gt");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::AddAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("AddAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::SubAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("SubAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::MulAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("MulAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::DivAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("DivAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::RemAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("RemAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitXorAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("BitXorAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitAndAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("BitAndAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::BitOrAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("BitOrAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::ShlAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("ShlAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            BinOp::ShrAssign(v0) => {
+                let mut formatter = formatter.debug_tuple("ShrAssign");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Block {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Block");
+        formatter.field("brace_token", &self.brace_token);
+        formatter.field("stmts", &self.stmts);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for BoundLifetimes {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BoundLifetimes");
+        formatter.field("for_token", &self.for_token);
+        formatter.field("lt_token", &self.lt_token);
+        formatter.field("lifetimes", &self.lifetimes);
+        formatter.field("gt_token", &self.gt_token);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ConstParam {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ConstParam");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("const_token", &self.const_token);
+        formatter.field("ident", &self.ident);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("ty", &self.ty);
+        formatter.field("eq_token", &self.eq_token);
+        formatter.field("default", &self.default);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Constraint {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Constraint");
+        formatter.field("ident", &self.ident);
+        formatter.field("generics", &self.generics);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("bounds", &self.bounds);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Data {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Data::")?;
+        match self {
+            Data::Struct(v0) => v0.debug(formatter, "Struct"),
+            Data::Enum(v0) => v0.debug(formatter, "Enum"),
+            Data::Union(v0) => v0.debug(formatter, "Union"),
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for DataEnum {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl DataEnum {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("enum_token", &self.enum_token);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("variants", &self.variants);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "DataEnum")
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for DataStruct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl DataStruct {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("struct_token", &self.struct_token);
+                formatter.field("fields", &self.fields);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "DataStruct")
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for DataUnion {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl DataUnion {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("union_token", &self.union_token);
+                formatter.field("fields", &self.fields);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "DataUnion")
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for DeriveInput {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("DeriveInput");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("vis", &self.vis);
+        formatter.field("ident", &self.ident);
+        formatter.field("generics", &self.generics);
+        formatter.field("data", &self.data);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Expr {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Expr::")?;
+        match self {
+            #[cfg(feature = "full")]
+            Expr::Array(v0) => v0.debug(formatter, "Array"),
+            #[cfg(feature = "full")]
+            Expr::Assign(v0) => v0.debug(formatter, "Assign"),
+            #[cfg(feature = "full")]
+            Expr::Async(v0) => v0.debug(formatter, "Async"),
+            #[cfg(feature = "full")]
+            Expr::Await(v0) => v0.debug(formatter, "Await"),
+            Expr::Binary(v0) => v0.debug(formatter, "Binary"),
+            #[cfg(feature = "full")]
+            Expr::Block(v0) => v0.debug(formatter, "Block"),
+            #[cfg(feature = "full")]
+            Expr::Break(v0) => v0.debug(formatter, "Break"),
+            Expr::Call(v0) => v0.debug(formatter, "Call"),
+            Expr::Cast(v0) => v0.debug(formatter, "Cast"),
+            #[cfg(feature = "full")]
+            Expr::Closure(v0) => v0.debug(formatter, "Closure"),
+            #[cfg(feature = "full")]
+            Expr::Const(v0) => v0.debug(formatter, "Const"),
+            #[cfg(feature = "full")]
+            Expr::Continue(v0) => v0.debug(formatter, "Continue"),
+            Expr::Field(v0) => v0.debug(formatter, "Field"),
+            #[cfg(feature = "full")]
+            Expr::ForLoop(v0) => v0.debug(formatter, "ForLoop"),
+            Expr::Group(v0) => v0.debug(formatter, "Group"),
+            #[cfg(feature = "full")]
+            Expr::If(v0) => v0.debug(formatter, "If"),
+            Expr::Index(v0) => v0.debug(formatter, "Index"),
+            #[cfg(feature = "full")]
+            Expr::Infer(v0) => v0.debug(formatter, "Infer"),
+            #[cfg(feature = "full")]
+            Expr::Let(v0) => v0.debug(formatter, "Let"),
+            Expr::Lit(v0) => v0.debug(formatter, "Lit"),
+            #[cfg(feature = "full")]
+            Expr::Loop(v0) => v0.debug(formatter, "Loop"),
+            Expr::Macro(v0) => v0.debug(formatter, "Macro"),
+            #[cfg(feature = "full")]
+            Expr::Match(v0) => v0.debug(formatter, "Match"),
+            #[cfg(feature = "full")]
+            Expr::MethodCall(v0) => v0.debug(formatter, "MethodCall"),
+            Expr::Paren(v0) => v0.debug(formatter, "Paren"),
+            Expr::Path(v0) => v0.debug(formatter, "Path"),
+            #[cfg(feature = "full")]
+            Expr::Range(v0) => v0.debug(formatter, "Range"),
+            #[cfg(feature = "full")]
+            Expr::Reference(v0) => v0.debug(formatter, "Reference"),
+            #[cfg(feature = "full")]
+            Expr::Repeat(v0) => v0.debug(formatter, "Repeat"),
+            #[cfg(feature = "full")]
+            Expr::Return(v0) => v0.debug(formatter, "Return"),
+            #[cfg(feature = "full")]
+            Expr::Struct(v0) => v0.debug(formatter, "Struct"),
+            #[cfg(feature = "full")]
+            Expr::Try(v0) => v0.debug(formatter, "Try"),
+            #[cfg(feature = "full")]
+            Expr::TryBlock(v0) => v0.debug(formatter, "TryBlock"),
+            #[cfg(feature = "full")]
+            Expr::Tuple(v0) => v0.debug(formatter, "Tuple"),
+            Expr::Unary(v0) => v0.debug(formatter, "Unary"),
+            #[cfg(feature = "full")]
+            Expr::Unsafe(v0) => v0.debug(formatter, "Unsafe"),
+            Expr::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            #[cfg(feature = "full")]
+            Expr::While(v0) => v0.debug(formatter, "While"),
+            #[cfg(feature = "full")]
+            Expr::Yield(v0) => v0.debug(formatter, "Yield"),
+            #[cfg(not(feature = "full"))]
+            _ => unreachable!(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprArray {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprArray {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprArray")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprAssign {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprAssign {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("left", &self.left);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("right", &self.right);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprAssign")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprAsync {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprAsync {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("async_token", &self.async_token);
+                formatter.field("capture", &self.capture);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprAsync")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprAwait {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprAwait {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("base", &self.base);
+                formatter.field("dot_token", &self.dot_token);
+                formatter.field("await_token", &self.await_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprAwait")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprBinary {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprBinary {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("left", &self.left);
+                formatter.field("op", &self.op);
+                formatter.field("right", &self.right);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprBinary")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprBlock {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprBlock {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("label", &self.label);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprBlock")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprBreak {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprBreak {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("break_token", &self.break_token);
+                formatter.field("label", &self.label);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprBreak")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprCall {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprCall {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("func", &self.func);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("args", &self.args);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprCall")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprCast {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprCast {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("expr", &self.expr);
+                formatter.field("as_token", &self.as_token);
+                formatter.field("ty", &self.ty);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprCast")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprClosure {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprClosure {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("lifetimes", &self.lifetimes);
+                formatter.field("constness", &self.constness);
+                formatter.field("movability", &self.movability);
+                formatter.field("asyncness", &self.asyncness);
+                formatter.field("capture", &self.capture);
+                formatter.field("or1_token", &self.or1_token);
+                formatter.field("inputs", &self.inputs);
+                formatter.field("or2_token", &self.or2_token);
+                formatter.field("output", &self.output);
+                formatter.field("body", &self.body);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprClosure")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprConst {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprConst {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("const_token", &self.const_token);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprConst")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprContinue {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprContinue {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("continue_token", &self.continue_token);
+                formatter.field("label", &self.label);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprContinue")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprField {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprField {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("base", &self.base);
+                formatter.field("dot_token", &self.dot_token);
+                formatter.field("member", &self.member);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprField")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprForLoop {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprForLoop {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("label", &self.label);
+                formatter.field("for_token", &self.for_token);
+                formatter.field("pat", &self.pat);
+                formatter.field("in_token", &self.in_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("body", &self.body);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprForLoop")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprGroup {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprGroup {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("group_token", &self.group_token);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprGroup")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprIf {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprIf {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("if_token", &self.if_token);
+                formatter.field("cond", &self.cond);
+                formatter.field("then_branch", &self.then_branch);
+                formatter.field("else_branch", &self.else_branch);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprIf")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprIndex {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprIndex {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("expr", &self.expr);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("index", &self.index);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprIndex")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprInfer {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprInfer {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("underscore_token", &self.underscore_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprInfer")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprLet {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprLet {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("let_token", &self.let_token);
+                formatter.field("pat", &self.pat);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprLet")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprLit {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprLit {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("lit", &self.lit);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprLit")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprLoop {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprLoop {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("label", &self.label);
+                formatter.field("loop_token", &self.loop_token);
+                formatter.field("body", &self.body);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprLoop")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("mac", &self.mac);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprMacro")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprMatch {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprMatch {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("match_token", &self.match_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("arms", &self.arms);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprMatch")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprMethodCall {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprMethodCall {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("receiver", &self.receiver);
+                formatter.field("dot_token", &self.dot_token);
+                formatter.field("method", &self.method);
+                formatter.field("turbofish", &self.turbofish);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("args", &self.args);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprMethodCall")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprParen {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprParen {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprParen")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprPath {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprPath {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("qself", &self.qself);
+                formatter.field("path", &self.path);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprPath")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprRange {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprRange {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("start", &self.start);
+                formatter.field("limits", &self.limits);
+                formatter.field("end", &self.end);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprRange")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprReference {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprReference {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("and_token", &self.and_token);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprReference")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprRepeat {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprRepeat {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.field("len", &self.len);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprRepeat")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprReturn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprReturn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("return_token", &self.return_token);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprReturn")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprStruct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprStruct {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("qself", &self.qself);
+                formatter.field("path", &self.path);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("fields", &self.fields);
+                formatter.field("dot2_token", &self.dot2_token);
+                formatter.field("rest", &self.rest);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprStruct")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprTry {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprTry {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("expr", &self.expr);
+                formatter.field("question_token", &self.question_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprTry")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprTryBlock {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprTryBlock {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("try_token", &self.try_token);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprTryBlock")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprTuple {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprTuple {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprTuple")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprUnary {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprUnary {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("op", &self.op);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprUnary")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprUnsafe {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprUnsafe {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("unsafe_token", &self.unsafe_token);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprUnsafe")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprWhile {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprWhile {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("label", &self.label);
+                formatter.field("while_token", &self.while_token);
+                formatter.field("cond", &self.cond);
+                formatter.field("body", &self.body);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprWhile")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ExprYield {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ExprYield {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("yield_token", &self.yield_token);
+                formatter.field("expr", &self.expr);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ExprYield")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Field {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Field");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("vis", &self.vis);
+        formatter.field("mutability", &self.mutability);
+        formatter.field("ident", &self.ident);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("ty", &self.ty);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FieldMutability {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("FieldMutability::")?;
+        match self {
+            FieldMutability::None => formatter.write_str("None"),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FieldPat {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldPat");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("member", &self.member);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("pat", &self.pat);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FieldValue {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldValue");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("member", &self.member);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("expr", &self.expr);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Fields {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Fields::")?;
+        match self {
+            Fields::Named(v0) => v0.debug(formatter, "Named"),
+            Fields::Unnamed(v0) => v0.debug(formatter, "Unnamed"),
+            Fields::Unit => formatter.write_str("Unit"),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FieldsNamed {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl FieldsNamed {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("named", &self.named);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "FieldsNamed")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FieldsUnnamed {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl FieldsUnnamed {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("unnamed", &self.unnamed);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "FieldsUnnamed")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for File {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("File");
+        formatter.field("shebang", &self.shebang);
+        formatter.field("attrs", &self.attrs);
+        formatter.field("items", &self.items);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for FnArg {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("FnArg::")?;
+        match self {
+            FnArg::Receiver(v0) => {
+                let mut formatter = formatter.debug_tuple("Receiver");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            FnArg::Typed(v0) => {
+                let mut formatter = formatter.debug_tuple("Typed");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ForeignItem {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("ForeignItem::")?;
+        match self {
+            ForeignItem::Fn(v0) => v0.debug(formatter, "Fn"),
+            ForeignItem::Static(v0) => v0.debug(formatter, "Static"),
+            ForeignItem::Type(v0) => v0.debug(formatter, "Type"),
+            ForeignItem::Macro(v0) => v0.debug(formatter, "Macro"),
+            ForeignItem::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ForeignItemFn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ForeignItemFn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("sig", &self.sig);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ForeignItemFn")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ForeignItemMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ForeignItemMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("mac", &self.mac);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ForeignItemMacro")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ForeignItemStatic {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ForeignItemStatic {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("static_token", &self.static_token);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("ident", &self.ident);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ForeignItemStatic")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ForeignItemType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ForeignItemType {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("type_token", &self.type_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ForeignItemType")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for GenericArgument {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("GenericArgument::")?;
+        match self {
+            GenericArgument::Lifetime(v0) => {
+                let mut formatter = formatter.debug_tuple("Lifetime");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericArgument::Type(v0) => {
+                let mut formatter = formatter.debug_tuple("Type");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericArgument::Const(v0) => {
+                let mut formatter = formatter.debug_tuple("Const");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericArgument::AssocType(v0) => {
+                let mut formatter = formatter.debug_tuple("AssocType");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericArgument::AssocConst(v0) => {
+                let mut formatter = formatter.debug_tuple("AssocConst");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericArgument::Constraint(v0) => {
+                let mut formatter = formatter.debug_tuple("Constraint");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for GenericParam {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("GenericParam::")?;
+        match self {
+            GenericParam::Lifetime(v0) => {
+                let mut formatter = formatter.debug_tuple("Lifetime");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericParam::Type(v0) => {
+                let mut formatter = formatter.debug_tuple("Type");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            GenericParam::Const(v0) => {
+                let mut formatter = formatter.debug_tuple("Const");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Generics {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Generics");
+        formatter.field("lt_token", &self.lt_token);
+        formatter.field("params", &self.params);
+        formatter.field("gt_token", &self.gt_token);
+        formatter.field("where_clause", &self.where_clause);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplItem {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("ImplItem::")?;
+        match self {
+            ImplItem::Const(v0) => v0.debug(formatter, "Const"),
+            ImplItem::Fn(v0) => v0.debug(formatter, "Fn"),
+            ImplItem::Type(v0) => v0.debug(formatter, "Type"),
+            ImplItem::Macro(v0) => v0.debug(formatter, "Macro"),
+            ImplItem::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplItemConst {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ImplItemConst {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("defaultness", &self.defaultness);
+                formatter.field("const_token", &self.const_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ImplItemConst")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplItemFn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ImplItemFn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("defaultness", &self.defaultness);
+                formatter.field("sig", &self.sig);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ImplItemFn")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplItemMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ImplItemMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("mac", &self.mac);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ImplItemMacro")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplItemType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ImplItemType {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("defaultness", &self.defaultness);
+                formatter.field("type_token", &self.type_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ImplItemType")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ImplRestriction {
+    fn fmt(&self, _formatter: &mut fmt::Formatter) -> fmt::Result {
+        match *self {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Index {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Index");
+        formatter.field("index", &self.index);
+        formatter.field("span", &self.span);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Item {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Item::")?;
+        match self {
+            Item::Const(v0) => v0.debug(formatter, "Const"),
+            Item::Enum(v0) => v0.debug(formatter, "Enum"),
+            Item::ExternCrate(v0) => v0.debug(formatter, "ExternCrate"),
+            Item::Fn(v0) => v0.debug(formatter, "Fn"),
+            Item::ForeignMod(v0) => v0.debug(formatter, "ForeignMod"),
+            Item::Impl(v0) => v0.debug(formatter, "Impl"),
+            Item::Macro(v0) => v0.debug(formatter, "Macro"),
+            Item::Mod(v0) => v0.debug(formatter, "Mod"),
+            Item::Static(v0) => v0.debug(formatter, "Static"),
+            Item::Struct(v0) => v0.debug(formatter, "Struct"),
+            Item::Trait(v0) => v0.debug(formatter, "Trait"),
+            Item::TraitAlias(v0) => v0.debug(formatter, "TraitAlias"),
+            Item::Type(v0) => v0.debug(formatter, "Type"),
+            Item::Union(v0) => v0.debug(formatter, "Union"),
+            Item::Use(v0) => v0.debug(formatter, "Use"),
+            Item::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemConst {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemConst {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("const_token", &self.const_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemConst")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemEnum {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemEnum {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("enum_token", &self.enum_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("variants", &self.variants);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemEnum")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemExternCrate {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemExternCrate {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("extern_token", &self.extern_token);
+                formatter.field("crate_token", &self.crate_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("rename", &self.rename);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemExternCrate")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemFn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemFn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("sig", &self.sig);
+                formatter.field("block", &self.block);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemFn")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemForeignMod {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemForeignMod {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("unsafety", &self.unsafety);
+                formatter.field("abi", &self.abi);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("items", &self.items);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemForeignMod")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemImpl {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemImpl {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("defaultness", &self.defaultness);
+                formatter.field("unsafety", &self.unsafety);
+                formatter.field("impl_token", &self.impl_token);
+                formatter.field("generics", &self.generics);
+                formatter.field("trait_", &self.trait_);
+                formatter.field("self_ty", &self.self_ty);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("items", &self.items);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemImpl")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("ident", &self.ident);
+                formatter.field("mac", &self.mac);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemMacro")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemMod {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemMod {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("unsafety", &self.unsafety);
+                formatter.field("mod_token", &self.mod_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("content", &self.content);
+                formatter.field("semi", &self.semi);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemMod")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemStatic {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemStatic {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("static_token", &self.static_token);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("ident", &self.ident);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("expr", &self.expr);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemStatic")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemStruct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemStruct {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("struct_token", &self.struct_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("fields", &self.fields);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemStruct")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemTrait {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemTrait {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("unsafety", &self.unsafety);
+                formatter.field("auto_token", &self.auto_token);
+                formatter.field("restriction", &self.restriction);
+                formatter.field("trait_token", &self.trait_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("supertraits", &self.supertraits);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("items", &self.items);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemTrait")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemTraitAlias {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemTraitAlias {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("trait_token", &self.trait_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("bounds", &self.bounds);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemTraitAlias")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemType {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("type_token", &self.type_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemType")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemUnion {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemUnion {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("union_token", &self.union_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("fields", &self.fields);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemUnion")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ItemUse {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ItemUse {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("vis", &self.vis);
+                formatter.field("use_token", &self.use_token);
+                formatter.field("leading_colon", &self.leading_colon);
+                formatter.field("tree", &self.tree);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ItemUse")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Label {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Label");
+        formatter.field("name", &self.name);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.finish()
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Lifetime {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl Lifetime {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("apostrophe", &self.apostrophe);
+                formatter.field("ident", &self.ident);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "Lifetime")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for LifetimeParam {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("LifetimeParam");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("lifetime", &self.lifetime);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("bounds", &self.bounds);
+        formatter.finish()
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Lit {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Lit::")?;
+        match self {
+            Lit::Str(v0) => v0.debug(formatter, "Str"),
+            Lit::ByteStr(v0) => v0.debug(formatter, "ByteStr"),
+            Lit::Byte(v0) => v0.debug(formatter, "Byte"),
+            Lit::Char(v0) => v0.debug(formatter, "Char"),
+            Lit::Int(v0) => v0.debug(formatter, "Int"),
+            Lit::Float(v0) => v0.debug(formatter, "Float"),
+            Lit::Bool(v0) => v0.debug(formatter, "Bool"),
+            Lit::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Local {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl Local {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("let_token", &self.let_token);
+                formatter.field("pat", &self.pat);
+                formatter.field("init", &self.init);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "Local")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for LocalInit {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("LocalInit");
+        formatter.field("eq_token", &self.eq_token);
+        formatter.field("expr", &self.expr);
+        formatter.field("diverge", &self.diverge);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Macro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Macro");
+        formatter.field("path", &self.path);
+        formatter.field("bang_token", &self.bang_token);
+        formatter.field("delimiter", &self.delimiter);
+        formatter.field("tokens", &self.tokens);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for MacroDelimiter {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("MacroDelimiter::")?;
+        match self {
+            MacroDelimiter::Paren(v0) => {
+                let mut formatter = formatter.debug_tuple("Paren");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            MacroDelimiter::Brace(v0) => {
+                let mut formatter = formatter.debug_tuple("Brace");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            MacroDelimiter::Bracket(v0) => {
+                let mut formatter = formatter.debug_tuple("Bracket");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Member {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Member::")?;
+        match self {
+            Member::Named(v0) => {
+                let mut formatter = formatter.debug_tuple("Named");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            Member::Unnamed(v0) => {
+                let mut formatter = formatter.debug_tuple("Unnamed");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Meta {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Meta::")?;
+        match self {
+            Meta::Path(v0) => v0.debug(formatter, "Path"),
+            Meta::List(v0) => v0.debug(formatter, "List"),
+            Meta::NameValue(v0) => v0.debug(formatter, "NameValue"),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for MetaList {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl MetaList {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("path", &self.path);
+                formatter.field("delimiter", &self.delimiter);
+                formatter.field("tokens", &self.tokens);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "MetaList")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for MetaNameValue {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl MetaNameValue {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("path", &self.path);
+                formatter.field("eq_token", &self.eq_token);
+                formatter.field("value", &self.value);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "MetaNameValue")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ParenthesizedGenericArguments {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl ParenthesizedGenericArguments {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("inputs", &self.inputs);
+                formatter.field("output", &self.output);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "ParenthesizedGenericArguments")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Pat {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Pat::")?;
+        match self {
+            Pat::Const(v0) => v0.debug(formatter, "Const"),
+            Pat::Ident(v0) => v0.debug(formatter, "Ident"),
+            Pat::Lit(v0) => v0.debug(formatter, "Lit"),
+            Pat::Macro(v0) => v0.debug(formatter, "Macro"),
+            Pat::Or(v0) => v0.debug(formatter, "Or"),
+            Pat::Paren(v0) => v0.debug(formatter, "Paren"),
+            Pat::Path(v0) => v0.debug(formatter, "Path"),
+            Pat::Range(v0) => v0.debug(formatter, "Range"),
+            Pat::Reference(v0) => v0.debug(formatter, "Reference"),
+            Pat::Rest(v0) => v0.debug(formatter, "Rest"),
+            Pat::Slice(v0) => v0.debug(formatter, "Slice"),
+            Pat::Struct(v0) => v0.debug(formatter, "Struct"),
+            Pat::Tuple(v0) => v0.debug(formatter, "Tuple"),
+            Pat::TupleStruct(v0) => v0.debug(formatter, "TupleStruct"),
+            Pat::Type(v0) => v0.debug(formatter, "Type"),
+            Pat::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            Pat::Wild(v0) => v0.debug(formatter, "Wild"),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatIdent {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatIdent {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("by_ref", &self.by_ref);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("ident", &self.ident);
+                formatter.field("subpat", &self.subpat);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatIdent")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatOr {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatOr {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("leading_vert", &self.leading_vert);
+                formatter.field("cases", &self.cases);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatOr")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatParen {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatParen {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("pat", &self.pat);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatParen")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatReference {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatReference {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("and_token", &self.and_token);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("pat", &self.pat);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatReference")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatRest {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatRest {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("dot2_token", &self.dot2_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatRest")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatSlice {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatSlice {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatSlice")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatStruct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatStruct {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("qself", &self.qself);
+                formatter.field("path", &self.path);
+                formatter.field("brace_token", &self.brace_token);
+                formatter.field("fields", &self.fields);
+                formatter.field("rest", &self.rest);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatStruct")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatTuple {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatTuple {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatTuple")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatTupleStruct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatTupleStruct {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("qself", &self.qself);
+                formatter.field("path", &self.path);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatTupleStruct")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatType {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("pat", &self.pat);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatType")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PatWild {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl PatWild {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("underscore_token", &self.underscore_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "PatWild")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Path {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl Path {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("leading_colon", &self.leading_colon);
+                formatter.field("segments", &self.segments);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "Path")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PathArguments {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("PathArguments::")?;
+        match self {
+            PathArguments::None => formatter.write_str("None"),
+            PathArguments::AngleBracketed(v0) => v0.debug(formatter, "AngleBracketed"),
+            PathArguments::Parenthesized(v0) => v0.debug(formatter, "Parenthesized"),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PathSegment {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PathSegment");
+        formatter.field("ident", &self.ident);
+        formatter.field("arguments", &self.arguments);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PredicateLifetime {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PredicateLifetime");
+        formatter.field("lifetime", &self.lifetime);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("bounds", &self.bounds);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for PredicateType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PredicateType");
+        formatter.field("lifetimes", &self.lifetimes);
+        formatter.field("bounded_ty", &self.bounded_ty);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("bounds", &self.bounds);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for QSelf {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("QSelf");
+        formatter.field("lt_token", &self.lt_token);
+        formatter.field("ty", &self.ty);
+        formatter.field("position", &self.position);
+        formatter.field("as_token", &self.as_token);
+        formatter.field("gt_token", &self.gt_token);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for RangeLimits {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("RangeLimits::")?;
+        match self {
+            RangeLimits::HalfOpen(v0) => {
+                let mut formatter = formatter.debug_tuple("HalfOpen");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            RangeLimits::Closed(v0) => {
+                let mut formatter = formatter.debug_tuple("Closed");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Receiver {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Receiver");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("reference", &self.reference);
+        formatter.field("mutability", &self.mutability);
+        formatter.field("self_token", &self.self_token);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("ty", &self.ty);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for ReturnType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("ReturnType::")?;
+        match self {
+            ReturnType::Default => formatter.write_str("Default"),
+            ReturnType::Type(v0, v1) => {
+                let mut formatter = formatter.debug_tuple("Type");
+                formatter.field(v0);
+                formatter.field(v1);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Signature {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Signature");
+        formatter.field("constness", &self.constness);
+        formatter.field("asyncness", &self.asyncness);
+        formatter.field("unsafety", &self.unsafety);
+        formatter.field("abi", &self.abi);
+        formatter.field("fn_token", &self.fn_token);
+        formatter.field("ident", &self.ident);
+        formatter.field("generics", &self.generics);
+        formatter.field("paren_token", &self.paren_token);
+        formatter.field("inputs", &self.inputs);
+        formatter.field("variadic", &self.variadic);
+        formatter.field("output", &self.output);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for StaticMutability {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("StaticMutability::")?;
+        match self {
+            StaticMutability::Mut(v0) => {
+                let mut formatter = formatter.debug_tuple("Mut");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            StaticMutability::None => formatter.write_str("None"),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Stmt {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Stmt::")?;
+        match self {
+            Stmt::Local(v0) => v0.debug(formatter, "Local"),
+            Stmt::Item(v0) => {
+                let mut formatter = formatter.debug_tuple("Item");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            Stmt::Expr(v0, v1) => {
+                let mut formatter = formatter.debug_tuple("Expr");
+                formatter.field(v0);
+                formatter.field(v1);
+                formatter.finish()
+            }
+            Stmt::Macro(v0) => v0.debug(formatter, "Macro"),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for StmtMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl StmtMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("mac", &self.mac);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "StmtMacro")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitBound {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitBound");
+        formatter.field("paren_token", &self.paren_token);
+        formatter.field("modifier", &self.modifier);
+        formatter.field("lifetimes", &self.lifetimes);
+        formatter.field("path", &self.path);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitBoundModifier {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("TraitBoundModifier::")?;
+        match self {
+            TraitBoundModifier::None => formatter.write_str("None"),
+            TraitBoundModifier::Maybe(v0) => {
+                let mut formatter = formatter.debug_tuple("Maybe");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitItem {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("TraitItem::")?;
+        match self {
+            TraitItem::Const(v0) => v0.debug(formatter, "Const"),
+            TraitItem::Fn(v0) => v0.debug(formatter, "Fn"),
+            TraitItem::Type(v0) => v0.debug(formatter, "Type"),
+            TraitItem::Macro(v0) => v0.debug(formatter, "Macro"),
+            TraitItem::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitItemConst {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TraitItemConst {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("const_token", &self.const_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("ty", &self.ty);
+                formatter.field("default", &self.default);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TraitItemConst")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitItemFn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TraitItemFn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("sig", &self.sig);
+                formatter.field("default", &self.default);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TraitItemFn")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitItemMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TraitItemMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("mac", &self.mac);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TraitItemMacro")
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TraitItemType {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TraitItemType {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("attrs", &self.attrs);
+                formatter.field("type_token", &self.type_token);
+                formatter.field("ident", &self.ident);
+                formatter.field("generics", &self.generics);
+                formatter.field("colon_token", &self.colon_token);
+                formatter.field("bounds", &self.bounds);
+                formatter.field("default", &self.default);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TraitItemType")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Type {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Type::")?;
+        match self {
+            Type::Array(v0) => v0.debug(formatter, "Array"),
+            Type::BareFn(v0) => v0.debug(formatter, "BareFn"),
+            Type::Group(v0) => v0.debug(formatter, "Group"),
+            Type::ImplTrait(v0) => v0.debug(formatter, "ImplTrait"),
+            Type::Infer(v0) => v0.debug(formatter, "Infer"),
+            Type::Macro(v0) => v0.debug(formatter, "Macro"),
+            Type::Never(v0) => v0.debug(formatter, "Never"),
+            Type::Paren(v0) => v0.debug(formatter, "Paren"),
+            Type::Path(v0) => v0.debug(formatter, "Path"),
+            Type::Ptr(v0) => v0.debug(formatter, "Ptr"),
+            Type::Reference(v0) => v0.debug(formatter, "Reference"),
+            Type::Slice(v0) => v0.debug(formatter, "Slice"),
+            Type::TraitObject(v0) => v0.debug(formatter, "TraitObject"),
+            Type::Tuple(v0) => v0.debug(formatter, "Tuple"),
+            Type::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeArray {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeArray {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("elem", &self.elem);
+                formatter.field("semi_token", &self.semi_token);
+                formatter.field("len", &self.len);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeArray")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeBareFn {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeBareFn {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("lifetimes", &self.lifetimes);
+                formatter.field("unsafety", &self.unsafety);
+                formatter.field("abi", &self.abi);
+                formatter.field("fn_token", &self.fn_token);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("inputs", &self.inputs);
+                formatter.field("variadic", &self.variadic);
+                formatter.field("output", &self.output);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeBareFn")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeGroup {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeGroup {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("group_token", &self.group_token);
+                formatter.field("elem", &self.elem);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeGroup")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeImplTrait {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeImplTrait {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("impl_token", &self.impl_token);
+                formatter.field("bounds", &self.bounds);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeImplTrait")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeInfer {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeInfer {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("underscore_token", &self.underscore_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeInfer")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeMacro {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeMacro {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("mac", &self.mac);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeMacro")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeNever {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeNever {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("bang_token", &self.bang_token);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeNever")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeParam {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeParam");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("ident", &self.ident);
+        formatter.field("colon_token", &self.colon_token);
+        formatter.field("bounds", &self.bounds);
+        formatter.field("eq_token", &self.eq_token);
+        formatter.field("default", &self.default);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeParamBound {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("TypeParamBound::")?;
+        match self {
+            TypeParamBound::Trait(v0) => {
+                let mut formatter = formatter.debug_tuple("Trait");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            TypeParamBound::Lifetime(v0) => v0.debug(formatter, "Lifetime"),
+            TypeParamBound::Verbatim(v0) => {
+                let mut formatter = formatter.debug_tuple("Verbatim");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeParen {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeParen {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("elem", &self.elem);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeParen")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypePath {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypePath {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("qself", &self.qself);
+                formatter.field("path", &self.path);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypePath")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypePtr {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypePtr {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("star_token", &self.star_token);
+                formatter.field("const_token", &self.const_token);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("elem", &self.elem);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypePtr")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeReference {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeReference {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("and_token", &self.and_token);
+                formatter.field("lifetime", &self.lifetime);
+                formatter.field("mutability", &self.mutability);
+                formatter.field("elem", &self.elem);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeReference")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeSlice {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeSlice {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("bracket_token", &self.bracket_token);
+                formatter.field("elem", &self.elem);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeSlice")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeTraitObject {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeTraitObject {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("dyn_token", &self.dyn_token);
+                formatter.field("bounds", &self.bounds);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeTraitObject")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for TypeTuple {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl TypeTuple {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("elems", &self.elems);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "TypeTuple")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UnOp {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("UnOp::")?;
+        match self {
+            UnOp::Deref(v0) => {
+                let mut formatter = formatter.debug_tuple("Deref");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UnOp::Not(v0) => {
+                let mut formatter = formatter.debug_tuple("Not");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UnOp::Neg(v0) => {
+                let mut formatter = formatter.debug_tuple("Neg");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UseGlob {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseGlob");
+        formatter.field("star_token", &self.star_token);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UseGroup {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseGroup");
+        formatter.field("brace_token", &self.brace_token);
+        formatter.field("items", &self.items);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UseName {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseName");
+        formatter.field("ident", &self.ident);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UsePath {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UsePath");
+        formatter.field("ident", &self.ident);
+        formatter.field("colon2_token", &self.colon2_token);
+        formatter.field("tree", &self.tree);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UseRename {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseRename");
+        formatter.field("ident", &self.ident);
+        formatter.field("as_token", &self.as_token);
+        formatter.field("rename", &self.rename);
+        formatter.finish()
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for UseTree {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("UseTree::")?;
+        match self {
+            UseTree::Path(v0) => {
+                let mut formatter = formatter.debug_tuple("Path");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UseTree::Name(v0) => {
+                let mut formatter = formatter.debug_tuple("Name");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UseTree::Rename(v0) => {
+                let mut formatter = formatter.debug_tuple("Rename");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UseTree::Glob(v0) => {
+                let mut formatter = formatter.debug_tuple("Glob");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            UseTree::Group(v0) => {
+                let mut formatter = formatter.debug_tuple("Group");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Variadic {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Variadic");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("pat", &self.pat);
+        formatter.field("dots", &self.dots);
+        formatter.field("comma", &self.comma);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Variant {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Variant");
+        formatter.field("attrs", &self.attrs);
+        formatter.field("ident", &self.ident);
+        formatter.field("fields", &self.fields);
+        formatter.field("discriminant", &self.discriminant);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for VisRestricted {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        impl VisRestricted {
+            fn debug(&self, formatter: &mut fmt::Formatter, name: &str) -> fmt::Result {
+                let mut formatter = formatter.debug_struct(name);
+                formatter.field("pub_token", &self.pub_token);
+                formatter.field("paren_token", &self.paren_token);
+                formatter.field("in_token", &self.in_token);
+                formatter.field("path", &self.path);
+                formatter.finish()
+            }
+        }
+        self.debug(formatter, "VisRestricted")
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Visibility {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Visibility::")?;
+        match self {
+            Visibility::Public(v0) => {
+                let mut formatter = formatter.debug_tuple("Public");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            Visibility::Restricted(v0) => v0.debug(formatter, "Restricted"),
+            Visibility::Inherited => formatter.write_str("Inherited"),
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for WhereClause {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("WhereClause");
+        formatter.field("where_token", &self.where_token);
+        formatter.field("predicates", &self.predicates);
+        formatter.finish()
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for WherePredicate {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("WherePredicate::")?;
+        match self {
+            WherePredicate::Lifetime(v0) => {
+                let mut formatter = formatter.debug_tuple("Lifetime");
+                formatter.field(v0);
+                formatter.finish()
+            }
+            WherePredicate::Type(v0) => {
+                let mut formatter = formatter.debug_tuple("Type");
+                formatter.field(v0);
+                formatter.finish()
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/eq.rs b/vendor/syn/src/gen/eq.rs
new file mode 100644
index 0000000..a7479c3
--- /dev/null
+++ b/vendor/syn/src/gen/eq.rs
@@ -0,0 +1,2151 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#[cfg(any(feature = "derive", feature = "full"))]
+use crate::tt::TokenStreamHelper;
+use crate::*;
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Abi {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Abi {
+    fn eq(&self, other: &Self) -> bool {
+        self.name == other.name
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for AngleBracketedGenericArguments {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for AngleBracketedGenericArguments {
+    fn eq(&self, other: &Self) -> bool {
+        self.colon2_token == other.colon2_token && self.args == other.args
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Arm {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Arm {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat && self.guard == other.guard
+            && self.body == other.body && self.comma == other.comma
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for AssocConst {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for AssocConst {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.generics == other.generics
+            && self.value == other.value
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for AssocType {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for AssocType {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.generics == other.generics
+            && self.ty == other.ty
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for AttrStyle {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for AttrStyle {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (AttrStyle::Outer, AttrStyle::Outer) => true,
+            (AttrStyle::Inner(_), AttrStyle::Inner(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Attribute {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Attribute {
+    fn eq(&self, other: &Self) -> bool {
+        self.style == other.style && self.meta == other.meta
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for BareFnArg {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for BareFnArg {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.name == other.name && self.ty == other.ty
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for BareVariadic {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for BareVariadic {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.name == other.name && self.comma == other.comma
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for BinOp {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for BinOp {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (BinOp::Add(_), BinOp::Add(_)) => true,
+            (BinOp::Sub(_), BinOp::Sub(_)) => true,
+            (BinOp::Mul(_), BinOp::Mul(_)) => true,
+            (BinOp::Div(_), BinOp::Div(_)) => true,
+            (BinOp::Rem(_), BinOp::Rem(_)) => true,
+            (BinOp::And(_), BinOp::And(_)) => true,
+            (BinOp::Or(_), BinOp::Or(_)) => true,
+            (BinOp::BitXor(_), BinOp::BitXor(_)) => true,
+            (BinOp::BitAnd(_), BinOp::BitAnd(_)) => true,
+            (BinOp::BitOr(_), BinOp::BitOr(_)) => true,
+            (BinOp::Shl(_), BinOp::Shl(_)) => true,
+            (BinOp::Shr(_), BinOp::Shr(_)) => true,
+            (BinOp::Eq(_), BinOp::Eq(_)) => true,
+            (BinOp::Lt(_), BinOp::Lt(_)) => true,
+            (BinOp::Le(_), BinOp::Le(_)) => true,
+            (BinOp::Ne(_), BinOp::Ne(_)) => true,
+            (BinOp::Ge(_), BinOp::Ge(_)) => true,
+            (BinOp::Gt(_), BinOp::Gt(_)) => true,
+            (BinOp::AddAssign(_), BinOp::AddAssign(_)) => true,
+            (BinOp::SubAssign(_), BinOp::SubAssign(_)) => true,
+            (BinOp::MulAssign(_), BinOp::MulAssign(_)) => true,
+            (BinOp::DivAssign(_), BinOp::DivAssign(_)) => true,
+            (BinOp::RemAssign(_), BinOp::RemAssign(_)) => true,
+            (BinOp::BitXorAssign(_), BinOp::BitXorAssign(_)) => true,
+            (BinOp::BitAndAssign(_), BinOp::BitAndAssign(_)) => true,
+            (BinOp::BitOrAssign(_), BinOp::BitOrAssign(_)) => true,
+            (BinOp::ShlAssign(_), BinOp::ShlAssign(_)) => true,
+            (BinOp::ShrAssign(_), BinOp::ShrAssign(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Block {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Block {
+    fn eq(&self, other: &Self) -> bool {
+        self.stmts == other.stmts
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for BoundLifetimes {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for BoundLifetimes {
+    fn eq(&self, other: &Self) -> bool {
+        self.lifetimes == other.lifetimes
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ConstParam {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ConstParam {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident && self.ty == other.ty
+            && self.eq_token == other.eq_token && self.default == other.default
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Constraint {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Constraint {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.generics == other.generics
+            && self.bounds == other.bounds
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Data {}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Data {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Data::Struct(self0), Data::Struct(other0)) => self0 == other0,
+            (Data::Enum(self0), Data::Enum(other0)) => self0 == other0,
+            (Data::Union(self0), Data::Union(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for DataEnum {}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for DataEnum {
+    fn eq(&self, other: &Self) -> bool {
+        self.variants == other.variants
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for DataStruct {}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for DataStruct {
+    fn eq(&self, other: &Self) -> bool {
+        self.fields == other.fields && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for DataUnion {}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for DataUnion {
+    fn eq(&self, other: &Self) -> bool {
+        self.fields == other.fields
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for DeriveInput {}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for DeriveInput {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.data == other.data
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Expr {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Expr {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            #[cfg(feature = "full")]
+            (Expr::Array(self0), Expr::Array(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Assign(self0), Expr::Assign(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Async(self0), Expr::Async(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Await(self0), Expr::Await(other0)) => self0 == other0,
+            (Expr::Binary(self0), Expr::Binary(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Block(self0), Expr::Block(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Break(self0), Expr::Break(other0)) => self0 == other0,
+            (Expr::Call(self0), Expr::Call(other0)) => self0 == other0,
+            (Expr::Cast(self0), Expr::Cast(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Closure(self0), Expr::Closure(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Const(self0), Expr::Const(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Continue(self0), Expr::Continue(other0)) => self0 == other0,
+            (Expr::Field(self0), Expr::Field(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::ForLoop(self0), Expr::ForLoop(other0)) => self0 == other0,
+            (Expr::Group(self0), Expr::Group(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::If(self0), Expr::If(other0)) => self0 == other0,
+            (Expr::Index(self0), Expr::Index(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Infer(self0), Expr::Infer(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Let(self0), Expr::Let(other0)) => self0 == other0,
+            (Expr::Lit(self0), Expr::Lit(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Loop(self0), Expr::Loop(other0)) => self0 == other0,
+            (Expr::Macro(self0), Expr::Macro(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Match(self0), Expr::Match(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::MethodCall(self0), Expr::MethodCall(other0)) => self0 == other0,
+            (Expr::Paren(self0), Expr::Paren(other0)) => self0 == other0,
+            (Expr::Path(self0), Expr::Path(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Range(self0), Expr::Range(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Reference(self0), Expr::Reference(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Repeat(self0), Expr::Repeat(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Return(self0), Expr::Return(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Struct(self0), Expr::Struct(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Try(self0), Expr::Try(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::TryBlock(self0), Expr::TryBlock(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Tuple(self0), Expr::Tuple(other0)) => self0 == other0,
+            (Expr::Unary(self0), Expr::Unary(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Unsafe(self0), Expr::Unsafe(other0)) => self0 == other0,
+            (Expr::Verbatim(self0), Expr::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            #[cfg(feature = "full")]
+            (Expr::While(self0), Expr::While(other0)) => self0 == other0,
+            #[cfg(feature = "full")]
+            (Expr::Yield(self0), Expr::Yield(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprArray {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprArray {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.elems == other.elems
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprAssign {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprAssign {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.left == other.left && self.right == other.right
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprAsync {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprAsync {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.capture == other.capture
+            && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprAwait {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprAwait {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.base == other.base
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprBinary {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprBinary {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.left == other.left && self.op == other.op
+            && self.right == other.right
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprBlock {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprBlock {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label
+            && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprBreak {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprBreak {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label && self.expr == other.expr
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprCall {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprCall {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.func == other.func && self.args == other.args
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprCast {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprCast {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr && self.ty == other.ty
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprClosure {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprClosure {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.lifetimes == other.lifetimes
+            && self.constness == other.constness && self.movability == other.movability
+            && self.asyncness == other.asyncness && self.capture == other.capture
+            && self.inputs == other.inputs && self.output == other.output
+            && self.body == other.body
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprConst {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprConst {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprContinue {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprContinue {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprField {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprField {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.base == other.base
+            && self.member == other.member
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprForLoop {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprForLoop {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label && self.pat == other.pat
+            && self.expr == other.expr && self.body == other.body
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprGroup {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprGroup {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprIf {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprIf {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.cond == other.cond
+            && self.then_branch == other.then_branch
+            && self.else_branch == other.else_branch
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprIndex {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprIndex {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr && self.index == other.index
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprInfer {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprInfer {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprLet {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprLet {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat && self.expr == other.expr
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprLit {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprLit {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.lit == other.lit
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprLoop {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprLoop {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label && self.body == other.body
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprMacro {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mac == other.mac
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprMatch {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprMatch {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr && self.arms == other.arms
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprMethodCall {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprMethodCall {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.receiver == other.receiver
+            && self.method == other.method && self.turbofish == other.turbofish
+            && self.args == other.args
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprParen {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprParen {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprPath {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprPath {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.qself == other.qself && self.path == other.path
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprRange {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprRange {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.start == other.start
+            && self.limits == other.limits && self.end == other.end
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprReference {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprReference {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mutability == other.mutability
+            && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprRepeat {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprRepeat {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr && self.len == other.len
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprReturn {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprReturn {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprStruct {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprStruct {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.qself == other.qself && self.path == other.path
+            && self.fields == other.fields && self.dot2_token == other.dot2_token
+            && self.rest == other.rest
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprTry {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprTry {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprTryBlock {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprTryBlock {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprTuple {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprTuple {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.elems == other.elems
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprUnary {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprUnary {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.op == other.op && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprUnsafe {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprUnsafe {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprWhile {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprWhile {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.label == other.label && self.cond == other.cond
+            && self.body == other.body
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ExprYield {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ExprYield {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.expr == other.expr
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Field {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Field {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.mutability == other.mutability && self.ident == other.ident
+            && self.colon_token == other.colon_token && self.ty == other.ty
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FieldMutability {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FieldMutability {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (FieldMutability::None, FieldMutability::None) => true,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FieldPat {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FieldPat {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.member == other.member
+            && self.colon_token == other.colon_token && self.pat == other.pat
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FieldValue {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FieldValue {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.member == other.member
+            && self.colon_token == other.colon_token && self.expr == other.expr
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Fields {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Fields {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Fields::Named(self0), Fields::Named(other0)) => self0 == other0,
+            (Fields::Unnamed(self0), Fields::Unnamed(other0)) => self0 == other0,
+            (Fields::Unit, Fields::Unit) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FieldsNamed {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FieldsNamed {
+    fn eq(&self, other: &Self) -> bool {
+        self.named == other.named
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FieldsUnnamed {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FieldsUnnamed {
+    fn eq(&self, other: &Self) -> bool {
+        self.unnamed == other.unnamed
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for File {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for File {
+    fn eq(&self, other: &Self) -> bool {
+        self.shebang == other.shebang && self.attrs == other.attrs
+            && self.items == other.items
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for FnArg {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for FnArg {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (FnArg::Receiver(self0), FnArg::Receiver(other0)) => self0 == other0,
+            (FnArg::Typed(self0), FnArg::Typed(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ForeignItem {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ForeignItem {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (ForeignItem::Fn(self0), ForeignItem::Fn(other0)) => self0 == other0,
+            (ForeignItem::Static(self0), ForeignItem::Static(other0)) => self0 == other0,
+            (ForeignItem::Type(self0), ForeignItem::Type(other0)) => self0 == other0,
+            (ForeignItem::Macro(self0), ForeignItem::Macro(other0)) => self0 == other0,
+            (ForeignItem::Verbatim(self0), ForeignItem::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ForeignItemFn {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ForeignItemFn {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.sig == other.sig
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ForeignItemMacro {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ForeignItemMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mac == other.mac
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ForeignItemStatic {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ForeignItemStatic {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.mutability == other.mutability && self.ident == other.ident
+            && self.ty == other.ty
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ForeignItemType {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ForeignItemType {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for GenericArgument {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for GenericArgument {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (GenericArgument::Lifetime(self0), GenericArgument::Lifetime(other0)) => {
+                self0 == other0
+            }
+            (GenericArgument::Type(self0), GenericArgument::Type(other0)) => {
+                self0 == other0
+            }
+            (GenericArgument::Const(self0), GenericArgument::Const(other0)) => {
+                self0 == other0
+            }
+            (GenericArgument::AssocType(self0), GenericArgument::AssocType(other0)) => {
+                self0 == other0
+            }
+            (GenericArgument::AssocConst(self0), GenericArgument::AssocConst(other0)) => {
+                self0 == other0
+            }
+            (GenericArgument::Constraint(self0), GenericArgument::Constraint(other0)) => {
+                self0 == other0
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for GenericParam {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for GenericParam {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (GenericParam::Lifetime(self0), GenericParam::Lifetime(other0)) => {
+                self0 == other0
+            }
+            (GenericParam::Type(self0), GenericParam::Type(other0)) => self0 == other0,
+            (GenericParam::Const(self0), GenericParam::Const(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Generics {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Generics {
+    fn eq(&self, other: &Self) -> bool {
+        self.lt_token == other.lt_token && self.params == other.params
+            && self.gt_token == other.gt_token && self.where_clause == other.where_clause
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplItem {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplItem {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (ImplItem::Const(self0), ImplItem::Const(other0)) => self0 == other0,
+            (ImplItem::Fn(self0), ImplItem::Fn(other0)) => self0 == other0,
+            (ImplItem::Type(self0), ImplItem::Type(other0)) => self0 == other0,
+            (ImplItem::Macro(self0), ImplItem::Macro(other0)) => self0 == other0,
+            (ImplItem::Verbatim(self0), ImplItem::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplItemConst {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplItemConst {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.defaultness == other.defaultness && self.ident == other.ident
+            && self.generics == other.generics && self.ty == other.ty
+            && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplItemFn {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplItemFn {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.defaultness == other.defaultness && self.sig == other.sig
+            && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplItemMacro {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplItemMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mac == other.mac
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplItemType {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplItemType {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.defaultness == other.defaultness && self.ident == other.ident
+            && self.generics == other.generics && self.ty == other.ty
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ImplRestriction {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ImplRestriction {
+    fn eq(&self, _other: &Self) -> bool {
+        match *self {}
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Item {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Item {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Item::Const(self0), Item::Const(other0)) => self0 == other0,
+            (Item::Enum(self0), Item::Enum(other0)) => self0 == other0,
+            (Item::ExternCrate(self0), Item::ExternCrate(other0)) => self0 == other0,
+            (Item::Fn(self0), Item::Fn(other0)) => self0 == other0,
+            (Item::ForeignMod(self0), Item::ForeignMod(other0)) => self0 == other0,
+            (Item::Impl(self0), Item::Impl(other0)) => self0 == other0,
+            (Item::Macro(self0), Item::Macro(other0)) => self0 == other0,
+            (Item::Mod(self0), Item::Mod(other0)) => self0 == other0,
+            (Item::Static(self0), Item::Static(other0)) => self0 == other0,
+            (Item::Struct(self0), Item::Struct(other0)) => self0 == other0,
+            (Item::Trait(self0), Item::Trait(other0)) => self0 == other0,
+            (Item::TraitAlias(self0), Item::TraitAlias(other0)) => self0 == other0,
+            (Item::Type(self0), Item::Type(other0)) => self0 == other0,
+            (Item::Union(self0), Item::Union(other0)) => self0 == other0,
+            (Item::Use(self0), Item::Use(other0)) => self0 == other0,
+            (Item::Verbatim(self0), Item::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemConst {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemConst {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.ty == other.ty
+            && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemEnum {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemEnum {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.variants == other.variants
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemExternCrate {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemExternCrate {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.rename == other.rename
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemFn {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemFn {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.sig == other.sig
+            && self.block == other.block
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemForeignMod {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemForeignMod {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.unsafety == other.unsafety
+            && self.abi == other.abi && self.items == other.items
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemImpl {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemImpl {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.defaultness == other.defaultness
+            && self.unsafety == other.unsafety && self.generics == other.generics
+            && self.trait_ == other.trait_ && self.self_ty == other.self_ty
+            && self.items == other.items
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemMacro {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident && self.mac == other.mac
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemMod {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemMod {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.unsafety == other.unsafety && self.ident == other.ident
+            && self.content == other.content && self.semi == other.semi
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemStatic {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemStatic {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.mutability == other.mutability && self.ident == other.ident
+            && self.ty == other.ty && self.expr == other.expr
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemStruct {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemStruct {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.fields == other.fields
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemTrait {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemTrait {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.unsafety == other.unsafety && self.auto_token == other.auto_token
+            && self.restriction == other.restriction && self.ident == other.ident
+            && self.generics == other.generics && self.colon_token == other.colon_token
+            && self.supertraits == other.supertraits && self.items == other.items
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemTraitAlias {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemTraitAlias {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.bounds == other.bounds
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemType {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemType {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.ty == other.ty
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemUnion {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemUnion {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis && self.ident == other.ident
+            && self.generics == other.generics && self.fields == other.fields
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ItemUse {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ItemUse {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.vis == other.vis
+            && self.leading_colon == other.leading_colon && self.tree == other.tree
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Label {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Label {
+    fn eq(&self, other: &Self) -> bool {
+        self.name == other.name
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LifetimeParam {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for LifetimeParam {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.lifetime == other.lifetime
+            && self.colon_token == other.colon_token && self.bounds == other.bounds
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Lit {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Lit {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Lit::Str(self0), Lit::Str(other0)) => self0 == other0,
+            (Lit::ByteStr(self0), Lit::ByteStr(other0)) => self0 == other0,
+            (Lit::Byte(self0), Lit::Byte(other0)) => self0 == other0,
+            (Lit::Char(self0), Lit::Char(other0)) => self0 == other0,
+            (Lit::Int(self0), Lit::Int(other0)) => self0 == other0,
+            (Lit::Float(self0), Lit::Float(other0)) => self0 == other0,
+            (Lit::Bool(self0), Lit::Bool(other0)) => self0 == other0,
+            (Lit::Verbatim(self0), Lit::Verbatim(other0)) => {
+                self0.to_string() == other0.to_string()
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitBool {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for LitBool {
+    fn eq(&self, other: &Self) -> bool {
+        self.value == other.value
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitByte {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitByteStr {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitChar {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitFloat {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitInt {}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LitStr {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Local {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Local {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat && self.init == other.init
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for LocalInit {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for LocalInit {
+    fn eq(&self, other: &Self) -> bool {
+        self.expr == other.expr && self.diverge == other.diverge
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Macro {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Macro {
+    fn eq(&self, other: &Self) -> bool {
+        self.path == other.path && self.delimiter == other.delimiter
+            && TokenStreamHelper(&self.tokens) == TokenStreamHelper(&other.tokens)
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for MacroDelimiter {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for MacroDelimiter {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (MacroDelimiter::Paren(_), MacroDelimiter::Paren(_)) => true,
+            (MacroDelimiter::Brace(_), MacroDelimiter::Brace(_)) => true,
+            (MacroDelimiter::Bracket(_), MacroDelimiter::Bracket(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Meta {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Meta {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Meta::Path(self0), Meta::Path(other0)) => self0 == other0,
+            (Meta::List(self0), Meta::List(other0)) => self0 == other0,
+            (Meta::NameValue(self0), Meta::NameValue(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for MetaList {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for MetaList {
+    fn eq(&self, other: &Self) -> bool {
+        self.path == other.path && self.delimiter == other.delimiter
+            && TokenStreamHelper(&self.tokens) == TokenStreamHelper(&other.tokens)
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for MetaNameValue {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for MetaNameValue {
+    fn eq(&self, other: &Self) -> bool {
+        self.path == other.path && self.value == other.value
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ParenthesizedGenericArguments {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ParenthesizedGenericArguments {
+    fn eq(&self, other: &Self) -> bool {
+        self.inputs == other.inputs && self.output == other.output
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Pat {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Pat {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Pat::Const(self0), Pat::Const(other0)) => self0 == other0,
+            (Pat::Ident(self0), Pat::Ident(other0)) => self0 == other0,
+            (Pat::Lit(self0), Pat::Lit(other0)) => self0 == other0,
+            (Pat::Macro(self0), Pat::Macro(other0)) => self0 == other0,
+            (Pat::Or(self0), Pat::Or(other0)) => self0 == other0,
+            (Pat::Paren(self0), Pat::Paren(other0)) => self0 == other0,
+            (Pat::Path(self0), Pat::Path(other0)) => self0 == other0,
+            (Pat::Range(self0), Pat::Range(other0)) => self0 == other0,
+            (Pat::Reference(self0), Pat::Reference(other0)) => self0 == other0,
+            (Pat::Rest(self0), Pat::Rest(other0)) => self0 == other0,
+            (Pat::Slice(self0), Pat::Slice(other0)) => self0 == other0,
+            (Pat::Struct(self0), Pat::Struct(other0)) => self0 == other0,
+            (Pat::Tuple(self0), Pat::Tuple(other0)) => self0 == other0,
+            (Pat::TupleStruct(self0), Pat::TupleStruct(other0)) => self0 == other0,
+            (Pat::Type(self0), Pat::Type(other0)) => self0 == other0,
+            (Pat::Verbatim(self0), Pat::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            (Pat::Wild(self0), Pat::Wild(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatIdent {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatIdent {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.by_ref == other.by_ref
+            && self.mutability == other.mutability && self.ident == other.ident
+            && self.subpat == other.subpat
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatOr {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatOr {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.leading_vert == other.leading_vert
+            && self.cases == other.cases
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatParen {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatParen {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatReference {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatReference {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mutability == other.mutability
+            && self.pat == other.pat
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatRest {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatRest {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatSlice {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatSlice {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.elems == other.elems
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatStruct {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatStruct {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.qself == other.qself && self.path == other.path
+            && self.fields == other.fields && self.rest == other.rest
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatTuple {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatTuple {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.elems == other.elems
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatTupleStruct {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatTupleStruct {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.qself == other.qself && self.path == other.path
+            && self.elems == other.elems
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatType {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatType {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat && self.ty == other.ty
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PatWild {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PatWild {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Path {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Path {
+    fn eq(&self, other: &Self) -> bool {
+        self.leading_colon == other.leading_colon && self.segments == other.segments
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PathArguments {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PathArguments {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (PathArguments::None, PathArguments::None) => true,
+            (
+                PathArguments::AngleBracketed(self0),
+                PathArguments::AngleBracketed(other0),
+            ) => self0 == other0,
+            (
+                PathArguments::Parenthesized(self0),
+                PathArguments::Parenthesized(other0),
+            ) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PathSegment {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PathSegment {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.arguments == other.arguments
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PredicateLifetime {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PredicateLifetime {
+    fn eq(&self, other: &Self) -> bool {
+        self.lifetime == other.lifetime && self.bounds == other.bounds
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for PredicateType {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for PredicateType {
+    fn eq(&self, other: &Self) -> bool {
+        self.lifetimes == other.lifetimes && self.bounded_ty == other.bounded_ty
+            && self.bounds == other.bounds
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for QSelf {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for QSelf {
+    fn eq(&self, other: &Self) -> bool {
+        self.ty == other.ty && self.position == other.position
+            && self.as_token == other.as_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for RangeLimits {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for RangeLimits {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (RangeLimits::HalfOpen(_), RangeLimits::HalfOpen(_)) => true,
+            (RangeLimits::Closed(_), RangeLimits::Closed(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Receiver {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Receiver {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.reference == other.reference
+            && self.mutability == other.mutability
+            && self.colon_token == other.colon_token && self.ty == other.ty
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for ReturnType {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for ReturnType {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (ReturnType::Default, ReturnType::Default) => true,
+            (ReturnType::Type(_, self1), ReturnType::Type(_, other1)) => self1 == other1,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Signature {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Signature {
+    fn eq(&self, other: &Self) -> bool {
+        self.constness == other.constness && self.asyncness == other.asyncness
+            && self.unsafety == other.unsafety && self.abi == other.abi
+            && self.ident == other.ident && self.generics == other.generics
+            && self.inputs == other.inputs && self.variadic == other.variadic
+            && self.output == other.output
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for StaticMutability {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for StaticMutability {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (StaticMutability::Mut(_), StaticMutability::Mut(_)) => true,
+            (StaticMutability::None, StaticMutability::None) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Stmt {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Stmt {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Stmt::Local(self0), Stmt::Local(other0)) => self0 == other0,
+            (Stmt::Item(self0), Stmt::Item(other0)) => self0 == other0,
+            (Stmt::Expr(self0, self1), Stmt::Expr(other0, other1)) => {
+                self0 == other0 && self1 == other1
+            }
+            (Stmt::Macro(self0), Stmt::Macro(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for StmtMacro {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for StmtMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mac == other.mac
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitBound {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitBound {
+    fn eq(&self, other: &Self) -> bool {
+        self.paren_token == other.paren_token && self.modifier == other.modifier
+            && self.lifetimes == other.lifetimes && self.path == other.path
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitBoundModifier {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitBoundModifier {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (TraitBoundModifier::None, TraitBoundModifier::None) => true,
+            (TraitBoundModifier::Maybe(_), TraitBoundModifier::Maybe(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitItem {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitItem {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (TraitItem::Const(self0), TraitItem::Const(other0)) => self0 == other0,
+            (TraitItem::Fn(self0), TraitItem::Fn(other0)) => self0 == other0,
+            (TraitItem::Type(self0), TraitItem::Type(other0)) => self0 == other0,
+            (TraitItem::Macro(self0), TraitItem::Macro(other0)) => self0 == other0,
+            (TraitItem::Verbatim(self0), TraitItem::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitItemConst {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitItemConst {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident
+            && self.generics == other.generics && self.ty == other.ty
+            && self.default == other.default
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitItemFn {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitItemFn {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.sig == other.sig
+            && self.default == other.default && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitItemMacro {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitItemMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.mac == other.mac
+            && self.semi_token == other.semi_token
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TraitItemType {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TraitItemType {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident
+            && self.generics == other.generics && self.colon_token == other.colon_token
+            && self.bounds == other.bounds && self.default == other.default
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Type {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Type {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Type::Array(self0), Type::Array(other0)) => self0 == other0,
+            (Type::BareFn(self0), Type::BareFn(other0)) => self0 == other0,
+            (Type::Group(self0), Type::Group(other0)) => self0 == other0,
+            (Type::ImplTrait(self0), Type::ImplTrait(other0)) => self0 == other0,
+            (Type::Infer(self0), Type::Infer(other0)) => self0 == other0,
+            (Type::Macro(self0), Type::Macro(other0)) => self0 == other0,
+            (Type::Never(self0), Type::Never(other0)) => self0 == other0,
+            (Type::Paren(self0), Type::Paren(other0)) => self0 == other0,
+            (Type::Path(self0), Type::Path(other0)) => self0 == other0,
+            (Type::Ptr(self0), Type::Ptr(other0)) => self0 == other0,
+            (Type::Reference(self0), Type::Reference(other0)) => self0 == other0,
+            (Type::Slice(self0), Type::Slice(other0)) => self0 == other0,
+            (Type::TraitObject(self0), Type::TraitObject(other0)) => self0 == other0,
+            (Type::Tuple(self0), Type::Tuple(other0)) => self0 == other0,
+            (Type::Verbatim(self0), Type::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeArray {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeArray {
+    fn eq(&self, other: &Self) -> bool {
+        self.elem == other.elem && self.len == other.len
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeBareFn {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeBareFn {
+    fn eq(&self, other: &Self) -> bool {
+        self.lifetimes == other.lifetimes && self.unsafety == other.unsafety
+            && self.abi == other.abi && self.inputs == other.inputs
+            && self.variadic == other.variadic && self.output == other.output
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeGroup {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeGroup {
+    fn eq(&self, other: &Self) -> bool {
+        self.elem == other.elem
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeImplTrait {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeImplTrait {
+    fn eq(&self, other: &Self) -> bool {
+        self.bounds == other.bounds
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeInfer {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeInfer {
+    fn eq(&self, _other: &Self) -> bool {
+        true
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeMacro {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeMacro {
+    fn eq(&self, other: &Self) -> bool {
+        self.mac == other.mac
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeNever {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeNever {
+    fn eq(&self, _other: &Self) -> bool {
+        true
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeParam {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeParam {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident
+            && self.colon_token == other.colon_token && self.bounds == other.bounds
+            && self.eq_token == other.eq_token && self.default == other.default
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeParamBound {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeParamBound {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (TypeParamBound::Trait(self0), TypeParamBound::Trait(other0)) => {
+                self0 == other0
+            }
+            (TypeParamBound::Lifetime(self0), TypeParamBound::Lifetime(other0)) => {
+                self0 == other0
+            }
+            (TypeParamBound::Verbatim(self0), TypeParamBound::Verbatim(other0)) => {
+                TokenStreamHelper(self0) == TokenStreamHelper(other0)
+            }
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeParen {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeParen {
+    fn eq(&self, other: &Self) -> bool {
+        self.elem == other.elem
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypePath {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypePath {
+    fn eq(&self, other: &Self) -> bool {
+        self.qself == other.qself && self.path == other.path
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypePtr {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypePtr {
+    fn eq(&self, other: &Self) -> bool {
+        self.const_token == other.const_token && self.mutability == other.mutability
+            && self.elem == other.elem
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeReference {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeReference {
+    fn eq(&self, other: &Self) -> bool {
+        self.lifetime == other.lifetime && self.mutability == other.mutability
+            && self.elem == other.elem
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeSlice {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeSlice {
+    fn eq(&self, other: &Self) -> bool {
+        self.elem == other.elem
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeTraitObject {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeTraitObject {
+    fn eq(&self, other: &Self) -> bool {
+        self.dyn_token == other.dyn_token && self.bounds == other.bounds
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for TypeTuple {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for TypeTuple {
+    fn eq(&self, other: &Self) -> bool {
+        self.elems == other.elems
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UnOp {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UnOp {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (UnOp::Deref(_), UnOp::Deref(_)) => true,
+            (UnOp::Not(_), UnOp::Not(_)) => true,
+            (UnOp::Neg(_), UnOp::Neg(_)) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UseGlob {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UseGlob {
+    fn eq(&self, _other: &Self) -> bool {
+        true
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UseGroup {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UseGroup {
+    fn eq(&self, other: &Self) -> bool {
+        self.items == other.items
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UseName {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UseName {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UsePath {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UsePath {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.tree == other.tree
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UseRename {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UseRename {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident && self.rename == other.rename
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for UseTree {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for UseTree {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (UseTree::Path(self0), UseTree::Path(other0)) => self0 == other0,
+            (UseTree::Name(self0), UseTree::Name(other0)) => self0 == other0,
+            (UseTree::Rename(self0), UseTree::Rename(other0)) => self0 == other0,
+            (UseTree::Glob(self0), UseTree::Glob(other0)) => self0 == other0,
+            (UseTree::Group(self0), UseTree::Group(other0)) => self0 == other0,
+            _ => false,
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Variadic {}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Variadic {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.pat == other.pat && self.comma == other.comma
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Variant {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Variant {
+    fn eq(&self, other: &Self) -> bool {
+        self.attrs == other.attrs && self.ident == other.ident
+            && self.fields == other.fields && self.discriminant == other.discriminant
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for VisRestricted {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for VisRestricted {
+    fn eq(&self, other: &Self) -> bool {
+        self.in_token == other.in_token && self.path == other.path
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Visibility {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Visibility {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Visibility::Public(_), Visibility::Public(_)) => true,
+            (Visibility::Restricted(self0), Visibility::Restricted(other0)) => {
+                self0 == other0
+            }
+            (Visibility::Inherited, Visibility::Inherited) => true,
+            _ => false,
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for WhereClause {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for WhereClause {
+    fn eq(&self, other: &Self) -> bool {
+        self.predicates == other.predicates
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for WherePredicate {}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for WherePredicate {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (WherePredicate::Lifetime(self0), WherePredicate::Lifetime(other0)) => {
+                self0 == other0
+            }
+            (WherePredicate::Type(self0), WherePredicate::Type(other0)) => {
+                self0 == other0
+            }
+            _ => false,
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/fold.rs b/vendor/syn/src/gen/fold.rs
new file mode 100644
index 0000000..8ea6c75
--- /dev/null
+++ b/vendor/syn/src/gen/fold.rs
@@ -0,0 +1,3119 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#![allow(unreachable_code, unused_variables)]
+#![allow(
+    clippy::match_wildcard_for_single_variants,
+    clippy::needless_match,
+    clippy::needless_pass_by_ref_mut,
+)]
+#[cfg(any(feature = "full", feature = "derive"))]
+use crate::gen::helper::fold::*;
+use crate::*;
+use proc_macro2::Span;
+#[cfg(feature = "full")]
+macro_rules! full {
+    ($e:expr) => {
+        $e
+    };
+}
+#[cfg(all(feature = "derive", not(feature = "full")))]
+macro_rules! full {
+    ($e:expr) => {
+        unreachable!()
+    };
+}
+/// Syntax tree traversal to transform the nodes of an owned syntax tree.
+///
+/// See the [module documentation] for details.
+///
+/// [module documentation]: self
+pub trait Fold {
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_abi(&mut self, i: Abi) -> Abi {
+        fold_abi(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_angle_bracketed_generic_arguments(
+        &mut self,
+        i: AngleBracketedGenericArguments,
+    ) -> AngleBracketedGenericArguments {
+        fold_angle_bracketed_generic_arguments(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_arm(&mut self, i: Arm) -> Arm {
+        fold_arm(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_assoc_const(&mut self, i: AssocConst) -> AssocConst {
+        fold_assoc_const(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_assoc_type(&mut self, i: AssocType) -> AssocType {
+        fold_assoc_type(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_attr_style(&mut self, i: AttrStyle) -> AttrStyle {
+        fold_attr_style(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_attribute(&mut self, i: Attribute) -> Attribute {
+        fold_attribute(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_bare_fn_arg(&mut self, i: BareFnArg) -> BareFnArg {
+        fold_bare_fn_arg(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_bare_variadic(&mut self, i: BareVariadic) -> BareVariadic {
+        fold_bare_variadic(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_bin_op(&mut self, i: BinOp) -> BinOp {
+        fold_bin_op(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_block(&mut self, i: Block) -> Block {
+        fold_block(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_bound_lifetimes(&mut self, i: BoundLifetimes) -> BoundLifetimes {
+        fold_bound_lifetimes(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_const_param(&mut self, i: ConstParam) -> ConstParam {
+        fold_const_param(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_constraint(&mut self, i: Constraint) -> Constraint {
+        fold_constraint(self, i)
+    }
+    #[cfg(feature = "derive")]
+    fn fold_data(&mut self, i: Data) -> Data {
+        fold_data(self, i)
+    }
+    #[cfg(feature = "derive")]
+    fn fold_data_enum(&mut self, i: DataEnum) -> DataEnum {
+        fold_data_enum(self, i)
+    }
+    #[cfg(feature = "derive")]
+    fn fold_data_struct(&mut self, i: DataStruct) -> DataStruct {
+        fold_data_struct(self, i)
+    }
+    #[cfg(feature = "derive")]
+    fn fold_data_union(&mut self, i: DataUnion) -> DataUnion {
+        fold_data_union(self, i)
+    }
+    #[cfg(feature = "derive")]
+    fn fold_derive_input(&mut self, i: DeriveInput) -> DeriveInput {
+        fold_derive_input(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr(&mut self, i: Expr) -> Expr {
+        fold_expr(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_array(&mut self, i: ExprArray) -> ExprArray {
+        fold_expr_array(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_assign(&mut self, i: ExprAssign) -> ExprAssign {
+        fold_expr_assign(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_async(&mut self, i: ExprAsync) -> ExprAsync {
+        fold_expr_async(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_await(&mut self, i: ExprAwait) -> ExprAwait {
+        fold_expr_await(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_binary(&mut self, i: ExprBinary) -> ExprBinary {
+        fold_expr_binary(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_block(&mut self, i: ExprBlock) -> ExprBlock {
+        fold_expr_block(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_break(&mut self, i: ExprBreak) -> ExprBreak {
+        fold_expr_break(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_call(&mut self, i: ExprCall) -> ExprCall {
+        fold_expr_call(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_cast(&mut self, i: ExprCast) -> ExprCast {
+        fold_expr_cast(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_closure(&mut self, i: ExprClosure) -> ExprClosure {
+        fold_expr_closure(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_const(&mut self, i: ExprConst) -> ExprConst {
+        fold_expr_const(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_continue(&mut self, i: ExprContinue) -> ExprContinue {
+        fold_expr_continue(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_field(&mut self, i: ExprField) -> ExprField {
+        fold_expr_field(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_for_loop(&mut self, i: ExprForLoop) -> ExprForLoop {
+        fold_expr_for_loop(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_group(&mut self, i: ExprGroup) -> ExprGroup {
+        fold_expr_group(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_if(&mut self, i: ExprIf) -> ExprIf {
+        fold_expr_if(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_index(&mut self, i: ExprIndex) -> ExprIndex {
+        fold_expr_index(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_infer(&mut self, i: ExprInfer) -> ExprInfer {
+        fold_expr_infer(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_let(&mut self, i: ExprLet) -> ExprLet {
+        fold_expr_let(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_lit(&mut self, i: ExprLit) -> ExprLit {
+        fold_expr_lit(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_loop(&mut self, i: ExprLoop) -> ExprLoop {
+        fold_expr_loop(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_macro(&mut self, i: ExprMacro) -> ExprMacro {
+        fold_expr_macro(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_match(&mut self, i: ExprMatch) -> ExprMatch {
+        fold_expr_match(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_method_call(&mut self, i: ExprMethodCall) -> ExprMethodCall {
+        fold_expr_method_call(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_paren(&mut self, i: ExprParen) -> ExprParen {
+        fold_expr_paren(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_path(&mut self, i: ExprPath) -> ExprPath {
+        fold_expr_path(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_range(&mut self, i: ExprRange) -> ExprRange {
+        fold_expr_range(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_reference(&mut self, i: ExprReference) -> ExprReference {
+        fold_expr_reference(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_repeat(&mut self, i: ExprRepeat) -> ExprRepeat {
+        fold_expr_repeat(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_return(&mut self, i: ExprReturn) -> ExprReturn {
+        fold_expr_return(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_struct(&mut self, i: ExprStruct) -> ExprStruct {
+        fold_expr_struct(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_try(&mut self, i: ExprTry) -> ExprTry {
+        fold_expr_try(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_try_block(&mut self, i: ExprTryBlock) -> ExprTryBlock {
+        fold_expr_try_block(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_tuple(&mut self, i: ExprTuple) -> ExprTuple {
+        fold_expr_tuple(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_expr_unary(&mut self, i: ExprUnary) -> ExprUnary {
+        fold_expr_unary(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_unsafe(&mut self, i: ExprUnsafe) -> ExprUnsafe {
+        fold_expr_unsafe(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_while(&mut self, i: ExprWhile) -> ExprWhile {
+        fold_expr_while(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_expr_yield(&mut self, i: ExprYield) -> ExprYield {
+        fold_expr_yield(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_field(&mut self, i: Field) -> Field {
+        fold_field(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_field_mutability(&mut self, i: FieldMutability) -> FieldMutability {
+        fold_field_mutability(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_field_pat(&mut self, i: FieldPat) -> FieldPat {
+        fold_field_pat(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_field_value(&mut self, i: FieldValue) -> FieldValue {
+        fold_field_value(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_fields(&mut self, i: Fields) -> Fields {
+        fold_fields(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_fields_named(&mut self, i: FieldsNamed) -> FieldsNamed {
+        fold_fields_named(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_fields_unnamed(&mut self, i: FieldsUnnamed) -> FieldsUnnamed {
+        fold_fields_unnamed(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_file(&mut self, i: File) -> File {
+        fold_file(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_fn_arg(&mut self, i: FnArg) -> FnArg {
+        fold_fn_arg(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_foreign_item(&mut self, i: ForeignItem) -> ForeignItem {
+        fold_foreign_item(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_foreign_item_fn(&mut self, i: ForeignItemFn) -> ForeignItemFn {
+        fold_foreign_item_fn(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_foreign_item_macro(&mut self, i: ForeignItemMacro) -> ForeignItemMacro {
+        fold_foreign_item_macro(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_foreign_item_static(&mut self, i: ForeignItemStatic) -> ForeignItemStatic {
+        fold_foreign_item_static(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_foreign_item_type(&mut self, i: ForeignItemType) -> ForeignItemType {
+        fold_foreign_item_type(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_generic_argument(&mut self, i: GenericArgument) -> GenericArgument {
+        fold_generic_argument(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_generic_param(&mut self, i: GenericParam) -> GenericParam {
+        fold_generic_param(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_generics(&mut self, i: Generics) -> Generics {
+        fold_generics(self, i)
+    }
+    fn fold_ident(&mut self, i: Ident) -> Ident {
+        fold_ident(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_item(&mut self, i: ImplItem) -> ImplItem {
+        fold_impl_item(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_item_const(&mut self, i: ImplItemConst) -> ImplItemConst {
+        fold_impl_item_const(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_item_fn(&mut self, i: ImplItemFn) -> ImplItemFn {
+        fold_impl_item_fn(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_item_macro(&mut self, i: ImplItemMacro) -> ImplItemMacro {
+        fold_impl_item_macro(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_item_type(&mut self, i: ImplItemType) -> ImplItemType {
+        fold_impl_item_type(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_impl_restriction(&mut self, i: ImplRestriction) -> ImplRestriction {
+        fold_impl_restriction(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_index(&mut self, i: Index) -> Index {
+        fold_index(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item(&mut self, i: Item) -> Item {
+        fold_item(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_const(&mut self, i: ItemConst) -> ItemConst {
+        fold_item_const(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_enum(&mut self, i: ItemEnum) -> ItemEnum {
+        fold_item_enum(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_extern_crate(&mut self, i: ItemExternCrate) -> ItemExternCrate {
+        fold_item_extern_crate(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_fn(&mut self, i: ItemFn) -> ItemFn {
+        fold_item_fn(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_foreign_mod(&mut self, i: ItemForeignMod) -> ItemForeignMod {
+        fold_item_foreign_mod(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_impl(&mut self, i: ItemImpl) -> ItemImpl {
+        fold_item_impl(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_macro(&mut self, i: ItemMacro) -> ItemMacro {
+        fold_item_macro(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_mod(&mut self, i: ItemMod) -> ItemMod {
+        fold_item_mod(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_static(&mut self, i: ItemStatic) -> ItemStatic {
+        fold_item_static(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_struct(&mut self, i: ItemStruct) -> ItemStruct {
+        fold_item_struct(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_trait(&mut self, i: ItemTrait) -> ItemTrait {
+        fold_item_trait(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_trait_alias(&mut self, i: ItemTraitAlias) -> ItemTraitAlias {
+        fold_item_trait_alias(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_type(&mut self, i: ItemType) -> ItemType {
+        fold_item_type(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_union(&mut self, i: ItemUnion) -> ItemUnion {
+        fold_item_union(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_item_use(&mut self, i: ItemUse) -> ItemUse {
+        fold_item_use(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_label(&mut self, i: Label) -> Label {
+        fold_label(self, i)
+    }
+    fn fold_lifetime(&mut self, i: Lifetime) -> Lifetime {
+        fold_lifetime(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_lifetime_param(&mut self, i: LifetimeParam) -> LifetimeParam {
+        fold_lifetime_param(self, i)
+    }
+    fn fold_lit(&mut self, i: Lit) -> Lit {
+        fold_lit(self, i)
+    }
+    fn fold_lit_bool(&mut self, i: LitBool) -> LitBool {
+        fold_lit_bool(self, i)
+    }
+    fn fold_lit_byte(&mut self, i: LitByte) -> LitByte {
+        fold_lit_byte(self, i)
+    }
+    fn fold_lit_byte_str(&mut self, i: LitByteStr) -> LitByteStr {
+        fold_lit_byte_str(self, i)
+    }
+    fn fold_lit_char(&mut self, i: LitChar) -> LitChar {
+        fold_lit_char(self, i)
+    }
+    fn fold_lit_float(&mut self, i: LitFloat) -> LitFloat {
+        fold_lit_float(self, i)
+    }
+    fn fold_lit_int(&mut self, i: LitInt) -> LitInt {
+        fold_lit_int(self, i)
+    }
+    fn fold_lit_str(&mut self, i: LitStr) -> LitStr {
+        fold_lit_str(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_local(&mut self, i: Local) -> Local {
+        fold_local(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_local_init(&mut self, i: LocalInit) -> LocalInit {
+        fold_local_init(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_macro(&mut self, i: Macro) -> Macro {
+        fold_macro(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_macro_delimiter(&mut self, i: MacroDelimiter) -> MacroDelimiter {
+        fold_macro_delimiter(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_member(&mut self, i: Member) -> Member {
+        fold_member(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_meta(&mut self, i: Meta) -> Meta {
+        fold_meta(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_meta_list(&mut self, i: MetaList) -> MetaList {
+        fold_meta_list(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_meta_name_value(&mut self, i: MetaNameValue) -> MetaNameValue {
+        fold_meta_name_value(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_parenthesized_generic_arguments(
+        &mut self,
+        i: ParenthesizedGenericArguments,
+    ) -> ParenthesizedGenericArguments {
+        fold_parenthesized_generic_arguments(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat(&mut self, i: Pat) -> Pat {
+        fold_pat(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_ident(&mut self, i: PatIdent) -> PatIdent {
+        fold_pat_ident(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_or(&mut self, i: PatOr) -> PatOr {
+        fold_pat_or(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_paren(&mut self, i: PatParen) -> PatParen {
+        fold_pat_paren(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_reference(&mut self, i: PatReference) -> PatReference {
+        fold_pat_reference(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_rest(&mut self, i: PatRest) -> PatRest {
+        fold_pat_rest(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_slice(&mut self, i: PatSlice) -> PatSlice {
+        fold_pat_slice(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_struct(&mut self, i: PatStruct) -> PatStruct {
+        fold_pat_struct(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_tuple(&mut self, i: PatTuple) -> PatTuple {
+        fold_pat_tuple(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_tuple_struct(&mut self, i: PatTupleStruct) -> PatTupleStruct {
+        fold_pat_tuple_struct(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_type(&mut self, i: PatType) -> PatType {
+        fold_pat_type(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_pat_wild(&mut self, i: PatWild) -> PatWild {
+        fold_pat_wild(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_path(&mut self, i: Path) -> Path {
+        fold_path(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_path_arguments(&mut self, i: PathArguments) -> PathArguments {
+        fold_path_arguments(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_path_segment(&mut self, i: PathSegment) -> PathSegment {
+        fold_path_segment(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_predicate_lifetime(&mut self, i: PredicateLifetime) -> PredicateLifetime {
+        fold_predicate_lifetime(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_predicate_type(&mut self, i: PredicateType) -> PredicateType {
+        fold_predicate_type(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_qself(&mut self, i: QSelf) -> QSelf {
+        fold_qself(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_range_limits(&mut self, i: RangeLimits) -> RangeLimits {
+        fold_range_limits(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_receiver(&mut self, i: Receiver) -> Receiver {
+        fold_receiver(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_return_type(&mut self, i: ReturnType) -> ReturnType {
+        fold_return_type(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_signature(&mut self, i: Signature) -> Signature {
+        fold_signature(self, i)
+    }
+    fn fold_span(&mut self, i: Span) -> Span {
+        fold_span(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_static_mutability(&mut self, i: StaticMutability) -> StaticMutability {
+        fold_static_mutability(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_stmt(&mut self, i: Stmt) -> Stmt {
+        fold_stmt(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_stmt_macro(&mut self, i: StmtMacro) -> StmtMacro {
+        fold_stmt_macro(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_trait_bound(&mut self, i: TraitBound) -> TraitBound {
+        fold_trait_bound(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_trait_bound_modifier(
+        &mut self,
+        i: TraitBoundModifier,
+    ) -> TraitBoundModifier {
+        fold_trait_bound_modifier(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_trait_item(&mut self, i: TraitItem) -> TraitItem {
+        fold_trait_item(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_trait_item_const(&mut self, i: TraitItemConst) -> TraitItemConst {
+        fold_trait_item_const(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_trait_item_fn(&mut self, i: TraitItemFn) -> TraitItemFn {
+        fold_trait_item_fn(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_trait_item_macro(&mut self, i: TraitItemMacro) -> TraitItemMacro {
+        fold_trait_item_macro(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_trait_item_type(&mut self, i: TraitItemType) -> TraitItemType {
+        fold_trait_item_type(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type(&mut self, i: Type) -> Type {
+        fold_type(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_array(&mut self, i: TypeArray) -> TypeArray {
+        fold_type_array(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_bare_fn(&mut self, i: TypeBareFn) -> TypeBareFn {
+        fold_type_bare_fn(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_group(&mut self, i: TypeGroup) -> TypeGroup {
+        fold_type_group(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_impl_trait(&mut self, i: TypeImplTrait) -> TypeImplTrait {
+        fold_type_impl_trait(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_infer(&mut self, i: TypeInfer) -> TypeInfer {
+        fold_type_infer(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_macro(&mut self, i: TypeMacro) -> TypeMacro {
+        fold_type_macro(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_never(&mut self, i: TypeNever) -> TypeNever {
+        fold_type_never(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_param(&mut self, i: TypeParam) -> TypeParam {
+        fold_type_param(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_param_bound(&mut self, i: TypeParamBound) -> TypeParamBound {
+        fold_type_param_bound(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_paren(&mut self, i: TypeParen) -> TypeParen {
+        fold_type_paren(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_path(&mut self, i: TypePath) -> TypePath {
+        fold_type_path(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_ptr(&mut self, i: TypePtr) -> TypePtr {
+        fold_type_ptr(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_reference(&mut self, i: TypeReference) -> TypeReference {
+        fold_type_reference(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_slice(&mut self, i: TypeSlice) -> TypeSlice {
+        fold_type_slice(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_trait_object(&mut self, i: TypeTraitObject) -> TypeTraitObject {
+        fold_type_trait_object(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_type_tuple(&mut self, i: TypeTuple) -> TypeTuple {
+        fold_type_tuple(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_un_op(&mut self, i: UnOp) -> UnOp {
+        fold_un_op(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_glob(&mut self, i: UseGlob) -> UseGlob {
+        fold_use_glob(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_group(&mut self, i: UseGroup) -> UseGroup {
+        fold_use_group(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_name(&mut self, i: UseName) -> UseName {
+        fold_use_name(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_path(&mut self, i: UsePath) -> UsePath {
+        fold_use_path(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_rename(&mut self, i: UseRename) -> UseRename {
+        fold_use_rename(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_use_tree(&mut self, i: UseTree) -> UseTree {
+        fold_use_tree(self, i)
+    }
+    #[cfg(feature = "full")]
+    fn fold_variadic(&mut self, i: Variadic) -> Variadic {
+        fold_variadic(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_variant(&mut self, i: Variant) -> Variant {
+        fold_variant(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_vis_restricted(&mut self, i: VisRestricted) -> VisRestricted {
+        fold_vis_restricted(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_visibility(&mut self, i: Visibility) -> Visibility {
+        fold_visibility(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_where_clause(&mut self, i: WhereClause) -> WhereClause {
+        fold_where_clause(self, i)
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn fold_where_predicate(&mut self, i: WherePredicate) -> WherePredicate {
+        fold_where_predicate(self, i)
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_abi<F>(f: &mut F, node: Abi) -> Abi
+where
+    F: Fold + ?Sized,
+{
+    Abi {
+        extern_token: node.extern_token,
+        name: (node.name).map(|it| f.fold_lit_str(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_angle_bracketed_generic_arguments<F>(
+    f: &mut F,
+    node: AngleBracketedGenericArguments,
+) -> AngleBracketedGenericArguments
+where
+    F: Fold + ?Sized,
+{
+    AngleBracketedGenericArguments {
+        colon2_token: node.colon2_token,
+        lt_token: node.lt_token,
+        args: FoldHelper::lift(node.args, |it| f.fold_generic_argument(it)),
+        gt_token: node.gt_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_arm<F>(f: &mut F, node: Arm) -> Arm
+where
+    F: Fold + ?Sized,
+{
+    Arm {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        pat: f.fold_pat(node.pat),
+        guard: (node.guard).map(|it| ((it).0, Box::new(f.fold_expr(*(it).1)))),
+        fat_arrow_token: node.fat_arrow_token,
+        body: Box::new(f.fold_expr(*node.body)),
+        comma: node.comma,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_assoc_const<F>(f: &mut F, node: AssocConst) -> AssocConst
+where
+    F: Fold + ?Sized,
+{
+    AssocConst {
+        ident: f.fold_ident(node.ident),
+        generics: (node.generics).map(|it| f.fold_angle_bracketed_generic_arguments(it)),
+        eq_token: node.eq_token,
+        value: f.fold_expr(node.value),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_assoc_type<F>(f: &mut F, node: AssocType) -> AssocType
+where
+    F: Fold + ?Sized,
+{
+    AssocType {
+        ident: f.fold_ident(node.ident),
+        generics: (node.generics).map(|it| f.fold_angle_bracketed_generic_arguments(it)),
+        eq_token: node.eq_token,
+        ty: f.fold_type(node.ty),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_attr_style<F>(f: &mut F, node: AttrStyle) -> AttrStyle
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        AttrStyle::Outer => AttrStyle::Outer,
+        AttrStyle::Inner(_binding_0) => AttrStyle::Inner(_binding_0),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_attribute<F>(f: &mut F, node: Attribute) -> Attribute
+where
+    F: Fold + ?Sized,
+{
+    Attribute {
+        pound_token: node.pound_token,
+        style: f.fold_attr_style(node.style),
+        bracket_token: node.bracket_token,
+        meta: f.fold_meta(node.meta),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_bare_fn_arg<F>(f: &mut F, node: BareFnArg) -> BareFnArg
+where
+    F: Fold + ?Sized,
+{
+    BareFnArg {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        name: (node.name).map(|it| (f.fold_ident((it).0), (it).1)),
+        ty: f.fold_type(node.ty),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_bare_variadic<F>(f: &mut F, node: BareVariadic) -> BareVariadic
+where
+    F: Fold + ?Sized,
+{
+    BareVariadic {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        name: (node.name).map(|it| (f.fold_ident((it).0), (it).1)),
+        dots: node.dots,
+        comma: node.comma,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_bin_op<F>(f: &mut F, node: BinOp) -> BinOp
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        BinOp::Add(_binding_0) => BinOp::Add(_binding_0),
+        BinOp::Sub(_binding_0) => BinOp::Sub(_binding_0),
+        BinOp::Mul(_binding_0) => BinOp::Mul(_binding_0),
+        BinOp::Div(_binding_0) => BinOp::Div(_binding_0),
+        BinOp::Rem(_binding_0) => BinOp::Rem(_binding_0),
+        BinOp::And(_binding_0) => BinOp::And(_binding_0),
+        BinOp::Or(_binding_0) => BinOp::Or(_binding_0),
+        BinOp::BitXor(_binding_0) => BinOp::BitXor(_binding_0),
+        BinOp::BitAnd(_binding_0) => BinOp::BitAnd(_binding_0),
+        BinOp::BitOr(_binding_0) => BinOp::BitOr(_binding_0),
+        BinOp::Shl(_binding_0) => BinOp::Shl(_binding_0),
+        BinOp::Shr(_binding_0) => BinOp::Shr(_binding_0),
+        BinOp::Eq(_binding_0) => BinOp::Eq(_binding_0),
+        BinOp::Lt(_binding_0) => BinOp::Lt(_binding_0),
+        BinOp::Le(_binding_0) => BinOp::Le(_binding_0),
+        BinOp::Ne(_binding_0) => BinOp::Ne(_binding_0),
+        BinOp::Ge(_binding_0) => BinOp::Ge(_binding_0),
+        BinOp::Gt(_binding_0) => BinOp::Gt(_binding_0),
+        BinOp::AddAssign(_binding_0) => BinOp::AddAssign(_binding_0),
+        BinOp::SubAssign(_binding_0) => BinOp::SubAssign(_binding_0),
+        BinOp::MulAssign(_binding_0) => BinOp::MulAssign(_binding_0),
+        BinOp::DivAssign(_binding_0) => BinOp::DivAssign(_binding_0),
+        BinOp::RemAssign(_binding_0) => BinOp::RemAssign(_binding_0),
+        BinOp::BitXorAssign(_binding_0) => BinOp::BitXorAssign(_binding_0),
+        BinOp::BitAndAssign(_binding_0) => BinOp::BitAndAssign(_binding_0),
+        BinOp::BitOrAssign(_binding_0) => BinOp::BitOrAssign(_binding_0),
+        BinOp::ShlAssign(_binding_0) => BinOp::ShlAssign(_binding_0),
+        BinOp::ShrAssign(_binding_0) => BinOp::ShrAssign(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_block<F>(f: &mut F, node: Block) -> Block
+where
+    F: Fold + ?Sized,
+{
+    Block {
+        brace_token: node.brace_token,
+        stmts: FoldHelper::lift(node.stmts, |it| f.fold_stmt(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_bound_lifetimes<F>(f: &mut F, node: BoundLifetimes) -> BoundLifetimes
+where
+    F: Fold + ?Sized,
+{
+    BoundLifetimes {
+        for_token: node.for_token,
+        lt_token: node.lt_token,
+        lifetimes: FoldHelper::lift(node.lifetimes, |it| f.fold_generic_param(it)),
+        gt_token: node.gt_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_const_param<F>(f: &mut F, node: ConstParam) -> ConstParam
+where
+    F: Fold + ?Sized,
+{
+    ConstParam {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        const_token: node.const_token,
+        ident: f.fold_ident(node.ident),
+        colon_token: node.colon_token,
+        ty: f.fold_type(node.ty),
+        eq_token: node.eq_token,
+        default: (node.default).map(|it| f.fold_expr(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_constraint<F>(f: &mut F, node: Constraint) -> Constraint
+where
+    F: Fold + ?Sized,
+{
+    Constraint {
+        ident: f.fold_ident(node.ident),
+        generics: (node.generics).map(|it| f.fold_angle_bracketed_generic_arguments(it)),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+    }
+}
+#[cfg(feature = "derive")]
+pub fn fold_data<F>(f: &mut F, node: Data) -> Data
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Data::Struct(_binding_0) => Data::Struct(f.fold_data_struct(_binding_0)),
+        Data::Enum(_binding_0) => Data::Enum(f.fold_data_enum(_binding_0)),
+        Data::Union(_binding_0) => Data::Union(f.fold_data_union(_binding_0)),
+    }
+}
+#[cfg(feature = "derive")]
+pub fn fold_data_enum<F>(f: &mut F, node: DataEnum) -> DataEnum
+where
+    F: Fold + ?Sized,
+{
+    DataEnum {
+        enum_token: node.enum_token,
+        brace_token: node.brace_token,
+        variants: FoldHelper::lift(node.variants, |it| f.fold_variant(it)),
+    }
+}
+#[cfg(feature = "derive")]
+pub fn fold_data_struct<F>(f: &mut F, node: DataStruct) -> DataStruct
+where
+    F: Fold + ?Sized,
+{
+    DataStruct {
+        struct_token: node.struct_token,
+        fields: f.fold_fields(node.fields),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "derive")]
+pub fn fold_data_union<F>(f: &mut F, node: DataUnion) -> DataUnion
+where
+    F: Fold + ?Sized,
+{
+    DataUnion {
+        union_token: node.union_token,
+        fields: f.fold_fields_named(node.fields),
+    }
+}
+#[cfg(feature = "derive")]
+pub fn fold_derive_input<F>(f: &mut F, node: DeriveInput) -> DeriveInput
+where
+    F: Fold + ?Sized,
+{
+    DeriveInput {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        data: f.fold_data(node.data),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr<F>(f: &mut F, node: Expr) -> Expr
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Expr::Array(_binding_0) => Expr::Array(full!(f.fold_expr_array(_binding_0))),
+        Expr::Assign(_binding_0) => Expr::Assign(full!(f.fold_expr_assign(_binding_0))),
+        Expr::Async(_binding_0) => Expr::Async(full!(f.fold_expr_async(_binding_0))),
+        Expr::Await(_binding_0) => Expr::Await(full!(f.fold_expr_await(_binding_0))),
+        Expr::Binary(_binding_0) => Expr::Binary(f.fold_expr_binary(_binding_0)),
+        Expr::Block(_binding_0) => Expr::Block(full!(f.fold_expr_block(_binding_0))),
+        Expr::Break(_binding_0) => Expr::Break(full!(f.fold_expr_break(_binding_0))),
+        Expr::Call(_binding_0) => Expr::Call(f.fold_expr_call(_binding_0)),
+        Expr::Cast(_binding_0) => Expr::Cast(f.fold_expr_cast(_binding_0)),
+        Expr::Closure(_binding_0) => {
+            Expr::Closure(full!(f.fold_expr_closure(_binding_0)))
+        }
+        Expr::Const(_binding_0) => Expr::Const(full!(f.fold_expr_const(_binding_0))),
+        Expr::Continue(_binding_0) => {
+            Expr::Continue(full!(f.fold_expr_continue(_binding_0)))
+        }
+        Expr::Field(_binding_0) => Expr::Field(f.fold_expr_field(_binding_0)),
+        Expr::ForLoop(_binding_0) => {
+            Expr::ForLoop(full!(f.fold_expr_for_loop(_binding_0)))
+        }
+        Expr::Group(_binding_0) => Expr::Group(f.fold_expr_group(_binding_0)),
+        Expr::If(_binding_0) => Expr::If(full!(f.fold_expr_if(_binding_0))),
+        Expr::Index(_binding_0) => Expr::Index(f.fold_expr_index(_binding_0)),
+        Expr::Infer(_binding_0) => Expr::Infer(full!(f.fold_expr_infer(_binding_0))),
+        Expr::Let(_binding_0) => Expr::Let(full!(f.fold_expr_let(_binding_0))),
+        Expr::Lit(_binding_0) => Expr::Lit(f.fold_expr_lit(_binding_0)),
+        Expr::Loop(_binding_0) => Expr::Loop(full!(f.fold_expr_loop(_binding_0))),
+        Expr::Macro(_binding_0) => Expr::Macro(f.fold_expr_macro(_binding_0)),
+        Expr::Match(_binding_0) => Expr::Match(full!(f.fold_expr_match(_binding_0))),
+        Expr::MethodCall(_binding_0) => {
+            Expr::MethodCall(full!(f.fold_expr_method_call(_binding_0)))
+        }
+        Expr::Paren(_binding_0) => Expr::Paren(f.fold_expr_paren(_binding_0)),
+        Expr::Path(_binding_0) => Expr::Path(f.fold_expr_path(_binding_0)),
+        Expr::Range(_binding_0) => Expr::Range(full!(f.fold_expr_range(_binding_0))),
+        Expr::Reference(_binding_0) => {
+            Expr::Reference(full!(f.fold_expr_reference(_binding_0)))
+        }
+        Expr::Repeat(_binding_0) => Expr::Repeat(full!(f.fold_expr_repeat(_binding_0))),
+        Expr::Return(_binding_0) => Expr::Return(full!(f.fold_expr_return(_binding_0))),
+        Expr::Struct(_binding_0) => Expr::Struct(full!(f.fold_expr_struct(_binding_0))),
+        Expr::Try(_binding_0) => Expr::Try(full!(f.fold_expr_try(_binding_0))),
+        Expr::TryBlock(_binding_0) => {
+            Expr::TryBlock(full!(f.fold_expr_try_block(_binding_0)))
+        }
+        Expr::Tuple(_binding_0) => Expr::Tuple(full!(f.fold_expr_tuple(_binding_0))),
+        Expr::Unary(_binding_0) => Expr::Unary(f.fold_expr_unary(_binding_0)),
+        Expr::Unsafe(_binding_0) => Expr::Unsafe(full!(f.fold_expr_unsafe(_binding_0))),
+        Expr::Verbatim(_binding_0) => Expr::Verbatim(_binding_0),
+        Expr::While(_binding_0) => Expr::While(full!(f.fold_expr_while(_binding_0))),
+        Expr::Yield(_binding_0) => Expr::Yield(full!(f.fold_expr_yield(_binding_0))),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_array<F>(f: &mut F, node: ExprArray) -> ExprArray
+where
+    F: Fold + ?Sized,
+{
+    ExprArray {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        bracket_token: node.bracket_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_expr(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_assign<F>(f: &mut F, node: ExprAssign) -> ExprAssign
+where
+    F: Fold + ?Sized,
+{
+    ExprAssign {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        left: Box::new(f.fold_expr(*node.left)),
+        eq_token: node.eq_token,
+        right: Box::new(f.fold_expr(*node.right)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_async<F>(f: &mut F, node: ExprAsync) -> ExprAsync
+where
+    F: Fold + ?Sized,
+{
+    ExprAsync {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        async_token: node.async_token,
+        capture: node.capture,
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_await<F>(f: &mut F, node: ExprAwait) -> ExprAwait
+where
+    F: Fold + ?Sized,
+{
+    ExprAwait {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        base: Box::new(f.fold_expr(*node.base)),
+        dot_token: node.dot_token,
+        await_token: node.await_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_binary<F>(f: &mut F, node: ExprBinary) -> ExprBinary
+where
+    F: Fold + ?Sized,
+{
+    ExprBinary {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        left: Box::new(f.fold_expr(*node.left)),
+        op: f.fold_bin_op(node.op),
+        right: Box::new(f.fold_expr(*node.right)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_block<F>(f: &mut F, node: ExprBlock) -> ExprBlock
+where
+    F: Fold + ?Sized,
+{
+    ExprBlock {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        label: (node.label).map(|it| f.fold_label(it)),
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_break<F>(f: &mut F, node: ExprBreak) -> ExprBreak
+where
+    F: Fold + ?Sized,
+{
+    ExprBreak {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        break_token: node.break_token,
+        label: (node.label).map(|it| f.fold_lifetime(it)),
+        expr: (node.expr).map(|it| Box::new(f.fold_expr(*it))),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_call<F>(f: &mut F, node: ExprCall) -> ExprCall
+where
+    F: Fold + ?Sized,
+{
+    ExprCall {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        func: Box::new(f.fold_expr(*node.func)),
+        paren_token: node.paren_token,
+        args: FoldHelper::lift(node.args, |it| f.fold_expr(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_cast<F>(f: &mut F, node: ExprCast) -> ExprCast
+where
+    F: Fold + ?Sized,
+{
+    ExprCast {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        expr: Box::new(f.fold_expr(*node.expr)),
+        as_token: node.as_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_closure<F>(f: &mut F, node: ExprClosure) -> ExprClosure
+where
+    F: Fold + ?Sized,
+{
+    ExprClosure {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        lifetimes: (node.lifetimes).map(|it| f.fold_bound_lifetimes(it)),
+        constness: node.constness,
+        movability: node.movability,
+        asyncness: node.asyncness,
+        capture: node.capture,
+        or1_token: node.or1_token,
+        inputs: FoldHelper::lift(node.inputs, |it| f.fold_pat(it)),
+        or2_token: node.or2_token,
+        output: f.fold_return_type(node.output),
+        body: Box::new(f.fold_expr(*node.body)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_const<F>(f: &mut F, node: ExprConst) -> ExprConst
+where
+    F: Fold + ?Sized,
+{
+    ExprConst {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        const_token: node.const_token,
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_continue<F>(f: &mut F, node: ExprContinue) -> ExprContinue
+where
+    F: Fold + ?Sized,
+{
+    ExprContinue {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        continue_token: node.continue_token,
+        label: (node.label).map(|it| f.fold_lifetime(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_field<F>(f: &mut F, node: ExprField) -> ExprField
+where
+    F: Fold + ?Sized,
+{
+    ExprField {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        base: Box::new(f.fold_expr(*node.base)),
+        dot_token: node.dot_token,
+        member: f.fold_member(node.member),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_for_loop<F>(f: &mut F, node: ExprForLoop) -> ExprForLoop
+where
+    F: Fold + ?Sized,
+{
+    ExprForLoop {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        label: (node.label).map(|it| f.fold_label(it)),
+        for_token: node.for_token,
+        pat: Box::new(f.fold_pat(*node.pat)),
+        in_token: node.in_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        body: f.fold_block(node.body),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_group<F>(f: &mut F, node: ExprGroup) -> ExprGroup
+where
+    F: Fold + ?Sized,
+{
+    ExprGroup {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        group_token: node.group_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_if<F>(f: &mut F, node: ExprIf) -> ExprIf
+where
+    F: Fold + ?Sized,
+{
+    ExprIf {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        if_token: node.if_token,
+        cond: Box::new(f.fold_expr(*node.cond)),
+        then_branch: f.fold_block(node.then_branch),
+        else_branch: (node.else_branch)
+            .map(|it| ((it).0, Box::new(f.fold_expr(*(it).1)))),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_index<F>(f: &mut F, node: ExprIndex) -> ExprIndex
+where
+    F: Fold + ?Sized,
+{
+    ExprIndex {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        expr: Box::new(f.fold_expr(*node.expr)),
+        bracket_token: node.bracket_token,
+        index: Box::new(f.fold_expr(*node.index)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_infer<F>(f: &mut F, node: ExprInfer) -> ExprInfer
+where
+    F: Fold + ?Sized,
+{
+    ExprInfer {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        underscore_token: node.underscore_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_let<F>(f: &mut F, node: ExprLet) -> ExprLet
+where
+    F: Fold + ?Sized,
+{
+    ExprLet {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        let_token: node.let_token,
+        pat: Box::new(f.fold_pat(*node.pat)),
+        eq_token: node.eq_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_lit<F>(f: &mut F, node: ExprLit) -> ExprLit
+where
+    F: Fold + ?Sized,
+{
+    ExprLit {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        lit: f.fold_lit(node.lit),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_loop<F>(f: &mut F, node: ExprLoop) -> ExprLoop
+where
+    F: Fold + ?Sized,
+{
+    ExprLoop {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        label: (node.label).map(|it| f.fold_label(it)),
+        loop_token: node.loop_token,
+        body: f.fold_block(node.body),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_macro<F>(f: &mut F, node: ExprMacro) -> ExprMacro
+where
+    F: Fold + ?Sized,
+{
+    ExprMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        mac: f.fold_macro(node.mac),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_match<F>(f: &mut F, node: ExprMatch) -> ExprMatch
+where
+    F: Fold + ?Sized,
+{
+    ExprMatch {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        match_token: node.match_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        brace_token: node.brace_token,
+        arms: FoldHelper::lift(node.arms, |it| f.fold_arm(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_method_call<F>(f: &mut F, node: ExprMethodCall) -> ExprMethodCall
+where
+    F: Fold + ?Sized,
+{
+    ExprMethodCall {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        receiver: Box::new(f.fold_expr(*node.receiver)),
+        dot_token: node.dot_token,
+        method: f.fold_ident(node.method),
+        turbofish: (node.turbofish)
+            .map(|it| f.fold_angle_bracketed_generic_arguments(it)),
+        paren_token: node.paren_token,
+        args: FoldHelper::lift(node.args, |it| f.fold_expr(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_paren<F>(f: &mut F, node: ExprParen) -> ExprParen
+where
+    F: Fold + ?Sized,
+{
+    ExprParen {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        paren_token: node.paren_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_path<F>(f: &mut F, node: ExprPath) -> ExprPath
+where
+    F: Fold + ?Sized,
+{
+    ExprPath {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        qself: (node.qself).map(|it| f.fold_qself(it)),
+        path: f.fold_path(node.path),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_range<F>(f: &mut F, node: ExprRange) -> ExprRange
+where
+    F: Fold + ?Sized,
+{
+    ExprRange {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        start: (node.start).map(|it| Box::new(f.fold_expr(*it))),
+        limits: f.fold_range_limits(node.limits),
+        end: (node.end).map(|it| Box::new(f.fold_expr(*it))),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_reference<F>(f: &mut F, node: ExprReference) -> ExprReference
+where
+    F: Fold + ?Sized,
+{
+    ExprReference {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        and_token: node.and_token,
+        mutability: node.mutability,
+        expr: Box::new(f.fold_expr(*node.expr)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_repeat<F>(f: &mut F, node: ExprRepeat) -> ExprRepeat
+where
+    F: Fold + ?Sized,
+{
+    ExprRepeat {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        bracket_token: node.bracket_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        semi_token: node.semi_token,
+        len: Box::new(f.fold_expr(*node.len)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_return<F>(f: &mut F, node: ExprReturn) -> ExprReturn
+where
+    F: Fold + ?Sized,
+{
+    ExprReturn {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        return_token: node.return_token,
+        expr: (node.expr).map(|it| Box::new(f.fold_expr(*it))),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_struct<F>(f: &mut F, node: ExprStruct) -> ExprStruct
+where
+    F: Fold + ?Sized,
+{
+    ExprStruct {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        qself: (node.qself).map(|it| f.fold_qself(it)),
+        path: f.fold_path(node.path),
+        brace_token: node.brace_token,
+        fields: FoldHelper::lift(node.fields, |it| f.fold_field_value(it)),
+        dot2_token: node.dot2_token,
+        rest: (node.rest).map(|it| Box::new(f.fold_expr(*it))),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_try<F>(f: &mut F, node: ExprTry) -> ExprTry
+where
+    F: Fold + ?Sized,
+{
+    ExprTry {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        expr: Box::new(f.fold_expr(*node.expr)),
+        question_token: node.question_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_try_block<F>(f: &mut F, node: ExprTryBlock) -> ExprTryBlock
+where
+    F: Fold + ?Sized,
+{
+    ExprTryBlock {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        try_token: node.try_token,
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_tuple<F>(f: &mut F, node: ExprTuple) -> ExprTuple
+where
+    F: Fold + ?Sized,
+{
+    ExprTuple {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        paren_token: node.paren_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_expr(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_expr_unary<F>(f: &mut F, node: ExprUnary) -> ExprUnary
+where
+    F: Fold + ?Sized,
+{
+    ExprUnary {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        op: f.fold_un_op(node.op),
+        expr: Box::new(f.fold_expr(*node.expr)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_unsafe<F>(f: &mut F, node: ExprUnsafe) -> ExprUnsafe
+where
+    F: Fold + ?Sized,
+{
+    ExprUnsafe {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        unsafe_token: node.unsafe_token,
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_while<F>(f: &mut F, node: ExprWhile) -> ExprWhile
+where
+    F: Fold + ?Sized,
+{
+    ExprWhile {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        label: (node.label).map(|it| f.fold_label(it)),
+        while_token: node.while_token,
+        cond: Box::new(f.fold_expr(*node.cond)),
+        body: f.fold_block(node.body),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_expr_yield<F>(f: &mut F, node: ExprYield) -> ExprYield
+where
+    F: Fold + ?Sized,
+{
+    ExprYield {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        yield_token: node.yield_token,
+        expr: (node.expr).map(|it| Box::new(f.fold_expr(*it))),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_field<F>(f: &mut F, node: Field) -> Field
+where
+    F: Fold + ?Sized,
+{
+    Field {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        mutability: f.fold_field_mutability(node.mutability),
+        ident: (node.ident).map(|it| f.fold_ident(it)),
+        colon_token: node.colon_token,
+        ty: f.fold_type(node.ty),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_field_mutability<F>(f: &mut F, node: FieldMutability) -> FieldMutability
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        FieldMutability::None => FieldMutability::None,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_field_pat<F>(f: &mut F, node: FieldPat) -> FieldPat
+where
+    F: Fold + ?Sized,
+{
+    FieldPat {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        member: f.fold_member(node.member),
+        colon_token: node.colon_token,
+        pat: Box::new(f.fold_pat(*node.pat)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_field_value<F>(f: &mut F, node: FieldValue) -> FieldValue
+where
+    F: Fold + ?Sized,
+{
+    FieldValue {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        member: f.fold_member(node.member),
+        colon_token: node.colon_token,
+        expr: f.fold_expr(node.expr),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_fields<F>(f: &mut F, node: Fields) -> Fields
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Fields::Named(_binding_0) => Fields::Named(f.fold_fields_named(_binding_0)),
+        Fields::Unnamed(_binding_0) => Fields::Unnamed(f.fold_fields_unnamed(_binding_0)),
+        Fields::Unit => Fields::Unit,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_fields_named<F>(f: &mut F, node: FieldsNamed) -> FieldsNamed
+where
+    F: Fold + ?Sized,
+{
+    FieldsNamed {
+        brace_token: node.brace_token,
+        named: FoldHelper::lift(node.named, |it| f.fold_field(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_fields_unnamed<F>(f: &mut F, node: FieldsUnnamed) -> FieldsUnnamed
+where
+    F: Fold + ?Sized,
+{
+    FieldsUnnamed {
+        paren_token: node.paren_token,
+        unnamed: FoldHelper::lift(node.unnamed, |it| f.fold_field(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_file<F>(f: &mut F, node: File) -> File
+where
+    F: Fold + ?Sized,
+{
+    File {
+        shebang: node.shebang,
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        items: FoldHelper::lift(node.items, |it| f.fold_item(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_fn_arg<F>(f: &mut F, node: FnArg) -> FnArg
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        FnArg::Receiver(_binding_0) => FnArg::Receiver(f.fold_receiver(_binding_0)),
+        FnArg::Typed(_binding_0) => FnArg::Typed(f.fold_pat_type(_binding_0)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_foreign_item<F>(f: &mut F, node: ForeignItem) -> ForeignItem
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        ForeignItem::Fn(_binding_0) => {
+            ForeignItem::Fn(f.fold_foreign_item_fn(_binding_0))
+        }
+        ForeignItem::Static(_binding_0) => {
+            ForeignItem::Static(f.fold_foreign_item_static(_binding_0))
+        }
+        ForeignItem::Type(_binding_0) => {
+            ForeignItem::Type(f.fold_foreign_item_type(_binding_0))
+        }
+        ForeignItem::Macro(_binding_0) => {
+            ForeignItem::Macro(f.fold_foreign_item_macro(_binding_0))
+        }
+        ForeignItem::Verbatim(_binding_0) => ForeignItem::Verbatim(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_foreign_item_fn<F>(f: &mut F, node: ForeignItemFn) -> ForeignItemFn
+where
+    F: Fold + ?Sized,
+{
+    ForeignItemFn {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        sig: f.fold_signature(node.sig),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_foreign_item_macro<F>(f: &mut F, node: ForeignItemMacro) -> ForeignItemMacro
+where
+    F: Fold + ?Sized,
+{
+    ForeignItemMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        mac: f.fold_macro(node.mac),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_foreign_item_static<F>(
+    f: &mut F,
+    node: ForeignItemStatic,
+) -> ForeignItemStatic
+where
+    F: Fold + ?Sized,
+{
+    ForeignItemStatic {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        static_token: node.static_token,
+        mutability: f.fold_static_mutability(node.mutability),
+        ident: f.fold_ident(node.ident),
+        colon_token: node.colon_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_foreign_item_type<F>(f: &mut F, node: ForeignItemType) -> ForeignItemType
+where
+    F: Fold + ?Sized,
+{
+    ForeignItemType {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        type_token: node.type_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_generic_argument<F>(f: &mut F, node: GenericArgument) -> GenericArgument
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        GenericArgument::Lifetime(_binding_0) => {
+            GenericArgument::Lifetime(f.fold_lifetime(_binding_0))
+        }
+        GenericArgument::Type(_binding_0) => {
+            GenericArgument::Type(f.fold_type(_binding_0))
+        }
+        GenericArgument::Const(_binding_0) => {
+            GenericArgument::Const(f.fold_expr(_binding_0))
+        }
+        GenericArgument::AssocType(_binding_0) => {
+            GenericArgument::AssocType(f.fold_assoc_type(_binding_0))
+        }
+        GenericArgument::AssocConst(_binding_0) => {
+            GenericArgument::AssocConst(f.fold_assoc_const(_binding_0))
+        }
+        GenericArgument::Constraint(_binding_0) => {
+            GenericArgument::Constraint(f.fold_constraint(_binding_0))
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_generic_param<F>(f: &mut F, node: GenericParam) -> GenericParam
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        GenericParam::Lifetime(_binding_0) => {
+            GenericParam::Lifetime(f.fold_lifetime_param(_binding_0))
+        }
+        GenericParam::Type(_binding_0) => {
+            GenericParam::Type(f.fold_type_param(_binding_0))
+        }
+        GenericParam::Const(_binding_0) => {
+            GenericParam::Const(f.fold_const_param(_binding_0))
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_generics<F>(f: &mut F, node: Generics) -> Generics
+where
+    F: Fold + ?Sized,
+{
+    Generics {
+        lt_token: node.lt_token,
+        params: FoldHelper::lift(node.params, |it| f.fold_generic_param(it)),
+        gt_token: node.gt_token,
+        where_clause: (node.where_clause).map(|it| f.fold_where_clause(it)),
+    }
+}
+pub fn fold_ident<F>(f: &mut F, node: Ident) -> Ident
+where
+    F: Fold + ?Sized,
+{
+    let mut node = node;
+    let span = f.fold_span(node.span());
+    node.set_span(span);
+    node
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_item<F>(f: &mut F, node: ImplItem) -> ImplItem
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        ImplItem::Const(_binding_0) => {
+            ImplItem::Const(f.fold_impl_item_const(_binding_0))
+        }
+        ImplItem::Fn(_binding_0) => ImplItem::Fn(f.fold_impl_item_fn(_binding_0)),
+        ImplItem::Type(_binding_0) => ImplItem::Type(f.fold_impl_item_type(_binding_0)),
+        ImplItem::Macro(_binding_0) => {
+            ImplItem::Macro(f.fold_impl_item_macro(_binding_0))
+        }
+        ImplItem::Verbatim(_binding_0) => ImplItem::Verbatim(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_item_const<F>(f: &mut F, node: ImplItemConst) -> ImplItemConst
+where
+    F: Fold + ?Sized,
+{
+    ImplItemConst {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        defaultness: node.defaultness,
+        const_token: node.const_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        colon_token: node.colon_token,
+        ty: f.fold_type(node.ty),
+        eq_token: node.eq_token,
+        expr: f.fold_expr(node.expr),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_item_fn<F>(f: &mut F, node: ImplItemFn) -> ImplItemFn
+where
+    F: Fold + ?Sized,
+{
+    ImplItemFn {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        defaultness: node.defaultness,
+        sig: f.fold_signature(node.sig),
+        block: f.fold_block(node.block),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_item_macro<F>(f: &mut F, node: ImplItemMacro) -> ImplItemMacro
+where
+    F: Fold + ?Sized,
+{
+    ImplItemMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        mac: f.fold_macro(node.mac),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_item_type<F>(f: &mut F, node: ImplItemType) -> ImplItemType
+where
+    F: Fold + ?Sized,
+{
+    ImplItemType {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        defaultness: node.defaultness,
+        type_token: node.type_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        eq_token: node.eq_token,
+        ty: f.fold_type(node.ty),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_impl_restriction<F>(f: &mut F, node: ImplRestriction) -> ImplRestriction
+where
+    F: Fold + ?Sized,
+{
+    match node {}
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_index<F>(f: &mut F, node: Index) -> Index
+where
+    F: Fold + ?Sized,
+{
+    Index {
+        index: node.index,
+        span: f.fold_span(node.span),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item<F>(f: &mut F, node: Item) -> Item
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Item::Const(_binding_0) => Item::Const(f.fold_item_const(_binding_0)),
+        Item::Enum(_binding_0) => Item::Enum(f.fold_item_enum(_binding_0)),
+        Item::ExternCrate(_binding_0) => {
+            Item::ExternCrate(f.fold_item_extern_crate(_binding_0))
+        }
+        Item::Fn(_binding_0) => Item::Fn(f.fold_item_fn(_binding_0)),
+        Item::ForeignMod(_binding_0) => {
+            Item::ForeignMod(f.fold_item_foreign_mod(_binding_0))
+        }
+        Item::Impl(_binding_0) => Item::Impl(f.fold_item_impl(_binding_0)),
+        Item::Macro(_binding_0) => Item::Macro(f.fold_item_macro(_binding_0)),
+        Item::Mod(_binding_0) => Item::Mod(f.fold_item_mod(_binding_0)),
+        Item::Static(_binding_0) => Item::Static(f.fold_item_static(_binding_0)),
+        Item::Struct(_binding_0) => Item::Struct(f.fold_item_struct(_binding_0)),
+        Item::Trait(_binding_0) => Item::Trait(f.fold_item_trait(_binding_0)),
+        Item::TraitAlias(_binding_0) => {
+            Item::TraitAlias(f.fold_item_trait_alias(_binding_0))
+        }
+        Item::Type(_binding_0) => Item::Type(f.fold_item_type(_binding_0)),
+        Item::Union(_binding_0) => Item::Union(f.fold_item_union(_binding_0)),
+        Item::Use(_binding_0) => Item::Use(f.fold_item_use(_binding_0)),
+        Item::Verbatim(_binding_0) => Item::Verbatim(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_const<F>(f: &mut F, node: ItemConst) -> ItemConst
+where
+    F: Fold + ?Sized,
+{
+    ItemConst {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        const_token: node.const_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        colon_token: node.colon_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+        eq_token: node.eq_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_enum<F>(f: &mut F, node: ItemEnum) -> ItemEnum
+where
+    F: Fold + ?Sized,
+{
+    ItemEnum {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        enum_token: node.enum_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        brace_token: node.brace_token,
+        variants: FoldHelper::lift(node.variants, |it| f.fold_variant(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_extern_crate<F>(f: &mut F, node: ItemExternCrate) -> ItemExternCrate
+where
+    F: Fold + ?Sized,
+{
+    ItemExternCrate {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        extern_token: node.extern_token,
+        crate_token: node.crate_token,
+        ident: f.fold_ident(node.ident),
+        rename: (node.rename).map(|it| ((it).0, f.fold_ident((it).1))),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_fn<F>(f: &mut F, node: ItemFn) -> ItemFn
+where
+    F: Fold + ?Sized,
+{
+    ItemFn {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        sig: f.fold_signature(node.sig),
+        block: Box::new(f.fold_block(*node.block)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_foreign_mod<F>(f: &mut F, node: ItemForeignMod) -> ItemForeignMod
+where
+    F: Fold + ?Sized,
+{
+    ItemForeignMod {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        unsafety: node.unsafety,
+        abi: f.fold_abi(node.abi),
+        brace_token: node.brace_token,
+        items: FoldHelper::lift(node.items, |it| f.fold_foreign_item(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_impl<F>(f: &mut F, node: ItemImpl) -> ItemImpl
+where
+    F: Fold + ?Sized,
+{
+    ItemImpl {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        defaultness: node.defaultness,
+        unsafety: node.unsafety,
+        impl_token: node.impl_token,
+        generics: f.fold_generics(node.generics),
+        trait_: (node.trait_).map(|it| ((it).0, f.fold_path((it).1), (it).2)),
+        self_ty: Box::new(f.fold_type(*node.self_ty)),
+        brace_token: node.brace_token,
+        items: FoldHelper::lift(node.items, |it| f.fold_impl_item(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_macro<F>(f: &mut F, node: ItemMacro) -> ItemMacro
+where
+    F: Fold + ?Sized,
+{
+    ItemMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        ident: (node.ident).map(|it| f.fold_ident(it)),
+        mac: f.fold_macro(node.mac),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_mod<F>(f: &mut F, node: ItemMod) -> ItemMod
+where
+    F: Fold + ?Sized,
+{
+    ItemMod {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        unsafety: node.unsafety,
+        mod_token: node.mod_token,
+        ident: f.fold_ident(node.ident),
+        content: (node.content)
+            .map(|it| ((it).0, FoldHelper::lift((it).1, |it| f.fold_item(it)))),
+        semi: node.semi,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_static<F>(f: &mut F, node: ItemStatic) -> ItemStatic
+where
+    F: Fold + ?Sized,
+{
+    ItemStatic {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        static_token: node.static_token,
+        mutability: f.fold_static_mutability(node.mutability),
+        ident: f.fold_ident(node.ident),
+        colon_token: node.colon_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+        eq_token: node.eq_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_struct<F>(f: &mut F, node: ItemStruct) -> ItemStruct
+where
+    F: Fold + ?Sized,
+{
+    ItemStruct {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        struct_token: node.struct_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        fields: f.fold_fields(node.fields),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_trait<F>(f: &mut F, node: ItemTrait) -> ItemTrait
+where
+    F: Fold + ?Sized,
+{
+    ItemTrait {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        unsafety: node.unsafety,
+        auto_token: node.auto_token,
+        restriction: (node.restriction).map(|it| f.fold_impl_restriction(it)),
+        trait_token: node.trait_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        colon_token: node.colon_token,
+        supertraits: FoldHelper::lift(
+            node.supertraits,
+            |it| f.fold_type_param_bound(it),
+        ),
+        brace_token: node.brace_token,
+        items: FoldHelper::lift(node.items, |it| f.fold_trait_item(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_trait_alias<F>(f: &mut F, node: ItemTraitAlias) -> ItemTraitAlias
+where
+    F: Fold + ?Sized,
+{
+    ItemTraitAlias {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        trait_token: node.trait_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        eq_token: node.eq_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_type<F>(f: &mut F, node: ItemType) -> ItemType
+where
+    F: Fold + ?Sized,
+{
+    ItemType {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        type_token: node.type_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        eq_token: node.eq_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_union<F>(f: &mut F, node: ItemUnion) -> ItemUnion
+where
+    F: Fold + ?Sized,
+{
+    ItemUnion {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        union_token: node.union_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        fields: f.fold_fields_named(node.fields),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_item_use<F>(f: &mut F, node: ItemUse) -> ItemUse
+where
+    F: Fold + ?Sized,
+{
+    ItemUse {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        vis: f.fold_visibility(node.vis),
+        use_token: node.use_token,
+        leading_colon: node.leading_colon,
+        tree: f.fold_use_tree(node.tree),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_label<F>(f: &mut F, node: Label) -> Label
+where
+    F: Fold + ?Sized,
+{
+    Label {
+        name: f.fold_lifetime(node.name),
+        colon_token: node.colon_token,
+    }
+}
+pub fn fold_lifetime<F>(f: &mut F, node: Lifetime) -> Lifetime
+where
+    F: Fold + ?Sized,
+{
+    Lifetime {
+        apostrophe: f.fold_span(node.apostrophe),
+        ident: f.fold_ident(node.ident),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_lifetime_param<F>(f: &mut F, node: LifetimeParam) -> LifetimeParam
+where
+    F: Fold + ?Sized,
+{
+    LifetimeParam {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        lifetime: f.fold_lifetime(node.lifetime),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_lifetime(it)),
+    }
+}
+pub fn fold_lit<F>(f: &mut F, node: Lit) -> Lit
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Lit::Str(_binding_0) => Lit::Str(f.fold_lit_str(_binding_0)),
+        Lit::ByteStr(_binding_0) => Lit::ByteStr(f.fold_lit_byte_str(_binding_0)),
+        Lit::Byte(_binding_0) => Lit::Byte(f.fold_lit_byte(_binding_0)),
+        Lit::Char(_binding_0) => Lit::Char(f.fold_lit_char(_binding_0)),
+        Lit::Int(_binding_0) => Lit::Int(f.fold_lit_int(_binding_0)),
+        Lit::Float(_binding_0) => Lit::Float(f.fold_lit_float(_binding_0)),
+        Lit::Bool(_binding_0) => Lit::Bool(f.fold_lit_bool(_binding_0)),
+        Lit::Verbatim(_binding_0) => Lit::Verbatim(_binding_0),
+    }
+}
+pub fn fold_lit_bool<F>(f: &mut F, node: LitBool) -> LitBool
+where
+    F: Fold + ?Sized,
+{
+    LitBool {
+        value: node.value,
+        span: f.fold_span(node.span),
+    }
+}
+pub fn fold_lit_byte<F>(f: &mut F, node: LitByte) -> LitByte
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+pub fn fold_lit_byte_str<F>(f: &mut F, node: LitByteStr) -> LitByteStr
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+pub fn fold_lit_char<F>(f: &mut F, node: LitChar) -> LitChar
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+pub fn fold_lit_float<F>(f: &mut F, node: LitFloat) -> LitFloat
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+pub fn fold_lit_int<F>(f: &mut F, node: LitInt) -> LitInt
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+pub fn fold_lit_str<F>(f: &mut F, node: LitStr) -> LitStr
+where
+    F: Fold + ?Sized,
+{
+    let span = f.fold_span(node.span());
+    let mut node = node;
+    node.set_span(span);
+    node
+}
+#[cfg(feature = "full")]
+pub fn fold_local<F>(f: &mut F, node: Local) -> Local
+where
+    F: Fold + ?Sized,
+{
+    Local {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        let_token: node.let_token,
+        pat: f.fold_pat(node.pat),
+        init: (node.init).map(|it| f.fold_local_init(it)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_local_init<F>(f: &mut F, node: LocalInit) -> LocalInit
+where
+    F: Fold + ?Sized,
+{
+    LocalInit {
+        eq_token: node.eq_token,
+        expr: Box::new(f.fold_expr(*node.expr)),
+        diverge: (node.diverge).map(|it| ((it).0, Box::new(f.fold_expr(*(it).1)))),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_macro<F>(f: &mut F, node: Macro) -> Macro
+where
+    F: Fold + ?Sized,
+{
+    Macro {
+        path: f.fold_path(node.path),
+        bang_token: node.bang_token,
+        delimiter: f.fold_macro_delimiter(node.delimiter),
+        tokens: node.tokens,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_macro_delimiter<F>(f: &mut F, node: MacroDelimiter) -> MacroDelimiter
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        MacroDelimiter::Paren(_binding_0) => MacroDelimiter::Paren(_binding_0),
+        MacroDelimiter::Brace(_binding_0) => MacroDelimiter::Brace(_binding_0),
+        MacroDelimiter::Bracket(_binding_0) => MacroDelimiter::Bracket(_binding_0),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_member<F>(f: &mut F, node: Member) -> Member
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Member::Named(_binding_0) => Member::Named(f.fold_ident(_binding_0)),
+        Member::Unnamed(_binding_0) => Member::Unnamed(f.fold_index(_binding_0)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_meta<F>(f: &mut F, node: Meta) -> Meta
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Meta::Path(_binding_0) => Meta::Path(f.fold_path(_binding_0)),
+        Meta::List(_binding_0) => Meta::List(f.fold_meta_list(_binding_0)),
+        Meta::NameValue(_binding_0) => {
+            Meta::NameValue(f.fold_meta_name_value(_binding_0))
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_meta_list<F>(f: &mut F, node: MetaList) -> MetaList
+where
+    F: Fold + ?Sized,
+{
+    MetaList {
+        path: f.fold_path(node.path),
+        delimiter: f.fold_macro_delimiter(node.delimiter),
+        tokens: node.tokens,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_meta_name_value<F>(f: &mut F, node: MetaNameValue) -> MetaNameValue
+where
+    F: Fold + ?Sized,
+{
+    MetaNameValue {
+        path: f.fold_path(node.path),
+        eq_token: node.eq_token,
+        value: f.fold_expr(node.value),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_parenthesized_generic_arguments<F>(
+    f: &mut F,
+    node: ParenthesizedGenericArguments,
+) -> ParenthesizedGenericArguments
+where
+    F: Fold + ?Sized,
+{
+    ParenthesizedGenericArguments {
+        paren_token: node.paren_token,
+        inputs: FoldHelper::lift(node.inputs, |it| f.fold_type(it)),
+        output: f.fold_return_type(node.output),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat<F>(f: &mut F, node: Pat) -> Pat
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Pat::Const(_binding_0) => Pat::Const(f.fold_expr_const(_binding_0)),
+        Pat::Ident(_binding_0) => Pat::Ident(f.fold_pat_ident(_binding_0)),
+        Pat::Lit(_binding_0) => Pat::Lit(f.fold_expr_lit(_binding_0)),
+        Pat::Macro(_binding_0) => Pat::Macro(f.fold_expr_macro(_binding_0)),
+        Pat::Or(_binding_0) => Pat::Or(f.fold_pat_or(_binding_0)),
+        Pat::Paren(_binding_0) => Pat::Paren(f.fold_pat_paren(_binding_0)),
+        Pat::Path(_binding_0) => Pat::Path(f.fold_expr_path(_binding_0)),
+        Pat::Range(_binding_0) => Pat::Range(f.fold_expr_range(_binding_0)),
+        Pat::Reference(_binding_0) => Pat::Reference(f.fold_pat_reference(_binding_0)),
+        Pat::Rest(_binding_0) => Pat::Rest(f.fold_pat_rest(_binding_0)),
+        Pat::Slice(_binding_0) => Pat::Slice(f.fold_pat_slice(_binding_0)),
+        Pat::Struct(_binding_0) => Pat::Struct(f.fold_pat_struct(_binding_0)),
+        Pat::Tuple(_binding_0) => Pat::Tuple(f.fold_pat_tuple(_binding_0)),
+        Pat::TupleStruct(_binding_0) => {
+            Pat::TupleStruct(f.fold_pat_tuple_struct(_binding_0))
+        }
+        Pat::Type(_binding_0) => Pat::Type(f.fold_pat_type(_binding_0)),
+        Pat::Verbatim(_binding_0) => Pat::Verbatim(_binding_0),
+        Pat::Wild(_binding_0) => Pat::Wild(f.fold_pat_wild(_binding_0)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_ident<F>(f: &mut F, node: PatIdent) -> PatIdent
+where
+    F: Fold + ?Sized,
+{
+    PatIdent {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        by_ref: node.by_ref,
+        mutability: node.mutability,
+        ident: f.fold_ident(node.ident),
+        subpat: (node.subpat).map(|it| ((it).0, Box::new(f.fold_pat(*(it).1)))),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_or<F>(f: &mut F, node: PatOr) -> PatOr
+where
+    F: Fold + ?Sized,
+{
+    PatOr {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        leading_vert: node.leading_vert,
+        cases: FoldHelper::lift(node.cases, |it| f.fold_pat(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_paren<F>(f: &mut F, node: PatParen) -> PatParen
+where
+    F: Fold + ?Sized,
+{
+    PatParen {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        paren_token: node.paren_token,
+        pat: Box::new(f.fold_pat(*node.pat)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_reference<F>(f: &mut F, node: PatReference) -> PatReference
+where
+    F: Fold + ?Sized,
+{
+    PatReference {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        and_token: node.and_token,
+        mutability: node.mutability,
+        pat: Box::new(f.fold_pat(*node.pat)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_rest<F>(f: &mut F, node: PatRest) -> PatRest
+where
+    F: Fold + ?Sized,
+{
+    PatRest {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        dot2_token: node.dot2_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_slice<F>(f: &mut F, node: PatSlice) -> PatSlice
+where
+    F: Fold + ?Sized,
+{
+    PatSlice {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        bracket_token: node.bracket_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_pat(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_struct<F>(f: &mut F, node: PatStruct) -> PatStruct
+where
+    F: Fold + ?Sized,
+{
+    PatStruct {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        qself: (node.qself).map(|it| f.fold_qself(it)),
+        path: f.fold_path(node.path),
+        brace_token: node.brace_token,
+        fields: FoldHelper::lift(node.fields, |it| f.fold_field_pat(it)),
+        rest: (node.rest).map(|it| f.fold_pat_rest(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_tuple<F>(f: &mut F, node: PatTuple) -> PatTuple
+where
+    F: Fold + ?Sized,
+{
+    PatTuple {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        paren_token: node.paren_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_pat(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_tuple_struct<F>(f: &mut F, node: PatTupleStruct) -> PatTupleStruct
+where
+    F: Fold + ?Sized,
+{
+    PatTupleStruct {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        qself: (node.qself).map(|it| f.fold_qself(it)),
+        path: f.fold_path(node.path),
+        paren_token: node.paren_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_pat(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_type<F>(f: &mut F, node: PatType) -> PatType
+where
+    F: Fold + ?Sized,
+{
+    PatType {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        pat: Box::new(f.fold_pat(*node.pat)),
+        colon_token: node.colon_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_pat_wild<F>(f: &mut F, node: PatWild) -> PatWild
+where
+    F: Fold + ?Sized,
+{
+    PatWild {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        underscore_token: node.underscore_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_path<F>(f: &mut F, node: Path) -> Path
+where
+    F: Fold + ?Sized,
+{
+    Path {
+        leading_colon: node.leading_colon,
+        segments: FoldHelper::lift(node.segments, |it| f.fold_path_segment(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_path_arguments<F>(f: &mut F, node: PathArguments) -> PathArguments
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        PathArguments::None => PathArguments::None,
+        PathArguments::AngleBracketed(_binding_0) => {
+            PathArguments::AngleBracketed(
+                f.fold_angle_bracketed_generic_arguments(_binding_0),
+            )
+        }
+        PathArguments::Parenthesized(_binding_0) => {
+            PathArguments::Parenthesized(
+                f.fold_parenthesized_generic_arguments(_binding_0),
+            )
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_path_segment<F>(f: &mut F, node: PathSegment) -> PathSegment
+where
+    F: Fold + ?Sized,
+{
+    PathSegment {
+        ident: f.fold_ident(node.ident),
+        arguments: f.fold_path_arguments(node.arguments),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_predicate_lifetime<F>(
+    f: &mut F,
+    node: PredicateLifetime,
+) -> PredicateLifetime
+where
+    F: Fold + ?Sized,
+{
+    PredicateLifetime {
+        lifetime: f.fold_lifetime(node.lifetime),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_lifetime(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_predicate_type<F>(f: &mut F, node: PredicateType) -> PredicateType
+where
+    F: Fold + ?Sized,
+{
+    PredicateType {
+        lifetimes: (node.lifetimes).map(|it| f.fold_bound_lifetimes(it)),
+        bounded_ty: f.fold_type(node.bounded_ty),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_qself<F>(f: &mut F, node: QSelf) -> QSelf
+where
+    F: Fold + ?Sized,
+{
+    QSelf {
+        lt_token: node.lt_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+        position: node.position,
+        as_token: node.as_token,
+        gt_token: node.gt_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_range_limits<F>(f: &mut F, node: RangeLimits) -> RangeLimits
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        RangeLimits::HalfOpen(_binding_0) => RangeLimits::HalfOpen(_binding_0),
+        RangeLimits::Closed(_binding_0) => RangeLimits::Closed(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_receiver<F>(f: &mut F, node: Receiver) -> Receiver
+where
+    F: Fold + ?Sized,
+{
+    Receiver {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        reference: (node.reference)
+            .map(|it| ((it).0, ((it).1).map(|it| f.fold_lifetime(it)))),
+        mutability: node.mutability,
+        self_token: node.self_token,
+        colon_token: node.colon_token,
+        ty: Box::new(f.fold_type(*node.ty)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_return_type<F>(f: &mut F, node: ReturnType) -> ReturnType
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        ReturnType::Default => ReturnType::Default,
+        ReturnType::Type(_binding_0, _binding_1) => {
+            ReturnType::Type(_binding_0, Box::new(f.fold_type(*_binding_1)))
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_signature<F>(f: &mut F, node: Signature) -> Signature
+where
+    F: Fold + ?Sized,
+{
+    Signature {
+        constness: node.constness,
+        asyncness: node.asyncness,
+        unsafety: node.unsafety,
+        abi: (node.abi).map(|it| f.fold_abi(it)),
+        fn_token: node.fn_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        paren_token: node.paren_token,
+        inputs: FoldHelper::lift(node.inputs, |it| f.fold_fn_arg(it)),
+        variadic: (node.variadic).map(|it| f.fold_variadic(it)),
+        output: f.fold_return_type(node.output),
+    }
+}
+pub fn fold_span<F>(f: &mut F, node: Span) -> Span
+where
+    F: Fold + ?Sized,
+{
+    node
+}
+#[cfg(feature = "full")]
+pub fn fold_static_mutability<F>(f: &mut F, node: StaticMutability) -> StaticMutability
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        StaticMutability::Mut(_binding_0) => StaticMutability::Mut(_binding_0),
+        StaticMutability::None => StaticMutability::None,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_stmt<F>(f: &mut F, node: Stmt) -> Stmt
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Stmt::Local(_binding_0) => Stmt::Local(f.fold_local(_binding_0)),
+        Stmt::Item(_binding_0) => Stmt::Item(f.fold_item(_binding_0)),
+        Stmt::Expr(_binding_0, _binding_1) => {
+            Stmt::Expr(f.fold_expr(_binding_0), _binding_1)
+        }
+        Stmt::Macro(_binding_0) => Stmt::Macro(f.fold_stmt_macro(_binding_0)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_stmt_macro<F>(f: &mut F, node: StmtMacro) -> StmtMacro
+where
+    F: Fold + ?Sized,
+{
+    StmtMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        mac: f.fold_macro(node.mac),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_trait_bound<F>(f: &mut F, node: TraitBound) -> TraitBound
+where
+    F: Fold + ?Sized,
+{
+    TraitBound {
+        paren_token: node.paren_token,
+        modifier: f.fold_trait_bound_modifier(node.modifier),
+        lifetimes: (node.lifetimes).map(|it| f.fold_bound_lifetimes(it)),
+        path: f.fold_path(node.path),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_trait_bound_modifier<F>(
+    f: &mut F,
+    node: TraitBoundModifier,
+) -> TraitBoundModifier
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        TraitBoundModifier::None => TraitBoundModifier::None,
+        TraitBoundModifier::Maybe(_binding_0) => TraitBoundModifier::Maybe(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_trait_item<F>(f: &mut F, node: TraitItem) -> TraitItem
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        TraitItem::Const(_binding_0) => {
+            TraitItem::Const(f.fold_trait_item_const(_binding_0))
+        }
+        TraitItem::Fn(_binding_0) => TraitItem::Fn(f.fold_trait_item_fn(_binding_0)),
+        TraitItem::Type(_binding_0) => {
+            TraitItem::Type(f.fold_trait_item_type(_binding_0))
+        }
+        TraitItem::Macro(_binding_0) => {
+            TraitItem::Macro(f.fold_trait_item_macro(_binding_0))
+        }
+        TraitItem::Verbatim(_binding_0) => TraitItem::Verbatim(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_trait_item_const<F>(f: &mut F, node: TraitItemConst) -> TraitItemConst
+where
+    F: Fold + ?Sized,
+{
+    TraitItemConst {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        const_token: node.const_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        colon_token: node.colon_token,
+        ty: f.fold_type(node.ty),
+        default: (node.default).map(|it| ((it).0, f.fold_expr((it).1))),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_trait_item_fn<F>(f: &mut F, node: TraitItemFn) -> TraitItemFn
+where
+    F: Fold + ?Sized,
+{
+    TraitItemFn {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        sig: f.fold_signature(node.sig),
+        default: (node.default).map(|it| f.fold_block(it)),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_trait_item_macro<F>(f: &mut F, node: TraitItemMacro) -> TraitItemMacro
+where
+    F: Fold + ?Sized,
+{
+    TraitItemMacro {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        mac: f.fold_macro(node.mac),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_trait_item_type<F>(f: &mut F, node: TraitItemType) -> TraitItemType
+where
+    F: Fold + ?Sized,
+{
+    TraitItemType {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        type_token: node.type_token,
+        ident: f.fold_ident(node.ident),
+        generics: f.fold_generics(node.generics),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+        default: (node.default).map(|it| ((it).0, f.fold_type((it).1))),
+        semi_token: node.semi_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type<F>(f: &mut F, node: Type) -> Type
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Type::Array(_binding_0) => Type::Array(f.fold_type_array(_binding_0)),
+        Type::BareFn(_binding_0) => Type::BareFn(f.fold_type_bare_fn(_binding_0)),
+        Type::Group(_binding_0) => Type::Group(f.fold_type_group(_binding_0)),
+        Type::ImplTrait(_binding_0) => {
+            Type::ImplTrait(f.fold_type_impl_trait(_binding_0))
+        }
+        Type::Infer(_binding_0) => Type::Infer(f.fold_type_infer(_binding_0)),
+        Type::Macro(_binding_0) => Type::Macro(f.fold_type_macro(_binding_0)),
+        Type::Never(_binding_0) => Type::Never(f.fold_type_never(_binding_0)),
+        Type::Paren(_binding_0) => Type::Paren(f.fold_type_paren(_binding_0)),
+        Type::Path(_binding_0) => Type::Path(f.fold_type_path(_binding_0)),
+        Type::Ptr(_binding_0) => Type::Ptr(f.fold_type_ptr(_binding_0)),
+        Type::Reference(_binding_0) => Type::Reference(f.fold_type_reference(_binding_0)),
+        Type::Slice(_binding_0) => Type::Slice(f.fold_type_slice(_binding_0)),
+        Type::TraitObject(_binding_0) => {
+            Type::TraitObject(f.fold_type_trait_object(_binding_0))
+        }
+        Type::Tuple(_binding_0) => Type::Tuple(f.fold_type_tuple(_binding_0)),
+        Type::Verbatim(_binding_0) => Type::Verbatim(_binding_0),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_array<F>(f: &mut F, node: TypeArray) -> TypeArray
+where
+    F: Fold + ?Sized,
+{
+    TypeArray {
+        bracket_token: node.bracket_token,
+        elem: Box::new(f.fold_type(*node.elem)),
+        semi_token: node.semi_token,
+        len: f.fold_expr(node.len),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_bare_fn<F>(f: &mut F, node: TypeBareFn) -> TypeBareFn
+where
+    F: Fold + ?Sized,
+{
+    TypeBareFn {
+        lifetimes: (node.lifetimes).map(|it| f.fold_bound_lifetimes(it)),
+        unsafety: node.unsafety,
+        abi: (node.abi).map(|it| f.fold_abi(it)),
+        fn_token: node.fn_token,
+        paren_token: node.paren_token,
+        inputs: FoldHelper::lift(node.inputs, |it| f.fold_bare_fn_arg(it)),
+        variadic: (node.variadic).map(|it| f.fold_bare_variadic(it)),
+        output: f.fold_return_type(node.output),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_group<F>(f: &mut F, node: TypeGroup) -> TypeGroup
+where
+    F: Fold + ?Sized,
+{
+    TypeGroup {
+        group_token: node.group_token,
+        elem: Box::new(f.fold_type(*node.elem)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_impl_trait<F>(f: &mut F, node: TypeImplTrait) -> TypeImplTrait
+where
+    F: Fold + ?Sized,
+{
+    TypeImplTrait {
+        impl_token: node.impl_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_infer<F>(f: &mut F, node: TypeInfer) -> TypeInfer
+where
+    F: Fold + ?Sized,
+{
+    TypeInfer {
+        underscore_token: node.underscore_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_macro<F>(f: &mut F, node: TypeMacro) -> TypeMacro
+where
+    F: Fold + ?Sized,
+{
+    TypeMacro {
+        mac: f.fold_macro(node.mac),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_never<F>(f: &mut F, node: TypeNever) -> TypeNever
+where
+    F: Fold + ?Sized,
+{
+    TypeNever {
+        bang_token: node.bang_token,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_param<F>(f: &mut F, node: TypeParam) -> TypeParam
+where
+    F: Fold + ?Sized,
+{
+    TypeParam {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        ident: f.fold_ident(node.ident),
+        colon_token: node.colon_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+        eq_token: node.eq_token,
+        default: (node.default).map(|it| f.fold_type(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_param_bound<F>(f: &mut F, node: TypeParamBound) -> TypeParamBound
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        TypeParamBound::Trait(_binding_0) => {
+            TypeParamBound::Trait(f.fold_trait_bound(_binding_0))
+        }
+        TypeParamBound::Lifetime(_binding_0) => {
+            TypeParamBound::Lifetime(f.fold_lifetime(_binding_0))
+        }
+        TypeParamBound::Verbatim(_binding_0) => TypeParamBound::Verbatim(_binding_0),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_paren<F>(f: &mut F, node: TypeParen) -> TypeParen
+where
+    F: Fold + ?Sized,
+{
+    TypeParen {
+        paren_token: node.paren_token,
+        elem: Box::new(f.fold_type(*node.elem)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_path<F>(f: &mut F, node: TypePath) -> TypePath
+where
+    F: Fold + ?Sized,
+{
+    TypePath {
+        qself: (node.qself).map(|it| f.fold_qself(it)),
+        path: f.fold_path(node.path),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_ptr<F>(f: &mut F, node: TypePtr) -> TypePtr
+where
+    F: Fold + ?Sized,
+{
+    TypePtr {
+        star_token: node.star_token,
+        const_token: node.const_token,
+        mutability: node.mutability,
+        elem: Box::new(f.fold_type(*node.elem)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_reference<F>(f: &mut F, node: TypeReference) -> TypeReference
+where
+    F: Fold + ?Sized,
+{
+    TypeReference {
+        and_token: node.and_token,
+        lifetime: (node.lifetime).map(|it| f.fold_lifetime(it)),
+        mutability: node.mutability,
+        elem: Box::new(f.fold_type(*node.elem)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_slice<F>(f: &mut F, node: TypeSlice) -> TypeSlice
+where
+    F: Fold + ?Sized,
+{
+    TypeSlice {
+        bracket_token: node.bracket_token,
+        elem: Box::new(f.fold_type(*node.elem)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_trait_object<F>(f: &mut F, node: TypeTraitObject) -> TypeTraitObject
+where
+    F: Fold + ?Sized,
+{
+    TypeTraitObject {
+        dyn_token: node.dyn_token,
+        bounds: FoldHelper::lift(node.bounds, |it| f.fold_type_param_bound(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_type_tuple<F>(f: &mut F, node: TypeTuple) -> TypeTuple
+where
+    F: Fold + ?Sized,
+{
+    TypeTuple {
+        paren_token: node.paren_token,
+        elems: FoldHelper::lift(node.elems, |it| f.fold_type(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_un_op<F>(f: &mut F, node: UnOp) -> UnOp
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        UnOp::Deref(_binding_0) => UnOp::Deref(_binding_0),
+        UnOp::Not(_binding_0) => UnOp::Not(_binding_0),
+        UnOp::Neg(_binding_0) => UnOp::Neg(_binding_0),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_glob<F>(f: &mut F, node: UseGlob) -> UseGlob
+where
+    F: Fold + ?Sized,
+{
+    UseGlob {
+        star_token: node.star_token,
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_group<F>(f: &mut F, node: UseGroup) -> UseGroup
+where
+    F: Fold + ?Sized,
+{
+    UseGroup {
+        brace_token: node.brace_token,
+        items: FoldHelper::lift(node.items, |it| f.fold_use_tree(it)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_name<F>(f: &mut F, node: UseName) -> UseName
+where
+    F: Fold + ?Sized,
+{
+    UseName {
+        ident: f.fold_ident(node.ident),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_path<F>(f: &mut F, node: UsePath) -> UsePath
+where
+    F: Fold + ?Sized,
+{
+    UsePath {
+        ident: f.fold_ident(node.ident),
+        colon2_token: node.colon2_token,
+        tree: Box::new(f.fold_use_tree(*node.tree)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_rename<F>(f: &mut F, node: UseRename) -> UseRename
+where
+    F: Fold + ?Sized,
+{
+    UseRename {
+        ident: f.fold_ident(node.ident),
+        as_token: node.as_token,
+        rename: f.fold_ident(node.rename),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_use_tree<F>(f: &mut F, node: UseTree) -> UseTree
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        UseTree::Path(_binding_0) => UseTree::Path(f.fold_use_path(_binding_0)),
+        UseTree::Name(_binding_0) => UseTree::Name(f.fold_use_name(_binding_0)),
+        UseTree::Rename(_binding_0) => UseTree::Rename(f.fold_use_rename(_binding_0)),
+        UseTree::Glob(_binding_0) => UseTree::Glob(f.fold_use_glob(_binding_0)),
+        UseTree::Group(_binding_0) => UseTree::Group(f.fold_use_group(_binding_0)),
+    }
+}
+#[cfg(feature = "full")]
+pub fn fold_variadic<F>(f: &mut F, node: Variadic) -> Variadic
+where
+    F: Fold + ?Sized,
+{
+    Variadic {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        pat: (node.pat).map(|it| (Box::new(f.fold_pat(*(it).0)), (it).1)),
+        dots: node.dots,
+        comma: node.comma,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_variant<F>(f: &mut F, node: Variant) -> Variant
+where
+    F: Fold + ?Sized,
+{
+    Variant {
+        attrs: FoldHelper::lift(node.attrs, |it| f.fold_attribute(it)),
+        ident: f.fold_ident(node.ident),
+        fields: f.fold_fields(node.fields),
+        discriminant: (node.discriminant).map(|it| ((it).0, f.fold_expr((it).1))),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_vis_restricted<F>(f: &mut F, node: VisRestricted) -> VisRestricted
+where
+    F: Fold + ?Sized,
+{
+    VisRestricted {
+        pub_token: node.pub_token,
+        paren_token: node.paren_token,
+        in_token: node.in_token,
+        path: Box::new(f.fold_path(*node.path)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_visibility<F>(f: &mut F, node: Visibility) -> Visibility
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        Visibility::Public(_binding_0) => Visibility::Public(_binding_0),
+        Visibility::Restricted(_binding_0) => {
+            Visibility::Restricted(f.fold_vis_restricted(_binding_0))
+        }
+        Visibility::Inherited => Visibility::Inherited,
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_where_clause<F>(f: &mut F, node: WhereClause) -> WhereClause
+where
+    F: Fold + ?Sized,
+{
+    WhereClause {
+        where_token: node.where_token,
+        predicates: FoldHelper::lift(node.predicates, |it| f.fold_where_predicate(it)),
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn fold_where_predicate<F>(f: &mut F, node: WherePredicate) -> WherePredicate
+where
+    F: Fold + ?Sized,
+{
+    match node {
+        WherePredicate::Lifetime(_binding_0) => {
+            WherePredicate::Lifetime(f.fold_predicate_lifetime(_binding_0))
+        }
+        WherePredicate::Type(_binding_0) => {
+            WherePredicate::Type(f.fold_predicate_type(_binding_0))
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/hash.rs b/vendor/syn/src/gen/hash.rs
new file mode 100644
index 0000000..40dfc57
--- /dev/null
+++ b/vendor/syn/src/gen/hash.rs
@@ -0,0 +1,2807 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#[cfg(any(feature = "derive", feature = "full"))]
+use crate::tt::TokenStreamHelper;
+use crate::*;
+use std::hash::{Hash, Hasher};
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Abi {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.name.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for AngleBracketedGenericArguments {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.colon2_token.hash(state);
+        self.args.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Arm {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+        self.guard.hash(state);
+        self.body.hash(state);
+        self.comma.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for AssocConst {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.value.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for AssocType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for AttrStyle {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            AttrStyle::Outer => {
+                state.write_u8(0u8);
+            }
+            AttrStyle::Inner(_) => {
+                state.write_u8(1u8);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Attribute {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.style.hash(state);
+        self.meta.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for BareFnArg {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.name.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for BareVariadic {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.name.hash(state);
+        self.comma.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for BinOp {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            BinOp::Add(_) => {
+                state.write_u8(0u8);
+            }
+            BinOp::Sub(_) => {
+                state.write_u8(1u8);
+            }
+            BinOp::Mul(_) => {
+                state.write_u8(2u8);
+            }
+            BinOp::Div(_) => {
+                state.write_u8(3u8);
+            }
+            BinOp::Rem(_) => {
+                state.write_u8(4u8);
+            }
+            BinOp::And(_) => {
+                state.write_u8(5u8);
+            }
+            BinOp::Or(_) => {
+                state.write_u8(6u8);
+            }
+            BinOp::BitXor(_) => {
+                state.write_u8(7u8);
+            }
+            BinOp::BitAnd(_) => {
+                state.write_u8(8u8);
+            }
+            BinOp::BitOr(_) => {
+                state.write_u8(9u8);
+            }
+            BinOp::Shl(_) => {
+                state.write_u8(10u8);
+            }
+            BinOp::Shr(_) => {
+                state.write_u8(11u8);
+            }
+            BinOp::Eq(_) => {
+                state.write_u8(12u8);
+            }
+            BinOp::Lt(_) => {
+                state.write_u8(13u8);
+            }
+            BinOp::Le(_) => {
+                state.write_u8(14u8);
+            }
+            BinOp::Ne(_) => {
+                state.write_u8(15u8);
+            }
+            BinOp::Ge(_) => {
+                state.write_u8(16u8);
+            }
+            BinOp::Gt(_) => {
+                state.write_u8(17u8);
+            }
+            BinOp::AddAssign(_) => {
+                state.write_u8(18u8);
+            }
+            BinOp::SubAssign(_) => {
+                state.write_u8(19u8);
+            }
+            BinOp::MulAssign(_) => {
+                state.write_u8(20u8);
+            }
+            BinOp::DivAssign(_) => {
+                state.write_u8(21u8);
+            }
+            BinOp::RemAssign(_) => {
+                state.write_u8(22u8);
+            }
+            BinOp::BitXorAssign(_) => {
+                state.write_u8(23u8);
+            }
+            BinOp::BitAndAssign(_) => {
+                state.write_u8(24u8);
+            }
+            BinOp::BitOrAssign(_) => {
+                state.write_u8(25u8);
+            }
+            BinOp::ShlAssign(_) => {
+                state.write_u8(26u8);
+            }
+            BinOp::ShrAssign(_) => {
+                state.write_u8(27u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Block {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.stmts.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for BoundLifetimes {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lifetimes.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ConstParam {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.ty.hash(state);
+        self.eq_token.hash(state);
+        self.default.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Constraint {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Data {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Data::Struct(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Data::Enum(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Data::Union(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for DataEnum {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.variants.hash(state);
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for DataStruct {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.fields.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for DataUnion {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.fields.hash(state);
+    }
+}
+#[cfg(feature = "derive")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for DeriveInput {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.data.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Expr {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            #[cfg(feature = "full")]
+            Expr::Array(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Assign(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Async(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Await(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            Expr::Binary(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Block(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Break(v0) => {
+                state.write_u8(6u8);
+                v0.hash(state);
+            }
+            Expr::Call(v0) => {
+                state.write_u8(7u8);
+                v0.hash(state);
+            }
+            Expr::Cast(v0) => {
+                state.write_u8(8u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Closure(v0) => {
+                state.write_u8(9u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Const(v0) => {
+                state.write_u8(10u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Continue(v0) => {
+                state.write_u8(11u8);
+                v0.hash(state);
+            }
+            Expr::Field(v0) => {
+                state.write_u8(12u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::ForLoop(v0) => {
+                state.write_u8(13u8);
+                v0.hash(state);
+            }
+            Expr::Group(v0) => {
+                state.write_u8(14u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::If(v0) => {
+                state.write_u8(15u8);
+                v0.hash(state);
+            }
+            Expr::Index(v0) => {
+                state.write_u8(16u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Infer(v0) => {
+                state.write_u8(17u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Let(v0) => {
+                state.write_u8(18u8);
+                v0.hash(state);
+            }
+            Expr::Lit(v0) => {
+                state.write_u8(19u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Loop(v0) => {
+                state.write_u8(20u8);
+                v0.hash(state);
+            }
+            Expr::Macro(v0) => {
+                state.write_u8(21u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Match(v0) => {
+                state.write_u8(22u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::MethodCall(v0) => {
+                state.write_u8(23u8);
+                v0.hash(state);
+            }
+            Expr::Paren(v0) => {
+                state.write_u8(24u8);
+                v0.hash(state);
+            }
+            Expr::Path(v0) => {
+                state.write_u8(25u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Range(v0) => {
+                state.write_u8(26u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Reference(v0) => {
+                state.write_u8(27u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Repeat(v0) => {
+                state.write_u8(28u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Return(v0) => {
+                state.write_u8(29u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Struct(v0) => {
+                state.write_u8(30u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Try(v0) => {
+                state.write_u8(31u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::TryBlock(v0) => {
+                state.write_u8(32u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Tuple(v0) => {
+                state.write_u8(33u8);
+                v0.hash(state);
+            }
+            Expr::Unary(v0) => {
+                state.write_u8(34u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Unsafe(v0) => {
+                state.write_u8(35u8);
+                v0.hash(state);
+            }
+            Expr::Verbatim(v0) => {
+                state.write_u8(36u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::While(v0) => {
+                state.write_u8(37u8);
+                v0.hash(state);
+            }
+            #[cfg(feature = "full")]
+            Expr::Yield(v0) => {
+                state.write_u8(38u8);
+                v0.hash(state);
+            }
+            #[cfg(not(feature = "full"))]
+            _ => unreachable!(),
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprArray {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.elems.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprAssign {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.left.hash(state);
+        self.right.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprAsync {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.capture.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprAwait {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.base.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprBinary {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.left.hash(state);
+        self.op.hash(state);
+        self.right.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprBlock {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprBreak {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprCall {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.func.hash(state);
+        self.args.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprCast {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprClosure {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.lifetimes.hash(state);
+        self.constness.hash(state);
+        self.movability.hash(state);
+        self.asyncness.hash(state);
+        self.capture.hash(state);
+        self.inputs.hash(state);
+        self.output.hash(state);
+        self.body.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprConst {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprContinue {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprField {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.base.hash(state);
+        self.member.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprForLoop {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+        self.pat.hash(state);
+        self.expr.hash(state);
+        self.body.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprGroup {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprIf {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.cond.hash(state);
+        self.then_branch.hash(state);
+        self.else_branch.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprIndex {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+        self.index.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprInfer {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprLet {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprLit {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.lit.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprLoop {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+        self.body.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mac.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprMatch {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+        self.arms.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprMethodCall {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.receiver.hash(state);
+        self.method.hash(state);
+        self.turbofish.hash(state);
+        self.args.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprParen {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprPath {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.qself.hash(state);
+        self.path.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprRange {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.start.hash(state);
+        self.limits.hash(state);
+        self.end.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprReference {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mutability.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprRepeat {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+        self.len.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprReturn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprStruct {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.qself.hash(state);
+        self.path.hash(state);
+        self.fields.hash(state);
+        self.dot2_token.hash(state);
+        self.rest.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprTry {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprTryBlock {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprTuple {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.elems.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprUnary {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.op.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprUnsafe {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprWhile {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.label.hash(state);
+        self.cond.hash(state);
+        self.body.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ExprYield {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Field {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.mutability.hash(state);
+        self.ident.hash(state);
+        self.colon_token.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FieldMutability {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            FieldMutability::None => {
+                state.write_u8(0u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FieldPat {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.member.hash(state);
+        self.colon_token.hash(state);
+        self.pat.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FieldValue {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.member.hash(state);
+        self.colon_token.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Fields {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Fields::Named(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Fields::Unnamed(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Fields::Unit => {
+                state.write_u8(2u8);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FieldsNamed {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.named.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FieldsUnnamed {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.unnamed.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for File {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.shebang.hash(state);
+        self.attrs.hash(state);
+        self.items.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for FnArg {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            FnArg::Receiver(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            FnArg::Typed(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ForeignItem {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            ForeignItem::Fn(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            ForeignItem::Static(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            ForeignItem::Type(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            ForeignItem::Macro(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            ForeignItem::Verbatim(v0) => {
+                state.write_u8(4u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ForeignItemFn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.sig.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ForeignItemMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mac.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ForeignItemStatic {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.mutability.hash(state);
+        self.ident.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ForeignItemType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for GenericArgument {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            GenericArgument::Lifetime(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            GenericArgument::Type(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            GenericArgument::Const(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            GenericArgument::AssocType(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            GenericArgument::AssocConst(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            GenericArgument::Constraint(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for GenericParam {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            GenericParam::Lifetime(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            GenericParam::Type(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            GenericParam::Const(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Generics {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lt_token.hash(state);
+        self.params.hash(state);
+        self.gt_token.hash(state);
+        self.where_clause.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplItem {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            ImplItem::Const(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            ImplItem::Fn(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            ImplItem::Type(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            ImplItem::Macro(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            ImplItem::Verbatim(v0) => {
+                state.write_u8(4u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplItemConst {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.defaultness.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplItemFn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.defaultness.hash(state);
+        self.sig.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplItemMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mac.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplItemType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.defaultness.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ImplRestriction {
+    fn hash<H>(&self, _state: &mut H)
+    where
+        H: Hasher,
+    {
+        match *self {}
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Item {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Item::Const(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Item::Enum(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Item::ExternCrate(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            Item::Fn(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            Item::ForeignMod(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            Item::Impl(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+            Item::Macro(v0) => {
+                state.write_u8(6u8);
+                v0.hash(state);
+            }
+            Item::Mod(v0) => {
+                state.write_u8(7u8);
+                v0.hash(state);
+            }
+            Item::Static(v0) => {
+                state.write_u8(8u8);
+                v0.hash(state);
+            }
+            Item::Struct(v0) => {
+                state.write_u8(9u8);
+                v0.hash(state);
+            }
+            Item::Trait(v0) => {
+                state.write_u8(10u8);
+                v0.hash(state);
+            }
+            Item::TraitAlias(v0) => {
+                state.write_u8(11u8);
+                v0.hash(state);
+            }
+            Item::Type(v0) => {
+                state.write_u8(12u8);
+                v0.hash(state);
+            }
+            Item::Union(v0) => {
+                state.write_u8(13u8);
+                v0.hash(state);
+            }
+            Item::Use(v0) => {
+                state.write_u8(14u8);
+                v0.hash(state);
+            }
+            Item::Verbatim(v0) => {
+                state.write_u8(15u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemConst {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemEnum {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.variants.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemExternCrate {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.rename.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemFn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.sig.hash(state);
+        self.block.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemForeignMod {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.unsafety.hash(state);
+        self.abi.hash(state);
+        self.items.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemImpl {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.defaultness.hash(state);
+        self.unsafety.hash(state);
+        self.generics.hash(state);
+        self.trait_.hash(state);
+        self.self_ty.hash(state);
+        self.items.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.mac.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemMod {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.unsafety.hash(state);
+        self.ident.hash(state);
+        self.content.hash(state);
+        self.semi.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemStatic {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.mutability.hash(state);
+        self.ident.hash(state);
+        self.ty.hash(state);
+        self.expr.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemStruct {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.fields.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemTrait {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.unsafety.hash(state);
+        self.auto_token.hash(state);
+        self.restriction.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.colon_token.hash(state);
+        self.supertraits.hash(state);
+        self.items.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemTraitAlias {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemUnion {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.fields.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ItemUse {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.vis.hash(state);
+        self.leading_colon.hash(state);
+        self.tree.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Label {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.name.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for LifetimeParam {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.lifetime.hash(state);
+        self.colon_token.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Lit {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Lit::Str(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Lit::ByteStr(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Lit::Byte(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            Lit::Char(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            Lit::Int(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            Lit::Float(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+            Lit::Bool(v0) => {
+                state.write_u8(6u8);
+                v0.hash(state);
+            }
+            Lit::Verbatim(v0) => {
+                state.write_u8(7u8);
+                v0.to_string().hash(state);
+            }
+        }
+    }
+}
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for LitBool {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.value.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Local {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+        self.init.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for LocalInit {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.expr.hash(state);
+        self.diverge.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Macro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.path.hash(state);
+        self.delimiter.hash(state);
+        TokenStreamHelper(&self.tokens).hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for MacroDelimiter {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            MacroDelimiter::Paren(_) => {
+                state.write_u8(0u8);
+            }
+            MacroDelimiter::Brace(_) => {
+                state.write_u8(1u8);
+            }
+            MacroDelimiter::Bracket(_) => {
+                state.write_u8(2u8);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Meta {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Meta::Path(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Meta::List(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Meta::NameValue(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for MetaList {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.path.hash(state);
+        self.delimiter.hash(state);
+        TokenStreamHelper(&self.tokens).hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for MetaNameValue {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.path.hash(state);
+        self.value.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ParenthesizedGenericArguments {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.inputs.hash(state);
+        self.output.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Pat {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Pat::Const(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Pat::Ident(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Pat::Lit(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            Pat::Macro(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            Pat::Or(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            Pat::Paren(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+            Pat::Path(v0) => {
+                state.write_u8(6u8);
+                v0.hash(state);
+            }
+            Pat::Range(v0) => {
+                state.write_u8(7u8);
+                v0.hash(state);
+            }
+            Pat::Reference(v0) => {
+                state.write_u8(8u8);
+                v0.hash(state);
+            }
+            Pat::Rest(v0) => {
+                state.write_u8(9u8);
+                v0.hash(state);
+            }
+            Pat::Slice(v0) => {
+                state.write_u8(10u8);
+                v0.hash(state);
+            }
+            Pat::Struct(v0) => {
+                state.write_u8(11u8);
+                v0.hash(state);
+            }
+            Pat::Tuple(v0) => {
+                state.write_u8(12u8);
+                v0.hash(state);
+            }
+            Pat::TupleStruct(v0) => {
+                state.write_u8(13u8);
+                v0.hash(state);
+            }
+            Pat::Type(v0) => {
+                state.write_u8(14u8);
+                v0.hash(state);
+            }
+            Pat::Verbatim(v0) => {
+                state.write_u8(15u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+            Pat::Wild(v0) => {
+                state.write_u8(16u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatIdent {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.by_ref.hash(state);
+        self.mutability.hash(state);
+        self.ident.hash(state);
+        self.subpat.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatOr {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.leading_vert.hash(state);
+        self.cases.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatParen {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatReference {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mutability.hash(state);
+        self.pat.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatRest {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatSlice {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.elems.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatStruct {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.qself.hash(state);
+        self.path.hash(state);
+        self.fields.hash(state);
+        self.rest.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatTuple {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.elems.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatTupleStruct {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.qself.hash(state);
+        self.path.hash(state);
+        self.elems.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PatWild {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Path {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.leading_colon.hash(state);
+        self.segments.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PathArguments {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            PathArguments::None => {
+                state.write_u8(0u8);
+            }
+            PathArguments::AngleBracketed(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            PathArguments::Parenthesized(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PathSegment {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.arguments.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PredicateLifetime {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lifetime.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for PredicateType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lifetimes.hash(state);
+        self.bounded_ty.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for QSelf {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ty.hash(state);
+        self.position.hash(state);
+        self.as_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for RangeLimits {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            RangeLimits::HalfOpen(_) => {
+                state.write_u8(0u8);
+            }
+            RangeLimits::Closed(_) => {
+                state.write_u8(1u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Receiver {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.reference.hash(state);
+        self.mutability.hash(state);
+        self.colon_token.hash(state);
+        self.ty.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for ReturnType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            ReturnType::Default => {
+                state.write_u8(0u8);
+            }
+            ReturnType::Type(_, v1) => {
+                state.write_u8(1u8);
+                v1.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Signature {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.constness.hash(state);
+        self.asyncness.hash(state);
+        self.unsafety.hash(state);
+        self.abi.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.inputs.hash(state);
+        self.variadic.hash(state);
+        self.output.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for StaticMutability {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            StaticMutability::Mut(_) => {
+                state.write_u8(0u8);
+            }
+            StaticMutability::None => {
+                state.write_u8(1u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Stmt {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Stmt::Local(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Stmt::Item(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Stmt::Expr(v0, v1) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+                v1.hash(state);
+            }
+            Stmt::Macro(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for StmtMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mac.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitBound {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.paren_token.hash(state);
+        self.modifier.hash(state);
+        self.lifetimes.hash(state);
+        self.path.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitBoundModifier {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            TraitBoundModifier::None => {
+                state.write_u8(0u8);
+            }
+            TraitBoundModifier::Maybe(_) => {
+                state.write_u8(1u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitItem {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            TraitItem::Const(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            TraitItem::Fn(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            TraitItem::Type(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            TraitItem::Macro(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            TraitItem::Verbatim(v0) => {
+                state.write_u8(4u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitItemConst {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.ty.hash(state);
+        self.default.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitItemFn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.sig.hash(state);
+        self.default.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitItemMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.mac.hash(state);
+        self.semi_token.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TraitItemType {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.generics.hash(state);
+        self.colon_token.hash(state);
+        self.bounds.hash(state);
+        self.default.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Type {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Type::Array(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            Type::BareFn(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Type::Group(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            Type::ImplTrait(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            Type::Infer(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+            Type::Macro(v0) => {
+                state.write_u8(5u8);
+                v0.hash(state);
+            }
+            Type::Never(v0) => {
+                state.write_u8(6u8);
+                v0.hash(state);
+            }
+            Type::Paren(v0) => {
+                state.write_u8(7u8);
+                v0.hash(state);
+            }
+            Type::Path(v0) => {
+                state.write_u8(8u8);
+                v0.hash(state);
+            }
+            Type::Ptr(v0) => {
+                state.write_u8(9u8);
+                v0.hash(state);
+            }
+            Type::Reference(v0) => {
+                state.write_u8(10u8);
+                v0.hash(state);
+            }
+            Type::Slice(v0) => {
+                state.write_u8(11u8);
+                v0.hash(state);
+            }
+            Type::TraitObject(v0) => {
+                state.write_u8(12u8);
+                v0.hash(state);
+            }
+            Type::Tuple(v0) => {
+                state.write_u8(13u8);
+                v0.hash(state);
+            }
+            Type::Verbatim(v0) => {
+                state.write_u8(14u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeArray {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.elem.hash(state);
+        self.len.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeBareFn {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lifetimes.hash(state);
+        self.unsafety.hash(state);
+        self.abi.hash(state);
+        self.inputs.hash(state);
+        self.variadic.hash(state);
+        self.output.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeGroup {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.elem.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeImplTrait {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.bounds.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeInfer {
+    fn hash<H>(&self, _state: &mut H)
+    where
+        H: Hasher,
+    {}
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeMacro {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.mac.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeNever {
+    fn hash<H>(&self, _state: &mut H)
+    where
+        H: Hasher,
+    {}
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeParam {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.colon_token.hash(state);
+        self.bounds.hash(state);
+        self.eq_token.hash(state);
+        self.default.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeParamBound {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            TypeParamBound::Trait(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            TypeParamBound::Lifetime(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            TypeParamBound::Verbatim(v0) => {
+                state.write_u8(2u8);
+                TokenStreamHelper(v0).hash(state);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeParen {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.elem.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypePath {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.qself.hash(state);
+        self.path.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypePtr {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.const_token.hash(state);
+        self.mutability.hash(state);
+        self.elem.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeReference {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.lifetime.hash(state);
+        self.mutability.hash(state);
+        self.elem.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeSlice {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.elem.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeTraitObject {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.dyn_token.hash(state);
+        self.bounds.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for TypeTuple {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.elems.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UnOp {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            UnOp::Deref(_) => {
+                state.write_u8(0u8);
+            }
+            UnOp::Not(_) => {
+                state.write_u8(1u8);
+            }
+            UnOp::Neg(_) => {
+                state.write_u8(2u8);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UseGlob {
+    fn hash<H>(&self, _state: &mut H)
+    where
+        H: Hasher,
+    {}
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UseGroup {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.items.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UseName {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UsePath {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.tree.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UseRename {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.ident.hash(state);
+        self.rename.hash(state);
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for UseTree {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            UseTree::Path(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            UseTree::Name(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            UseTree::Rename(v0) => {
+                state.write_u8(2u8);
+                v0.hash(state);
+            }
+            UseTree::Glob(v0) => {
+                state.write_u8(3u8);
+                v0.hash(state);
+            }
+            UseTree::Group(v0) => {
+                state.write_u8(4u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
+#[cfg(feature = "full")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Variadic {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.pat.hash(state);
+        self.comma.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Variant {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.attrs.hash(state);
+        self.ident.hash(state);
+        self.fields.hash(state);
+        self.discriminant.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for VisRestricted {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.in_token.hash(state);
+        self.path.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Visibility {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            Visibility::Public(_) => {
+                state.write_u8(0u8);
+            }
+            Visibility::Restricted(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+            Visibility::Inherited => {
+                state.write_u8(2u8);
+            }
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for WhereClause {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        self.predicates.hash(state);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for WherePredicate {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        match self {
+            WherePredicate::Lifetime(v0) => {
+                state.write_u8(0u8);
+                v0.hash(state);
+            }
+            WherePredicate::Type(v0) => {
+                state.write_u8(1u8);
+                v0.hash(state);
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/visit.rs b/vendor/syn/src/gen/visit.rs
new file mode 100644
index 0000000..fe81fb6
--- /dev/null
+++ b/vendor/syn/src/gen/visit.rs
@@ -0,0 +1,3502 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#![allow(unused_variables)]
+#![allow(clippy::needless_pass_by_ref_mut)]
+#[cfg(any(feature = "full", feature = "derive"))]
+use crate::punctuated::Punctuated;
+use crate::*;
+use proc_macro2::Span;
+#[cfg(feature = "full")]
+macro_rules! full {
+    ($e:expr) => {
+        $e
+    };
+}
+#[cfg(all(feature = "derive", not(feature = "full")))]
+macro_rules! full {
+    ($e:expr) => {
+        unreachable!()
+    };
+}
+macro_rules! skip {
+    ($($tt:tt)*) => {};
+}
+/// Syntax tree traversal to walk a shared borrow of a syntax tree.
+///
+/// See the [module documentation] for details.
+///
+/// [module documentation]: self
+pub trait Visit<'ast> {
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_abi(&mut self, i: &'ast Abi) {
+        visit_abi(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_angle_bracketed_generic_arguments(
+        &mut self,
+        i: &'ast AngleBracketedGenericArguments,
+    ) {
+        visit_angle_bracketed_generic_arguments(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_arm(&mut self, i: &'ast Arm) {
+        visit_arm(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_assoc_const(&mut self, i: &'ast AssocConst) {
+        visit_assoc_const(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_assoc_type(&mut self, i: &'ast AssocType) {
+        visit_assoc_type(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_attr_style(&mut self, i: &'ast AttrStyle) {
+        visit_attr_style(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_attribute(&mut self, i: &'ast Attribute) {
+        visit_attribute(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bare_fn_arg(&mut self, i: &'ast BareFnArg) {
+        visit_bare_fn_arg(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bare_variadic(&mut self, i: &'ast BareVariadic) {
+        visit_bare_variadic(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bin_op(&mut self, i: &'ast BinOp) {
+        visit_bin_op(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_block(&mut self, i: &'ast Block) {
+        visit_block(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bound_lifetimes(&mut self, i: &'ast BoundLifetimes) {
+        visit_bound_lifetimes(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_const_param(&mut self, i: &'ast ConstParam) {
+        visit_const_param(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_constraint(&mut self, i: &'ast Constraint) {
+        visit_constraint(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data(&mut self, i: &'ast Data) {
+        visit_data(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_enum(&mut self, i: &'ast DataEnum) {
+        visit_data_enum(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_struct(&mut self, i: &'ast DataStruct) {
+        visit_data_struct(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_union(&mut self, i: &'ast DataUnion) {
+        visit_data_union(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_derive_input(&mut self, i: &'ast DeriveInput) {
+        visit_derive_input(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr(&mut self, i: &'ast Expr) {
+        visit_expr(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_array(&mut self, i: &'ast ExprArray) {
+        visit_expr_array(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_assign(&mut self, i: &'ast ExprAssign) {
+        visit_expr_assign(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_async(&mut self, i: &'ast ExprAsync) {
+        visit_expr_async(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_await(&mut self, i: &'ast ExprAwait) {
+        visit_expr_await(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_binary(&mut self, i: &'ast ExprBinary) {
+        visit_expr_binary(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_block(&mut self, i: &'ast ExprBlock) {
+        visit_expr_block(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_break(&mut self, i: &'ast ExprBreak) {
+        visit_expr_break(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_call(&mut self, i: &'ast ExprCall) {
+        visit_expr_call(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_cast(&mut self, i: &'ast ExprCast) {
+        visit_expr_cast(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_closure(&mut self, i: &'ast ExprClosure) {
+        visit_expr_closure(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_const(&mut self, i: &'ast ExprConst) {
+        visit_expr_const(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_continue(&mut self, i: &'ast ExprContinue) {
+        visit_expr_continue(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_field(&mut self, i: &'ast ExprField) {
+        visit_expr_field(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_for_loop(&mut self, i: &'ast ExprForLoop) {
+        visit_expr_for_loop(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_group(&mut self, i: &'ast ExprGroup) {
+        visit_expr_group(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_if(&mut self, i: &'ast ExprIf) {
+        visit_expr_if(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_index(&mut self, i: &'ast ExprIndex) {
+        visit_expr_index(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_infer(&mut self, i: &'ast ExprInfer) {
+        visit_expr_infer(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_let(&mut self, i: &'ast ExprLet) {
+        visit_expr_let(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_lit(&mut self, i: &'ast ExprLit) {
+        visit_expr_lit(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_loop(&mut self, i: &'ast ExprLoop) {
+        visit_expr_loop(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_macro(&mut self, i: &'ast ExprMacro) {
+        visit_expr_macro(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_match(&mut self, i: &'ast ExprMatch) {
+        visit_expr_match(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_method_call(&mut self, i: &'ast ExprMethodCall) {
+        visit_expr_method_call(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_paren(&mut self, i: &'ast ExprParen) {
+        visit_expr_paren(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_path(&mut self, i: &'ast ExprPath) {
+        visit_expr_path(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_range(&mut self, i: &'ast ExprRange) {
+        visit_expr_range(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_reference(&mut self, i: &'ast ExprReference) {
+        visit_expr_reference(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_repeat(&mut self, i: &'ast ExprRepeat) {
+        visit_expr_repeat(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_return(&mut self, i: &'ast ExprReturn) {
+        visit_expr_return(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_struct(&mut self, i: &'ast ExprStruct) {
+        visit_expr_struct(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_try(&mut self, i: &'ast ExprTry) {
+        visit_expr_try(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_try_block(&mut self, i: &'ast ExprTryBlock) {
+        visit_expr_try_block(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_tuple(&mut self, i: &'ast ExprTuple) {
+        visit_expr_tuple(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_unary(&mut self, i: &'ast ExprUnary) {
+        visit_expr_unary(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_unsafe(&mut self, i: &'ast ExprUnsafe) {
+        visit_expr_unsafe(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_while(&mut self, i: &'ast ExprWhile) {
+        visit_expr_while(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_yield(&mut self, i: &'ast ExprYield) {
+        visit_expr_yield(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_field(&mut self, i: &'ast Field) {
+        visit_field(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_field_mutability(&mut self, i: &'ast FieldMutability) {
+        visit_field_mutability(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_field_pat(&mut self, i: &'ast FieldPat) {
+        visit_field_pat(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_field_value(&mut self, i: &'ast FieldValue) {
+        visit_field_value(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields(&mut self, i: &'ast Fields) {
+        visit_fields(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields_named(&mut self, i: &'ast FieldsNamed) {
+        visit_fields_named(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields_unnamed(&mut self, i: &'ast FieldsUnnamed) {
+        visit_fields_unnamed(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_file(&mut self, i: &'ast File) {
+        visit_file(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_fn_arg(&mut self, i: &'ast FnArg) {
+        visit_fn_arg(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item(&mut self, i: &'ast ForeignItem) {
+        visit_foreign_item(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_fn(&mut self, i: &'ast ForeignItemFn) {
+        visit_foreign_item_fn(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_macro(&mut self, i: &'ast ForeignItemMacro) {
+        visit_foreign_item_macro(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_static(&mut self, i: &'ast ForeignItemStatic) {
+        visit_foreign_item_static(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_type(&mut self, i: &'ast ForeignItemType) {
+        visit_foreign_item_type(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generic_argument(&mut self, i: &'ast GenericArgument) {
+        visit_generic_argument(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generic_param(&mut self, i: &'ast GenericParam) {
+        visit_generic_param(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generics(&mut self, i: &'ast Generics) {
+        visit_generics(self, i);
+    }
+    fn visit_ident(&mut self, i: &'ast Ident) {
+        visit_ident(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item(&mut self, i: &'ast ImplItem) {
+        visit_impl_item(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_const(&mut self, i: &'ast ImplItemConst) {
+        visit_impl_item_const(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_fn(&mut self, i: &'ast ImplItemFn) {
+        visit_impl_item_fn(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_macro(&mut self, i: &'ast ImplItemMacro) {
+        visit_impl_item_macro(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_type(&mut self, i: &'ast ImplItemType) {
+        visit_impl_item_type(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_restriction(&mut self, i: &'ast ImplRestriction) {
+        visit_impl_restriction(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_index(&mut self, i: &'ast Index) {
+        visit_index(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item(&mut self, i: &'ast Item) {
+        visit_item(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_const(&mut self, i: &'ast ItemConst) {
+        visit_item_const(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_enum(&mut self, i: &'ast ItemEnum) {
+        visit_item_enum(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_extern_crate(&mut self, i: &'ast ItemExternCrate) {
+        visit_item_extern_crate(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_fn(&mut self, i: &'ast ItemFn) {
+        visit_item_fn(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_foreign_mod(&mut self, i: &'ast ItemForeignMod) {
+        visit_item_foreign_mod(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_impl(&mut self, i: &'ast ItemImpl) {
+        visit_item_impl(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_macro(&mut self, i: &'ast ItemMacro) {
+        visit_item_macro(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_mod(&mut self, i: &'ast ItemMod) {
+        visit_item_mod(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_static(&mut self, i: &'ast ItemStatic) {
+        visit_item_static(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_struct(&mut self, i: &'ast ItemStruct) {
+        visit_item_struct(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_trait(&mut self, i: &'ast ItemTrait) {
+        visit_item_trait(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_trait_alias(&mut self, i: &'ast ItemTraitAlias) {
+        visit_item_trait_alias(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_type(&mut self, i: &'ast ItemType) {
+        visit_item_type(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_union(&mut self, i: &'ast ItemUnion) {
+        visit_item_union(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_use(&mut self, i: &'ast ItemUse) {
+        visit_item_use(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_label(&mut self, i: &'ast Label) {
+        visit_label(self, i);
+    }
+    fn visit_lifetime(&mut self, i: &'ast Lifetime) {
+        visit_lifetime(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_lifetime_param(&mut self, i: &'ast LifetimeParam) {
+        visit_lifetime_param(self, i);
+    }
+    fn visit_lit(&mut self, i: &'ast Lit) {
+        visit_lit(self, i);
+    }
+    fn visit_lit_bool(&mut self, i: &'ast LitBool) {
+        visit_lit_bool(self, i);
+    }
+    fn visit_lit_byte(&mut self, i: &'ast LitByte) {
+        visit_lit_byte(self, i);
+    }
+    fn visit_lit_byte_str(&mut self, i: &'ast LitByteStr) {
+        visit_lit_byte_str(self, i);
+    }
+    fn visit_lit_char(&mut self, i: &'ast LitChar) {
+        visit_lit_char(self, i);
+    }
+    fn visit_lit_float(&mut self, i: &'ast LitFloat) {
+        visit_lit_float(self, i);
+    }
+    fn visit_lit_int(&mut self, i: &'ast LitInt) {
+        visit_lit_int(self, i);
+    }
+    fn visit_lit_str(&mut self, i: &'ast LitStr) {
+        visit_lit_str(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_local(&mut self, i: &'ast Local) {
+        visit_local(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_local_init(&mut self, i: &'ast LocalInit) {
+        visit_local_init(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_macro(&mut self, i: &'ast Macro) {
+        visit_macro(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_macro_delimiter(&mut self, i: &'ast MacroDelimiter) {
+        visit_macro_delimiter(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_member(&mut self, i: &'ast Member) {
+        visit_member(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta(&mut self, i: &'ast Meta) {
+        visit_meta(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta_list(&mut self, i: &'ast MetaList) {
+        visit_meta_list(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta_name_value(&mut self, i: &'ast MetaNameValue) {
+        visit_meta_name_value(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_parenthesized_generic_arguments(
+        &mut self,
+        i: &'ast ParenthesizedGenericArguments,
+    ) {
+        visit_parenthesized_generic_arguments(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat(&mut self, i: &'ast Pat) {
+        visit_pat(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_ident(&mut self, i: &'ast PatIdent) {
+        visit_pat_ident(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_or(&mut self, i: &'ast PatOr) {
+        visit_pat_or(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_paren(&mut self, i: &'ast PatParen) {
+        visit_pat_paren(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_reference(&mut self, i: &'ast PatReference) {
+        visit_pat_reference(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_rest(&mut self, i: &'ast PatRest) {
+        visit_pat_rest(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_slice(&mut self, i: &'ast PatSlice) {
+        visit_pat_slice(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_struct(&mut self, i: &'ast PatStruct) {
+        visit_pat_struct(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_tuple(&mut self, i: &'ast PatTuple) {
+        visit_pat_tuple(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_tuple_struct(&mut self, i: &'ast PatTupleStruct) {
+        visit_pat_tuple_struct(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_type(&mut self, i: &'ast PatType) {
+        visit_pat_type(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_wild(&mut self, i: &'ast PatWild) {
+        visit_pat_wild(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path(&mut self, i: &'ast Path) {
+        visit_path(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path_arguments(&mut self, i: &'ast PathArguments) {
+        visit_path_arguments(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path_segment(&mut self, i: &'ast PathSegment) {
+        visit_path_segment(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_predicate_lifetime(&mut self, i: &'ast PredicateLifetime) {
+        visit_predicate_lifetime(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_predicate_type(&mut self, i: &'ast PredicateType) {
+        visit_predicate_type(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_qself(&mut self, i: &'ast QSelf) {
+        visit_qself(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_range_limits(&mut self, i: &'ast RangeLimits) {
+        visit_range_limits(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_receiver(&mut self, i: &'ast Receiver) {
+        visit_receiver(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_return_type(&mut self, i: &'ast ReturnType) {
+        visit_return_type(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_signature(&mut self, i: &'ast Signature) {
+        visit_signature(self, i);
+    }
+    fn visit_span(&mut self, i: &Span) {
+        visit_span(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_static_mutability(&mut self, i: &'ast StaticMutability) {
+        visit_static_mutability(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_stmt(&mut self, i: &'ast Stmt) {
+        visit_stmt(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_stmt_macro(&mut self, i: &'ast StmtMacro) {
+        visit_stmt_macro(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_trait_bound(&mut self, i: &'ast TraitBound) {
+        visit_trait_bound(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_trait_bound_modifier(&mut self, i: &'ast TraitBoundModifier) {
+        visit_trait_bound_modifier(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item(&mut self, i: &'ast TraitItem) {
+        visit_trait_item(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_const(&mut self, i: &'ast TraitItemConst) {
+        visit_trait_item_const(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_fn(&mut self, i: &'ast TraitItemFn) {
+        visit_trait_item_fn(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_macro(&mut self, i: &'ast TraitItemMacro) {
+        visit_trait_item_macro(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_type(&mut self, i: &'ast TraitItemType) {
+        visit_trait_item_type(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type(&mut self, i: &'ast Type) {
+        visit_type(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_array(&mut self, i: &'ast TypeArray) {
+        visit_type_array(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_bare_fn(&mut self, i: &'ast TypeBareFn) {
+        visit_type_bare_fn(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_group(&mut self, i: &'ast TypeGroup) {
+        visit_type_group(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_impl_trait(&mut self, i: &'ast TypeImplTrait) {
+        visit_type_impl_trait(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_infer(&mut self, i: &'ast TypeInfer) {
+        visit_type_infer(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_macro(&mut self, i: &'ast TypeMacro) {
+        visit_type_macro(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_never(&mut self, i: &'ast TypeNever) {
+        visit_type_never(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_param(&mut self, i: &'ast TypeParam) {
+        visit_type_param(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_param_bound(&mut self, i: &'ast TypeParamBound) {
+        visit_type_param_bound(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_paren(&mut self, i: &'ast TypeParen) {
+        visit_type_paren(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_path(&mut self, i: &'ast TypePath) {
+        visit_type_path(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_ptr(&mut self, i: &'ast TypePtr) {
+        visit_type_ptr(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_reference(&mut self, i: &'ast TypeReference) {
+        visit_type_reference(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_slice(&mut self, i: &'ast TypeSlice) {
+        visit_type_slice(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_trait_object(&mut self, i: &'ast TypeTraitObject) {
+        visit_type_trait_object(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_tuple(&mut self, i: &'ast TypeTuple) {
+        visit_type_tuple(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_un_op(&mut self, i: &'ast UnOp) {
+        visit_un_op(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_glob(&mut self, i: &'ast UseGlob) {
+        visit_use_glob(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_group(&mut self, i: &'ast UseGroup) {
+        visit_use_group(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_name(&mut self, i: &'ast UseName) {
+        visit_use_name(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_path(&mut self, i: &'ast UsePath) {
+        visit_use_path(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_rename(&mut self, i: &'ast UseRename) {
+        visit_use_rename(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_tree(&mut self, i: &'ast UseTree) {
+        visit_use_tree(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_variadic(&mut self, i: &'ast Variadic) {
+        visit_variadic(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_variant(&mut self, i: &'ast Variant) {
+        visit_variant(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_vis_restricted(&mut self, i: &'ast VisRestricted) {
+        visit_vis_restricted(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_visibility(&mut self, i: &'ast Visibility) {
+        visit_visibility(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_where_clause(&mut self, i: &'ast WhereClause) {
+        visit_where_clause(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_where_predicate(&mut self, i: &'ast WherePredicate) {
+        visit_where_predicate(self, i);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_abi<'ast, V>(v: &mut V, node: &'ast Abi)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.extern_token);
+    if let Some(it) = &node.name {
+        v.visit_lit_str(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_angle_bracketed_generic_arguments<'ast, V>(
+    v: &mut V,
+    node: &'ast AngleBracketedGenericArguments,
+)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.colon2_token);
+    skip!(node.lt_token);
+    for el in Punctuated::pairs(&node.args) {
+        let it = el.value();
+        v.visit_generic_argument(it);
+    }
+    skip!(node.gt_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_arm<'ast, V>(v: &mut V, node: &'ast Arm)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_pat(&node.pat);
+    if let Some(it) = &node.guard {
+        skip!((it).0);
+        v.visit_expr(&*(it).1);
+    }
+    skip!(node.fat_arrow_token);
+    v.visit_expr(&*node.body);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_assoc_const<'ast, V>(v: &mut V, node: &'ast AssocConst)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.generics {
+        v.visit_angle_bracketed_generic_arguments(it);
+    }
+    skip!(node.eq_token);
+    v.visit_expr(&node.value);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_assoc_type<'ast, V>(v: &mut V, node: &'ast AssocType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.generics {
+        v.visit_angle_bracketed_generic_arguments(it);
+    }
+    skip!(node.eq_token);
+    v.visit_type(&node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_attr_style<'ast, V>(v: &mut V, node: &'ast AttrStyle)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        AttrStyle::Outer => {}
+        AttrStyle::Inner(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_attribute<'ast, V>(v: &mut V, node: &'ast Attribute)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.pound_token);
+    v.visit_attr_style(&node.style);
+    skip!(node.bracket_token);
+    v.visit_meta(&node.meta);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bare_fn_arg<'ast, V>(v: &mut V, node: &'ast BareFnArg)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.name {
+        v.visit_ident(&(it).0);
+        skip!((it).1);
+    }
+    v.visit_type(&node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bare_variadic<'ast, V>(v: &mut V, node: &'ast BareVariadic)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.name {
+        v.visit_ident(&(it).0);
+        skip!((it).1);
+    }
+    skip!(node.dots);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bin_op<'ast, V>(v: &mut V, node: &'ast BinOp)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        BinOp::Add(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Sub(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Mul(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Div(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Rem(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::And(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Or(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitXor(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitAnd(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitOr(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Shl(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Shr(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Eq(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Lt(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Le(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Ne(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Ge(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Gt(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::AddAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::SubAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::MulAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::DivAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::RemAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitXorAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitAndAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitOrAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::ShlAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::ShrAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_block<'ast, V>(v: &mut V, node: &'ast Block)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.brace_token);
+    for it in &node.stmts {
+        v.visit_stmt(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bound_lifetimes<'ast, V>(v: &mut V, node: &'ast BoundLifetimes)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.for_token);
+    skip!(node.lt_token);
+    for el in Punctuated::pairs(&node.lifetimes) {
+        let it = el.value();
+        v.visit_generic_param(it);
+    }
+    skip!(node.gt_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_const_param<'ast, V>(v: &mut V, node: &'ast ConstParam)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.const_token);
+    v.visit_ident(&node.ident);
+    skip!(node.colon_token);
+    v.visit_type(&node.ty);
+    skip!(node.eq_token);
+    if let Some(it) = &node.default {
+        v.visit_expr(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_constraint<'ast, V>(v: &mut V, node: &'ast Constraint)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.generics {
+        v.visit_angle_bracketed_generic_arguments(it);
+    }
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data<'ast, V>(v: &mut V, node: &'ast Data)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Data::Struct(_binding_0) => {
+            v.visit_data_struct(_binding_0);
+        }
+        Data::Enum(_binding_0) => {
+            v.visit_data_enum(_binding_0);
+        }
+        Data::Union(_binding_0) => {
+            v.visit_data_union(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_enum<'ast, V>(v: &mut V, node: &'ast DataEnum)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.enum_token);
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.variants) {
+        let it = el.value();
+        v.visit_variant(it);
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_struct<'ast, V>(v: &mut V, node: &'ast DataStruct)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.struct_token);
+    v.visit_fields(&node.fields);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_union<'ast, V>(v: &mut V, node: &'ast DataUnion)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.union_token);
+    v.visit_fields_named(&node.fields);
+}
+#[cfg(feature = "derive")]
+pub fn visit_derive_input<'ast, V>(v: &mut V, node: &'ast DeriveInput)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    v.visit_data(&node.data);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr<'ast, V>(v: &mut V, node: &'ast Expr)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Expr::Array(_binding_0) => {
+            full!(v.visit_expr_array(_binding_0));
+        }
+        Expr::Assign(_binding_0) => {
+            full!(v.visit_expr_assign(_binding_0));
+        }
+        Expr::Async(_binding_0) => {
+            full!(v.visit_expr_async(_binding_0));
+        }
+        Expr::Await(_binding_0) => {
+            full!(v.visit_expr_await(_binding_0));
+        }
+        Expr::Binary(_binding_0) => {
+            v.visit_expr_binary(_binding_0);
+        }
+        Expr::Block(_binding_0) => {
+            full!(v.visit_expr_block(_binding_0));
+        }
+        Expr::Break(_binding_0) => {
+            full!(v.visit_expr_break(_binding_0));
+        }
+        Expr::Call(_binding_0) => {
+            v.visit_expr_call(_binding_0);
+        }
+        Expr::Cast(_binding_0) => {
+            v.visit_expr_cast(_binding_0);
+        }
+        Expr::Closure(_binding_0) => {
+            full!(v.visit_expr_closure(_binding_0));
+        }
+        Expr::Const(_binding_0) => {
+            full!(v.visit_expr_const(_binding_0));
+        }
+        Expr::Continue(_binding_0) => {
+            full!(v.visit_expr_continue(_binding_0));
+        }
+        Expr::Field(_binding_0) => {
+            v.visit_expr_field(_binding_0);
+        }
+        Expr::ForLoop(_binding_0) => {
+            full!(v.visit_expr_for_loop(_binding_0));
+        }
+        Expr::Group(_binding_0) => {
+            v.visit_expr_group(_binding_0);
+        }
+        Expr::If(_binding_0) => {
+            full!(v.visit_expr_if(_binding_0));
+        }
+        Expr::Index(_binding_0) => {
+            v.visit_expr_index(_binding_0);
+        }
+        Expr::Infer(_binding_0) => {
+            full!(v.visit_expr_infer(_binding_0));
+        }
+        Expr::Let(_binding_0) => {
+            full!(v.visit_expr_let(_binding_0));
+        }
+        Expr::Lit(_binding_0) => {
+            v.visit_expr_lit(_binding_0);
+        }
+        Expr::Loop(_binding_0) => {
+            full!(v.visit_expr_loop(_binding_0));
+        }
+        Expr::Macro(_binding_0) => {
+            v.visit_expr_macro(_binding_0);
+        }
+        Expr::Match(_binding_0) => {
+            full!(v.visit_expr_match(_binding_0));
+        }
+        Expr::MethodCall(_binding_0) => {
+            full!(v.visit_expr_method_call(_binding_0));
+        }
+        Expr::Paren(_binding_0) => {
+            v.visit_expr_paren(_binding_0);
+        }
+        Expr::Path(_binding_0) => {
+            v.visit_expr_path(_binding_0);
+        }
+        Expr::Range(_binding_0) => {
+            full!(v.visit_expr_range(_binding_0));
+        }
+        Expr::Reference(_binding_0) => {
+            full!(v.visit_expr_reference(_binding_0));
+        }
+        Expr::Repeat(_binding_0) => {
+            full!(v.visit_expr_repeat(_binding_0));
+        }
+        Expr::Return(_binding_0) => {
+            full!(v.visit_expr_return(_binding_0));
+        }
+        Expr::Struct(_binding_0) => {
+            full!(v.visit_expr_struct(_binding_0));
+        }
+        Expr::Try(_binding_0) => {
+            full!(v.visit_expr_try(_binding_0));
+        }
+        Expr::TryBlock(_binding_0) => {
+            full!(v.visit_expr_try_block(_binding_0));
+        }
+        Expr::Tuple(_binding_0) => {
+            full!(v.visit_expr_tuple(_binding_0));
+        }
+        Expr::Unary(_binding_0) => {
+            v.visit_expr_unary(_binding_0);
+        }
+        Expr::Unsafe(_binding_0) => {
+            full!(v.visit_expr_unsafe(_binding_0));
+        }
+        Expr::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Expr::While(_binding_0) => {
+            full!(v.visit_expr_while(_binding_0));
+        }
+        Expr::Yield(_binding_0) => {
+            full!(v.visit_expr_yield(_binding_0));
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_array<'ast, V>(v: &mut V, node: &'ast ExprArray)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.bracket_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_expr(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_assign<'ast, V>(v: &mut V, node: &'ast ExprAssign)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.left);
+    skip!(node.eq_token);
+    v.visit_expr(&*node.right);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_async<'ast, V>(v: &mut V, node: &'ast ExprAsync)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.async_token);
+    skip!(node.capture);
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_await<'ast, V>(v: &mut V, node: &'ast ExprAwait)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.base);
+    skip!(node.dot_token);
+    skip!(node.await_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_binary<'ast, V>(v: &mut V, node: &'ast ExprBinary)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.left);
+    v.visit_bin_op(&node.op);
+    v.visit_expr(&*node.right);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_block<'ast, V>(v: &mut V, node: &'ast ExprBlock)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.label {
+        v.visit_label(it);
+    }
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_break<'ast, V>(v: &mut V, node: &'ast ExprBreak)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.break_token);
+    if let Some(it) = &node.label {
+        v.visit_lifetime(it);
+    }
+    if let Some(it) = &node.expr {
+        v.visit_expr(&**it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_call<'ast, V>(v: &mut V, node: &'ast ExprCall)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.func);
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.args) {
+        let it = el.value();
+        v.visit_expr(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_cast<'ast, V>(v: &mut V, node: &'ast ExprCast)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.expr);
+    skip!(node.as_token);
+    v.visit_type(&*node.ty);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_closure<'ast, V>(v: &mut V, node: &'ast ExprClosure)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.lifetimes {
+        v.visit_bound_lifetimes(it);
+    }
+    skip!(node.constness);
+    skip!(node.movability);
+    skip!(node.asyncness);
+    skip!(node.capture);
+    skip!(node.or1_token);
+    for el in Punctuated::pairs(&node.inputs) {
+        let it = el.value();
+        v.visit_pat(it);
+    }
+    skip!(node.or2_token);
+    v.visit_return_type(&node.output);
+    v.visit_expr(&*node.body);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_const<'ast, V>(v: &mut V, node: &'ast ExprConst)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.const_token);
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_continue<'ast, V>(v: &mut V, node: &'ast ExprContinue)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.continue_token);
+    if let Some(it) = &node.label {
+        v.visit_lifetime(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_field<'ast, V>(v: &mut V, node: &'ast ExprField)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.base);
+    skip!(node.dot_token);
+    v.visit_member(&node.member);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_for_loop<'ast, V>(v: &mut V, node: &'ast ExprForLoop)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.label {
+        v.visit_label(it);
+    }
+    skip!(node.for_token);
+    v.visit_pat(&*node.pat);
+    skip!(node.in_token);
+    v.visit_expr(&*node.expr);
+    v.visit_block(&node.body);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_group<'ast, V>(v: &mut V, node: &'ast ExprGroup)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.group_token);
+    v.visit_expr(&*node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_if<'ast, V>(v: &mut V, node: &'ast ExprIf)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.if_token);
+    v.visit_expr(&*node.cond);
+    v.visit_block(&node.then_branch);
+    if let Some(it) = &node.else_branch {
+        skip!((it).0);
+        v.visit_expr(&*(it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_index<'ast, V>(v: &mut V, node: &'ast ExprIndex)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.expr);
+    skip!(node.bracket_token);
+    v.visit_expr(&*node.index);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_infer<'ast, V>(v: &mut V, node: &'ast ExprInfer)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.underscore_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_let<'ast, V>(v: &mut V, node: &'ast ExprLet)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.let_token);
+    v.visit_pat(&*node.pat);
+    skip!(node.eq_token);
+    v.visit_expr(&*node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_lit<'ast, V>(v: &mut V, node: &'ast ExprLit)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_lit(&node.lit);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_loop<'ast, V>(v: &mut V, node: &'ast ExprLoop)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.label {
+        v.visit_label(it);
+    }
+    skip!(node.loop_token);
+    v.visit_block(&node.body);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_macro<'ast, V>(v: &mut V, node: &'ast ExprMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_macro(&node.mac);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_match<'ast, V>(v: &mut V, node: &'ast ExprMatch)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.match_token);
+    v.visit_expr(&*node.expr);
+    skip!(node.brace_token);
+    for it in &node.arms {
+        v.visit_arm(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_method_call<'ast, V>(v: &mut V, node: &'ast ExprMethodCall)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.receiver);
+    skip!(node.dot_token);
+    v.visit_ident(&node.method);
+    if let Some(it) = &node.turbofish {
+        v.visit_angle_bracketed_generic_arguments(it);
+    }
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.args) {
+        let it = el.value();
+        v.visit_expr(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_paren<'ast, V>(v: &mut V, node: &'ast ExprParen)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.paren_token);
+    v.visit_expr(&*node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_path<'ast, V>(v: &mut V, node: &'ast ExprPath)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.qself {
+        v.visit_qself(it);
+    }
+    v.visit_path(&node.path);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_range<'ast, V>(v: &mut V, node: &'ast ExprRange)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.start {
+        v.visit_expr(&**it);
+    }
+    v.visit_range_limits(&node.limits);
+    if let Some(it) = &node.end {
+        v.visit_expr(&**it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_reference<'ast, V>(v: &mut V, node: &'ast ExprReference)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.and_token);
+    skip!(node.mutability);
+    v.visit_expr(&*node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_repeat<'ast, V>(v: &mut V, node: &'ast ExprRepeat)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.bracket_token);
+    v.visit_expr(&*node.expr);
+    skip!(node.semi_token);
+    v.visit_expr(&*node.len);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_return<'ast, V>(v: &mut V, node: &'ast ExprReturn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.return_token);
+    if let Some(it) = &node.expr {
+        v.visit_expr(&**it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_struct<'ast, V>(v: &mut V, node: &'ast ExprStruct)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.qself {
+        v.visit_qself(it);
+    }
+    v.visit_path(&node.path);
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.fields) {
+        let it = el.value();
+        v.visit_field_value(it);
+    }
+    skip!(node.dot2_token);
+    if let Some(it) = &node.rest {
+        v.visit_expr(&**it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_try<'ast, V>(v: &mut V, node: &'ast ExprTry)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_expr(&*node.expr);
+    skip!(node.question_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_try_block<'ast, V>(v: &mut V, node: &'ast ExprTryBlock)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.try_token);
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_tuple<'ast, V>(v: &mut V, node: &'ast ExprTuple)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_expr(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_unary<'ast, V>(v: &mut V, node: &'ast ExprUnary)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_un_op(&node.op);
+    v.visit_expr(&*node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_unsafe<'ast, V>(v: &mut V, node: &'ast ExprUnsafe)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.unsafe_token);
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_while<'ast, V>(v: &mut V, node: &'ast ExprWhile)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.label {
+        v.visit_label(it);
+    }
+    skip!(node.while_token);
+    v.visit_expr(&*node.cond);
+    v.visit_block(&node.body);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_yield<'ast, V>(v: &mut V, node: &'ast ExprYield)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.yield_token);
+    if let Some(it) = &node.expr {
+        v.visit_expr(&**it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_field<'ast, V>(v: &mut V, node: &'ast Field)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    v.visit_field_mutability(&node.mutability);
+    if let Some(it) = &node.ident {
+        v.visit_ident(it);
+    }
+    skip!(node.colon_token);
+    v.visit_type(&node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_field_mutability<'ast, V>(v: &mut V, node: &'ast FieldMutability)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        FieldMutability::None => {}
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_field_pat<'ast, V>(v: &mut V, node: &'ast FieldPat)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_member(&node.member);
+    skip!(node.colon_token);
+    v.visit_pat(&*node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_field_value<'ast, V>(v: &mut V, node: &'ast FieldValue)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_member(&node.member);
+    skip!(node.colon_token);
+    v.visit_expr(&node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields<'ast, V>(v: &mut V, node: &'ast Fields)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Fields::Named(_binding_0) => {
+            v.visit_fields_named(_binding_0);
+        }
+        Fields::Unnamed(_binding_0) => {
+            v.visit_fields_unnamed(_binding_0);
+        }
+        Fields::Unit => {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields_named<'ast, V>(v: &mut V, node: &'ast FieldsNamed)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.named) {
+        let it = el.value();
+        v.visit_field(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields_unnamed<'ast, V>(v: &mut V, node: &'ast FieldsUnnamed)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.unnamed) {
+        let it = el.value();
+        v.visit_field(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_file<'ast, V>(v: &mut V, node: &'ast File)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.shebang);
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    for it in &node.items {
+        v.visit_item(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_fn_arg<'ast, V>(v: &mut V, node: &'ast FnArg)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        FnArg::Receiver(_binding_0) => {
+            v.visit_receiver(_binding_0);
+        }
+        FnArg::Typed(_binding_0) => {
+            v.visit_pat_type(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item<'ast, V>(v: &mut V, node: &'ast ForeignItem)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        ForeignItem::Fn(_binding_0) => {
+            v.visit_foreign_item_fn(_binding_0);
+        }
+        ForeignItem::Static(_binding_0) => {
+            v.visit_foreign_item_static(_binding_0);
+        }
+        ForeignItem::Type(_binding_0) => {
+            v.visit_foreign_item_type(_binding_0);
+        }
+        ForeignItem::Macro(_binding_0) => {
+            v.visit_foreign_item_macro(_binding_0);
+        }
+        ForeignItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_fn<'ast, V>(v: &mut V, node: &'ast ForeignItemFn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    v.visit_signature(&node.sig);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_macro<'ast, V>(v: &mut V, node: &'ast ForeignItemMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_macro(&node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_static<'ast, V>(v: &mut V, node: &'ast ForeignItemStatic)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.static_token);
+    v.visit_static_mutability(&node.mutability);
+    v.visit_ident(&node.ident);
+    skip!(node.colon_token);
+    v.visit_type(&*node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_type<'ast, V>(v: &mut V, node: &'ast ForeignItemType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.type_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generic_argument<'ast, V>(v: &mut V, node: &'ast GenericArgument)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        GenericArgument::Lifetime(_binding_0) => {
+            v.visit_lifetime(_binding_0);
+        }
+        GenericArgument::Type(_binding_0) => {
+            v.visit_type(_binding_0);
+        }
+        GenericArgument::Const(_binding_0) => {
+            v.visit_expr(_binding_0);
+        }
+        GenericArgument::AssocType(_binding_0) => {
+            v.visit_assoc_type(_binding_0);
+        }
+        GenericArgument::AssocConst(_binding_0) => {
+            v.visit_assoc_const(_binding_0);
+        }
+        GenericArgument::Constraint(_binding_0) => {
+            v.visit_constraint(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generic_param<'ast, V>(v: &mut V, node: &'ast GenericParam)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        GenericParam::Lifetime(_binding_0) => {
+            v.visit_lifetime_param(_binding_0);
+        }
+        GenericParam::Type(_binding_0) => {
+            v.visit_type_param(_binding_0);
+        }
+        GenericParam::Const(_binding_0) => {
+            v.visit_const_param(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generics<'ast, V>(v: &mut V, node: &'ast Generics)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.lt_token);
+    for el in Punctuated::pairs(&node.params) {
+        let it = el.value();
+        v.visit_generic_param(it);
+    }
+    skip!(node.gt_token);
+    if let Some(it) = &node.where_clause {
+        v.visit_where_clause(it);
+    }
+}
+pub fn visit_ident<'ast, V>(v: &mut V, node: &'ast Ident)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_span(&node.span());
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item<'ast, V>(v: &mut V, node: &'ast ImplItem)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        ImplItem::Const(_binding_0) => {
+            v.visit_impl_item_const(_binding_0);
+        }
+        ImplItem::Fn(_binding_0) => {
+            v.visit_impl_item_fn(_binding_0);
+        }
+        ImplItem::Type(_binding_0) => {
+            v.visit_impl_item_type(_binding_0);
+        }
+        ImplItem::Macro(_binding_0) => {
+            v.visit_impl_item_macro(_binding_0);
+        }
+        ImplItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_const<'ast, V>(v: &mut V, node: &'ast ImplItemConst)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.defaultness);
+    skip!(node.const_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.colon_token);
+    v.visit_type(&node.ty);
+    skip!(node.eq_token);
+    v.visit_expr(&node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_fn<'ast, V>(v: &mut V, node: &'ast ImplItemFn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.defaultness);
+    v.visit_signature(&node.sig);
+    v.visit_block(&node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_macro<'ast, V>(v: &mut V, node: &'ast ImplItemMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_macro(&node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_type<'ast, V>(v: &mut V, node: &'ast ImplItemType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.defaultness);
+    skip!(node.type_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.eq_token);
+    v.visit_type(&node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_restriction<'ast, V>(v: &mut V, node: &'ast ImplRestriction)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match *node {}
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_index<'ast, V>(v: &mut V, node: &'ast Index)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.index);
+    v.visit_span(&node.span);
+}
+#[cfg(feature = "full")]
+pub fn visit_item<'ast, V>(v: &mut V, node: &'ast Item)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Item::Const(_binding_0) => {
+            v.visit_item_const(_binding_0);
+        }
+        Item::Enum(_binding_0) => {
+            v.visit_item_enum(_binding_0);
+        }
+        Item::ExternCrate(_binding_0) => {
+            v.visit_item_extern_crate(_binding_0);
+        }
+        Item::Fn(_binding_0) => {
+            v.visit_item_fn(_binding_0);
+        }
+        Item::ForeignMod(_binding_0) => {
+            v.visit_item_foreign_mod(_binding_0);
+        }
+        Item::Impl(_binding_0) => {
+            v.visit_item_impl(_binding_0);
+        }
+        Item::Macro(_binding_0) => {
+            v.visit_item_macro(_binding_0);
+        }
+        Item::Mod(_binding_0) => {
+            v.visit_item_mod(_binding_0);
+        }
+        Item::Static(_binding_0) => {
+            v.visit_item_static(_binding_0);
+        }
+        Item::Struct(_binding_0) => {
+            v.visit_item_struct(_binding_0);
+        }
+        Item::Trait(_binding_0) => {
+            v.visit_item_trait(_binding_0);
+        }
+        Item::TraitAlias(_binding_0) => {
+            v.visit_item_trait_alias(_binding_0);
+        }
+        Item::Type(_binding_0) => {
+            v.visit_item_type(_binding_0);
+        }
+        Item::Union(_binding_0) => {
+            v.visit_item_union(_binding_0);
+        }
+        Item::Use(_binding_0) => {
+            v.visit_item_use(_binding_0);
+        }
+        Item::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_const<'ast, V>(v: &mut V, node: &'ast ItemConst)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.const_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.colon_token);
+    v.visit_type(&*node.ty);
+    skip!(node.eq_token);
+    v.visit_expr(&*node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_enum<'ast, V>(v: &mut V, node: &'ast ItemEnum)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.enum_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.variants) {
+        let it = el.value();
+        v.visit_variant(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_extern_crate<'ast, V>(v: &mut V, node: &'ast ItemExternCrate)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.extern_token);
+    skip!(node.crate_token);
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.rename {
+        skip!((it).0);
+        v.visit_ident(&(it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_fn<'ast, V>(v: &mut V, node: &'ast ItemFn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    v.visit_signature(&node.sig);
+    v.visit_block(&*node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_foreign_mod<'ast, V>(v: &mut V, node: &'ast ItemForeignMod)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.unsafety);
+    v.visit_abi(&node.abi);
+    skip!(node.brace_token);
+    for it in &node.items {
+        v.visit_foreign_item(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_impl<'ast, V>(v: &mut V, node: &'ast ItemImpl)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.defaultness);
+    skip!(node.unsafety);
+    skip!(node.impl_token);
+    v.visit_generics(&node.generics);
+    if let Some(it) = &node.trait_ {
+        skip!((it).0);
+        v.visit_path(&(it).1);
+        skip!((it).2);
+    }
+    v.visit_type(&*node.self_ty);
+    skip!(node.brace_token);
+    for it in &node.items {
+        v.visit_impl_item(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_macro<'ast, V>(v: &mut V, node: &'ast ItemMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.ident {
+        v.visit_ident(it);
+    }
+    v.visit_macro(&node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_mod<'ast, V>(v: &mut V, node: &'ast ItemMod)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.unsafety);
+    skip!(node.mod_token);
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.content {
+        skip!((it).0);
+        for it in &(it).1 {
+            v.visit_item(it);
+        }
+    }
+    skip!(node.semi);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_static<'ast, V>(v: &mut V, node: &'ast ItemStatic)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.static_token);
+    v.visit_static_mutability(&node.mutability);
+    v.visit_ident(&node.ident);
+    skip!(node.colon_token);
+    v.visit_type(&*node.ty);
+    skip!(node.eq_token);
+    v.visit_expr(&*node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_struct<'ast, V>(v: &mut V, node: &'ast ItemStruct)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.struct_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    v.visit_fields(&node.fields);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_trait<'ast, V>(v: &mut V, node: &'ast ItemTrait)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.unsafety);
+    skip!(node.auto_token);
+    if let Some(it) = &node.restriction {
+        v.visit_impl_restriction(it);
+    }
+    skip!(node.trait_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.supertraits) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+    skip!(node.brace_token);
+    for it in &node.items {
+        v.visit_trait_item(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_trait_alias<'ast, V>(v: &mut V, node: &'ast ItemTraitAlias)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.trait_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.eq_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_type<'ast, V>(v: &mut V, node: &'ast ItemType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.type_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.eq_token);
+    v.visit_type(&*node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_union<'ast, V>(v: &mut V, node: &'ast ItemUnion)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.union_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    v.visit_fields_named(&node.fields);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_use<'ast, V>(v: &mut V, node: &'ast ItemUse)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_visibility(&node.vis);
+    skip!(node.use_token);
+    skip!(node.leading_colon);
+    v.visit_use_tree(&node.tree);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_label<'ast, V>(v: &mut V, node: &'ast Label)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_lifetime(&node.name);
+    skip!(node.colon_token);
+}
+pub fn visit_lifetime<'ast, V>(v: &mut V, node: &'ast Lifetime)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_span(&node.apostrophe);
+    v.visit_ident(&node.ident);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_lifetime_param<'ast, V>(v: &mut V, node: &'ast LifetimeParam)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_lifetime(&node.lifetime);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_lifetime(it);
+    }
+}
+pub fn visit_lit<'ast, V>(v: &mut V, node: &'ast Lit)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Lit::Str(_binding_0) => {
+            v.visit_lit_str(_binding_0);
+        }
+        Lit::ByteStr(_binding_0) => {
+            v.visit_lit_byte_str(_binding_0);
+        }
+        Lit::Byte(_binding_0) => {
+            v.visit_lit_byte(_binding_0);
+        }
+        Lit::Char(_binding_0) => {
+            v.visit_lit_char(_binding_0);
+        }
+        Lit::Int(_binding_0) => {
+            v.visit_lit_int(_binding_0);
+        }
+        Lit::Float(_binding_0) => {
+            v.visit_lit_float(_binding_0);
+        }
+        Lit::Bool(_binding_0) => {
+            v.visit_lit_bool(_binding_0);
+        }
+        Lit::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+pub fn visit_lit_bool<'ast, V>(v: &mut V, node: &'ast LitBool)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.value);
+    v.visit_span(&node.span);
+}
+pub fn visit_lit_byte<'ast, V>(v: &mut V, node: &'ast LitByte)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+pub fn visit_lit_byte_str<'ast, V>(v: &mut V, node: &'ast LitByteStr)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+pub fn visit_lit_char<'ast, V>(v: &mut V, node: &'ast LitChar)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+pub fn visit_lit_float<'ast, V>(v: &mut V, node: &'ast LitFloat)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+pub fn visit_lit_int<'ast, V>(v: &mut V, node: &'ast LitInt)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+pub fn visit_lit_str<'ast, V>(v: &mut V, node: &'ast LitStr)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+#[cfg(feature = "full")]
+pub fn visit_local<'ast, V>(v: &mut V, node: &'ast Local)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.let_token);
+    v.visit_pat(&node.pat);
+    if let Some(it) = &node.init {
+        v.visit_local_init(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_local_init<'ast, V>(v: &mut V, node: &'ast LocalInit)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.eq_token);
+    v.visit_expr(&*node.expr);
+    if let Some(it) = &node.diverge {
+        skip!((it).0);
+        v.visit_expr(&*(it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_macro<'ast, V>(v: &mut V, node: &'ast Macro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_path(&node.path);
+    skip!(node.bang_token);
+    v.visit_macro_delimiter(&node.delimiter);
+    skip!(node.tokens);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_macro_delimiter<'ast, V>(v: &mut V, node: &'ast MacroDelimiter)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        MacroDelimiter::Paren(_binding_0) => {
+            skip!(_binding_0);
+        }
+        MacroDelimiter::Brace(_binding_0) => {
+            skip!(_binding_0);
+        }
+        MacroDelimiter::Bracket(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_member<'ast, V>(v: &mut V, node: &'ast Member)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Member::Named(_binding_0) => {
+            v.visit_ident(_binding_0);
+        }
+        Member::Unnamed(_binding_0) => {
+            v.visit_index(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta<'ast, V>(v: &mut V, node: &'ast Meta)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Meta::Path(_binding_0) => {
+            v.visit_path(_binding_0);
+        }
+        Meta::List(_binding_0) => {
+            v.visit_meta_list(_binding_0);
+        }
+        Meta::NameValue(_binding_0) => {
+            v.visit_meta_name_value(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta_list<'ast, V>(v: &mut V, node: &'ast MetaList)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_path(&node.path);
+    v.visit_macro_delimiter(&node.delimiter);
+    skip!(node.tokens);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta_name_value<'ast, V>(v: &mut V, node: &'ast MetaNameValue)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_path(&node.path);
+    skip!(node.eq_token);
+    v.visit_expr(&node.value);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_parenthesized_generic_arguments<'ast, V>(
+    v: &mut V,
+    node: &'ast ParenthesizedGenericArguments,
+)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.inputs) {
+        let it = el.value();
+        v.visit_type(it);
+    }
+    v.visit_return_type(&node.output);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat<'ast, V>(v: &mut V, node: &'ast Pat)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Pat::Const(_binding_0) => {
+            v.visit_expr_const(_binding_0);
+        }
+        Pat::Ident(_binding_0) => {
+            v.visit_pat_ident(_binding_0);
+        }
+        Pat::Lit(_binding_0) => {
+            v.visit_expr_lit(_binding_0);
+        }
+        Pat::Macro(_binding_0) => {
+            v.visit_expr_macro(_binding_0);
+        }
+        Pat::Or(_binding_0) => {
+            v.visit_pat_or(_binding_0);
+        }
+        Pat::Paren(_binding_0) => {
+            v.visit_pat_paren(_binding_0);
+        }
+        Pat::Path(_binding_0) => {
+            v.visit_expr_path(_binding_0);
+        }
+        Pat::Range(_binding_0) => {
+            v.visit_expr_range(_binding_0);
+        }
+        Pat::Reference(_binding_0) => {
+            v.visit_pat_reference(_binding_0);
+        }
+        Pat::Rest(_binding_0) => {
+            v.visit_pat_rest(_binding_0);
+        }
+        Pat::Slice(_binding_0) => {
+            v.visit_pat_slice(_binding_0);
+        }
+        Pat::Struct(_binding_0) => {
+            v.visit_pat_struct(_binding_0);
+        }
+        Pat::Tuple(_binding_0) => {
+            v.visit_pat_tuple(_binding_0);
+        }
+        Pat::TupleStruct(_binding_0) => {
+            v.visit_pat_tuple_struct(_binding_0);
+        }
+        Pat::Type(_binding_0) => {
+            v.visit_pat_type(_binding_0);
+        }
+        Pat::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Pat::Wild(_binding_0) => {
+            v.visit_pat_wild(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_ident<'ast, V>(v: &mut V, node: &'ast PatIdent)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.by_ref);
+    skip!(node.mutability);
+    v.visit_ident(&node.ident);
+    if let Some(it) = &node.subpat {
+        skip!((it).0);
+        v.visit_pat(&*(it).1);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_or<'ast, V>(v: &mut V, node: &'ast PatOr)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.leading_vert);
+    for el in Punctuated::pairs(&node.cases) {
+        let it = el.value();
+        v.visit_pat(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_paren<'ast, V>(v: &mut V, node: &'ast PatParen)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.paren_token);
+    v.visit_pat(&*node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_reference<'ast, V>(v: &mut V, node: &'ast PatReference)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.and_token);
+    skip!(node.mutability);
+    v.visit_pat(&*node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_rest<'ast, V>(v: &mut V, node: &'ast PatRest)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.dot2_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_slice<'ast, V>(v: &mut V, node: &'ast PatSlice)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.bracket_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_pat(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_struct<'ast, V>(v: &mut V, node: &'ast PatStruct)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.qself {
+        v.visit_qself(it);
+    }
+    v.visit_path(&node.path);
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.fields) {
+        let it = el.value();
+        v.visit_field_pat(it);
+    }
+    if let Some(it) = &node.rest {
+        v.visit_pat_rest(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_tuple<'ast, V>(v: &mut V, node: &'ast PatTuple)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_pat(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_tuple_struct<'ast, V>(v: &mut V, node: &'ast PatTupleStruct)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.qself {
+        v.visit_qself(it);
+    }
+    v.visit_path(&node.path);
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_pat(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_type<'ast, V>(v: &mut V, node: &'ast PatType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_pat(&*node.pat);
+    skip!(node.colon_token);
+    v.visit_type(&*node.ty);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_wild<'ast, V>(v: &mut V, node: &'ast PatWild)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.underscore_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path<'ast, V>(v: &mut V, node: &'ast Path)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.leading_colon);
+    for el in Punctuated::pairs(&node.segments) {
+        let it = el.value();
+        v.visit_path_segment(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path_arguments<'ast, V>(v: &mut V, node: &'ast PathArguments)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        PathArguments::None => {}
+        PathArguments::AngleBracketed(_binding_0) => {
+            v.visit_angle_bracketed_generic_arguments(_binding_0);
+        }
+        PathArguments::Parenthesized(_binding_0) => {
+            v.visit_parenthesized_generic_arguments(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path_segment<'ast, V>(v: &mut V, node: &'ast PathSegment)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    v.visit_path_arguments(&node.arguments);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_predicate_lifetime<'ast, V>(v: &mut V, node: &'ast PredicateLifetime)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_lifetime(&node.lifetime);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_lifetime(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_predicate_type<'ast, V>(v: &mut V, node: &'ast PredicateType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    if let Some(it) = &node.lifetimes {
+        v.visit_bound_lifetimes(it);
+    }
+    v.visit_type(&node.bounded_ty);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_qself<'ast, V>(v: &mut V, node: &'ast QSelf)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.lt_token);
+    v.visit_type(&*node.ty);
+    skip!(node.position);
+    skip!(node.as_token);
+    skip!(node.gt_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_range_limits<'ast, V>(v: &mut V, node: &'ast RangeLimits)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        RangeLimits::HalfOpen(_binding_0) => {
+            skip!(_binding_0);
+        }
+        RangeLimits::Closed(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_receiver<'ast, V>(v: &mut V, node: &'ast Receiver)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.reference {
+        skip!((it).0);
+        if let Some(it) = &(it).1 {
+            v.visit_lifetime(it);
+        }
+    }
+    skip!(node.mutability);
+    skip!(node.self_token);
+    skip!(node.colon_token);
+    v.visit_type(&*node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_return_type<'ast, V>(v: &mut V, node: &'ast ReturnType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        ReturnType::Default => {}
+        ReturnType::Type(_binding_0, _binding_1) => {
+            skip!(_binding_0);
+            v.visit_type(&**_binding_1);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_signature<'ast, V>(v: &mut V, node: &'ast Signature)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.constness);
+    skip!(node.asyncness);
+    skip!(node.unsafety);
+    if let Some(it) = &node.abi {
+        v.visit_abi(it);
+    }
+    skip!(node.fn_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.inputs) {
+        let it = el.value();
+        v.visit_fn_arg(it);
+    }
+    if let Some(it) = &node.variadic {
+        v.visit_variadic(it);
+    }
+    v.visit_return_type(&node.output);
+}
+pub fn visit_span<'ast, V>(v: &mut V, node: &Span)
+where
+    V: Visit<'ast> + ?Sized,
+{}
+#[cfg(feature = "full")]
+pub fn visit_static_mutability<'ast, V>(v: &mut V, node: &'ast StaticMutability)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        StaticMutability::Mut(_binding_0) => {
+            skip!(_binding_0);
+        }
+        StaticMutability::None => {}
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_stmt<'ast, V>(v: &mut V, node: &'ast Stmt)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Stmt::Local(_binding_0) => {
+            v.visit_local(_binding_0);
+        }
+        Stmt::Item(_binding_0) => {
+            v.visit_item(_binding_0);
+        }
+        Stmt::Expr(_binding_0, _binding_1) => {
+            v.visit_expr(_binding_0);
+            skip!(_binding_1);
+        }
+        Stmt::Macro(_binding_0) => {
+            v.visit_stmt_macro(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_stmt_macro<'ast, V>(v: &mut V, node: &'ast StmtMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_macro(&node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_trait_bound<'ast, V>(v: &mut V, node: &'ast TraitBound)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.paren_token);
+    v.visit_trait_bound_modifier(&node.modifier);
+    if let Some(it) = &node.lifetimes {
+        v.visit_bound_lifetimes(it);
+    }
+    v.visit_path(&node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_trait_bound_modifier<'ast, V>(v: &mut V, node: &'ast TraitBoundModifier)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        TraitBoundModifier::None => {}
+        TraitBoundModifier::Maybe(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item<'ast, V>(v: &mut V, node: &'ast TraitItem)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        TraitItem::Const(_binding_0) => {
+            v.visit_trait_item_const(_binding_0);
+        }
+        TraitItem::Fn(_binding_0) => {
+            v.visit_trait_item_fn(_binding_0);
+        }
+        TraitItem::Type(_binding_0) => {
+            v.visit_trait_item_type(_binding_0);
+        }
+        TraitItem::Macro(_binding_0) => {
+            v.visit_trait_item_macro(_binding_0);
+        }
+        TraitItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_const<'ast, V>(v: &mut V, node: &'ast TraitItemConst)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.const_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.colon_token);
+    v.visit_type(&node.ty);
+    if let Some(it) = &node.default {
+        skip!((it).0);
+        v.visit_expr(&(it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_fn<'ast, V>(v: &mut V, node: &'ast TraitItemFn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_signature(&node.sig);
+    if let Some(it) = &node.default {
+        v.visit_block(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_macro<'ast, V>(v: &mut V, node: &'ast TraitItemMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_macro(&node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_type<'ast, V>(v: &mut V, node: &'ast TraitItemType)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    skip!(node.type_token);
+    v.visit_ident(&node.ident);
+    v.visit_generics(&node.generics);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+    if let Some(it) = &node.default {
+        skip!((it).0);
+        v.visit_type(&(it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type<'ast, V>(v: &mut V, node: &'ast Type)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Type::Array(_binding_0) => {
+            v.visit_type_array(_binding_0);
+        }
+        Type::BareFn(_binding_0) => {
+            v.visit_type_bare_fn(_binding_0);
+        }
+        Type::Group(_binding_0) => {
+            v.visit_type_group(_binding_0);
+        }
+        Type::ImplTrait(_binding_0) => {
+            v.visit_type_impl_trait(_binding_0);
+        }
+        Type::Infer(_binding_0) => {
+            v.visit_type_infer(_binding_0);
+        }
+        Type::Macro(_binding_0) => {
+            v.visit_type_macro(_binding_0);
+        }
+        Type::Never(_binding_0) => {
+            v.visit_type_never(_binding_0);
+        }
+        Type::Paren(_binding_0) => {
+            v.visit_type_paren(_binding_0);
+        }
+        Type::Path(_binding_0) => {
+            v.visit_type_path(_binding_0);
+        }
+        Type::Ptr(_binding_0) => {
+            v.visit_type_ptr(_binding_0);
+        }
+        Type::Reference(_binding_0) => {
+            v.visit_type_reference(_binding_0);
+        }
+        Type::Slice(_binding_0) => {
+            v.visit_type_slice(_binding_0);
+        }
+        Type::TraitObject(_binding_0) => {
+            v.visit_type_trait_object(_binding_0);
+        }
+        Type::Tuple(_binding_0) => {
+            v.visit_type_tuple(_binding_0);
+        }
+        Type::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_array<'ast, V>(v: &mut V, node: &'ast TypeArray)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.bracket_token);
+    v.visit_type(&*node.elem);
+    skip!(node.semi_token);
+    v.visit_expr(&node.len);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_bare_fn<'ast, V>(v: &mut V, node: &'ast TypeBareFn)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    if let Some(it) = &node.lifetimes {
+        v.visit_bound_lifetimes(it);
+    }
+    skip!(node.unsafety);
+    if let Some(it) = &node.abi {
+        v.visit_abi(it);
+    }
+    skip!(node.fn_token);
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.inputs) {
+        let it = el.value();
+        v.visit_bare_fn_arg(it);
+    }
+    if let Some(it) = &node.variadic {
+        v.visit_bare_variadic(it);
+    }
+    v.visit_return_type(&node.output);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_group<'ast, V>(v: &mut V, node: &'ast TypeGroup)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.group_token);
+    v.visit_type(&*node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_impl_trait<'ast, V>(v: &mut V, node: &'ast TypeImplTrait)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.impl_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_infer<'ast, V>(v: &mut V, node: &'ast TypeInfer)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.underscore_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_macro<'ast, V>(v: &mut V, node: &'ast TypeMacro)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_macro(&node.mac);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_never<'ast, V>(v: &mut V, node: &'ast TypeNever)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.bang_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_param<'ast, V>(v: &mut V, node: &'ast TypeParam)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_ident(&node.ident);
+    skip!(node.colon_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+    skip!(node.eq_token);
+    if let Some(it) = &node.default {
+        v.visit_type(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_param_bound<'ast, V>(v: &mut V, node: &'ast TypeParamBound)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        TypeParamBound::Trait(_binding_0) => {
+            v.visit_trait_bound(_binding_0);
+        }
+        TypeParamBound::Lifetime(_binding_0) => {
+            v.visit_lifetime(_binding_0);
+        }
+        TypeParamBound::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_paren<'ast, V>(v: &mut V, node: &'ast TypeParen)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.paren_token);
+    v.visit_type(&*node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_path<'ast, V>(v: &mut V, node: &'ast TypePath)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    if let Some(it) = &node.qself {
+        v.visit_qself(it);
+    }
+    v.visit_path(&node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_ptr<'ast, V>(v: &mut V, node: &'ast TypePtr)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.star_token);
+    skip!(node.const_token);
+    skip!(node.mutability);
+    v.visit_type(&*node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_reference<'ast, V>(v: &mut V, node: &'ast TypeReference)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.and_token);
+    if let Some(it) = &node.lifetime {
+        v.visit_lifetime(it);
+    }
+    skip!(node.mutability);
+    v.visit_type(&*node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_slice<'ast, V>(v: &mut V, node: &'ast TypeSlice)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.bracket_token);
+    v.visit_type(&*node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_trait_object<'ast, V>(v: &mut V, node: &'ast TypeTraitObject)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.dyn_token);
+    for el in Punctuated::pairs(&node.bounds) {
+        let it = el.value();
+        v.visit_type_param_bound(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_tuple<'ast, V>(v: &mut V, node: &'ast TypeTuple)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.paren_token);
+    for el in Punctuated::pairs(&node.elems) {
+        let it = el.value();
+        v.visit_type(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_un_op<'ast, V>(v: &mut V, node: &'ast UnOp)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        UnOp::Deref(_binding_0) => {
+            skip!(_binding_0);
+        }
+        UnOp::Not(_binding_0) => {
+            skip!(_binding_0);
+        }
+        UnOp::Neg(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_use_glob<'ast, V>(v: &mut V, node: &'ast UseGlob)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.star_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_group<'ast, V>(v: &mut V, node: &'ast UseGroup)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.brace_token);
+    for el in Punctuated::pairs(&node.items) {
+        let it = el.value();
+        v.visit_use_tree(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_use_name<'ast, V>(v: &mut V, node: &'ast UseName)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_path<'ast, V>(v: &mut V, node: &'ast UsePath)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    skip!(node.colon2_token);
+    v.visit_use_tree(&*node.tree);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_rename<'ast, V>(v: &mut V, node: &'ast UseRename)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    v.visit_ident(&node.ident);
+    skip!(node.as_token);
+    v.visit_ident(&node.rename);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_tree<'ast, V>(v: &mut V, node: &'ast UseTree)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        UseTree::Path(_binding_0) => {
+            v.visit_use_path(_binding_0);
+        }
+        UseTree::Name(_binding_0) => {
+            v.visit_use_name(_binding_0);
+        }
+        UseTree::Rename(_binding_0) => {
+            v.visit_use_rename(_binding_0);
+        }
+        UseTree::Glob(_binding_0) => {
+            v.visit_use_glob(_binding_0);
+        }
+        UseTree::Group(_binding_0) => {
+            v.visit_use_group(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_variadic<'ast, V>(v: &mut V, node: &'ast Variadic)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    if let Some(it) = &node.pat {
+        v.visit_pat(&*(it).0);
+        skip!((it).1);
+    }
+    skip!(node.dots);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_variant<'ast, V>(v: &mut V, node: &'ast Variant)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    for it in &node.attrs {
+        v.visit_attribute(it);
+    }
+    v.visit_ident(&node.ident);
+    v.visit_fields(&node.fields);
+    if let Some(it) = &node.discriminant {
+        skip!((it).0);
+        v.visit_expr(&(it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_vis_restricted<'ast, V>(v: &mut V, node: &'ast VisRestricted)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.pub_token);
+    skip!(node.paren_token);
+    skip!(node.in_token);
+    v.visit_path(&*node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_visibility<'ast, V>(v: &mut V, node: &'ast Visibility)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        Visibility::Public(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Visibility::Restricted(_binding_0) => {
+            v.visit_vis_restricted(_binding_0);
+        }
+        Visibility::Inherited => {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_where_clause<'ast, V>(v: &mut V, node: &'ast WhereClause)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    skip!(node.where_token);
+    for el in Punctuated::pairs(&node.predicates) {
+        let it = el.value();
+        v.visit_where_predicate(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_where_predicate<'ast, V>(v: &mut V, node: &'ast WherePredicate)
+where
+    V: Visit<'ast> + ?Sized,
+{
+    match node {
+        WherePredicate::Lifetime(_binding_0) => {
+            v.visit_predicate_lifetime(_binding_0);
+        }
+        WherePredicate::Type(_binding_0) => {
+            v.visit_predicate_type(_binding_0);
+        }
+    }
+}
diff --git a/vendor/syn/src/gen/visit_mut.rs b/vendor/syn/src/gen/visit_mut.rs
new file mode 100644
index 0000000..9e7d16f
--- /dev/null
+++ b/vendor/syn/src/gen/visit_mut.rs
@@ -0,0 +1,3505 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#![allow(unused_variables)]
+#![allow(clippy::needless_pass_by_ref_mut)]
+#[cfg(any(feature = "full", feature = "derive"))]
+use crate::punctuated::Punctuated;
+use crate::*;
+use proc_macro2::Span;
+#[cfg(feature = "full")]
+macro_rules! full {
+    ($e:expr) => {
+        $e
+    };
+}
+#[cfg(all(feature = "derive", not(feature = "full")))]
+macro_rules! full {
+    ($e:expr) => {
+        unreachable!()
+    };
+}
+macro_rules! skip {
+    ($($tt:tt)*) => {};
+}
+/// Syntax tree traversal to mutate an exclusive borrow of a syntax tree in
+/// place.
+///
+/// See the [module documentation] for details.
+///
+/// [module documentation]: self
+pub trait VisitMut {
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_abi_mut(&mut self, i: &mut Abi) {
+        visit_abi_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_angle_bracketed_generic_arguments_mut(
+        &mut self,
+        i: &mut AngleBracketedGenericArguments,
+    ) {
+        visit_angle_bracketed_generic_arguments_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_arm_mut(&mut self, i: &mut Arm) {
+        visit_arm_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_assoc_const_mut(&mut self, i: &mut AssocConst) {
+        visit_assoc_const_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_assoc_type_mut(&mut self, i: &mut AssocType) {
+        visit_assoc_type_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_attr_style_mut(&mut self, i: &mut AttrStyle) {
+        visit_attr_style_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_attribute_mut(&mut self, i: &mut Attribute) {
+        visit_attribute_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bare_fn_arg_mut(&mut self, i: &mut BareFnArg) {
+        visit_bare_fn_arg_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bare_variadic_mut(&mut self, i: &mut BareVariadic) {
+        visit_bare_variadic_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bin_op_mut(&mut self, i: &mut BinOp) {
+        visit_bin_op_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_block_mut(&mut self, i: &mut Block) {
+        visit_block_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_bound_lifetimes_mut(&mut self, i: &mut BoundLifetimes) {
+        visit_bound_lifetimes_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_const_param_mut(&mut self, i: &mut ConstParam) {
+        visit_const_param_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_constraint_mut(&mut self, i: &mut Constraint) {
+        visit_constraint_mut(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_mut(&mut self, i: &mut Data) {
+        visit_data_mut(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_enum_mut(&mut self, i: &mut DataEnum) {
+        visit_data_enum_mut(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_struct_mut(&mut self, i: &mut DataStruct) {
+        visit_data_struct_mut(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_data_union_mut(&mut self, i: &mut DataUnion) {
+        visit_data_union_mut(self, i);
+    }
+    #[cfg(feature = "derive")]
+    fn visit_derive_input_mut(&mut self, i: &mut DeriveInput) {
+        visit_derive_input_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_mut(&mut self, i: &mut Expr) {
+        visit_expr_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_array_mut(&mut self, i: &mut ExprArray) {
+        visit_expr_array_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_assign_mut(&mut self, i: &mut ExprAssign) {
+        visit_expr_assign_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_async_mut(&mut self, i: &mut ExprAsync) {
+        visit_expr_async_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_await_mut(&mut self, i: &mut ExprAwait) {
+        visit_expr_await_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_binary_mut(&mut self, i: &mut ExprBinary) {
+        visit_expr_binary_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_block_mut(&mut self, i: &mut ExprBlock) {
+        visit_expr_block_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_break_mut(&mut self, i: &mut ExprBreak) {
+        visit_expr_break_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_call_mut(&mut self, i: &mut ExprCall) {
+        visit_expr_call_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_cast_mut(&mut self, i: &mut ExprCast) {
+        visit_expr_cast_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_closure_mut(&mut self, i: &mut ExprClosure) {
+        visit_expr_closure_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_const_mut(&mut self, i: &mut ExprConst) {
+        visit_expr_const_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_continue_mut(&mut self, i: &mut ExprContinue) {
+        visit_expr_continue_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_field_mut(&mut self, i: &mut ExprField) {
+        visit_expr_field_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_for_loop_mut(&mut self, i: &mut ExprForLoop) {
+        visit_expr_for_loop_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_group_mut(&mut self, i: &mut ExprGroup) {
+        visit_expr_group_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_if_mut(&mut self, i: &mut ExprIf) {
+        visit_expr_if_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_index_mut(&mut self, i: &mut ExprIndex) {
+        visit_expr_index_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_infer_mut(&mut self, i: &mut ExprInfer) {
+        visit_expr_infer_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_let_mut(&mut self, i: &mut ExprLet) {
+        visit_expr_let_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_lit_mut(&mut self, i: &mut ExprLit) {
+        visit_expr_lit_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_loop_mut(&mut self, i: &mut ExprLoop) {
+        visit_expr_loop_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_macro_mut(&mut self, i: &mut ExprMacro) {
+        visit_expr_macro_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_match_mut(&mut self, i: &mut ExprMatch) {
+        visit_expr_match_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_method_call_mut(&mut self, i: &mut ExprMethodCall) {
+        visit_expr_method_call_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_paren_mut(&mut self, i: &mut ExprParen) {
+        visit_expr_paren_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_path_mut(&mut self, i: &mut ExprPath) {
+        visit_expr_path_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_range_mut(&mut self, i: &mut ExprRange) {
+        visit_expr_range_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_reference_mut(&mut self, i: &mut ExprReference) {
+        visit_expr_reference_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_repeat_mut(&mut self, i: &mut ExprRepeat) {
+        visit_expr_repeat_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_return_mut(&mut self, i: &mut ExprReturn) {
+        visit_expr_return_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_struct_mut(&mut self, i: &mut ExprStruct) {
+        visit_expr_struct_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_try_mut(&mut self, i: &mut ExprTry) {
+        visit_expr_try_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_try_block_mut(&mut self, i: &mut ExprTryBlock) {
+        visit_expr_try_block_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_tuple_mut(&mut self, i: &mut ExprTuple) {
+        visit_expr_tuple_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_expr_unary_mut(&mut self, i: &mut ExprUnary) {
+        visit_expr_unary_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_unsafe_mut(&mut self, i: &mut ExprUnsafe) {
+        visit_expr_unsafe_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_while_mut(&mut self, i: &mut ExprWhile) {
+        visit_expr_while_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_expr_yield_mut(&mut self, i: &mut ExprYield) {
+        visit_expr_yield_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_field_mut(&mut self, i: &mut Field) {
+        visit_field_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_field_mutability_mut(&mut self, i: &mut FieldMutability) {
+        visit_field_mutability_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_field_pat_mut(&mut self, i: &mut FieldPat) {
+        visit_field_pat_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_field_value_mut(&mut self, i: &mut FieldValue) {
+        visit_field_value_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields_mut(&mut self, i: &mut Fields) {
+        visit_fields_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields_named_mut(&mut self, i: &mut FieldsNamed) {
+        visit_fields_named_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_fields_unnamed_mut(&mut self, i: &mut FieldsUnnamed) {
+        visit_fields_unnamed_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_file_mut(&mut self, i: &mut File) {
+        visit_file_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_fn_arg_mut(&mut self, i: &mut FnArg) {
+        visit_fn_arg_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_mut(&mut self, i: &mut ForeignItem) {
+        visit_foreign_item_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_fn_mut(&mut self, i: &mut ForeignItemFn) {
+        visit_foreign_item_fn_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_macro_mut(&mut self, i: &mut ForeignItemMacro) {
+        visit_foreign_item_macro_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_static_mut(&mut self, i: &mut ForeignItemStatic) {
+        visit_foreign_item_static_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_foreign_item_type_mut(&mut self, i: &mut ForeignItemType) {
+        visit_foreign_item_type_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generic_argument_mut(&mut self, i: &mut GenericArgument) {
+        visit_generic_argument_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generic_param_mut(&mut self, i: &mut GenericParam) {
+        visit_generic_param_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_generics_mut(&mut self, i: &mut Generics) {
+        visit_generics_mut(self, i);
+    }
+    fn visit_ident_mut(&mut self, i: &mut Ident) {
+        visit_ident_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_mut(&mut self, i: &mut ImplItem) {
+        visit_impl_item_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_const_mut(&mut self, i: &mut ImplItemConst) {
+        visit_impl_item_const_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_fn_mut(&mut self, i: &mut ImplItemFn) {
+        visit_impl_item_fn_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_macro_mut(&mut self, i: &mut ImplItemMacro) {
+        visit_impl_item_macro_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_item_type_mut(&mut self, i: &mut ImplItemType) {
+        visit_impl_item_type_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_impl_restriction_mut(&mut self, i: &mut ImplRestriction) {
+        visit_impl_restriction_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_index_mut(&mut self, i: &mut Index) {
+        visit_index_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_mut(&mut self, i: &mut Item) {
+        visit_item_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_const_mut(&mut self, i: &mut ItemConst) {
+        visit_item_const_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_enum_mut(&mut self, i: &mut ItemEnum) {
+        visit_item_enum_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_extern_crate_mut(&mut self, i: &mut ItemExternCrate) {
+        visit_item_extern_crate_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_fn_mut(&mut self, i: &mut ItemFn) {
+        visit_item_fn_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_foreign_mod_mut(&mut self, i: &mut ItemForeignMod) {
+        visit_item_foreign_mod_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_impl_mut(&mut self, i: &mut ItemImpl) {
+        visit_item_impl_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_macro_mut(&mut self, i: &mut ItemMacro) {
+        visit_item_macro_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_mod_mut(&mut self, i: &mut ItemMod) {
+        visit_item_mod_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_static_mut(&mut self, i: &mut ItemStatic) {
+        visit_item_static_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_struct_mut(&mut self, i: &mut ItemStruct) {
+        visit_item_struct_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_trait_mut(&mut self, i: &mut ItemTrait) {
+        visit_item_trait_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_trait_alias_mut(&mut self, i: &mut ItemTraitAlias) {
+        visit_item_trait_alias_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_type_mut(&mut self, i: &mut ItemType) {
+        visit_item_type_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_union_mut(&mut self, i: &mut ItemUnion) {
+        visit_item_union_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_item_use_mut(&mut self, i: &mut ItemUse) {
+        visit_item_use_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_label_mut(&mut self, i: &mut Label) {
+        visit_label_mut(self, i);
+    }
+    fn visit_lifetime_mut(&mut self, i: &mut Lifetime) {
+        visit_lifetime_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_lifetime_param_mut(&mut self, i: &mut LifetimeParam) {
+        visit_lifetime_param_mut(self, i);
+    }
+    fn visit_lit_mut(&mut self, i: &mut Lit) {
+        visit_lit_mut(self, i);
+    }
+    fn visit_lit_bool_mut(&mut self, i: &mut LitBool) {
+        visit_lit_bool_mut(self, i);
+    }
+    fn visit_lit_byte_mut(&mut self, i: &mut LitByte) {
+        visit_lit_byte_mut(self, i);
+    }
+    fn visit_lit_byte_str_mut(&mut self, i: &mut LitByteStr) {
+        visit_lit_byte_str_mut(self, i);
+    }
+    fn visit_lit_char_mut(&mut self, i: &mut LitChar) {
+        visit_lit_char_mut(self, i);
+    }
+    fn visit_lit_float_mut(&mut self, i: &mut LitFloat) {
+        visit_lit_float_mut(self, i);
+    }
+    fn visit_lit_int_mut(&mut self, i: &mut LitInt) {
+        visit_lit_int_mut(self, i);
+    }
+    fn visit_lit_str_mut(&mut self, i: &mut LitStr) {
+        visit_lit_str_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_local_mut(&mut self, i: &mut Local) {
+        visit_local_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_local_init_mut(&mut self, i: &mut LocalInit) {
+        visit_local_init_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_macro_mut(&mut self, i: &mut Macro) {
+        visit_macro_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_macro_delimiter_mut(&mut self, i: &mut MacroDelimiter) {
+        visit_macro_delimiter_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_member_mut(&mut self, i: &mut Member) {
+        visit_member_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta_mut(&mut self, i: &mut Meta) {
+        visit_meta_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta_list_mut(&mut self, i: &mut MetaList) {
+        visit_meta_list_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_meta_name_value_mut(&mut self, i: &mut MetaNameValue) {
+        visit_meta_name_value_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_parenthesized_generic_arguments_mut(
+        &mut self,
+        i: &mut ParenthesizedGenericArguments,
+    ) {
+        visit_parenthesized_generic_arguments_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_mut(&mut self, i: &mut Pat) {
+        visit_pat_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_ident_mut(&mut self, i: &mut PatIdent) {
+        visit_pat_ident_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_or_mut(&mut self, i: &mut PatOr) {
+        visit_pat_or_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_paren_mut(&mut self, i: &mut PatParen) {
+        visit_pat_paren_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_reference_mut(&mut self, i: &mut PatReference) {
+        visit_pat_reference_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_rest_mut(&mut self, i: &mut PatRest) {
+        visit_pat_rest_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_slice_mut(&mut self, i: &mut PatSlice) {
+        visit_pat_slice_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_struct_mut(&mut self, i: &mut PatStruct) {
+        visit_pat_struct_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_tuple_mut(&mut self, i: &mut PatTuple) {
+        visit_pat_tuple_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_tuple_struct_mut(&mut self, i: &mut PatTupleStruct) {
+        visit_pat_tuple_struct_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_type_mut(&mut self, i: &mut PatType) {
+        visit_pat_type_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_pat_wild_mut(&mut self, i: &mut PatWild) {
+        visit_pat_wild_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path_mut(&mut self, i: &mut Path) {
+        visit_path_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path_arguments_mut(&mut self, i: &mut PathArguments) {
+        visit_path_arguments_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_path_segment_mut(&mut self, i: &mut PathSegment) {
+        visit_path_segment_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_predicate_lifetime_mut(&mut self, i: &mut PredicateLifetime) {
+        visit_predicate_lifetime_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_predicate_type_mut(&mut self, i: &mut PredicateType) {
+        visit_predicate_type_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_qself_mut(&mut self, i: &mut QSelf) {
+        visit_qself_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_range_limits_mut(&mut self, i: &mut RangeLimits) {
+        visit_range_limits_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_receiver_mut(&mut self, i: &mut Receiver) {
+        visit_receiver_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_return_type_mut(&mut self, i: &mut ReturnType) {
+        visit_return_type_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_signature_mut(&mut self, i: &mut Signature) {
+        visit_signature_mut(self, i);
+    }
+    fn visit_span_mut(&mut self, i: &mut Span) {
+        visit_span_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_static_mutability_mut(&mut self, i: &mut StaticMutability) {
+        visit_static_mutability_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_stmt_mut(&mut self, i: &mut Stmt) {
+        visit_stmt_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_stmt_macro_mut(&mut self, i: &mut StmtMacro) {
+        visit_stmt_macro_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_trait_bound_mut(&mut self, i: &mut TraitBound) {
+        visit_trait_bound_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_trait_bound_modifier_mut(&mut self, i: &mut TraitBoundModifier) {
+        visit_trait_bound_modifier_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_mut(&mut self, i: &mut TraitItem) {
+        visit_trait_item_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_const_mut(&mut self, i: &mut TraitItemConst) {
+        visit_trait_item_const_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_fn_mut(&mut self, i: &mut TraitItemFn) {
+        visit_trait_item_fn_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_macro_mut(&mut self, i: &mut TraitItemMacro) {
+        visit_trait_item_macro_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_trait_item_type_mut(&mut self, i: &mut TraitItemType) {
+        visit_trait_item_type_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_mut(&mut self, i: &mut Type) {
+        visit_type_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_array_mut(&mut self, i: &mut TypeArray) {
+        visit_type_array_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_bare_fn_mut(&mut self, i: &mut TypeBareFn) {
+        visit_type_bare_fn_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_group_mut(&mut self, i: &mut TypeGroup) {
+        visit_type_group_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_impl_trait_mut(&mut self, i: &mut TypeImplTrait) {
+        visit_type_impl_trait_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_infer_mut(&mut self, i: &mut TypeInfer) {
+        visit_type_infer_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_macro_mut(&mut self, i: &mut TypeMacro) {
+        visit_type_macro_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_never_mut(&mut self, i: &mut TypeNever) {
+        visit_type_never_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_param_mut(&mut self, i: &mut TypeParam) {
+        visit_type_param_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_param_bound_mut(&mut self, i: &mut TypeParamBound) {
+        visit_type_param_bound_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_paren_mut(&mut self, i: &mut TypeParen) {
+        visit_type_paren_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_path_mut(&mut self, i: &mut TypePath) {
+        visit_type_path_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_ptr_mut(&mut self, i: &mut TypePtr) {
+        visit_type_ptr_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_reference_mut(&mut self, i: &mut TypeReference) {
+        visit_type_reference_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_slice_mut(&mut self, i: &mut TypeSlice) {
+        visit_type_slice_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_trait_object_mut(&mut self, i: &mut TypeTraitObject) {
+        visit_type_trait_object_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_type_tuple_mut(&mut self, i: &mut TypeTuple) {
+        visit_type_tuple_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_un_op_mut(&mut self, i: &mut UnOp) {
+        visit_un_op_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_glob_mut(&mut self, i: &mut UseGlob) {
+        visit_use_glob_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_group_mut(&mut self, i: &mut UseGroup) {
+        visit_use_group_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_name_mut(&mut self, i: &mut UseName) {
+        visit_use_name_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_path_mut(&mut self, i: &mut UsePath) {
+        visit_use_path_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_rename_mut(&mut self, i: &mut UseRename) {
+        visit_use_rename_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_use_tree_mut(&mut self, i: &mut UseTree) {
+        visit_use_tree_mut(self, i);
+    }
+    #[cfg(feature = "full")]
+    fn visit_variadic_mut(&mut self, i: &mut Variadic) {
+        visit_variadic_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_variant_mut(&mut self, i: &mut Variant) {
+        visit_variant_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_vis_restricted_mut(&mut self, i: &mut VisRestricted) {
+        visit_vis_restricted_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_visibility_mut(&mut self, i: &mut Visibility) {
+        visit_visibility_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_where_clause_mut(&mut self, i: &mut WhereClause) {
+        visit_where_clause_mut(self, i);
+    }
+    #[cfg(any(feature = "derive", feature = "full"))]
+    fn visit_where_predicate_mut(&mut self, i: &mut WherePredicate) {
+        visit_where_predicate_mut(self, i);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_abi_mut<V>(v: &mut V, node: &mut Abi)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.extern_token);
+    if let Some(it) = &mut node.name {
+        v.visit_lit_str_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_angle_bracketed_generic_arguments_mut<V>(
+    v: &mut V,
+    node: &mut AngleBracketedGenericArguments,
+)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.colon2_token);
+    skip!(node.lt_token);
+    for mut el in Punctuated::pairs_mut(&mut node.args) {
+        let it = el.value_mut();
+        v.visit_generic_argument_mut(it);
+    }
+    skip!(node.gt_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_arm_mut<V>(v: &mut V, node: &mut Arm)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_pat_mut(&mut node.pat);
+    if let Some(it) = &mut node.guard {
+        skip!((it).0);
+        v.visit_expr_mut(&mut *(it).1);
+    }
+    skip!(node.fat_arrow_token);
+    v.visit_expr_mut(&mut *node.body);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_assoc_const_mut<V>(v: &mut V, node: &mut AssocConst)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.generics {
+        v.visit_angle_bracketed_generic_arguments_mut(it);
+    }
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut node.value);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_assoc_type_mut<V>(v: &mut V, node: &mut AssocType)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.generics {
+        v.visit_angle_bracketed_generic_arguments_mut(it);
+    }
+    skip!(node.eq_token);
+    v.visit_type_mut(&mut node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_attr_style_mut<V>(v: &mut V, node: &mut AttrStyle)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        AttrStyle::Outer => {}
+        AttrStyle::Inner(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_attribute_mut<V>(v: &mut V, node: &mut Attribute)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.pound_token);
+    v.visit_attr_style_mut(&mut node.style);
+    skip!(node.bracket_token);
+    v.visit_meta_mut(&mut node.meta);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bare_fn_arg_mut<V>(v: &mut V, node: &mut BareFnArg)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.name {
+        v.visit_ident_mut(&mut (it).0);
+        skip!((it).1);
+    }
+    v.visit_type_mut(&mut node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bare_variadic_mut<V>(v: &mut V, node: &mut BareVariadic)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.name {
+        v.visit_ident_mut(&mut (it).0);
+        skip!((it).1);
+    }
+    skip!(node.dots);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bin_op_mut<V>(v: &mut V, node: &mut BinOp)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        BinOp::Add(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Sub(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Mul(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Div(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Rem(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::And(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Or(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitXor(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitAnd(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitOr(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Shl(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Shr(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Eq(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Lt(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Le(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Ne(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Ge(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::Gt(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::AddAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::SubAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::MulAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::DivAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::RemAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitXorAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitAndAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::BitOrAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::ShlAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+        BinOp::ShrAssign(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_block_mut<V>(v: &mut V, node: &mut Block)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.brace_token);
+    for it in &mut node.stmts {
+        v.visit_stmt_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_bound_lifetimes_mut<V>(v: &mut V, node: &mut BoundLifetimes)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.for_token);
+    skip!(node.lt_token);
+    for mut el in Punctuated::pairs_mut(&mut node.lifetimes) {
+        let it = el.value_mut();
+        v.visit_generic_param_mut(it);
+    }
+    skip!(node.gt_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_const_param_mut<V>(v: &mut V, node: &mut ConstParam)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.const_token);
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut node.ty);
+    skip!(node.eq_token);
+    if let Some(it) = &mut node.default {
+        v.visit_expr_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_constraint_mut<V>(v: &mut V, node: &mut Constraint)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.generics {
+        v.visit_angle_bracketed_generic_arguments_mut(it);
+    }
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_mut<V>(v: &mut V, node: &mut Data)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Data::Struct(_binding_0) => {
+            v.visit_data_struct_mut(_binding_0);
+        }
+        Data::Enum(_binding_0) => {
+            v.visit_data_enum_mut(_binding_0);
+        }
+        Data::Union(_binding_0) => {
+            v.visit_data_union_mut(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_enum_mut<V>(v: &mut V, node: &mut DataEnum)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.enum_token);
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.variants) {
+        let it = el.value_mut();
+        v.visit_variant_mut(it);
+    }
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_struct_mut<V>(v: &mut V, node: &mut DataStruct)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.struct_token);
+    v.visit_fields_mut(&mut node.fields);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "derive")]
+pub fn visit_data_union_mut<V>(v: &mut V, node: &mut DataUnion)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.union_token);
+    v.visit_fields_named_mut(&mut node.fields);
+}
+#[cfg(feature = "derive")]
+pub fn visit_derive_input_mut<V>(v: &mut V, node: &mut DeriveInput)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    v.visit_data_mut(&mut node.data);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_mut<V>(v: &mut V, node: &mut Expr)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Expr::Array(_binding_0) => {
+            full!(v.visit_expr_array_mut(_binding_0));
+        }
+        Expr::Assign(_binding_0) => {
+            full!(v.visit_expr_assign_mut(_binding_0));
+        }
+        Expr::Async(_binding_0) => {
+            full!(v.visit_expr_async_mut(_binding_0));
+        }
+        Expr::Await(_binding_0) => {
+            full!(v.visit_expr_await_mut(_binding_0));
+        }
+        Expr::Binary(_binding_0) => {
+            v.visit_expr_binary_mut(_binding_0);
+        }
+        Expr::Block(_binding_0) => {
+            full!(v.visit_expr_block_mut(_binding_0));
+        }
+        Expr::Break(_binding_0) => {
+            full!(v.visit_expr_break_mut(_binding_0));
+        }
+        Expr::Call(_binding_0) => {
+            v.visit_expr_call_mut(_binding_0);
+        }
+        Expr::Cast(_binding_0) => {
+            v.visit_expr_cast_mut(_binding_0);
+        }
+        Expr::Closure(_binding_0) => {
+            full!(v.visit_expr_closure_mut(_binding_0));
+        }
+        Expr::Const(_binding_0) => {
+            full!(v.visit_expr_const_mut(_binding_0));
+        }
+        Expr::Continue(_binding_0) => {
+            full!(v.visit_expr_continue_mut(_binding_0));
+        }
+        Expr::Field(_binding_0) => {
+            v.visit_expr_field_mut(_binding_0);
+        }
+        Expr::ForLoop(_binding_0) => {
+            full!(v.visit_expr_for_loop_mut(_binding_0));
+        }
+        Expr::Group(_binding_0) => {
+            v.visit_expr_group_mut(_binding_0);
+        }
+        Expr::If(_binding_0) => {
+            full!(v.visit_expr_if_mut(_binding_0));
+        }
+        Expr::Index(_binding_0) => {
+            v.visit_expr_index_mut(_binding_0);
+        }
+        Expr::Infer(_binding_0) => {
+            full!(v.visit_expr_infer_mut(_binding_0));
+        }
+        Expr::Let(_binding_0) => {
+            full!(v.visit_expr_let_mut(_binding_0));
+        }
+        Expr::Lit(_binding_0) => {
+            v.visit_expr_lit_mut(_binding_0);
+        }
+        Expr::Loop(_binding_0) => {
+            full!(v.visit_expr_loop_mut(_binding_0));
+        }
+        Expr::Macro(_binding_0) => {
+            v.visit_expr_macro_mut(_binding_0);
+        }
+        Expr::Match(_binding_0) => {
+            full!(v.visit_expr_match_mut(_binding_0));
+        }
+        Expr::MethodCall(_binding_0) => {
+            full!(v.visit_expr_method_call_mut(_binding_0));
+        }
+        Expr::Paren(_binding_0) => {
+            v.visit_expr_paren_mut(_binding_0);
+        }
+        Expr::Path(_binding_0) => {
+            v.visit_expr_path_mut(_binding_0);
+        }
+        Expr::Range(_binding_0) => {
+            full!(v.visit_expr_range_mut(_binding_0));
+        }
+        Expr::Reference(_binding_0) => {
+            full!(v.visit_expr_reference_mut(_binding_0));
+        }
+        Expr::Repeat(_binding_0) => {
+            full!(v.visit_expr_repeat_mut(_binding_0));
+        }
+        Expr::Return(_binding_0) => {
+            full!(v.visit_expr_return_mut(_binding_0));
+        }
+        Expr::Struct(_binding_0) => {
+            full!(v.visit_expr_struct_mut(_binding_0));
+        }
+        Expr::Try(_binding_0) => {
+            full!(v.visit_expr_try_mut(_binding_0));
+        }
+        Expr::TryBlock(_binding_0) => {
+            full!(v.visit_expr_try_block_mut(_binding_0));
+        }
+        Expr::Tuple(_binding_0) => {
+            full!(v.visit_expr_tuple_mut(_binding_0));
+        }
+        Expr::Unary(_binding_0) => {
+            v.visit_expr_unary_mut(_binding_0);
+        }
+        Expr::Unsafe(_binding_0) => {
+            full!(v.visit_expr_unsafe_mut(_binding_0));
+        }
+        Expr::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Expr::While(_binding_0) => {
+            full!(v.visit_expr_while_mut(_binding_0));
+        }
+        Expr::Yield(_binding_0) => {
+            full!(v.visit_expr_yield_mut(_binding_0));
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_array_mut<V>(v: &mut V, node: &mut ExprArray)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.bracket_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_expr_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_assign_mut<V>(v: &mut V, node: &mut ExprAssign)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.left);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut *node.right);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_async_mut<V>(v: &mut V, node: &mut ExprAsync)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.async_token);
+    skip!(node.capture);
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_await_mut<V>(v: &mut V, node: &mut ExprAwait)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.base);
+    skip!(node.dot_token);
+    skip!(node.await_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_binary_mut<V>(v: &mut V, node: &mut ExprBinary)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.left);
+    v.visit_bin_op_mut(&mut node.op);
+    v.visit_expr_mut(&mut *node.right);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_block_mut<V>(v: &mut V, node: &mut ExprBlock)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.label {
+        v.visit_label_mut(it);
+    }
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_break_mut<V>(v: &mut V, node: &mut ExprBreak)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.break_token);
+    if let Some(it) = &mut node.label {
+        v.visit_lifetime_mut(it);
+    }
+    if let Some(it) = &mut node.expr {
+        v.visit_expr_mut(&mut **it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_call_mut<V>(v: &mut V, node: &mut ExprCall)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.func);
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.args) {
+        let it = el.value_mut();
+        v.visit_expr_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_cast_mut<V>(v: &mut V, node: &mut ExprCast)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.as_token);
+    v.visit_type_mut(&mut *node.ty);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_closure_mut<V>(v: &mut V, node: &mut ExprClosure)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.lifetimes {
+        v.visit_bound_lifetimes_mut(it);
+    }
+    skip!(node.constness);
+    skip!(node.movability);
+    skip!(node.asyncness);
+    skip!(node.capture);
+    skip!(node.or1_token);
+    for mut el in Punctuated::pairs_mut(&mut node.inputs) {
+        let it = el.value_mut();
+        v.visit_pat_mut(it);
+    }
+    skip!(node.or2_token);
+    v.visit_return_type_mut(&mut node.output);
+    v.visit_expr_mut(&mut *node.body);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_const_mut<V>(v: &mut V, node: &mut ExprConst)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.const_token);
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_continue_mut<V>(v: &mut V, node: &mut ExprContinue)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.continue_token);
+    if let Some(it) = &mut node.label {
+        v.visit_lifetime_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_field_mut<V>(v: &mut V, node: &mut ExprField)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.base);
+    skip!(node.dot_token);
+    v.visit_member_mut(&mut node.member);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_for_loop_mut<V>(v: &mut V, node: &mut ExprForLoop)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.label {
+        v.visit_label_mut(it);
+    }
+    skip!(node.for_token);
+    v.visit_pat_mut(&mut *node.pat);
+    skip!(node.in_token);
+    v.visit_expr_mut(&mut *node.expr);
+    v.visit_block_mut(&mut node.body);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_group_mut<V>(v: &mut V, node: &mut ExprGroup)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.group_token);
+    v.visit_expr_mut(&mut *node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_if_mut<V>(v: &mut V, node: &mut ExprIf)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.if_token);
+    v.visit_expr_mut(&mut *node.cond);
+    v.visit_block_mut(&mut node.then_branch);
+    if let Some(it) = &mut node.else_branch {
+        skip!((it).0);
+        v.visit_expr_mut(&mut *(it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_index_mut<V>(v: &mut V, node: &mut ExprIndex)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.bracket_token);
+    v.visit_expr_mut(&mut *node.index);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_infer_mut<V>(v: &mut V, node: &mut ExprInfer)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.underscore_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_let_mut<V>(v: &mut V, node: &mut ExprLet)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.let_token);
+    v.visit_pat_mut(&mut *node.pat);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut *node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_lit_mut<V>(v: &mut V, node: &mut ExprLit)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_lit_mut(&mut node.lit);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_loop_mut<V>(v: &mut V, node: &mut ExprLoop)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.label {
+        v.visit_label_mut(it);
+    }
+    skip!(node.loop_token);
+    v.visit_block_mut(&mut node.body);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_macro_mut<V>(v: &mut V, node: &mut ExprMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_match_mut<V>(v: &mut V, node: &mut ExprMatch)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.match_token);
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.brace_token);
+    for it in &mut node.arms {
+        v.visit_arm_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_method_call_mut<V>(v: &mut V, node: &mut ExprMethodCall)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.receiver);
+    skip!(node.dot_token);
+    v.visit_ident_mut(&mut node.method);
+    if let Some(it) = &mut node.turbofish {
+        v.visit_angle_bracketed_generic_arguments_mut(it);
+    }
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.args) {
+        let it = el.value_mut();
+        v.visit_expr_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_paren_mut<V>(v: &mut V, node: &mut ExprParen)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.paren_token);
+    v.visit_expr_mut(&mut *node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_path_mut<V>(v: &mut V, node: &mut ExprPath)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.qself {
+        v.visit_qself_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_range_mut<V>(v: &mut V, node: &mut ExprRange)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.start {
+        v.visit_expr_mut(&mut **it);
+    }
+    v.visit_range_limits_mut(&mut node.limits);
+    if let Some(it) = &mut node.end {
+        v.visit_expr_mut(&mut **it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_reference_mut<V>(v: &mut V, node: &mut ExprReference)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.and_token);
+    skip!(node.mutability);
+    v.visit_expr_mut(&mut *node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_repeat_mut<V>(v: &mut V, node: &mut ExprRepeat)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.bracket_token);
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.semi_token);
+    v.visit_expr_mut(&mut *node.len);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_return_mut<V>(v: &mut V, node: &mut ExprReturn)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.return_token);
+    if let Some(it) = &mut node.expr {
+        v.visit_expr_mut(&mut **it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_struct_mut<V>(v: &mut V, node: &mut ExprStruct)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.qself {
+        v.visit_qself_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.fields) {
+        let it = el.value_mut();
+        v.visit_field_value_mut(it);
+    }
+    skip!(node.dot2_token);
+    if let Some(it) = &mut node.rest {
+        v.visit_expr_mut(&mut **it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_try_mut<V>(v: &mut V, node: &mut ExprTry)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.question_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_try_block_mut<V>(v: &mut V, node: &mut ExprTryBlock)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.try_token);
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_tuple_mut<V>(v: &mut V, node: &mut ExprTuple)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_expr_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_expr_unary_mut<V>(v: &mut V, node: &mut ExprUnary)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_un_op_mut(&mut node.op);
+    v.visit_expr_mut(&mut *node.expr);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_unsafe_mut<V>(v: &mut V, node: &mut ExprUnsafe)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.unsafe_token);
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_while_mut<V>(v: &mut V, node: &mut ExprWhile)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.label {
+        v.visit_label_mut(it);
+    }
+    skip!(node.while_token);
+    v.visit_expr_mut(&mut *node.cond);
+    v.visit_block_mut(&mut node.body);
+}
+#[cfg(feature = "full")]
+pub fn visit_expr_yield_mut<V>(v: &mut V, node: &mut ExprYield)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.yield_token);
+    if let Some(it) = &mut node.expr {
+        v.visit_expr_mut(&mut **it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_field_mut<V>(v: &mut V, node: &mut Field)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    v.visit_field_mutability_mut(&mut node.mutability);
+    if let Some(it) = &mut node.ident {
+        v.visit_ident_mut(it);
+    }
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_field_mutability_mut<V>(v: &mut V, node: &mut FieldMutability)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        FieldMutability::None => {}
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_field_pat_mut<V>(v: &mut V, node: &mut FieldPat)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_member_mut(&mut node.member);
+    skip!(node.colon_token);
+    v.visit_pat_mut(&mut *node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_field_value_mut<V>(v: &mut V, node: &mut FieldValue)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_member_mut(&mut node.member);
+    skip!(node.colon_token);
+    v.visit_expr_mut(&mut node.expr);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields_mut<V>(v: &mut V, node: &mut Fields)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Fields::Named(_binding_0) => {
+            v.visit_fields_named_mut(_binding_0);
+        }
+        Fields::Unnamed(_binding_0) => {
+            v.visit_fields_unnamed_mut(_binding_0);
+        }
+        Fields::Unit => {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields_named_mut<V>(v: &mut V, node: &mut FieldsNamed)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.named) {
+        let it = el.value_mut();
+        v.visit_field_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_fields_unnamed_mut<V>(v: &mut V, node: &mut FieldsUnnamed)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.unnamed) {
+        let it = el.value_mut();
+        v.visit_field_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_file_mut<V>(v: &mut V, node: &mut File)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.shebang);
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    for it in &mut node.items {
+        v.visit_item_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_fn_arg_mut<V>(v: &mut V, node: &mut FnArg)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        FnArg::Receiver(_binding_0) => {
+            v.visit_receiver_mut(_binding_0);
+        }
+        FnArg::Typed(_binding_0) => {
+            v.visit_pat_type_mut(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_mut<V>(v: &mut V, node: &mut ForeignItem)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        ForeignItem::Fn(_binding_0) => {
+            v.visit_foreign_item_fn_mut(_binding_0);
+        }
+        ForeignItem::Static(_binding_0) => {
+            v.visit_foreign_item_static_mut(_binding_0);
+        }
+        ForeignItem::Type(_binding_0) => {
+            v.visit_foreign_item_type_mut(_binding_0);
+        }
+        ForeignItem::Macro(_binding_0) => {
+            v.visit_foreign_item_macro_mut(_binding_0);
+        }
+        ForeignItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_fn_mut<V>(v: &mut V, node: &mut ForeignItemFn)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    v.visit_signature_mut(&mut node.sig);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_macro_mut<V>(v: &mut V, node: &mut ForeignItemMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_static_mut<V>(v: &mut V, node: &mut ForeignItemStatic)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.static_token);
+    v.visit_static_mutability_mut(&mut node.mutability);
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut *node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_foreign_item_type_mut<V>(v: &mut V, node: &mut ForeignItemType)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.type_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generic_argument_mut<V>(v: &mut V, node: &mut GenericArgument)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        GenericArgument::Lifetime(_binding_0) => {
+            v.visit_lifetime_mut(_binding_0);
+        }
+        GenericArgument::Type(_binding_0) => {
+            v.visit_type_mut(_binding_0);
+        }
+        GenericArgument::Const(_binding_0) => {
+            v.visit_expr_mut(_binding_0);
+        }
+        GenericArgument::AssocType(_binding_0) => {
+            v.visit_assoc_type_mut(_binding_0);
+        }
+        GenericArgument::AssocConst(_binding_0) => {
+            v.visit_assoc_const_mut(_binding_0);
+        }
+        GenericArgument::Constraint(_binding_0) => {
+            v.visit_constraint_mut(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generic_param_mut<V>(v: &mut V, node: &mut GenericParam)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        GenericParam::Lifetime(_binding_0) => {
+            v.visit_lifetime_param_mut(_binding_0);
+        }
+        GenericParam::Type(_binding_0) => {
+            v.visit_type_param_mut(_binding_0);
+        }
+        GenericParam::Const(_binding_0) => {
+            v.visit_const_param_mut(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_generics_mut<V>(v: &mut V, node: &mut Generics)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.lt_token);
+    for mut el in Punctuated::pairs_mut(&mut node.params) {
+        let it = el.value_mut();
+        v.visit_generic_param_mut(it);
+    }
+    skip!(node.gt_token);
+    if let Some(it) = &mut node.where_clause {
+        v.visit_where_clause_mut(it);
+    }
+}
+pub fn visit_ident_mut<V>(v: &mut V, node: &mut Ident)
+where
+    V: VisitMut + ?Sized,
+{
+    let mut span = node.span();
+    v.visit_span_mut(&mut span);
+    node.set_span(span);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_mut<V>(v: &mut V, node: &mut ImplItem)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        ImplItem::Const(_binding_0) => {
+            v.visit_impl_item_const_mut(_binding_0);
+        }
+        ImplItem::Fn(_binding_0) => {
+            v.visit_impl_item_fn_mut(_binding_0);
+        }
+        ImplItem::Type(_binding_0) => {
+            v.visit_impl_item_type_mut(_binding_0);
+        }
+        ImplItem::Macro(_binding_0) => {
+            v.visit_impl_item_macro_mut(_binding_0);
+        }
+        ImplItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_const_mut<V>(v: &mut V, node: &mut ImplItemConst)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.defaultness);
+    skip!(node.const_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut node.ty);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_fn_mut<V>(v: &mut V, node: &mut ImplItemFn)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.defaultness);
+    v.visit_signature_mut(&mut node.sig);
+    v.visit_block_mut(&mut node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_macro_mut<V>(v: &mut V, node: &mut ImplItemMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_item_type_mut<V>(v: &mut V, node: &mut ImplItemType)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.defaultness);
+    skip!(node.type_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.eq_token);
+    v.visit_type_mut(&mut node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_impl_restriction_mut<V>(v: &mut V, node: &mut ImplRestriction)
+where
+    V: VisitMut + ?Sized,
+{
+    match *node {}
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_index_mut<V>(v: &mut V, node: &mut Index)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.index);
+    v.visit_span_mut(&mut node.span);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_mut<V>(v: &mut V, node: &mut Item)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Item::Const(_binding_0) => {
+            v.visit_item_const_mut(_binding_0);
+        }
+        Item::Enum(_binding_0) => {
+            v.visit_item_enum_mut(_binding_0);
+        }
+        Item::ExternCrate(_binding_0) => {
+            v.visit_item_extern_crate_mut(_binding_0);
+        }
+        Item::Fn(_binding_0) => {
+            v.visit_item_fn_mut(_binding_0);
+        }
+        Item::ForeignMod(_binding_0) => {
+            v.visit_item_foreign_mod_mut(_binding_0);
+        }
+        Item::Impl(_binding_0) => {
+            v.visit_item_impl_mut(_binding_0);
+        }
+        Item::Macro(_binding_0) => {
+            v.visit_item_macro_mut(_binding_0);
+        }
+        Item::Mod(_binding_0) => {
+            v.visit_item_mod_mut(_binding_0);
+        }
+        Item::Static(_binding_0) => {
+            v.visit_item_static_mut(_binding_0);
+        }
+        Item::Struct(_binding_0) => {
+            v.visit_item_struct_mut(_binding_0);
+        }
+        Item::Trait(_binding_0) => {
+            v.visit_item_trait_mut(_binding_0);
+        }
+        Item::TraitAlias(_binding_0) => {
+            v.visit_item_trait_alias_mut(_binding_0);
+        }
+        Item::Type(_binding_0) => {
+            v.visit_item_type_mut(_binding_0);
+        }
+        Item::Union(_binding_0) => {
+            v.visit_item_union_mut(_binding_0);
+        }
+        Item::Use(_binding_0) => {
+            v.visit_item_use_mut(_binding_0);
+        }
+        Item::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_const_mut<V>(v: &mut V, node: &mut ItemConst)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.const_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut *node.ty);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_enum_mut<V>(v: &mut V, node: &mut ItemEnum)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.enum_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.variants) {
+        let it = el.value_mut();
+        v.visit_variant_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_extern_crate_mut<V>(v: &mut V, node: &mut ItemExternCrate)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.extern_token);
+    skip!(node.crate_token);
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.rename {
+        skip!((it).0);
+        v.visit_ident_mut(&mut (it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_fn_mut<V>(v: &mut V, node: &mut ItemFn)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    v.visit_signature_mut(&mut node.sig);
+    v.visit_block_mut(&mut *node.block);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_foreign_mod_mut<V>(v: &mut V, node: &mut ItemForeignMod)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.unsafety);
+    v.visit_abi_mut(&mut node.abi);
+    skip!(node.brace_token);
+    for it in &mut node.items {
+        v.visit_foreign_item_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_impl_mut<V>(v: &mut V, node: &mut ItemImpl)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.defaultness);
+    skip!(node.unsafety);
+    skip!(node.impl_token);
+    v.visit_generics_mut(&mut node.generics);
+    if let Some(it) = &mut node.trait_ {
+        skip!((it).0);
+        v.visit_path_mut(&mut (it).1);
+        skip!((it).2);
+    }
+    v.visit_type_mut(&mut *node.self_ty);
+    skip!(node.brace_token);
+    for it in &mut node.items {
+        v.visit_impl_item_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_macro_mut<V>(v: &mut V, node: &mut ItemMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.ident {
+        v.visit_ident_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_mod_mut<V>(v: &mut V, node: &mut ItemMod)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.unsafety);
+    skip!(node.mod_token);
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.content {
+        skip!((it).0);
+        for it in &mut (it).1 {
+            v.visit_item_mut(it);
+        }
+    }
+    skip!(node.semi);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_static_mut<V>(v: &mut V, node: &mut ItemStatic)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.static_token);
+    v.visit_static_mutability_mut(&mut node.mutability);
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut *node.ty);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut *node.expr);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_struct_mut<V>(v: &mut V, node: &mut ItemStruct)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.struct_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    v.visit_fields_mut(&mut node.fields);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_trait_mut<V>(v: &mut V, node: &mut ItemTrait)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.unsafety);
+    skip!(node.auto_token);
+    if let Some(it) = &mut node.restriction {
+        v.visit_impl_restriction_mut(it);
+    }
+    skip!(node.trait_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.supertraits) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+    skip!(node.brace_token);
+    for it in &mut node.items {
+        v.visit_trait_item_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_item_trait_alias_mut<V>(v: &mut V, node: &mut ItemTraitAlias)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.trait_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.eq_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_type_mut<V>(v: &mut V, node: &mut ItemType)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.type_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.eq_token);
+    v.visit_type_mut(&mut *node.ty);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_union_mut<V>(v: &mut V, node: &mut ItemUnion)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.union_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    v.visit_fields_named_mut(&mut node.fields);
+}
+#[cfg(feature = "full")]
+pub fn visit_item_use_mut<V>(v: &mut V, node: &mut ItemUse)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_visibility_mut(&mut node.vis);
+    skip!(node.use_token);
+    skip!(node.leading_colon);
+    v.visit_use_tree_mut(&mut node.tree);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_label_mut<V>(v: &mut V, node: &mut Label)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_lifetime_mut(&mut node.name);
+    skip!(node.colon_token);
+}
+pub fn visit_lifetime_mut<V>(v: &mut V, node: &mut Lifetime)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_span_mut(&mut node.apostrophe);
+    v.visit_ident_mut(&mut node.ident);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_lifetime_param_mut<V>(v: &mut V, node: &mut LifetimeParam)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_lifetime_mut(&mut node.lifetime);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_lifetime_mut(it);
+    }
+}
+pub fn visit_lit_mut<V>(v: &mut V, node: &mut Lit)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Lit::Str(_binding_0) => {
+            v.visit_lit_str_mut(_binding_0);
+        }
+        Lit::ByteStr(_binding_0) => {
+            v.visit_lit_byte_str_mut(_binding_0);
+        }
+        Lit::Byte(_binding_0) => {
+            v.visit_lit_byte_mut(_binding_0);
+        }
+        Lit::Char(_binding_0) => {
+            v.visit_lit_char_mut(_binding_0);
+        }
+        Lit::Int(_binding_0) => {
+            v.visit_lit_int_mut(_binding_0);
+        }
+        Lit::Float(_binding_0) => {
+            v.visit_lit_float_mut(_binding_0);
+        }
+        Lit::Bool(_binding_0) => {
+            v.visit_lit_bool_mut(_binding_0);
+        }
+        Lit::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+pub fn visit_lit_bool_mut<V>(v: &mut V, node: &mut LitBool)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.value);
+    v.visit_span_mut(&mut node.span);
+}
+pub fn visit_lit_byte_mut<V>(v: &mut V, node: &mut LitByte)
+where
+    V: VisitMut + ?Sized,
+{}
+pub fn visit_lit_byte_str_mut<V>(v: &mut V, node: &mut LitByteStr)
+where
+    V: VisitMut + ?Sized,
+{}
+pub fn visit_lit_char_mut<V>(v: &mut V, node: &mut LitChar)
+where
+    V: VisitMut + ?Sized,
+{}
+pub fn visit_lit_float_mut<V>(v: &mut V, node: &mut LitFloat)
+where
+    V: VisitMut + ?Sized,
+{}
+pub fn visit_lit_int_mut<V>(v: &mut V, node: &mut LitInt)
+where
+    V: VisitMut + ?Sized,
+{}
+pub fn visit_lit_str_mut<V>(v: &mut V, node: &mut LitStr)
+where
+    V: VisitMut + ?Sized,
+{}
+#[cfg(feature = "full")]
+pub fn visit_local_mut<V>(v: &mut V, node: &mut Local)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.let_token);
+    v.visit_pat_mut(&mut node.pat);
+    if let Some(it) = &mut node.init {
+        v.visit_local_init_mut(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_local_init_mut<V>(v: &mut V, node: &mut LocalInit)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut *node.expr);
+    if let Some(it) = &mut node.diverge {
+        skip!((it).0);
+        v.visit_expr_mut(&mut *(it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_macro_mut<V>(v: &mut V, node: &mut Macro)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_path_mut(&mut node.path);
+    skip!(node.bang_token);
+    v.visit_macro_delimiter_mut(&mut node.delimiter);
+    skip!(node.tokens);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_macro_delimiter_mut<V>(v: &mut V, node: &mut MacroDelimiter)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        MacroDelimiter::Paren(_binding_0) => {
+            skip!(_binding_0);
+        }
+        MacroDelimiter::Brace(_binding_0) => {
+            skip!(_binding_0);
+        }
+        MacroDelimiter::Bracket(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_member_mut<V>(v: &mut V, node: &mut Member)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Member::Named(_binding_0) => {
+            v.visit_ident_mut(_binding_0);
+        }
+        Member::Unnamed(_binding_0) => {
+            v.visit_index_mut(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta_mut<V>(v: &mut V, node: &mut Meta)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Meta::Path(_binding_0) => {
+            v.visit_path_mut(_binding_0);
+        }
+        Meta::List(_binding_0) => {
+            v.visit_meta_list_mut(_binding_0);
+        }
+        Meta::NameValue(_binding_0) => {
+            v.visit_meta_name_value_mut(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta_list_mut<V>(v: &mut V, node: &mut MetaList)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_path_mut(&mut node.path);
+    v.visit_macro_delimiter_mut(&mut node.delimiter);
+    skip!(node.tokens);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_meta_name_value_mut<V>(v: &mut V, node: &mut MetaNameValue)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_path_mut(&mut node.path);
+    skip!(node.eq_token);
+    v.visit_expr_mut(&mut node.value);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_parenthesized_generic_arguments_mut<V>(
+    v: &mut V,
+    node: &mut ParenthesizedGenericArguments,
+)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.inputs) {
+        let it = el.value_mut();
+        v.visit_type_mut(it);
+    }
+    v.visit_return_type_mut(&mut node.output);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_mut<V>(v: &mut V, node: &mut Pat)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Pat::Const(_binding_0) => {
+            v.visit_expr_const_mut(_binding_0);
+        }
+        Pat::Ident(_binding_0) => {
+            v.visit_pat_ident_mut(_binding_0);
+        }
+        Pat::Lit(_binding_0) => {
+            v.visit_expr_lit_mut(_binding_0);
+        }
+        Pat::Macro(_binding_0) => {
+            v.visit_expr_macro_mut(_binding_0);
+        }
+        Pat::Or(_binding_0) => {
+            v.visit_pat_or_mut(_binding_0);
+        }
+        Pat::Paren(_binding_0) => {
+            v.visit_pat_paren_mut(_binding_0);
+        }
+        Pat::Path(_binding_0) => {
+            v.visit_expr_path_mut(_binding_0);
+        }
+        Pat::Range(_binding_0) => {
+            v.visit_expr_range_mut(_binding_0);
+        }
+        Pat::Reference(_binding_0) => {
+            v.visit_pat_reference_mut(_binding_0);
+        }
+        Pat::Rest(_binding_0) => {
+            v.visit_pat_rest_mut(_binding_0);
+        }
+        Pat::Slice(_binding_0) => {
+            v.visit_pat_slice_mut(_binding_0);
+        }
+        Pat::Struct(_binding_0) => {
+            v.visit_pat_struct_mut(_binding_0);
+        }
+        Pat::Tuple(_binding_0) => {
+            v.visit_pat_tuple_mut(_binding_0);
+        }
+        Pat::TupleStruct(_binding_0) => {
+            v.visit_pat_tuple_struct_mut(_binding_0);
+        }
+        Pat::Type(_binding_0) => {
+            v.visit_pat_type_mut(_binding_0);
+        }
+        Pat::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Pat::Wild(_binding_0) => {
+            v.visit_pat_wild_mut(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_ident_mut<V>(v: &mut V, node: &mut PatIdent)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.by_ref);
+    skip!(node.mutability);
+    v.visit_ident_mut(&mut node.ident);
+    if let Some(it) = &mut node.subpat {
+        skip!((it).0);
+        v.visit_pat_mut(&mut *(it).1);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_or_mut<V>(v: &mut V, node: &mut PatOr)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.leading_vert);
+    for mut el in Punctuated::pairs_mut(&mut node.cases) {
+        let it = el.value_mut();
+        v.visit_pat_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_paren_mut<V>(v: &mut V, node: &mut PatParen)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.paren_token);
+    v.visit_pat_mut(&mut *node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_reference_mut<V>(v: &mut V, node: &mut PatReference)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.and_token);
+    skip!(node.mutability);
+    v.visit_pat_mut(&mut *node.pat);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_rest_mut<V>(v: &mut V, node: &mut PatRest)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.dot2_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_slice_mut<V>(v: &mut V, node: &mut PatSlice)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.bracket_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_pat_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_struct_mut<V>(v: &mut V, node: &mut PatStruct)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.qself {
+        v.visit_qself_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.fields) {
+        let it = el.value_mut();
+        v.visit_field_pat_mut(it);
+    }
+    if let Some(it) = &mut node.rest {
+        v.visit_pat_rest_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_tuple_mut<V>(v: &mut V, node: &mut PatTuple)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_pat_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_tuple_struct_mut<V>(v: &mut V, node: &mut PatTupleStruct)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.qself {
+        v.visit_qself_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_pat_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_type_mut<V>(v: &mut V, node: &mut PatType)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_pat_mut(&mut *node.pat);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut *node.ty);
+}
+#[cfg(feature = "full")]
+pub fn visit_pat_wild_mut<V>(v: &mut V, node: &mut PatWild)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.underscore_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path_mut<V>(v: &mut V, node: &mut Path)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.leading_colon);
+    for mut el in Punctuated::pairs_mut(&mut node.segments) {
+        let it = el.value_mut();
+        v.visit_path_segment_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path_arguments_mut<V>(v: &mut V, node: &mut PathArguments)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        PathArguments::None => {}
+        PathArguments::AngleBracketed(_binding_0) => {
+            v.visit_angle_bracketed_generic_arguments_mut(_binding_0);
+        }
+        PathArguments::Parenthesized(_binding_0) => {
+            v.visit_parenthesized_generic_arguments_mut(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_path_segment_mut<V>(v: &mut V, node: &mut PathSegment)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_path_arguments_mut(&mut node.arguments);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_predicate_lifetime_mut<V>(v: &mut V, node: &mut PredicateLifetime)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_lifetime_mut(&mut node.lifetime);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_lifetime_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_predicate_type_mut<V>(v: &mut V, node: &mut PredicateType)
+where
+    V: VisitMut + ?Sized,
+{
+    if let Some(it) = &mut node.lifetimes {
+        v.visit_bound_lifetimes_mut(it);
+    }
+    v.visit_type_mut(&mut node.bounded_ty);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_qself_mut<V>(v: &mut V, node: &mut QSelf)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.lt_token);
+    v.visit_type_mut(&mut *node.ty);
+    skip!(node.position);
+    skip!(node.as_token);
+    skip!(node.gt_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_range_limits_mut<V>(v: &mut V, node: &mut RangeLimits)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        RangeLimits::HalfOpen(_binding_0) => {
+            skip!(_binding_0);
+        }
+        RangeLimits::Closed(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_receiver_mut<V>(v: &mut V, node: &mut Receiver)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.reference {
+        skip!((it).0);
+        if let Some(it) = &mut (it).1 {
+            v.visit_lifetime_mut(it);
+        }
+    }
+    skip!(node.mutability);
+    skip!(node.self_token);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut *node.ty);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_return_type_mut<V>(v: &mut V, node: &mut ReturnType)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        ReturnType::Default => {}
+        ReturnType::Type(_binding_0, _binding_1) => {
+            skip!(_binding_0);
+            v.visit_type_mut(&mut **_binding_1);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_signature_mut<V>(v: &mut V, node: &mut Signature)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.constness);
+    skip!(node.asyncness);
+    skip!(node.unsafety);
+    if let Some(it) = &mut node.abi {
+        v.visit_abi_mut(it);
+    }
+    skip!(node.fn_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.inputs) {
+        let it = el.value_mut();
+        v.visit_fn_arg_mut(it);
+    }
+    if let Some(it) = &mut node.variadic {
+        v.visit_variadic_mut(it);
+    }
+    v.visit_return_type_mut(&mut node.output);
+}
+pub fn visit_span_mut<V>(v: &mut V, node: &mut Span)
+where
+    V: VisitMut + ?Sized,
+{}
+#[cfg(feature = "full")]
+pub fn visit_static_mutability_mut<V>(v: &mut V, node: &mut StaticMutability)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        StaticMutability::Mut(_binding_0) => {
+            skip!(_binding_0);
+        }
+        StaticMutability::None => {}
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_stmt_mut<V>(v: &mut V, node: &mut Stmt)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Stmt::Local(_binding_0) => {
+            v.visit_local_mut(_binding_0);
+        }
+        Stmt::Item(_binding_0) => {
+            v.visit_item_mut(_binding_0);
+        }
+        Stmt::Expr(_binding_0, _binding_1) => {
+            v.visit_expr_mut(_binding_0);
+            skip!(_binding_1);
+        }
+        Stmt::Macro(_binding_0) => {
+            v.visit_stmt_macro_mut(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_stmt_macro_mut<V>(v: &mut V, node: &mut StmtMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_trait_bound_mut<V>(v: &mut V, node: &mut TraitBound)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.paren_token);
+    v.visit_trait_bound_modifier_mut(&mut node.modifier);
+    if let Some(it) = &mut node.lifetimes {
+        v.visit_bound_lifetimes_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_trait_bound_modifier_mut<V>(v: &mut V, node: &mut TraitBoundModifier)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        TraitBoundModifier::None => {}
+        TraitBoundModifier::Maybe(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_mut<V>(v: &mut V, node: &mut TraitItem)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        TraitItem::Const(_binding_0) => {
+            v.visit_trait_item_const_mut(_binding_0);
+        }
+        TraitItem::Fn(_binding_0) => {
+            v.visit_trait_item_fn_mut(_binding_0);
+        }
+        TraitItem::Type(_binding_0) => {
+            v.visit_trait_item_type_mut(_binding_0);
+        }
+        TraitItem::Macro(_binding_0) => {
+            v.visit_trait_item_macro_mut(_binding_0);
+        }
+        TraitItem::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_const_mut<V>(v: &mut V, node: &mut TraitItemConst)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.const_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.colon_token);
+    v.visit_type_mut(&mut node.ty);
+    if let Some(it) = &mut node.default {
+        skip!((it).0);
+        v.visit_expr_mut(&mut (it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_fn_mut<V>(v: &mut V, node: &mut TraitItemFn)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_signature_mut(&mut node.sig);
+    if let Some(it) = &mut node.default {
+        v.visit_block_mut(it);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_macro_mut<V>(v: &mut V, node: &mut TraitItemMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_macro_mut(&mut node.mac);
+    skip!(node.semi_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_trait_item_type_mut<V>(v: &mut V, node: &mut TraitItemType)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    skip!(node.type_token);
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_generics_mut(&mut node.generics);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+    if let Some(it) = &mut node.default {
+        skip!((it).0);
+        v.visit_type_mut(&mut (it).1);
+    }
+    skip!(node.semi_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_mut<V>(v: &mut V, node: &mut Type)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Type::Array(_binding_0) => {
+            v.visit_type_array_mut(_binding_0);
+        }
+        Type::BareFn(_binding_0) => {
+            v.visit_type_bare_fn_mut(_binding_0);
+        }
+        Type::Group(_binding_0) => {
+            v.visit_type_group_mut(_binding_0);
+        }
+        Type::ImplTrait(_binding_0) => {
+            v.visit_type_impl_trait_mut(_binding_0);
+        }
+        Type::Infer(_binding_0) => {
+            v.visit_type_infer_mut(_binding_0);
+        }
+        Type::Macro(_binding_0) => {
+            v.visit_type_macro_mut(_binding_0);
+        }
+        Type::Never(_binding_0) => {
+            v.visit_type_never_mut(_binding_0);
+        }
+        Type::Paren(_binding_0) => {
+            v.visit_type_paren_mut(_binding_0);
+        }
+        Type::Path(_binding_0) => {
+            v.visit_type_path_mut(_binding_0);
+        }
+        Type::Ptr(_binding_0) => {
+            v.visit_type_ptr_mut(_binding_0);
+        }
+        Type::Reference(_binding_0) => {
+            v.visit_type_reference_mut(_binding_0);
+        }
+        Type::Slice(_binding_0) => {
+            v.visit_type_slice_mut(_binding_0);
+        }
+        Type::TraitObject(_binding_0) => {
+            v.visit_type_trait_object_mut(_binding_0);
+        }
+        Type::Tuple(_binding_0) => {
+            v.visit_type_tuple_mut(_binding_0);
+        }
+        Type::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_array_mut<V>(v: &mut V, node: &mut TypeArray)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.bracket_token);
+    v.visit_type_mut(&mut *node.elem);
+    skip!(node.semi_token);
+    v.visit_expr_mut(&mut node.len);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_bare_fn_mut<V>(v: &mut V, node: &mut TypeBareFn)
+where
+    V: VisitMut + ?Sized,
+{
+    if let Some(it) = &mut node.lifetimes {
+        v.visit_bound_lifetimes_mut(it);
+    }
+    skip!(node.unsafety);
+    if let Some(it) = &mut node.abi {
+        v.visit_abi_mut(it);
+    }
+    skip!(node.fn_token);
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.inputs) {
+        let it = el.value_mut();
+        v.visit_bare_fn_arg_mut(it);
+    }
+    if let Some(it) = &mut node.variadic {
+        v.visit_bare_variadic_mut(it);
+    }
+    v.visit_return_type_mut(&mut node.output);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_group_mut<V>(v: &mut V, node: &mut TypeGroup)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.group_token);
+    v.visit_type_mut(&mut *node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_impl_trait_mut<V>(v: &mut V, node: &mut TypeImplTrait)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.impl_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_infer_mut<V>(v: &mut V, node: &mut TypeInfer)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.underscore_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_macro_mut<V>(v: &mut V, node: &mut TypeMacro)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_macro_mut(&mut node.mac);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_never_mut<V>(v: &mut V, node: &mut TypeNever)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.bang_token);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_param_mut<V>(v: &mut V, node: &mut TypeParam)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.colon_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+    skip!(node.eq_token);
+    if let Some(it) = &mut node.default {
+        v.visit_type_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_param_bound_mut<V>(v: &mut V, node: &mut TypeParamBound)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        TypeParamBound::Trait(_binding_0) => {
+            v.visit_trait_bound_mut(_binding_0);
+        }
+        TypeParamBound::Lifetime(_binding_0) => {
+            v.visit_lifetime_mut(_binding_0);
+        }
+        TypeParamBound::Verbatim(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_paren_mut<V>(v: &mut V, node: &mut TypeParen)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.paren_token);
+    v.visit_type_mut(&mut *node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_path_mut<V>(v: &mut V, node: &mut TypePath)
+where
+    V: VisitMut + ?Sized,
+{
+    if let Some(it) = &mut node.qself {
+        v.visit_qself_mut(it);
+    }
+    v.visit_path_mut(&mut node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_ptr_mut<V>(v: &mut V, node: &mut TypePtr)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.star_token);
+    skip!(node.const_token);
+    skip!(node.mutability);
+    v.visit_type_mut(&mut *node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_reference_mut<V>(v: &mut V, node: &mut TypeReference)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.and_token);
+    if let Some(it) = &mut node.lifetime {
+        v.visit_lifetime_mut(it);
+    }
+    skip!(node.mutability);
+    v.visit_type_mut(&mut *node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_slice_mut<V>(v: &mut V, node: &mut TypeSlice)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.bracket_token);
+    v.visit_type_mut(&mut *node.elem);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_trait_object_mut<V>(v: &mut V, node: &mut TypeTraitObject)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.dyn_token);
+    for mut el in Punctuated::pairs_mut(&mut node.bounds) {
+        let it = el.value_mut();
+        v.visit_type_param_bound_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_type_tuple_mut<V>(v: &mut V, node: &mut TypeTuple)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.paren_token);
+    for mut el in Punctuated::pairs_mut(&mut node.elems) {
+        let it = el.value_mut();
+        v.visit_type_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_un_op_mut<V>(v: &mut V, node: &mut UnOp)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        UnOp::Deref(_binding_0) => {
+            skip!(_binding_0);
+        }
+        UnOp::Not(_binding_0) => {
+            skip!(_binding_0);
+        }
+        UnOp::Neg(_binding_0) => {
+            skip!(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_use_glob_mut<V>(v: &mut V, node: &mut UseGlob)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.star_token);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_group_mut<V>(v: &mut V, node: &mut UseGroup)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.brace_token);
+    for mut el in Punctuated::pairs_mut(&mut node.items) {
+        let it = el.value_mut();
+        v.visit_use_tree_mut(it);
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_use_name_mut<V>(v: &mut V, node: &mut UseName)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_path_mut<V>(v: &mut V, node: &mut UsePath)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.colon2_token);
+    v.visit_use_tree_mut(&mut *node.tree);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_rename_mut<V>(v: &mut V, node: &mut UseRename)
+where
+    V: VisitMut + ?Sized,
+{
+    v.visit_ident_mut(&mut node.ident);
+    skip!(node.as_token);
+    v.visit_ident_mut(&mut node.rename);
+}
+#[cfg(feature = "full")]
+pub fn visit_use_tree_mut<V>(v: &mut V, node: &mut UseTree)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        UseTree::Path(_binding_0) => {
+            v.visit_use_path_mut(_binding_0);
+        }
+        UseTree::Name(_binding_0) => {
+            v.visit_use_name_mut(_binding_0);
+        }
+        UseTree::Rename(_binding_0) => {
+            v.visit_use_rename_mut(_binding_0);
+        }
+        UseTree::Glob(_binding_0) => {
+            v.visit_use_glob_mut(_binding_0);
+        }
+        UseTree::Group(_binding_0) => {
+            v.visit_use_group_mut(_binding_0);
+        }
+    }
+}
+#[cfg(feature = "full")]
+pub fn visit_variadic_mut<V>(v: &mut V, node: &mut Variadic)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    if let Some(it) = &mut node.pat {
+        v.visit_pat_mut(&mut *(it).0);
+        skip!((it).1);
+    }
+    skip!(node.dots);
+    skip!(node.comma);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_variant_mut<V>(v: &mut V, node: &mut Variant)
+where
+    V: VisitMut + ?Sized,
+{
+    for it in &mut node.attrs {
+        v.visit_attribute_mut(it);
+    }
+    v.visit_ident_mut(&mut node.ident);
+    v.visit_fields_mut(&mut node.fields);
+    if let Some(it) = &mut node.discriminant {
+        skip!((it).0);
+        v.visit_expr_mut(&mut (it).1);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_vis_restricted_mut<V>(v: &mut V, node: &mut VisRestricted)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.pub_token);
+    skip!(node.paren_token);
+    skip!(node.in_token);
+    v.visit_path_mut(&mut *node.path);
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_visibility_mut<V>(v: &mut V, node: &mut Visibility)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        Visibility::Public(_binding_0) => {
+            skip!(_binding_0);
+        }
+        Visibility::Restricted(_binding_0) => {
+            v.visit_vis_restricted_mut(_binding_0);
+        }
+        Visibility::Inherited => {}
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_where_clause_mut<V>(v: &mut V, node: &mut WhereClause)
+where
+    V: VisitMut + ?Sized,
+{
+    skip!(node.where_token);
+    for mut el in Punctuated::pairs_mut(&mut node.predicates) {
+        let it = el.value_mut();
+        v.visit_where_predicate_mut(it);
+    }
+}
+#[cfg(any(feature = "derive", feature = "full"))]
+pub fn visit_where_predicate_mut<V>(v: &mut V, node: &mut WherePredicate)
+where
+    V: VisitMut + ?Sized,
+{
+    match node {
+        WherePredicate::Lifetime(_binding_0) => {
+            v.visit_predicate_lifetime_mut(_binding_0);
+        }
+        WherePredicate::Type(_binding_0) => {
+            v.visit_predicate_type_mut(_binding_0);
+        }
+    }
+}
diff --git a/vendor/syn/src/gen_helper.rs b/vendor/syn/src/gen_helper.rs
new file mode 100644
index 0000000..e433bac
--- /dev/null
+++ b/vendor/syn/src/gen_helper.rs
@@ -0,0 +1,34 @@
+#[cfg(feature = "fold")]
+pub(crate) mod fold {
+    use crate::punctuated::{Pair, Punctuated};
+
+    pub(crate) trait FoldHelper {
+        type Item;
+        fn lift<F>(self, f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item;
+    }
+
+    impl<T> FoldHelper for Vec<T> {
+        type Item = T;
+        fn lift<F>(self, f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item,
+        {
+            self.into_iter().map(f).collect()
+        }
+    }
+
+    impl<T, U> FoldHelper for Punctuated<T, U> {
+        type Item = T;
+        fn lift<F>(self, mut f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item,
+        {
+            self.into_pairs()
+                .map(Pair::into_tuple)
+                .map(|(t, u)| Pair::new(f(t), u))
+                .collect()
+        }
+    }
+}
diff --git a/vendor/syn/src/generics.rs b/vendor/syn/src/generics.rs
new file mode 100644
index 0000000..2ad913d
--- /dev/null
+++ b/vendor/syn/src/generics.rs
@@ -0,0 +1,1227 @@
+use super::*;
+use crate::punctuated::{Iter, IterMut, Punctuated};
+use proc_macro2::TokenStream;
+#[cfg(all(feature = "printing", feature = "extra-traits"))]
+use std::fmt::{self, Debug};
+#[cfg(all(feature = "printing", feature = "extra-traits"))]
+use std::hash::{Hash, Hasher};
+
+ast_struct! {
+    /// Lifetimes and type parameters attached to a declaration of a function,
+    /// enum, trait, etc.
+    ///
+    /// This struct represents two distinct optional syntactic elements,
+    /// [generic parameters] and [where clause]. In some locations of the
+    /// grammar, there may be other tokens in between these two things.
+    ///
+    /// [generic parameters]: https://doc.rust-lang.org/stable/reference/items/generics.html#generic-parameters
+    /// [where clause]: https://doc.rust-lang.org/stable/reference/items/generics.html#where-clauses
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Generics {
+        pub lt_token: Option<Token![<]>,
+        pub params: Punctuated<GenericParam, Token![,]>,
+        pub gt_token: Option<Token![>]>,
+        pub where_clause: Option<WhereClause>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// A generic type parameter, lifetime, or const generic: `T: Into<String>`,
+    /// `'a: 'b`, `const LEN: usize`.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum GenericParam {
+        /// A lifetime parameter: `'a: 'b + 'c + 'd`.
+        Lifetime(LifetimeParam),
+
+        /// A generic type parameter: `T: Into<String>`.
+        Type(TypeParam),
+
+        /// A const generic parameter: `const LENGTH: usize`.
+        Const(ConstParam),
+    }
+}
+
+ast_struct! {
+    /// A lifetime definition: `'a: 'b + 'c + 'd`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct LifetimeParam {
+        pub attrs: Vec<Attribute>,
+        pub lifetime: Lifetime,
+        pub colon_token: Option<Token![:]>,
+        pub bounds: Punctuated<Lifetime, Token![+]>,
+    }
+}
+
+ast_struct! {
+    /// A generic type parameter: `T: Into<String>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeParam {
+        pub attrs: Vec<Attribute>,
+        pub ident: Ident,
+        pub colon_token: Option<Token![:]>,
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+        pub eq_token: Option<Token![=]>,
+        pub default: Option<Type>,
+    }
+}
+
+ast_struct! {
+    /// A const generic parameter: `const LENGTH: usize`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ConstParam {
+        pub attrs: Vec<Attribute>,
+        pub const_token: Token![const],
+        pub ident: Ident,
+        pub colon_token: Token![:],
+        pub ty: Type,
+        pub eq_token: Option<Token![=]>,
+        pub default: Option<Expr>,
+    }
+}
+
+impl Default for Generics {
+    fn default() -> Self {
+        Generics {
+            lt_token: None,
+            params: Punctuated::new(),
+            gt_token: None,
+            where_clause: None,
+        }
+    }
+}
+
+impl Generics {
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;</code><a
+    ///   href="struct.LifetimeParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">LifetimeParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the lifetime parameters in `self.params`.
+    pub fn lifetimes(&self) -> Lifetimes {
+        Lifetimes(self.params.iter())
+    }
+
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;mut </code><a
+    ///   href="struct.LifetimeParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">LifetimeParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the lifetime parameters in `self.params`.
+    pub fn lifetimes_mut(&mut self) -> LifetimesMut {
+        LifetimesMut(self.params.iter_mut())
+    }
+
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;</code><a
+    ///   href="struct.TypeParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">TypeParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the type parameters in `self.params`.
+    pub fn type_params(&self) -> TypeParams {
+        TypeParams(self.params.iter())
+    }
+
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;mut </code><a
+    ///   href="struct.TypeParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">TypeParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the type parameters in `self.params`.
+    pub fn type_params_mut(&mut self) -> TypeParamsMut {
+        TypeParamsMut(self.params.iter_mut())
+    }
+
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;</code><a
+    ///   href="struct.ConstParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">ConstParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the constant parameters in `self.params`.
+    pub fn const_params(&self) -> ConstParams {
+        ConstParams(self.params.iter())
+    }
+
+    /// Returns an
+    /// <code
+    ///   style="padding-right:0;">Iterator&lt;Item = &amp;mut </code><a
+    ///   href="struct.ConstParam.html"><code
+    ///   style="padding-left:0;padding-right:0;">ConstParam</code></a><code
+    ///   style="padding-left:0;">&gt;</code>
+    /// over the constant parameters in `self.params`.
+    pub fn const_params_mut(&mut self) -> ConstParamsMut {
+        ConstParamsMut(self.params.iter_mut())
+    }
+
+    /// Initializes an empty `where`-clause if there is not one present already.
+    pub fn make_where_clause(&mut self) -> &mut WhereClause {
+        self.where_clause.get_or_insert_with(|| WhereClause {
+            where_token: <Token![where]>::default(),
+            predicates: Punctuated::new(),
+        })
+    }
+}
+
+pub struct Lifetimes<'a>(Iter<'a, GenericParam>);
+
+impl<'a> Iterator for Lifetimes<'a> {
+    type Item = &'a LifetimeParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Lifetime(lifetime) = next {
+            Some(lifetime)
+        } else {
+            self.next()
+        }
+    }
+}
+
+pub struct LifetimesMut<'a>(IterMut<'a, GenericParam>);
+
+impl<'a> Iterator for LifetimesMut<'a> {
+    type Item = &'a mut LifetimeParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Lifetime(lifetime) = next {
+            Some(lifetime)
+        } else {
+            self.next()
+        }
+    }
+}
+
+pub struct TypeParams<'a>(Iter<'a, GenericParam>);
+
+impl<'a> Iterator for TypeParams<'a> {
+    type Item = &'a TypeParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Type(type_param) = next {
+            Some(type_param)
+        } else {
+            self.next()
+        }
+    }
+}
+
+pub struct TypeParamsMut<'a>(IterMut<'a, GenericParam>);
+
+impl<'a> Iterator for TypeParamsMut<'a> {
+    type Item = &'a mut TypeParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Type(type_param) = next {
+            Some(type_param)
+        } else {
+            self.next()
+        }
+    }
+}
+
+pub struct ConstParams<'a>(Iter<'a, GenericParam>);
+
+impl<'a> Iterator for ConstParams<'a> {
+    type Item = &'a ConstParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Const(const_param) = next {
+            Some(const_param)
+        } else {
+            self.next()
+        }
+    }
+}
+
+pub struct ConstParamsMut<'a>(IterMut<'a, GenericParam>);
+
+impl<'a> Iterator for ConstParamsMut<'a> {
+    type Item = &'a mut ConstParam;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let next = match self.0.next() {
+            Some(item) => item,
+            None => return None,
+        };
+        if let GenericParam::Const(const_param) = next {
+            Some(const_param)
+        } else {
+            self.next()
+        }
+    }
+}
+
+/// Returned by `Generics::split_for_impl`.
+#[cfg(feature = "printing")]
+#[cfg_attr(
+    doc_cfg,
+    doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing")))
+)]
+pub struct ImplGenerics<'a>(&'a Generics);
+
+/// Returned by `Generics::split_for_impl`.
+#[cfg(feature = "printing")]
+#[cfg_attr(
+    doc_cfg,
+    doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing")))
+)]
+pub struct TypeGenerics<'a>(&'a Generics);
+
+/// Returned by `TypeGenerics::as_turbofish`.
+#[cfg(feature = "printing")]
+#[cfg_attr(
+    doc_cfg,
+    doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing")))
+)]
+pub struct Turbofish<'a>(&'a Generics);
+
+#[cfg(feature = "printing")]
+impl Generics {
+    /// Split a type's generics into the pieces required for impl'ing a trait
+    /// for that type.
+    ///
+    /// ```
+    /// # use proc_macro2::{Span, Ident};
+    /// # use quote::quote;
+    /// #
+    /// # let generics: syn::Generics = Default::default();
+    /// # let name = Ident::new("MyType", Span::call_site());
+    /// #
+    /// let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+    /// quote! {
+    ///     impl #impl_generics MyTrait for #name #ty_generics #where_clause {
+    ///         // ...
+    ///     }
+    /// }
+    /// # ;
+    /// ```
+    #[cfg_attr(
+        doc_cfg,
+        doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing")))
+    )]
+    pub fn split_for_impl(&self) -> (ImplGenerics, TypeGenerics, Option<&WhereClause>) {
+        (
+            ImplGenerics(self),
+            TypeGenerics(self),
+            self.where_clause.as_ref(),
+        )
+    }
+}
+
+#[cfg(feature = "printing")]
+macro_rules! generics_wrapper_impls {
+    ($ty:ident) => {
+        #[cfg(feature = "clone-impls")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+        impl<'a> Clone for $ty<'a> {
+            fn clone(&self) -> Self {
+                $ty(self.0)
+            }
+        }
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl<'a> Debug for $ty<'a> {
+            fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter
+                    .debug_tuple(stringify!($ty))
+                    .field(self.0)
+                    .finish()
+            }
+        }
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl<'a> Eq for $ty<'a> {}
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl<'a> PartialEq for $ty<'a> {
+            fn eq(&self, other: &Self) -> bool {
+                self.0 == other.0
+            }
+        }
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl<'a> Hash for $ty<'a> {
+            fn hash<H: Hasher>(&self, state: &mut H) {
+                self.0.hash(state);
+            }
+        }
+    };
+}
+
+#[cfg(feature = "printing")]
+generics_wrapper_impls!(ImplGenerics);
+#[cfg(feature = "printing")]
+generics_wrapper_impls!(TypeGenerics);
+#[cfg(feature = "printing")]
+generics_wrapper_impls!(Turbofish);
+
+#[cfg(feature = "printing")]
+impl<'a> TypeGenerics<'a> {
+    /// Turn a type's generics like `<X, Y>` into a turbofish like `::<X, Y>`.
+    pub fn as_turbofish(&self) -> Turbofish {
+        Turbofish(self.0)
+    }
+}
+
+ast_struct! {
+    /// A set of bound lifetimes: `for<'a, 'b, 'c>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct BoundLifetimes {
+        pub for_token: Token![for],
+        pub lt_token: Token![<],
+        pub lifetimes: Punctuated<GenericParam, Token![,]>,
+        pub gt_token: Token![>],
+    }
+}
+
+impl Default for BoundLifetimes {
+    fn default() -> Self {
+        BoundLifetimes {
+            for_token: Default::default(),
+            lt_token: Default::default(),
+            lifetimes: Punctuated::new(),
+            gt_token: Default::default(),
+        }
+    }
+}
+
+impl LifetimeParam {
+    pub fn new(lifetime: Lifetime) -> Self {
+        LifetimeParam {
+            attrs: Vec::new(),
+            lifetime,
+            colon_token: None,
+            bounds: Punctuated::new(),
+        }
+    }
+}
+
+impl From<Ident> for TypeParam {
+    fn from(ident: Ident) -> Self {
+        TypeParam {
+            attrs: vec![],
+            ident,
+            colon_token: None,
+            bounds: Punctuated::new(),
+            eq_token: None,
+            default: None,
+        }
+    }
+}
+
+ast_enum_of_structs! {
+    /// A trait or lifetime used as a bound on a type parameter.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum TypeParamBound {
+        Trait(TraitBound),
+        Lifetime(Lifetime),
+        Verbatim(TokenStream),
+    }
+}
+
+ast_struct! {
+    /// A trait used as a bound on a type parameter.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TraitBound {
+        pub paren_token: Option<token::Paren>,
+        pub modifier: TraitBoundModifier,
+        /// The `for<'a>` in `for<'a> Foo<&'a T>`
+        pub lifetimes: Option<BoundLifetimes>,
+        /// The `Foo<&'a T>` in `for<'a> Foo<&'a T>`
+        pub path: Path,
+    }
+}
+
+ast_enum! {
+    /// A modifier on a trait bound, currently only used for the `?` in
+    /// `?Sized`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum TraitBoundModifier {
+        None,
+        Maybe(Token![?]),
+    }
+}
+
+ast_struct! {
+    /// A `where` clause in a definition: `where T: Deserialize<'de>, D:
+    /// 'static`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct WhereClause {
+        pub where_token: Token![where],
+        pub predicates: Punctuated<WherePredicate, Token![,]>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// A single predicate in a `where` clause: `T: Deserialize<'de>`.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum WherePredicate {
+        /// A lifetime predicate in a `where` clause: `'a: 'b + 'c`.
+        Lifetime(PredicateLifetime),
+
+        /// A type predicate in a `where` clause: `for<'c> Foo<'c>: Trait<'c>`.
+        Type(PredicateType),
+    }
+}
+
+ast_struct! {
+    /// A lifetime predicate in a `where` clause: `'a: 'b + 'c`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct PredicateLifetime {
+        pub lifetime: Lifetime,
+        pub colon_token: Token![:],
+        pub bounds: Punctuated<Lifetime, Token![+]>,
+    }
+}
+
+ast_struct! {
+    /// A type predicate in a `where` clause: `for<'c> Foo<'c>: Trait<'c>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct PredicateType {
+        /// Any lifetimes from a `for` binding
+        pub lifetimes: Option<BoundLifetimes>,
+        /// The type being bounded
+        pub bounded_ty: Type,
+        pub colon_token: Token![:],
+        /// Trait and lifetime bounds (`Clone+Send+'static`)
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Generics {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if !input.peek(Token![<]) {
+                return Ok(Generics::default());
+            }
+
+            let lt_token: Token![<] = input.parse()?;
+
+            let mut params = Punctuated::new();
+            loop {
+                if input.peek(Token![>]) {
+                    break;
+                }
+
+                let attrs = input.call(Attribute::parse_outer)?;
+                let lookahead = input.lookahead1();
+                if lookahead.peek(Lifetime) {
+                    params.push_value(GenericParam::Lifetime(LifetimeParam {
+                        attrs,
+                        ..input.parse()?
+                    }));
+                } else if lookahead.peek(Ident) {
+                    params.push_value(GenericParam::Type(TypeParam {
+                        attrs,
+                        ..input.parse()?
+                    }));
+                } else if lookahead.peek(Token![const]) {
+                    params.push_value(GenericParam::Const(ConstParam {
+                        attrs,
+                        ..input.parse()?
+                    }));
+                } else if input.peek(Token![_]) {
+                    params.push_value(GenericParam::Type(TypeParam {
+                        attrs,
+                        ident: input.call(Ident::parse_any)?,
+                        colon_token: None,
+                        bounds: Punctuated::new(),
+                        eq_token: None,
+                        default: None,
+                    }));
+                } else {
+                    return Err(lookahead.error());
+                }
+
+                if input.peek(Token![>]) {
+                    break;
+                }
+                let punct = input.parse()?;
+                params.push_punct(punct);
+            }
+
+            let gt_token: Token![>] = input.parse()?;
+
+            Ok(Generics {
+                lt_token: Some(lt_token),
+                params,
+                gt_token: Some(gt_token),
+                where_clause: None,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for GenericParam {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Ident) {
+                Ok(GenericParam::Type(TypeParam {
+                    attrs,
+                    ..input.parse()?
+                }))
+            } else if lookahead.peek(Lifetime) {
+                Ok(GenericParam::Lifetime(LifetimeParam {
+                    attrs,
+                    ..input.parse()?
+                }))
+            } else if lookahead.peek(Token![const]) {
+                Ok(GenericParam::Const(ConstParam {
+                    attrs,
+                    ..input.parse()?
+                }))
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LifetimeParam {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let has_colon;
+            Ok(LifetimeParam {
+                attrs: input.call(Attribute::parse_outer)?,
+                lifetime: input.parse()?,
+                colon_token: {
+                    if input.peek(Token![:]) {
+                        has_colon = true;
+                        Some(input.parse()?)
+                    } else {
+                        has_colon = false;
+                        None
+                    }
+                },
+                bounds: {
+                    let mut bounds = Punctuated::new();
+                    if has_colon {
+                        loop {
+                            if input.peek(Token![,]) || input.peek(Token![>]) {
+                                break;
+                            }
+                            let value = input.parse()?;
+                            bounds.push_value(value);
+                            if !input.peek(Token![+]) {
+                                break;
+                            }
+                            let punct = input.parse()?;
+                            bounds.push_punct(punct);
+                        }
+                    }
+                    bounds
+                },
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for BoundLifetimes {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(BoundLifetimes {
+                for_token: input.parse()?,
+                lt_token: input.parse()?,
+                lifetimes: {
+                    let mut lifetimes = Punctuated::new();
+                    while !input.peek(Token![>]) {
+                        let attrs = input.call(Attribute::parse_outer)?;
+                        let lifetime: Lifetime = input.parse()?;
+                        lifetimes.push_value(GenericParam::Lifetime(LifetimeParam {
+                            attrs,
+                            lifetime,
+                            colon_token: None,
+                            bounds: Punctuated::new(),
+                        }));
+                        if input.peek(Token![>]) {
+                            break;
+                        }
+                        lifetimes.push_punct(input.parse()?);
+                    }
+                    lifetimes
+                },
+                gt_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Option<BoundLifetimes> {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Token![for]) {
+                input.parse().map(Some)
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeParam {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let ident: Ident = input.parse()?;
+            let colon_token: Option<Token![:]> = input.parse()?;
+
+            let mut bounds = Punctuated::new();
+            if colon_token.is_some() {
+                loop {
+                    if input.peek(Token![,]) || input.peek(Token![>]) || input.peek(Token![=]) {
+                        break;
+                    }
+                    let value: TypeParamBound = input.parse()?;
+                    bounds.push_value(value);
+                    if !input.peek(Token![+]) {
+                        break;
+                    }
+                    let punct: Token![+] = input.parse()?;
+                    bounds.push_punct(punct);
+                }
+            }
+
+            let eq_token: Option<Token![=]> = input.parse()?;
+            let default = if eq_token.is_some() {
+                Some(input.parse::<Type>()?)
+            } else {
+                None
+            };
+
+            Ok(TypeParam {
+                attrs,
+                ident,
+                colon_token,
+                bounds,
+                eq_token,
+                default,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeParamBound {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Lifetime) {
+                return input.parse().map(TypeParamBound::Lifetime);
+            }
+
+            let begin = input.fork();
+
+            let content;
+            let (paren_token, content) = if input.peek(token::Paren) {
+                (Some(parenthesized!(content in input)), &content)
+            } else {
+                (None, input)
+            };
+
+            let is_tilde_const =
+                cfg!(feature = "full") && content.peek(Token![~]) && content.peek2(Token![const]);
+            if is_tilde_const {
+                content.parse::<Token![~]>()?;
+                content.parse::<Token![const]>()?;
+            }
+
+            let mut bound: TraitBound = content.parse()?;
+            bound.paren_token = paren_token;
+
+            if is_tilde_const {
+                Ok(TypeParamBound::Verbatim(verbatim::between(&begin, input)))
+            } else {
+                Ok(TypeParamBound::Trait(bound))
+            }
+        }
+    }
+
+    impl TypeParamBound {
+        pub(crate) fn parse_multiple(
+            input: ParseStream,
+            allow_plus: bool,
+        ) -> Result<Punctuated<Self, Token![+]>> {
+            let mut bounds = Punctuated::new();
+            loop {
+                bounds.push_value(input.parse()?);
+                if !(allow_plus && input.peek(Token![+])) {
+                    break;
+                }
+                bounds.push_punct(input.parse()?);
+                if !(input.peek(Ident::peek_any)
+                    || input.peek(Token![::])
+                    || input.peek(Token![?])
+                    || input.peek(Lifetime)
+                    || input.peek(token::Paren)
+                    || input.peek(Token![~]))
+                {
+                    break;
+                }
+            }
+            Ok(bounds)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitBound {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let modifier: TraitBoundModifier = input.parse()?;
+            let lifetimes: Option<BoundLifetimes> = input.parse()?;
+
+            let mut path: Path = input.parse()?;
+            if path.segments.last().unwrap().arguments.is_empty()
+                && (input.peek(token::Paren) || input.peek(Token![::]) && input.peek3(token::Paren))
+            {
+                input.parse::<Option<Token![::]>>()?;
+                let args: ParenthesizedGenericArguments = input.parse()?;
+                let parenthesized = PathArguments::Parenthesized(args);
+                path.segments.last_mut().unwrap().arguments = parenthesized;
+            }
+
+            Ok(TraitBound {
+                paren_token: None,
+                modifier,
+                lifetimes,
+                path,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitBoundModifier {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Token![?]) {
+                input.parse().map(TraitBoundModifier::Maybe)
+            } else {
+                Ok(TraitBoundModifier::None)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ConstParam {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut default = None;
+            Ok(ConstParam {
+                attrs: input.call(Attribute::parse_outer)?,
+                const_token: input.parse()?,
+                ident: input.parse()?,
+                colon_token: input.parse()?,
+                ty: input.parse()?,
+                eq_token: {
+                    if input.peek(Token![=]) {
+                        let eq_token = input.parse()?;
+                        default = Some(path::parsing::const_argument(input)?);
+                        Some(eq_token)
+                    } else {
+                        None
+                    }
+                },
+                default,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for WhereClause {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(WhereClause {
+                where_token: input.parse()?,
+                predicates: {
+                    let mut predicates = Punctuated::new();
+                    loop {
+                        if input.is_empty()
+                            || input.peek(token::Brace)
+                            || input.peek(Token![,])
+                            || input.peek(Token![;])
+                            || input.peek(Token![:]) && !input.peek(Token![::])
+                            || input.peek(Token![=])
+                        {
+                            break;
+                        }
+                        let value = input.parse()?;
+                        predicates.push_value(value);
+                        if !input.peek(Token![,]) {
+                            break;
+                        }
+                        let punct = input.parse()?;
+                        predicates.push_punct(punct);
+                    }
+                    predicates
+                },
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Option<WhereClause> {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Token![where]) {
+                input.parse().map(Some)
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for WherePredicate {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Lifetime) && input.peek2(Token![:]) {
+                Ok(WherePredicate::Lifetime(PredicateLifetime {
+                    lifetime: input.parse()?,
+                    colon_token: input.parse()?,
+                    bounds: {
+                        let mut bounds = Punctuated::new();
+                        loop {
+                            if input.is_empty()
+                                || input.peek(token::Brace)
+                                || input.peek(Token![,])
+                                || input.peek(Token![;])
+                                || input.peek(Token![:])
+                                || input.peek(Token![=])
+                            {
+                                break;
+                            }
+                            let value = input.parse()?;
+                            bounds.push_value(value);
+                            if !input.peek(Token![+]) {
+                                break;
+                            }
+                            let punct = input.parse()?;
+                            bounds.push_punct(punct);
+                        }
+                        bounds
+                    },
+                }))
+            } else {
+                Ok(WherePredicate::Type(PredicateType {
+                    lifetimes: input.parse()?,
+                    bounded_ty: input.parse()?,
+                    colon_token: input.parse()?,
+                    bounds: {
+                        let mut bounds = Punctuated::new();
+                        loop {
+                            if input.is_empty()
+                                || input.peek(token::Brace)
+                                || input.peek(Token![,])
+                                || input.peek(Token![;])
+                                || input.peek(Token![:]) && !input.peek(Token![::])
+                                || input.peek(Token![=])
+                            {
+                                break;
+                            }
+                            let value = input.parse()?;
+                            bounds.push_value(value);
+                            if !input.peek(Token![+]) {
+                                break;
+                            }
+                            let punct = input.parse()?;
+                            bounds.push_punct(punct);
+                        }
+                        bounds
+                    },
+                }))
+            }
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use crate::print::TokensOrDefault;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Generics {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            if self.params.is_empty() {
+                return;
+            }
+
+            TokensOrDefault(&self.lt_token).to_tokens(tokens);
+
+            // Print lifetimes before types and consts, regardless of their
+            // order in self.params.
+            let mut trailing_or_empty = true;
+            for param in self.params.pairs() {
+                if let GenericParam::Lifetime(_) = **param.value() {
+                    param.to_tokens(tokens);
+                    trailing_or_empty = param.punct().is_some();
+                }
+            }
+            for param in self.params.pairs() {
+                match param.value() {
+                    GenericParam::Type(_) | GenericParam::Const(_) => {
+                        if !trailing_or_empty {
+                            <Token![,]>::default().to_tokens(tokens);
+                            trailing_or_empty = true;
+                        }
+                        param.to_tokens(tokens);
+                    }
+                    GenericParam::Lifetime(_) => {}
+                }
+            }
+
+            TokensOrDefault(&self.gt_token).to_tokens(tokens);
+        }
+    }
+
+    impl<'a> ToTokens for ImplGenerics<'a> {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            if self.0.params.is_empty() {
+                return;
+            }
+
+            TokensOrDefault(&self.0.lt_token).to_tokens(tokens);
+
+            // Print lifetimes before types and consts, regardless of their
+            // order in self.params.
+            let mut trailing_or_empty = true;
+            for param in self.0.params.pairs() {
+                if let GenericParam::Lifetime(_) = **param.value() {
+                    param.to_tokens(tokens);
+                    trailing_or_empty = param.punct().is_some();
+                }
+            }
+            for param in self.0.params.pairs() {
+                if let GenericParam::Lifetime(_) = **param.value() {
+                    continue;
+                }
+                if !trailing_or_empty {
+                    <Token![,]>::default().to_tokens(tokens);
+                    trailing_or_empty = true;
+                }
+                match param.value() {
+                    GenericParam::Lifetime(_) => unreachable!(),
+                    GenericParam::Type(param) => {
+                        // Leave off the type parameter defaults
+                        tokens.append_all(param.attrs.outer());
+                        param.ident.to_tokens(tokens);
+                        if !param.bounds.is_empty() {
+                            TokensOrDefault(&param.colon_token).to_tokens(tokens);
+                            param.bounds.to_tokens(tokens);
+                        }
+                    }
+                    GenericParam::Const(param) => {
+                        // Leave off the const parameter defaults
+                        tokens.append_all(param.attrs.outer());
+                        param.const_token.to_tokens(tokens);
+                        param.ident.to_tokens(tokens);
+                        param.colon_token.to_tokens(tokens);
+                        param.ty.to_tokens(tokens);
+                    }
+                }
+                param.punct().to_tokens(tokens);
+            }
+
+            TokensOrDefault(&self.0.gt_token).to_tokens(tokens);
+        }
+    }
+
+    impl<'a> ToTokens for TypeGenerics<'a> {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            if self.0.params.is_empty() {
+                return;
+            }
+
+            TokensOrDefault(&self.0.lt_token).to_tokens(tokens);
+
+            // Print lifetimes before types and consts, regardless of their
+            // order in self.params.
+            let mut trailing_or_empty = true;
+            for param in self.0.params.pairs() {
+                if let GenericParam::Lifetime(def) = *param.value() {
+                    // Leave off the lifetime bounds and attributes
+                    def.lifetime.to_tokens(tokens);
+                    param.punct().to_tokens(tokens);
+                    trailing_or_empty = param.punct().is_some();
+                }
+            }
+            for param in self.0.params.pairs() {
+                if let GenericParam::Lifetime(_) = **param.value() {
+                    continue;
+                }
+                if !trailing_or_empty {
+                    <Token![,]>::default().to_tokens(tokens);
+                    trailing_or_empty = true;
+                }
+                match param.value() {
+                    GenericParam::Lifetime(_) => unreachable!(),
+                    GenericParam::Type(param) => {
+                        // Leave off the type parameter defaults
+                        param.ident.to_tokens(tokens);
+                    }
+                    GenericParam::Const(param) => {
+                        // Leave off the const parameter defaults
+                        param.ident.to_tokens(tokens);
+                    }
+                }
+                param.punct().to_tokens(tokens);
+            }
+
+            TokensOrDefault(&self.0.gt_token).to_tokens(tokens);
+        }
+    }
+
+    impl<'a> ToTokens for Turbofish<'a> {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            if !self.0.params.is_empty() {
+                <Token![::]>::default().to_tokens(tokens);
+                TypeGenerics(self.0).to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for BoundLifetimes {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.for_token.to_tokens(tokens);
+            self.lt_token.to_tokens(tokens);
+            self.lifetimes.to_tokens(tokens);
+            self.gt_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LifetimeParam {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.lifetime.to_tokens(tokens);
+            if !self.bounds.is_empty() {
+                TokensOrDefault(&self.colon_token).to_tokens(tokens);
+                self.bounds.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeParam {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.ident.to_tokens(tokens);
+            if !self.bounds.is_empty() {
+                TokensOrDefault(&self.colon_token).to_tokens(tokens);
+                self.bounds.to_tokens(tokens);
+            }
+            if let Some(default) = &self.default {
+                TokensOrDefault(&self.eq_token).to_tokens(tokens);
+                default.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitBound {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            let to_tokens = |tokens: &mut TokenStream| {
+                self.modifier.to_tokens(tokens);
+                self.lifetimes.to_tokens(tokens);
+                self.path.to_tokens(tokens);
+            };
+            match &self.paren_token {
+                Some(paren) => paren.surround(tokens, to_tokens),
+                None => to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitBoundModifier {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                TraitBoundModifier::None => {}
+                TraitBoundModifier::Maybe(t) => t.to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ConstParam {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.const_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            if let Some(default) = &self.default {
+                TokensOrDefault(&self.eq_token).to_tokens(tokens);
+                default.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for WhereClause {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            if !self.predicates.is_empty() {
+                self.where_token.to_tokens(tokens);
+                self.predicates.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PredicateLifetime {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.lifetime.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PredicateType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.lifetimes.to_tokens(tokens);
+            self.bounded_ty.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/group.rs b/vendor/syn/src/group.rs
new file mode 100644
index 0000000..2730233
--- /dev/null
+++ b/vendor/syn/src/group.rs
@@ -0,0 +1,291 @@
+use crate::error::Result;
+use crate::parse::ParseBuffer;
+use crate::token;
+use proc_macro2::extra::DelimSpan;
+use proc_macro2::Delimiter;
+
+// Not public API.
+#[doc(hidden)]
+pub struct Parens<'a> {
+    #[doc(hidden)]
+    pub token: token::Paren,
+    #[doc(hidden)]
+    pub content: ParseBuffer<'a>,
+}
+
+// Not public API.
+#[doc(hidden)]
+pub struct Braces<'a> {
+    #[doc(hidden)]
+    pub token: token::Brace,
+    #[doc(hidden)]
+    pub content: ParseBuffer<'a>,
+}
+
+// Not public API.
+#[doc(hidden)]
+pub struct Brackets<'a> {
+    #[doc(hidden)]
+    pub token: token::Bracket,
+    #[doc(hidden)]
+    pub content: ParseBuffer<'a>,
+}
+
+// Not public API.
+#[cfg(any(feature = "full", feature = "derive"))]
+#[doc(hidden)]
+pub struct Group<'a> {
+    #[doc(hidden)]
+    pub token: token::Group,
+    #[doc(hidden)]
+    pub content: ParseBuffer<'a>,
+}
+
+// Not public API.
+#[doc(hidden)]
+pub fn parse_parens<'a>(input: &ParseBuffer<'a>) -> Result<Parens<'a>> {
+    parse_delimited(input, Delimiter::Parenthesis).map(|(span, content)| Parens {
+        token: token::Paren(span),
+        content,
+    })
+}
+
+// Not public API.
+#[doc(hidden)]
+pub fn parse_braces<'a>(input: &ParseBuffer<'a>) -> Result<Braces<'a>> {
+    parse_delimited(input, Delimiter::Brace).map(|(span, content)| Braces {
+        token: token::Brace(span),
+        content,
+    })
+}
+
+// Not public API.
+#[doc(hidden)]
+pub fn parse_brackets<'a>(input: &ParseBuffer<'a>) -> Result<Brackets<'a>> {
+    parse_delimited(input, Delimiter::Bracket).map(|(span, content)| Brackets {
+        token: token::Bracket(span),
+        content,
+    })
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn parse_group<'a>(input: &ParseBuffer<'a>) -> Result<Group<'a>> {
+    parse_delimited(input, Delimiter::None).map(|(span, content)| Group {
+        token: token::Group(span.join()),
+        content,
+    })
+}
+
+fn parse_delimited<'a>(
+    input: &ParseBuffer<'a>,
+    delimiter: Delimiter,
+) -> Result<(DelimSpan, ParseBuffer<'a>)> {
+    input.step(|cursor| {
+        if let Some((content, span, rest)) = cursor.group(delimiter) {
+            let scope = crate::buffer::close_span_of_group(*cursor);
+            let nested = crate::parse::advance_step_cursor(cursor, content);
+            let unexpected = crate::parse::get_unexpected(input);
+            let content = crate::parse::new_parse_buffer(scope, nested, unexpected);
+            Ok(((span, content), rest))
+        } else {
+            let message = match delimiter {
+                Delimiter::Parenthesis => "expected parentheses",
+                Delimiter::Brace => "expected curly braces",
+                Delimiter::Bracket => "expected square brackets",
+                Delimiter::None => "expected invisible group",
+            };
+            Err(cursor.error(message))
+        }
+    })
+}
+
+/// Parse a set of parentheses and expose their content to subsequent parsers.
+///
+/// # Example
+///
+/// ```
+/// # use quote::quote;
+/// #
+/// use syn::{parenthesized, token, Ident, Result, Token, Type};
+/// use syn::parse::{Parse, ParseStream};
+/// use syn::punctuated::Punctuated;
+///
+/// // Parse a simplified tuple struct syntax like:
+/// //
+/// //     struct S(A, B);
+/// struct TupleStruct {
+///     struct_token: Token![struct],
+///     ident: Ident,
+///     paren_token: token::Paren,
+///     fields: Punctuated<Type, Token![,]>,
+///     semi_token: Token![;],
+/// }
+///
+/// impl Parse for TupleStruct {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let content;
+///         Ok(TupleStruct {
+///             struct_token: input.parse()?,
+///             ident: input.parse()?,
+///             paren_token: parenthesized!(content in input),
+///             fields: content.parse_terminated(Type::parse, Token![,])?,
+///             semi_token: input.parse()?,
+///         })
+///     }
+/// }
+/// #
+/// # fn main() {
+/// #     let input = quote! {
+/// #         struct S(A, B);
+/// #     };
+/// #     syn::parse2::<TupleStruct>(input).unwrap();
+/// # }
+/// ```
+#[macro_export]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+macro_rules! parenthesized {
+    ($content:ident in $cursor:expr) => {
+        match $crate::__private::parse_parens(&$cursor) {
+            $crate::__private::Ok(parens) => {
+                $content = parens.content;
+                parens.token
+            }
+            $crate::__private::Err(error) => {
+                return $crate::__private::Err(error);
+            }
+        }
+    };
+}
+
+/// Parse a set of curly braces and expose their content to subsequent parsers.
+///
+/// # Example
+///
+/// ```
+/// # use quote::quote;
+/// #
+/// use syn::{braced, token, Ident, Result, Token, Type};
+/// use syn::parse::{Parse, ParseStream};
+/// use syn::punctuated::Punctuated;
+///
+/// // Parse a simplified struct syntax like:
+/// //
+/// //     struct S {
+/// //         a: A,
+/// //         b: B,
+/// //     }
+/// struct Struct {
+///     struct_token: Token![struct],
+///     ident: Ident,
+///     brace_token: token::Brace,
+///     fields: Punctuated<Field, Token![,]>,
+/// }
+///
+/// struct Field {
+///     name: Ident,
+///     colon_token: Token![:],
+///     ty: Type,
+/// }
+///
+/// impl Parse for Struct {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let content;
+///         Ok(Struct {
+///             struct_token: input.parse()?,
+///             ident: input.parse()?,
+///             brace_token: braced!(content in input),
+///             fields: content.parse_terminated(Field::parse, Token![,])?,
+///         })
+///     }
+/// }
+///
+/// impl Parse for Field {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         Ok(Field {
+///             name: input.parse()?,
+///             colon_token: input.parse()?,
+///             ty: input.parse()?,
+///         })
+///     }
+/// }
+/// #
+/// # fn main() {
+/// #     let input = quote! {
+/// #         struct S {
+/// #             a: A,
+/// #             b: B,
+/// #         }
+/// #     };
+/// #     syn::parse2::<Struct>(input).unwrap();
+/// # }
+/// ```
+#[macro_export]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+macro_rules! braced {
+    ($content:ident in $cursor:expr) => {
+        match $crate::__private::parse_braces(&$cursor) {
+            $crate::__private::Ok(braces) => {
+                $content = braces.content;
+                braces.token
+            }
+            $crate::__private::Err(error) => {
+                return $crate::__private::Err(error);
+            }
+        }
+    };
+}
+
+/// Parse a set of square brackets and expose their content to subsequent
+/// parsers.
+///
+/// # Example
+///
+/// ```
+/// # use quote::quote;
+/// #
+/// use proc_macro2::TokenStream;
+/// use syn::{bracketed, token, Result, Token};
+/// use syn::parse::{Parse, ParseStream};
+///
+/// // Parse an outer attribute like:
+/// //
+/// //     #[repr(C, packed)]
+/// struct OuterAttribute {
+///     pound_token: Token![#],
+///     bracket_token: token::Bracket,
+///     content: TokenStream,
+/// }
+///
+/// impl Parse for OuterAttribute {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let content;
+///         Ok(OuterAttribute {
+///             pound_token: input.parse()?,
+///             bracket_token: bracketed!(content in input),
+///             content: content.parse()?,
+///         })
+///     }
+/// }
+/// #
+/// # fn main() {
+/// #     let input = quote! {
+/// #         #[repr(C, packed)]
+/// #     };
+/// #     syn::parse2::<OuterAttribute>(input).unwrap();
+/// # }
+/// ```
+#[macro_export]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+macro_rules! bracketed {
+    ($content:ident in $cursor:expr) => {
+        match $crate::__private::parse_brackets(&$cursor) {
+            $crate::__private::Ok(brackets) => {
+                $content = brackets.content;
+                brackets.token
+            }
+            $crate::__private::Err(error) => {
+                return $crate::__private::Err(error);
+            }
+        }
+    };
+}
diff --git a/vendor/syn/src/ident.rs b/vendor/syn/src/ident.rs
new file mode 100644
index 0000000..d0f4ba0
--- /dev/null
+++ b/vendor/syn/src/ident.rs
@@ -0,0 +1,107 @@
+#[cfg(feature = "parsing")]
+use crate::lookahead;
+
+pub use proc_macro2::Ident;
+
+#[cfg(feature = "parsing")]
+pub_if_not_doc! {
+    #[doc(hidden)]
+    #[allow(non_snake_case)]
+    pub fn Ident(marker: lookahead::TokenMarker) -> Ident {
+        match marker {}
+    }
+}
+
+macro_rules! ident_from_token {
+    ($token:ident) => {
+        impl From<Token![$token]> for Ident {
+            fn from(token: Token![$token]) -> Ident {
+                Ident::new(stringify!($token), token.span)
+            }
+        }
+    };
+}
+
+ident_from_token!(self);
+ident_from_token!(Self);
+ident_from_token!(super);
+ident_from_token!(crate);
+ident_from_token!(extern);
+
+impl From<Token![_]> for Ident {
+    fn from(token: Token![_]) -> Ident {
+        Ident::new("_", token.span)
+    }
+}
+
+pub(crate) fn xid_ok(symbol: &str) -> bool {
+    let mut chars = symbol.chars();
+    let first = chars.next().unwrap();
+    if !(first == '_' || unicode_ident::is_xid_start(first)) {
+        return false;
+    }
+    for ch in chars {
+        if !unicode_ident::is_xid_continue(ch) {
+            return false;
+        }
+    }
+    true
+}
+
+#[cfg(feature = "parsing")]
+mod parsing {
+    use crate::buffer::Cursor;
+    use crate::parse::{Parse, ParseStream, Result};
+    use crate::token::Token;
+    use proc_macro2::Ident;
+
+    fn accept_as_ident(ident: &Ident) -> bool {
+        match ident.to_string().as_str() {
+            "_" |
+            // Based on https://doc.rust-lang.org/1.65.0/reference/keywords.html
+            "abstract" | "as" | "async" | "await" | "become" | "box" | "break" |
+            "const" | "continue" | "crate" | "do" | "dyn" | "else" | "enum" |
+            "extern" | "false" | "final" | "fn" | "for" | "if" | "impl" | "in" |
+            "let" | "loop" | "macro" | "match" | "mod" | "move" | "mut" |
+            "override" | "priv" | "pub" | "ref" | "return" | "Self" | "self" |
+            "static" | "struct" | "super" | "trait" | "true" | "try" | "type" |
+            "typeof" | "unsafe" | "unsized" | "use" | "virtual" | "where" |
+            "while" | "yield" => false,
+            _ => true,
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Ident {
+        fn parse(input: ParseStream) -> Result<Self> {
+            input.step(|cursor| {
+                if let Some((ident, rest)) = cursor.ident() {
+                    if accept_as_ident(&ident) {
+                        Ok((ident, rest))
+                    } else {
+                        Err(cursor.error(format_args!(
+                            "expected identifier, found keyword `{}`",
+                            ident,
+                        )))
+                    }
+                } else {
+                    Err(cursor.error("expected identifier"))
+                }
+            })
+        }
+    }
+
+    impl Token for Ident {
+        fn peek(cursor: Cursor) -> bool {
+            if let Some((ident, _rest)) = cursor.ident() {
+                accept_as_ident(&ident)
+            } else {
+                false
+            }
+        }
+
+        fn display() -> &'static str {
+            "identifier"
+        }
+    }
+}
diff --git a/vendor/syn/src/item.rs b/vendor/syn/src/item.rs
new file mode 100644
index 0000000..ee91f59
--- /dev/null
+++ b/vendor/syn/src/item.rs
@@ -0,0 +1,3400 @@
+use super::*;
+use crate::derive::{Data, DataEnum, DataStruct, DataUnion, DeriveInput};
+use crate::punctuated::Punctuated;
+use proc_macro2::TokenStream;
+
+#[cfg(feature = "parsing")]
+use std::mem;
+
+ast_enum_of_structs! {
+    /// Things that can appear directly inside of a module or scope.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum Item {
+        /// A constant item: `const MAX: u16 = 65535`.
+        Const(ItemConst),
+
+        /// An enum definition: `enum Foo<A, B> { A(A), B(B) }`.
+        Enum(ItemEnum),
+
+        /// An `extern crate` item: `extern crate serde`.
+        ExternCrate(ItemExternCrate),
+
+        /// A free-standing function: `fn process(n: usize) -> Result<()> { ...
+        /// }`.
+        Fn(ItemFn),
+
+        /// A block of foreign items: `extern "C" { ... }`.
+        ForeignMod(ItemForeignMod),
+
+        /// An impl block providing trait or associated items: `impl<A> Trait
+        /// for Data<A> { ... }`.
+        Impl(ItemImpl),
+
+        /// A macro invocation, which includes `macro_rules!` definitions.
+        Macro(ItemMacro),
+
+        /// A module or module declaration: `mod m` or `mod m { ... }`.
+        Mod(ItemMod),
+
+        /// A static item: `static BIKE: Shed = Shed(42)`.
+        Static(ItemStatic),
+
+        /// A struct definition: `struct Foo<A> { x: A }`.
+        Struct(ItemStruct),
+
+        /// A trait definition: `pub trait Iterator { ... }`.
+        Trait(ItemTrait),
+
+        /// A trait alias: `pub trait SharableIterator = Iterator + Sync`.
+        TraitAlias(ItemTraitAlias),
+
+        /// A type alias: `type Result<T> = std::result::Result<T, MyError>`.
+        Type(ItemType),
+
+        /// A union definition: `union Foo<A, B> { x: A, y: B }`.
+        Union(ItemUnion),
+
+        /// A use declaration: `use std::collections::HashMap`.
+        Use(ItemUse),
+
+        /// Tokens forming an item not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match item {
+        //         Item::Const(item) => {...}
+        //         Item::Enum(item) => {...}
+        //         ...
+        //         Item::Verbatim(item) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A constant item: `const MAX: u16 = 65535`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemConst {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub const_token: Token![const],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub colon_token: Token![:],
+        pub ty: Box<Type>,
+        pub eq_token: Token![=],
+        pub expr: Box<Expr>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// An enum definition: `enum Foo<A, B> { A(A), B(B) }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemEnum {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub enum_token: Token![enum],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub brace_token: token::Brace,
+        pub variants: Punctuated<Variant, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// An `extern crate` item: `extern crate serde`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemExternCrate {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub extern_token: Token![extern],
+        pub crate_token: Token![crate],
+        pub ident: Ident,
+        pub rename: Option<(Token![as], Ident)>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A free-standing function: `fn process(n: usize) -> Result<()> { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemFn {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub sig: Signature,
+        pub block: Box<Block>,
+    }
+}
+
+ast_struct! {
+    /// A block of foreign items: `extern "C" { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemForeignMod {
+        pub attrs: Vec<Attribute>,
+        pub unsafety: Option<Token![unsafe]>,
+        pub abi: Abi,
+        pub brace_token: token::Brace,
+        pub items: Vec<ForeignItem>,
+    }
+}
+
+ast_struct! {
+    /// An impl block providing trait or associated items: `impl<A> Trait
+    /// for Data<A> { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemImpl {
+        pub attrs: Vec<Attribute>,
+        pub defaultness: Option<Token![default]>,
+        pub unsafety: Option<Token![unsafe]>,
+        pub impl_token: Token![impl],
+        pub generics: Generics,
+        /// Trait this impl implements.
+        pub trait_: Option<(Option<Token![!]>, Path, Token![for])>,
+        /// The Self type of the impl.
+        pub self_ty: Box<Type>,
+        pub brace_token: token::Brace,
+        pub items: Vec<ImplItem>,
+    }
+}
+
+ast_struct! {
+    /// A macro invocation, which includes `macro_rules!` definitions.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemMacro {
+        pub attrs: Vec<Attribute>,
+        /// The `example` in `macro_rules! example { ... }`.
+        pub ident: Option<Ident>,
+        pub mac: Macro,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// A module or module declaration: `mod m` or `mod m { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemMod {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub unsafety: Option<Token![unsafe]>,
+        pub mod_token: Token![mod],
+        pub ident: Ident,
+        pub content: Option<(token::Brace, Vec<Item>)>,
+        pub semi: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// A static item: `static BIKE: Shed = Shed(42)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemStatic {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub static_token: Token![static],
+        pub mutability: StaticMutability,
+        pub ident: Ident,
+        pub colon_token: Token![:],
+        pub ty: Box<Type>,
+        pub eq_token: Token![=],
+        pub expr: Box<Expr>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A struct definition: `struct Foo<A> { x: A }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemStruct {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub struct_token: Token![struct],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub fields: Fields,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// A trait definition: `pub trait Iterator { ... }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemTrait {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub unsafety: Option<Token![unsafe]>,
+        pub auto_token: Option<Token![auto]>,
+        pub restriction: Option<ImplRestriction>,
+        pub trait_token: Token![trait],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub colon_token: Option<Token![:]>,
+        pub supertraits: Punctuated<TypeParamBound, Token![+]>,
+        pub brace_token: token::Brace,
+        pub items: Vec<TraitItem>,
+    }
+}
+
+ast_struct! {
+    /// A trait alias: `pub trait SharableIterator = Iterator + Sync`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemTraitAlias {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub trait_token: Token![trait],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub eq_token: Token![=],
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A type alias: `type Result<T> = std::result::Result<T, MyError>`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemType {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub type_token: Token![type],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub eq_token: Token![=],
+        pub ty: Box<Type>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A union definition: `union Foo<A, B> { x: A, y: B }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemUnion {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub union_token: Token![union],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub fields: FieldsNamed,
+    }
+}
+
+ast_struct! {
+    /// A use declaration: `use std::collections::HashMap`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ItemUse {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub use_token: Token![use],
+        pub leading_colon: Option<Token![::]>,
+        pub tree: UseTree,
+        pub semi_token: Token![;],
+    }
+}
+
+impl Item {
+    #[cfg(feature = "parsing")]
+    pub(crate) fn replace_attrs(&mut self, new: Vec<Attribute>) -> Vec<Attribute> {
+        match self {
+            Item::Const(ItemConst { attrs, .. })
+            | Item::Enum(ItemEnum { attrs, .. })
+            | Item::ExternCrate(ItemExternCrate { attrs, .. })
+            | Item::Fn(ItemFn { attrs, .. })
+            | Item::ForeignMod(ItemForeignMod { attrs, .. })
+            | Item::Impl(ItemImpl { attrs, .. })
+            | Item::Macro(ItemMacro { attrs, .. })
+            | Item::Mod(ItemMod { attrs, .. })
+            | Item::Static(ItemStatic { attrs, .. })
+            | Item::Struct(ItemStruct { attrs, .. })
+            | Item::Trait(ItemTrait { attrs, .. })
+            | Item::TraitAlias(ItemTraitAlias { attrs, .. })
+            | Item::Type(ItemType { attrs, .. })
+            | Item::Union(ItemUnion { attrs, .. })
+            | Item::Use(ItemUse { attrs, .. }) => mem::replace(attrs, new),
+            Item::Verbatim(_) => Vec::new(),
+        }
+    }
+}
+
+impl From<DeriveInput> for Item {
+    fn from(input: DeriveInput) -> Item {
+        match input.data {
+            Data::Struct(data) => Item::Struct(ItemStruct {
+                attrs: input.attrs,
+                vis: input.vis,
+                struct_token: data.struct_token,
+                ident: input.ident,
+                generics: input.generics,
+                fields: data.fields,
+                semi_token: data.semi_token,
+            }),
+            Data::Enum(data) => Item::Enum(ItemEnum {
+                attrs: input.attrs,
+                vis: input.vis,
+                enum_token: data.enum_token,
+                ident: input.ident,
+                generics: input.generics,
+                brace_token: data.brace_token,
+                variants: data.variants,
+            }),
+            Data::Union(data) => Item::Union(ItemUnion {
+                attrs: input.attrs,
+                vis: input.vis,
+                union_token: data.union_token,
+                ident: input.ident,
+                generics: input.generics,
+                fields: data.fields,
+            }),
+        }
+    }
+}
+
+impl From<ItemStruct> for DeriveInput {
+    fn from(input: ItemStruct) -> DeriveInput {
+        DeriveInput {
+            attrs: input.attrs,
+            vis: input.vis,
+            ident: input.ident,
+            generics: input.generics,
+            data: Data::Struct(DataStruct {
+                struct_token: input.struct_token,
+                fields: input.fields,
+                semi_token: input.semi_token,
+            }),
+        }
+    }
+}
+
+impl From<ItemEnum> for DeriveInput {
+    fn from(input: ItemEnum) -> DeriveInput {
+        DeriveInput {
+            attrs: input.attrs,
+            vis: input.vis,
+            ident: input.ident,
+            generics: input.generics,
+            data: Data::Enum(DataEnum {
+                enum_token: input.enum_token,
+                brace_token: input.brace_token,
+                variants: input.variants,
+            }),
+        }
+    }
+}
+
+impl From<ItemUnion> for DeriveInput {
+    fn from(input: ItemUnion) -> DeriveInput {
+        DeriveInput {
+            attrs: input.attrs,
+            vis: input.vis,
+            ident: input.ident,
+            generics: input.generics,
+            data: Data::Union(DataUnion {
+                union_token: input.union_token,
+                fields: input.fields,
+            }),
+        }
+    }
+}
+
+ast_enum_of_structs! {
+    /// A suffix of an import tree in a `use` item: `Type as Renamed` or `*`.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub enum UseTree {
+        /// A path prefix of imports in a `use` item: `std::...`.
+        Path(UsePath),
+
+        /// An identifier imported by a `use` item: `HashMap`.
+        Name(UseName),
+
+        /// An renamed identifier imported by a `use` item: `HashMap as Map`.
+        Rename(UseRename),
+
+        /// A glob import in a `use` item: `*`.
+        Glob(UseGlob),
+
+        /// A braced group of imports in a `use` item: `{A, B, C}`.
+        Group(UseGroup),
+    }
+}
+
+ast_struct! {
+    /// A path prefix of imports in a `use` item: `std::...`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct UsePath {
+        pub ident: Ident,
+        pub colon2_token: Token![::],
+        pub tree: Box<UseTree>,
+    }
+}
+
+ast_struct! {
+    /// An identifier imported by a `use` item: `HashMap`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct UseName {
+        pub ident: Ident,
+    }
+}
+
+ast_struct! {
+    /// An renamed identifier imported by a `use` item: `HashMap as Map`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct UseRename {
+        pub ident: Ident,
+        pub as_token: Token![as],
+        pub rename: Ident,
+    }
+}
+
+ast_struct! {
+    /// A glob import in a `use` item: `*`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct UseGlob {
+        pub star_token: Token![*],
+    }
+}
+
+ast_struct! {
+    /// A braced group of imports in a `use` item: `{A, B, C}`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct UseGroup {
+        pub brace_token: token::Brace,
+        pub items: Punctuated<UseTree, Token![,]>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// An item within an `extern` block.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum ForeignItem {
+        /// A foreign function in an `extern` block.
+        Fn(ForeignItemFn),
+
+        /// A foreign static item in an `extern` block: `static ext: u8`.
+        Static(ForeignItemStatic),
+
+        /// A foreign type in an `extern` block: `type void`.
+        Type(ForeignItemType),
+
+        /// A macro invocation within an extern block.
+        Macro(ForeignItemMacro),
+
+        /// Tokens in an `extern` block not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match item {
+        //         ForeignItem::Fn(item) => {...}
+        //         ForeignItem::Static(item) => {...}
+        //         ...
+        //         ForeignItem::Verbatim(item) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A foreign function in an `extern` block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ForeignItemFn {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub sig: Signature,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A foreign static item in an `extern` block: `static ext: u8`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ForeignItemStatic {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub static_token: Token![static],
+        pub mutability: StaticMutability,
+        pub ident: Ident,
+        pub colon_token: Token![:],
+        pub ty: Box<Type>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A foreign type in an `extern` block: `type void`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ForeignItemType {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub type_token: Token![type],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A macro invocation within an extern block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ForeignItemMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// An item declaration within the definition of a trait.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum TraitItem {
+        /// An associated constant within the definition of a trait.
+        Const(TraitItemConst),
+
+        /// An associated function within the definition of a trait.
+        Fn(TraitItemFn),
+
+        /// An associated type within the definition of a trait.
+        Type(TraitItemType),
+
+        /// A macro invocation within the definition of a trait.
+        Macro(TraitItemMacro),
+
+        /// Tokens within the definition of a trait not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match item {
+        //         TraitItem::Const(item) => {...}
+        //         TraitItem::Fn(item) => {...}
+        //         ...
+        //         TraitItem::Verbatim(item) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// An associated constant within the definition of a trait.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct TraitItemConst {
+        pub attrs: Vec<Attribute>,
+        pub const_token: Token![const],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub colon_token: Token![:],
+        pub ty: Type,
+        pub default: Option<(Token![=], Expr)>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// An associated function within the definition of a trait.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct TraitItemFn {
+        pub attrs: Vec<Attribute>,
+        pub sig: Signature,
+        pub default: Option<Block>,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// An associated type within the definition of a trait.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct TraitItemType {
+        pub attrs: Vec<Attribute>,
+        pub type_token: Token![type],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub colon_token: Option<Token![:]>,
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+        pub default: Option<(Token![=], Type)>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A macro invocation within the definition of a trait.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct TraitItemMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// An item within an impl block.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum ImplItem {
+        /// An associated constant within an impl block.
+        Const(ImplItemConst),
+
+        /// An associated function within an impl block.
+        Fn(ImplItemFn),
+
+        /// An associated type within an impl block.
+        Type(ImplItemType),
+
+        /// A macro invocation within an impl block.
+        Macro(ImplItemMacro),
+
+        /// Tokens within an impl block not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match item {
+        //         ImplItem::Const(item) => {...}
+        //         ImplItem::Fn(item) => {...}
+        //         ...
+        //         ImplItem::Verbatim(item) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// An associated constant within an impl block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ImplItemConst {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub defaultness: Option<Token![default]>,
+        pub const_token: Token![const],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub colon_token: Token![:],
+        pub ty: Type,
+        pub eq_token: Token![=],
+        pub expr: Expr,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// An associated function within an impl block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ImplItemFn {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub defaultness: Option<Token![default]>,
+        pub sig: Signature,
+        pub block: Block,
+    }
+}
+
+ast_struct! {
+    /// An associated type within an impl block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ImplItemType {
+        pub attrs: Vec<Attribute>,
+        pub vis: Visibility,
+        pub defaultness: Option<Token![default]>,
+        pub type_token: Token![type],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub eq_token: Token![=],
+        pub ty: Type,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// A macro invocation within an impl block.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct ImplItemMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+ast_struct! {
+    /// A function signature in a trait or implementation: `unsafe fn
+    /// initialize(&self)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Signature {
+        pub constness: Option<Token![const]>,
+        pub asyncness: Option<Token![async]>,
+        pub unsafety: Option<Token![unsafe]>,
+        pub abi: Option<Abi>,
+        pub fn_token: Token![fn],
+        pub ident: Ident,
+        pub generics: Generics,
+        pub paren_token: token::Paren,
+        pub inputs: Punctuated<FnArg, Token![,]>,
+        pub variadic: Option<Variadic>,
+        pub output: ReturnType,
+    }
+}
+
+impl Signature {
+    /// A method's `self` receiver, such as `&self` or `self: Box<Self>`.
+    pub fn receiver(&self) -> Option<&Receiver> {
+        let arg = self.inputs.first()?;
+        match arg {
+            FnArg::Receiver(receiver) => Some(receiver),
+            FnArg::Typed(_) => None,
+        }
+    }
+}
+
+ast_enum_of_structs! {
+    /// An argument in a function signature: the `n: usize` in `fn f(n: usize)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub enum FnArg {
+        /// The `self` argument of an associated method.
+        Receiver(Receiver),
+
+        /// A function argument accepted by pattern and type.
+        Typed(PatType),
+    }
+}
+
+ast_struct! {
+    /// The `self` argument of an associated method.
+    ///
+    /// If `colon_token` is present, the receiver is written with an explicit
+    /// type such as `self: Box<Self>`. If `colon_token` is absent, the receiver
+    /// is written in shorthand such as `self` or `&self` or `&mut self`. In the
+    /// shorthand case, the type in `ty` is reconstructed as one of `Self`,
+    /// `&Self`, or `&mut Self`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Receiver {
+        pub attrs: Vec<Attribute>,
+        pub reference: Option<(Token![&], Option<Lifetime>)>,
+        pub mutability: Option<Token![mut]>,
+        pub self_token: Token![self],
+        pub colon_token: Option<Token![:]>,
+        pub ty: Box<Type>,
+    }
+}
+
+impl Receiver {
+    pub fn lifetime(&self) -> Option<&Lifetime> {
+        self.reference.as_ref()?.1.as_ref()
+    }
+}
+
+ast_struct! {
+    /// The variadic argument of a foreign function.
+    ///
+    /// ```rust
+    /// # struct c_char;
+    /// # struct c_int;
+    /// #
+    /// extern "C" {
+    ///     fn printf(format: *const c_char, ...) -> c_int;
+    ///     //                               ^^^
+    /// }
+    /// ```
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Variadic {
+        pub attrs: Vec<Attribute>,
+        pub pat: Option<(Box<Pat>, Token![:])>,
+        pub dots: Token![...],
+        pub comma: Option<Token![,]>,
+    }
+}
+
+ast_enum! {
+    /// The mutability of an `Item::Static` or `ForeignItem::Static`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum StaticMutability {
+        Mut(Token![mut]),
+        None,
+    }
+}
+
+ast_enum! {
+    /// Unused, but reserved for RFC 3323 restrictions.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum ImplRestriction {}
+
+
+    // TODO: https://rust-lang.github.io/rfcs/3323-restrictions.html
+    //
+    // pub struct ImplRestriction {
+    //     pub impl_token: Token![impl],
+    //     pub paren_token: token::Paren,
+    //     pub in_token: Option<Token![in]>,
+    //     pub path: Box<Path>,
+    // }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::discouraged::Speculative;
+    use crate::parse::{Parse, ParseBuffer, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Item {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let attrs = input.call(Attribute::parse_outer)?;
+            parse_rest_of_item(begin, attrs, input)
+        }
+    }
+
+    pub(crate) fn parse_rest_of_item(
+        begin: ParseBuffer,
+        mut attrs: Vec<Attribute>,
+        input: ParseStream,
+    ) -> Result<Item> {
+        let ahead = input.fork();
+        let vis: Visibility = ahead.parse()?;
+
+        let lookahead = ahead.lookahead1();
+        let mut item = if lookahead.peek(Token![fn]) || peek_signature(&ahead) {
+            let vis: Visibility = input.parse()?;
+            let sig: Signature = input.parse()?;
+            if input.peek(Token![;]) {
+                input.parse::<Token![;]>()?;
+                Ok(Item::Verbatim(verbatim::between(&begin, input)))
+            } else {
+                parse_rest_of_fn(input, Vec::new(), vis, sig).map(Item::Fn)
+            }
+        } else if lookahead.peek(Token![extern]) {
+            ahead.parse::<Token![extern]>()?;
+            let lookahead = ahead.lookahead1();
+            if lookahead.peek(Token![crate]) {
+                input.parse().map(Item::ExternCrate)
+            } else if lookahead.peek(token::Brace) {
+                input.parse().map(Item::ForeignMod)
+            } else if lookahead.peek(LitStr) {
+                ahead.parse::<LitStr>()?;
+                let lookahead = ahead.lookahead1();
+                if lookahead.peek(token::Brace) {
+                    input.parse().map(Item::ForeignMod)
+                } else {
+                    Err(lookahead.error())
+                }
+            } else {
+                Err(lookahead.error())
+            }
+        } else if lookahead.peek(Token![use]) {
+            let allow_crate_root_in_path = true;
+            match parse_item_use(input, allow_crate_root_in_path)? {
+                Some(item_use) => Ok(Item::Use(item_use)),
+                None => Ok(Item::Verbatim(verbatim::between(&begin, input))),
+            }
+        } else if lookahead.peek(Token![static]) {
+            let vis = input.parse()?;
+            let static_token = input.parse()?;
+            let mutability = input.parse()?;
+            let ident = input.parse()?;
+            if input.peek(Token![=]) {
+                input.parse::<Token![=]>()?;
+                input.parse::<Expr>()?;
+                input.parse::<Token![;]>()?;
+                Ok(Item::Verbatim(verbatim::between(&begin, input)))
+            } else {
+                let colon_token = input.parse()?;
+                let ty = input.parse()?;
+                if input.peek(Token![;]) {
+                    input.parse::<Token![;]>()?;
+                    Ok(Item::Verbatim(verbatim::between(&begin, input)))
+                } else {
+                    Ok(Item::Static(ItemStatic {
+                        attrs: Vec::new(),
+                        vis,
+                        static_token,
+                        mutability,
+                        ident,
+                        colon_token,
+                        ty,
+                        eq_token: input.parse()?,
+                        expr: input.parse()?,
+                        semi_token: input.parse()?,
+                    }))
+                }
+            }
+        } else if lookahead.peek(Token![const]) {
+            let vis = input.parse()?;
+            let const_token: Token![const] = input.parse()?;
+            let lookahead = input.lookahead1();
+            let ident = if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                input.call(Ident::parse_any)?
+            } else {
+                return Err(lookahead.error());
+            };
+            let mut generics: Generics = input.parse()?;
+            let colon_token = input.parse()?;
+            let ty = input.parse()?;
+            let value = if let Some(eq_token) = input.parse::<Option<Token![=]>>()? {
+                let expr: Expr = input.parse()?;
+                Some((eq_token, expr))
+            } else {
+                None
+            };
+            generics.where_clause = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+            match value {
+                Some((eq_token, expr))
+                    if generics.lt_token.is_none() && generics.where_clause.is_none() =>
+                {
+                    Ok(Item::Const(ItemConst {
+                        attrs: Vec::new(),
+                        vis,
+                        const_token,
+                        ident,
+                        generics,
+                        colon_token,
+                        ty,
+                        eq_token,
+                        expr: Box::new(expr),
+                        semi_token,
+                    }))
+                }
+                _ => Ok(Item::Verbatim(verbatim::between(&begin, input))),
+            }
+        } else if lookahead.peek(Token![unsafe]) {
+            ahead.parse::<Token![unsafe]>()?;
+            let lookahead = ahead.lookahead1();
+            if lookahead.peek(Token![trait])
+                || lookahead.peek(Token![auto]) && ahead.peek2(Token![trait])
+            {
+                input.parse().map(Item::Trait)
+            } else if lookahead.peek(Token![impl]) {
+                let allow_verbatim_impl = true;
+                if let Some(item) = parse_impl(input, allow_verbatim_impl)? {
+                    Ok(Item::Impl(item))
+                } else {
+                    Ok(Item::Verbatim(verbatim::between(&begin, input)))
+                }
+            } else if lookahead.peek(Token![extern]) {
+                input.parse().map(Item::ForeignMod)
+            } else if lookahead.peek(Token![mod]) {
+                input.parse().map(Item::Mod)
+            } else {
+                Err(lookahead.error())
+            }
+        } else if lookahead.peek(Token![mod]) {
+            input.parse().map(Item::Mod)
+        } else if lookahead.peek(Token![type]) {
+            parse_item_type(begin, input)
+        } else if lookahead.peek(Token![struct]) {
+            input.parse().map(Item::Struct)
+        } else if lookahead.peek(Token![enum]) {
+            input.parse().map(Item::Enum)
+        } else if lookahead.peek(Token![union]) && ahead.peek2(Ident) {
+            input.parse().map(Item::Union)
+        } else if lookahead.peek(Token![trait]) {
+            input.call(parse_trait_or_trait_alias)
+        } else if lookahead.peek(Token![auto]) && ahead.peek2(Token![trait]) {
+            input.parse().map(Item::Trait)
+        } else if lookahead.peek(Token![impl])
+            || lookahead.peek(Token![default]) && !ahead.peek2(Token![!])
+        {
+            let allow_verbatim_impl = true;
+            if let Some(item) = parse_impl(input, allow_verbatim_impl)? {
+                Ok(Item::Impl(item))
+            } else {
+                Ok(Item::Verbatim(verbatim::between(&begin, input)))
+            }
+        } else if lookahead.peek(Token![macro]) {
+            input.advance_to(&ahead);
+            parse_macro2(begin, vis, input)
+        } else if vis.is_inherited()
+            && (lookahead.peek(Ident)
+                || lookahead.peek(Token![self])
+                || lookahead.peek(Token![super])
+                || lookahead.peek(Token![crate])
+                || lookahead.peek(Token![::]))
+        {
+            input.parse().map(Item::Macro)
+        } else {
+            Err(lookahead.error())
+        }?;
+
+        attrs.extend(item.replace_attrs(Vec::new()));
+        item.replace_attrs(attrs);
+        Ok(item)
+    }
+
+    struct FlexibleItemType {
+        vis: Visibility,
+        defaultness: Option<Token![default]>,
+        type_token: Token![type],
+        ident: Ident,
+        generics: Generics,
+        colon_token: Option<Token![:]>,
+        bounds: Punctuated<TypeParamBound, Token![+]>,
+        ty: Option<(Token![=], Type)>,
+        semi_token: Token![;],
+    }
+
+    enum TypeDefaultness {
+        Optional,
+        Disallowed,
+    }
+
+    enum WhereClauseLocation {
+        // type Ty<T> where T: 'static = T;
+        BeforeEq,
+        // type Ty<T> = T where T: 'static;
+        AfterEq,
+        // TODO: goes away once the migration period on rust-lang/rust#89122 is over
+        Both,
+    }
+
+    impl FlexibleItemType {
+        fn parse(
+            input: ParseStream,
+            allow_defaultness: TypeDefaultness,
+            where_clause_location: WhereClauseLocation,
+        ) -> Result<Self> {
+            let vis: Visibility = input.parse()?;
+            let defaultness: Option<Token![default]> = match allow_defaultness {
+                TypeDefaultness::Optional => input.parse()?,
+                TypeDefaultness::Disallowed => None,
+            };
+            let type_token: Token![type] = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let mut generics: Generics = input.parse()?;
+            let (colon_token, bounds) = Self::parse_optional_bounds(input)?;
+
+            match where_clause_location {
+                WhereClauseLocation::BeforeEq | WhereClauseLocation::Both => {
+                    generics.where_clause = input.parse()?;
+                }
+                WhereClauseLocation::AfterEq => {}
+            }
+
+            let ty = Self::parse_optional_definition(input)?;
+
+            match where_clause_location {
+                WhereClauseLocation::AfterEq | WhereClauseLocation::Both
+                    if generics.where_clause.is_none() =>
+                {
+                    generics.where_clause = input.parse()?;
+                }
+                _ => {}
+            }
+
+            let semi_token: Token![;] = input.parse()?;
+
+            Ok(FlexibleItemType {
+                vis,
+                defaultness,
+                type_token,
+                ident,
+                generics,
+                colon_token,
+                bounds,
+                ty,
+                semi_token,
+            })
+        }
+
+        fn parse_optional_bounds(
+            input: ParseStream,
+        ) -> Result<(Option<Token![:]>, Punctuated<TypeParamBound, Token![+]>)> {
+            let colon_token: Option<Token![:]> = input.parse()?;
+
+            let mut bounds = Punctuated::new();
+            if colon_token.is_some() {
+                loop {
+                    if input.peek(Token![where]) || input.peek(Token![=]) || input.peek(Token![;]) {
+                        break;
+                    }
+                    bounds.push_value(input.parse::<TypeParamBound>()?);
+                    if input.peek(Token![where]) || input.peek(Token![=]) || input.peek(Token![;]) {
+                        break;
+                    }
+                    bounds.push_punct(input.parse::<Token![+]>()?);
+                }
+            }
+
+            Ok((colon_token, bounds))
+        }
+
+        fn parse_optional_definition(input: ParseStream) -> Result<Option<(Token![=], Type)>> {
+            let eq_token: Option<Token![=]> = input.parse()?;
+            if let Some(eq_token) = eq_token {
+                let definition: Type = input.parse()?;
+                Ok(Some((eq_token, definition)))
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let path = input.call(Path::parse_mod_style)?;
+            let bang_token: Token![!] = input.parse()?;
+            let ident: Option<Ident> = if input.peek(Token![try]) {
+                input.call(Ident::parse_any).map(Some)
+            } else {
+                input.parse()
+            }?;
+            let (delimiter, tokens) = input.call(mac::parse_delimiter)?;
+            let semi_token: Option<Token![;]> = if !delimiter.is_brace() {
+                Some(input.parse()?)
+            } else {
+                None
+            };
+            Ok(ItemMacro {
+                attrs,
+                ident,
+                mac: Macro {
+                    path,
+                    bang_token,
+                    delimiter,
+                    tokens,
+                },
+                semi_token,
+            })
+        }
+    }
+
+    fn parse_macro2(begin: ParseBuffer, _vis: Visibility, input: ParseStream) -> Result<Item> {
+        input.parse::<Token![macro]>()?;
+        input.parse::<Ident>()?;
+
+        let mut lookahead = input.lookahead1();
+        if lookahead.peek(token::Paren) {
+            let paren_content;
+            parenthesized!(paren_content in input);
+            paren_content.parse::<TokenStream>()?;
+            lookahead = input.lookahead1();
+        }
+
+        if lookahead.peek(token::Brace) {
+            let brace_content;
+            braced!(brace_content in input);
+            brace_content.parse::<TokenStream>()?;
+        } else {
+            return Err(lookahead.error());
+        }
+
+        Ok(Item::Verbatim(verbatim::between(&begin, input)))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemExternCrate {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ItemExternCrate {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                extern_token: input.parse()?,
+                crate_token: input.parse()?,
+                ident: {
+                    if input.peek(Token![self]) {
+                        input.call(Ident::parse_any)?
+                    } else {
+                        input.parse()?
+                    }
+                },
+                rename: {
+                    if input.peek(Token![as]) {
+                        let as_token: Token![as] = input.parse()?;
+                        let rename: Ident = if input.peek(Token![_]) {
+                            Ident::from(input.parse::<Token![_]>()?)
+                        } else {
+                            input.parse()?
+                        };
+                        Some((as_token, rename))
+                    } else {
+                        None
+                    }
+                },
+                semi_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemUse {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_crate_root_in_path = false;
+            parse_item_use(input, allow_crate_root_in_path).map(Option::unwrap)
+        }
+    }
+
+    fn parse_item_use(
+        input: ParseStream,
+        allow_crate_root_in_path: bool,
+    ) -> Result<Option<ItemUse>> {
+        let attrs = input.call(Attribute::parse_outer)?;
+        let vis: Visibility = input.parse()?;
+        let use_token: Token![use] = input.parse()?;
+        let leading_colon: Option<Token![::]> = input.parse()?;
+        let tree = parse_use_tree(input, allow_crate_root_in_path && leading_colon.is_none())?;
+        let semi_token: Token![;] = input.parse()?;
+
+        let tree = match tree {
+            Some(tree) => tree,
+            None => return Ok(None),
+        };
+
+        Ok(Some(ItemUse {
+            attrs,
+            vis,
+            use_token,
+            leading_colon,
+            tree,
+            semi_token,
+        }))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for UseTree {
+        fn parse(input: ParseStream) -> Result<UseTree> {
+            let allow_crate_root_in_path = false;
+            parse_use_tree(input, allow_crate_root_in_path).map(Option::unwrap)
+        }
+    }
+
+    fn parse_use_tree(
+        input: ParseStream,
+        allow_crate_root_in_path: bool,
+    ) -> Result<Option<UseTree>> {
+        let lookahead = input.lookahead1();
+        if lookahead.peek(Ident)
+            || lookahead.peek(Token![self])
+            || lookahead.peek(Token![super])
+            || lookahead.peek(Token![crate])
+            || lookahead.peek(Token![try])
+        {
+            let ident = input.call(Ident::parse_any)?;
+            if input.peek(Token![::]) {
+                Ok(Some(UseTree::Path(UsePath {
+                    ident,
+                    colon2_token: input.parse()?,
+                    tree: Box::new(input.parse()?),
+                })))
+            } else if input.peek(Token![as]) {
+                Ok(Some(UseTree::Rename(UseRename {
+                    ident,
+                    as_token: input.parse()?,
+                    rename: {
+                        if input.peek(Ident) {
+                            input.parse()?
+                        } else if input.peek(Token![_]) {
+                            Ident::from(input.parse::<Token![_]>()?)
+                        } else {
+                            return Err(input.error("expected identifier or underscore"));
+                        }
+                    },
+                })))
+            } else {
+                Ok(Some(UseTree::Name(UseName { ident })))
+            }
+        } else if lookahead.peek(Token![*]) {
+            Ok(Some(UseTree::Glob(UseGlob {
+                star_token: input.parse()?,
+            })))
+        } else if lookahead.peek(token::Brace) {
+            let content;
+            let brace_token = braced!(content in input);
+            let mut items = Punctuated::new();
+            let mut has_any_crate_root_in_path = false;
+            loop {
+                if content.is_empty() {
+                    break;
+                }
+                let this_tree_starts_with_crate_root =
+                    allow_crate_root_in_path && content.parse::<Option<Token![::]>>()?.is_some();
+                has_any_crate_root_in_path |= this_tree_starts_with_crate_root;
+                match parse_use_tree(
+                    &content,
+                    allow_crate_root_in_path && !this_tree_starts_with_crate_root,
+                )? {
+                    Some(tree) => items.push_value(tree),
+                    None => has_any_crate_root_in_path = true,
+                }
+                if content.is_empty() {
+                    break;
+                }
+                let comma: Token![,] = content.parse()?;
+                items.push_punct(comma);
+            }
+            if has_any_crate_root_in_path {
+                Ok(None)
+            } else {
+                Ok(Some(UseTree::Group(UseGroup { brace_token, items })))
+            }
+        } else {
+            Err(lookahead.error())
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemStatic {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ItemStatic {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                static_token: input.parse()?,
+                mutability: input.parse()?,
+                ident: input.parse()?,
+                colon_token: input.parse()?,
+                ty: input.parse()?,
+                eq_token: input.parse()?,
+                expr: input.parse()?,
+                semi_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemConst {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let const_token: Token![const] = input.parse()?;
+
+            let lookahead = input.lookahead1();
+            let ident = if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                input.call(Ident::parse_any)?
+            } else {
+                return Err(lookahead.error());
+            };
+
+            let colon_token: Token![:] = input.parse()?;
+            let ty: Type = input.parse()?;
+            let eq_token: Token![=] = input.parse()?;
+            let expr: Expr = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+
+            Ok(ItemConst {
+                attrs,
+                vis,
+                const_token,
+                ident,
+                generics: Generics::default(),
+                colon_token,
+                ty: Box::new(ty),
+                eq_token,
+                expr: Box::new(expr),
+                semi_token,
+            })
+        }
+    }
+
+    fn peek_signature(input: ParseStream) -> bool {
+        let fork = input.fork();
+        fork.parse::<Option<Token![const]>>().is_ok()
+            && fork.parse::<Option<Token![async]>>().is_ok()
+            && fork.parse::<Option<Token![unsafe]>>().is_ok()
+            && fork.parse::<Option<Abi>>().is_ok()
+            && fork.peek(Token![fn])
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Signature {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let constness: Option<Token![const]> = input.parse()?;
+            let asyncness: Option<Token![async]> = input.parse()?;
+            let unsafety: Option<Token![unsafe]> = input.parse()?;
+            let abi: Option<Abi> = input.parse()?;
+            let fn_token: Token![fn] = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let mut generics: Generics = input.parse()?;
+
+            let content;
+            let paren_token = parenthesized!(content in input);
+            let (inputs, variadic) = parse_fn_args(&content)?;
+
+            let output: ReturnType = input.parse()?;
+            generics.where_clause = input.parse()?;
+
+            Ok(Signature {
+                constness,
+                asyncness,
+                unsafety,
+                abi,
+                fn_token,
+                ident,
+                generics,
+                paren_token,
+                inputs,
+                variadic,
+                output,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemFn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let outer_attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let sig: Signature = input.parse()?;
+            parse_rest_of_fn(input, outer_attrs, vis, sig)
+        }
+    }
+
+    fn parse_rest_of_fn(
+        input: ParseStream,
+        mut attrs: Vec<Attribute>,
+        vis: Visibility,
+        sig: Signature,
+    ) -> Result<ItemFn> {
+        let content;
+        let brace_token = braced!(content in input);
+        attr::parsing::parse_inner(&content, &mut attrs)?;
+        let stmts = content.call(Block::parse_within)?;
+
+        Ok(ItemFn {
+            attrs,
+            vis,
+            sig,
+            block: Box::new(Block { brace_token, stmts }),
+        })
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for FnArg {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_variadic = false;
+            let attrs = input.call(Attribute::parse_outer)?;
+            match parse_fn_arg_or_variadic(input, attrs, allow_variadic)? {
+                FnArgOrVariadic::FnArg(arg) => Ok(arg),
+                FnArgOrVariadic::Variadic(_) => unreachable!(),
+            }
+        }
+    }
+
+    enum FnArgOrVariadic {
+        FnArg(FnArg),
+        Variadic(Variadic),
+    }
+
+    fn parse_fn_arg_or_variadic(
+        input: ParseStream,
+        attrs: Vec<Attribute>,
+        allow_variadic: bool,
+    ) -> Result<FnArgOrVariadic> {
+        let ahead = input.fork();
+        if let Ok(mut receiver) = ahead.parse::<Receiver>() {
+            input.advance_to(&ahead);
+            receiver.attrs = attrs;
+            return Ok(FnArgOrVariadic::FnArg(FnArg::Receiver(receiver)));
+        }
+
+        // Hack to parse pre-2018 syntax in
+        // test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs
+        // because the rest of the test case is valuable.
+        if input.peek(Ident) && input.peek2(Token![<]) {
+            let span = input.fork().parse::<Ident>()?.span();
+            return Ok(FnArgOrVariadic::FnArg(FnArg::Typed(PatType {
+                attrs,
+                pat: Box::new(Pat::Wild(PatWild {
+                    attrs: Vec::new(),
+                    underscore_token: Token![_](span),
+                })),
+                colon_token: Token![:](span),
+                ty: input.parse()?,
+            })));
+        }
+
+        let pat = Box::new(Pat::parse_single(input)?);
+        let colon_token: Token![:] = input.parse()?;
+
+        if allow_variadic {
+            if let Some(dots) = input.parse::<Option<Token![...]>>()? {
+                return Ok(FnArgOrVariadic::Variadic(Variadic {
+                    attrs,
+                    pat: Some((pat, colon_token)),
+                    dots,
+                    comma: None,
+                }));
+            }
+        }
+
+        Ok(FnArgOrVariadic::FnArg(FnArg::Typed(PatType {
+            attrs,
+            pat,
+            colon_token,
+            ty: input.parse()?,
+        })))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Receiver {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let reference = if input.peek(Token![&]) {
+                let ampersand: Token![&] = input.parse()?;
+                let lifetime: Option<Lifetime> = input.parse()?;
+                Some((ampersand, lifetime))
+            } else {
+                None
+            };
+            let mutability: Option<Token![mut]> = input.parse()?;
+            let self_token: Token![self] = input.parse()?;
+            let colon_token: Option<Token![:]> = if reference.is_some() {
+                None
+            } else {
+                input.parse()?
+            };
+            let ty: Type = if colon_token.is_some() {
+                input.parse()?
+            } else {
+                let mut ty = Type::Path(TypePath {
+                    qself: None,
+                    path: Path::from(Ident::new("Self", self_token.span)),
+                });
+                if let Some((ampersand, lifetime)) = reference.as_ref() {
+                    ty = Type::Reference(TypeReference {
+                        and_token: Token![&](ampersand.span),
+                        lifetime: lifetime.clone(),
+                        mutability: mutability.as_ref().map(|m| Token![mut](m.span)),
+                        elem: Box::new(ty),
+                    });
+                }
+                ty
+            };
+            Ok(Receiver {
+                attrs: Vec::new(),
+                reference,
+                mutability,
+                self_token,
+                colon_token,
+                ty: Box::new(ty),
+            })
+        }
+    }
+
+    fn parse_fn_args(
+        input: ParseStream,
+    ) -> Result<(Punctuated<FnArg, Token![,]>, Option<Variadic>)> {
+        let mut args = Punctuated::new();
+        let mut variadic = None;
+        let mut has_receiver = false;
+
+        while !input.is_empty() {
+            let attrs = input.call(Attribute::parse_outer)?;
+
+            if let Some(dots) = input.parse::<Option<Token![...]>>()? {
+                variadic = Some(Variadic {
+                    attrs,
+                    pat: None,
+                    dots,
+                    comma: if input.is_empty() {
+                        None
+                    } else {
+                        Some(input.parse()?)
+                    },
+                });
+                break;
+            }
+
+            let allow_variadic = true;
+            let arg = match parse_fn_arg_or_variadic(input, attrs, allow_variadic)? {
+                FnArgOrVariadic::FnArg(arg) => arg,
+                FnArgOrVariadic::Variadic(arg) => {
+                    variadic = Some(Variadic {
+                        comma: if input.is_empty() {
+                            None
+                        } else {
+                            Some(input.parse()?)
+                        },
+                        ..arg
+                    });
+                    break;
+                }
+            };
+
+            match &arg {
+                FnArg::Receiver(receiver) if has_receiver => {
+                    return Err(Error::new(
+                        receiver.self_token.span,
+                        "unexpected second method receiver",
+                    ));
+                }
+                FnArg::Receiver(receiver) if !args.is_empty() => {
+                    return Err(Error::new(
+                        receiver.self_token.span,
+                        "unexpected method receiver",
+                    ));
+                }
+                FnArg::Receiver(_) => has_receiver = true,
+                FnArg::Typed(_) => {}
+            }
+            args.push_value(arg);
+
+            if input.is_empty() {
+                break;
+            }
+
+            let comma: Token![,] = input.parse()?;
+            args.push_punct(comma);
+        }
+
+        Ok((args, variadic))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemMod {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let unsafety: Option<Token![unsafe]> = input.parse()?;
+            let mod_token: Token![mod] = input.parse()?;
+            let ident: Ident = if input.peek(Token![try]) {
+                input.call(Ident::parse_any)
+            } else {
+                input.parse()
+            }?;
+
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Token![;]) {
+                Ok(ItemMod {
+                    attrs,
+                    vis,
+                    unsafety,
+                    mod_token,
+                    ident,
+                    content: None,
+                    semi: Some(input.parse()?),
+                })
+            } else if lookahead.peek(token::Brace) {
+                let content;
+                let brace_token = braced!(content in input);
+                attr::parsing::parse_inner(&content, &mut attrs)?;
+
+                let mut items = Vec::new();
+                while !content.is_empty() {
+                    items.push(content.parse()?);
+                }
+
+                Ok(ItemMod {
+                    attrs,
+                    vis,
+                    unsafety,
+                    mod_token,
+                    ident,
+                    content: Some((brace_token, items)),
+                    semi: None,
+                })
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemForeignMod {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let unsafety: Option<Token![unsafe]> = input.parse()?;
+            let abi: Abi = input.parse()?;
+
+            let content;
+            let brace_token = braced!(content in input);
+            attr::parsing::parse_inner(&content, &mut attrs)?;
+            let mut items = Vec::new();
+            while !content.is_empty() {
+                items.push(content.parse()?);
+            }
+
+            Ok(ItemForeignMod {
+                attrs,
+                unsafety,
+                abi,
+                brace_token,
+                items,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ForeignItem {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let ahead = input.fork();
+            let vis: Visibility = ahead.parse()?;
+
+            let lookahead = ahead.lookahead1();
+            let mut item = if lookahead.peek(Token![fn]) || peek_signature(&ahead) {
+                let vis: Visibility = input.parse()?;
+                let sig: Signature = input.parse()?;
+                if input.peek(token::Brace) {
+                    let content;
+                    braced!(content in input);
+                    content.call(Attribute::parse_inner)?;
+                    content.call(Block::parse_within)?;
+
+                    Ok(ForeignItem::Verbatim(verbatim::between(&begin, input)))
+                } else {
+                    Ok(ForeignItem::Fn(ForeignItemFn {
+                        attrs: Vec::new(),
+                        vis,
+                        sig,
+                        semi_token: input.parse()?,
+                    }))
+                }
+            } else if lookahead.peek(Token![static]) {
+                let vis = input.parse()?;
+                let static_token = input.parse()?;
+                let mutability = input.parse()?;
+                let ident = input.parse()?;
+                let colon_token = input.parse()?;
+                let ty = input.parse()?;
+                if input.peek(Token![=]) {
+                    input.parse::<Token![=]>()?;
+                    input.parse::<Expr>()?;
+                    input.parse::<Token![;]>()?;
+                    Ok(ForeignItem::Verbatim(verbatim::between(&begin, input)))
+                } else {
+                    Ok(ForeignItem::Static(ForeignItemStatic {
+                        attrs: Vec::new(),
+                        vis,
+                        static_token,
+                        mutability,
+                        ident,
+                        colon_token,
+                        ty,
+                        semi_token: input.parse()?,
+                    }))
+                }
+            } else if lookahead.peek(Token![type]) {
+                parse_foreign_item_type(begin, input)
+            } else if vis.is_inherited()
+                && (lookahead.peek(Ident)
+                    || lookahead.peek(Token![self])
+                    || lookahead.peek(Token![super])
+                    || lookahead.peek(Token![crate])
+                    || lookahead.peek(Token![::]))
+            {
+                input.parse().map(ForeignItem::Macro)
+            } else {
+                Err(lookahead.error())
+            }?;
+
+            let item_attrs = match &mut item {
+                ForeignItem::Fn(item) => &mut item.attrs,
+                ForeignItem::Static(item) => &mut item.attrs,
+                ForeignItem::Type(item) => &mut item.attrs,
+                ForeignItem::Macro(item) => &mut item.attrs,
+                ForeignItem::Verbatim(_) => return Ok(item),
+            };
+            attrs.append(item_attrs);
+            *item_attrs = attrs;
+
+            Ok(item)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ForeignItemFn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let sig: Signature = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+            Ok(ForeignItemFn {
+                attrs,
+                vis,
+                sig,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ForeignItemStatic {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ForeignItemStatic {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                static_token: input.parse()?,
+                mutability: input.parse()?,
+                ident: input.parse()?,
+                colon_token: input.parse()?,
+                ty: input.parse()?,
+                semi_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ForeignItemType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ForeignItemType {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                type_token: input.parse()?,
+                ident: input.parse()?,
+                generics: {
+                    let mut generics: Generics = input.parse()?;
+                    generics.where_clause = input.parse()?;
+                    generics
+                },
+                semi_token: input.parse()?,
+            })
+        }
+    }
+
+    fn parse_foreign_item_type(begin: ParseBuffer, input: ParseStream) -> Result<ForeignItem> {
+        let FlexibleItemType {
+            vis,
+            defaultness: _,
+            type_token,
+            ident,
+            generics,
+            colon_token,
+            bounds: _,
+            ty,
+            semi_token,
+        } = FlexibleItemType::parse(
+            input,
+            TypeDefaultness::Disallowed,
+            WhereClauseLocation::Both,
+        )?;
+
+        if colon_token.is_some() || ty.is_some() {
+            Ok(ForeignItem::Verbatim(verbatim::between(&begin, input)))
+        } else {
+            Ok(ForeignItem::Type(ForeignItemType {
+                attrs: Vec::new(),
+                vis,
+                type_token,
+                ident,
+                generics,
+                semi_token,
+            }))
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ForeignItemMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let mac: Macro = input.parse()?;
+            let semi_token: Option<Token![;]> = if mac.delimiter.is_brace() {
+                None
+            } else {
+                Some(input.parse()?)
+            };
+            Ok(ForeignItemMacro {
+                attrs,
+                mac,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ItemType {
+                attrs: input.call(Attribute::parse_outer)?,
+                vis: input.parse()?,
+                type_token: input.parse()?,
+                ident: input.parse()?,
+                generics: {
+                    let mut generics: Generics = input.parse()?;
+                    generics.where_clause = input.parse()?;
+                    generics
+                },
+                eq_token: input.parse()?,
+                ty: input.parse()?,
+                semi_token: input.parse()?,
+            })
+        }
+    }
+
+    fn parse_item_type(begin: ParseBuffer, input: ParseStream) -> Result<Item> {
+        let FlexibleItemType {
+            vis,
+            defaultness: _,
+            type_token,
+            ident,
+            generics,
+            colon_token,
+            bounds: _,
+            ty,
+            semi_token,
+        } = FlexibleItemType::parse(
+            input,
+            TypeDefaultness::Disallowed,
+            WhereClauseLocation::BeforeEq,
+        )?;
+
+        let (eq_token, ty) = match ty {
+            Some(ty) if colon_token.is_none() => ty,
+            _ => return Ok(Item::Verbatim(verbatim::between(&begin, input))),
+        };
+
+        Ok(Item::Type(ItemType {
+            attrs: Vec::new(),
+            vis,
+            type_token,
+            ident,
+            generics,
+            eq_token,
+            ty: Box::new(ty),
+            semi_token,
+        }))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemStruct {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis = input.parse::<Visibility>()?;
+            let struct_token = input.parse::<Token![struct]>()?;
+            let ident = input.parse::<Ident>()?;
+            let generics = input.parse::<Generics>()?;
+            let (where_clause, fields, semi_token) = derive::parsing::data_struct(input)?;
+            Ok(ItemStruct {
+                attrs,
+                vis,
+                struct_token,
+                ident,
+                generics: Generics {
+                    where_clause,
+                    ..generics
+                },
+                fields,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemEnum {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis = input.parse::<Visibility>()?;
+            let enum_token = input.parse::<Token![enum]>()?;
+            let ident = input.parse::<Ident>()?;
+            let generics = input.parse::<Generics>()?;
+            let (where_clause, brace_token, variants) = derive::parsing::data_enum(input)?;
+            Ok(ItemEnum {
+                attrs,
+                vis,
+                enum_token,
+                ident,
+                generics: Generics {
+                    where_clause,
+                    ..generics
+                },
+                brace_token,
+                variants,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemUnion {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis = input.parse::<Visibility>()?;
+            let union_token = input.parse::<Token![union]>()?;
+            let ident = input.parse::<Ident>()?;
+            let generics = input.parse::<Generics>()?;
+            let (where_clause, fields) = derive::parsing::data_union(input)?;
+            Ok(ItemUnion {
+                attrs,
+                vis,
+                union_token,
+                ident,
+                generics: Generics {
+                    where_clause,
+                    ..generics
+                },
+                fields,
+            })
+        }
+    }
+
+    fn parse_trait_or_trait_alias(input: ParseStream) -> Result<Item> {
+        let (attrs, vis, trait_token, ident, generics) = parse_start_of_trait_alias(input)?;
+        let lookahead = input.lookahead1();
+        if lookahead.peek(token::Brace)
+            || lookahead.peek(Token![:])
+            || lookahead.peek(Token![where])
+        {
+            let unsafety = None;
+            let auto_token = None;
+            parse_rest_of_trait(
+                input,
+                attrs,
+                vis,
+                unsafety,
+                auto_token,
+                trait_token,
+                ident,
+                generics,
+            )
+            .map(Item::Trait)
+        } else if lookahead.peek(Token![=]) {
+            parse_rest_of_trait_alias(input, attrs, vis, trait_token, ident, generics)
+                .map(Item::TraitAlias)
+        } else {
+            Err(lookahead.error())
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemTrait {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let outer_attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let unsafety: Option<Token![unsafe]> = input.parse()?;
+            let auto_token: Option<Token![auto]> = input.parse()?;
+            let trait_token: Token![trait] = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let generics: Generics = input.parse()?;
+            parse_rest_of_trait(
+                input,
+                outer_attrs,
+                vis,
+                unsafety,
+                auto_token,
+                trait_token,
+                ident,
+                generics,
+            )
+        }
+    }
+
+    fn parse_rest_of_trait(
+        input: ParseStream,
+        mut attrs: Vec<Attribute>,
+        vis: Visibility,
+        unsafety: Option<Token![unsafe]>,
+        auto_token: Option<Token![auto]>,
+        trait_token: Token![trait],
+        ident: Ident,
+        mut generics: Generics,
+    ) -> Result<ItemTrait> {
+        let colon_token: Option<Token![:]> = input.parse()?;
+
+        let mut supertraits = Punctuated::new();
+        if colon_token.is_some() {
+            loop {
+                if input.peek(Token![where]) || input.peek(token::Brace) {
+                    break;
+                }
+                supertraits.push_value(input.parse()?);
+                if input.peek(Token![where]) || input.peek(token::Brace) {
+                    break;
+                }
+                supertraits.push_punct(input.parse()?);
+            }
+        }
+
+        generics.where_clause = input.parse()?;
+
+        let content;
+        let brace_token = braced!(content in input);
+        attr::parsing::parse_inner(&content, &mut attrs)?;
+        let mut items = Vec::new();
+        while !content.is_empty() {
+            items.push(content.parse()?);
+        }
+
+        Ok(ItemTrait {
+            attrs,
+            vis,
+            unsafety,
+            auto_token,
+            restriction: None,
+            trait_token,
+            ident,
+            generics,
+            colon_token,
+            supertraits,
+            brace_token,
+            items,
+        })
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemTraitAlias {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let (attrs, vis, trait_token, ident, generics) = parse_start_of_trait_alias(input)?;
+            parse_rest_of_trait_alias(input, attrs, vis, trait_token, ident, generics)
+        }
+    }
+
+    fn parse_start_of_trait_alias(
+        input: ParseStream,
+    ) -> Result<(Vec<Attribute>, Visibility, Token![trait], Ident, Generics)> {
+        let attrs = input.call(Attribute::parse_outer)?;
+        let vis: Visibility = input.parse()?;
+        let trait_token: Token![trait] = input.parse()?;
+        let ident: Ident = input.parse()?;
+        let generics: Generics = input.parse()?;
+        Ok((attrs, vis, trait_token, ident, generics))
+    }
+
+    fn parse_rest_of_trait_alias(
+        input: ParseStream,
+        attrs: Vec<Attribute>,
+        vis: Visibility,
+        trait_token: Token![trait],
+        ident: Ident,
+        mut generics: Generics,
+    ) -> Result<ItemTraitAlias> {
+        let eq_token: Token![=] = input.parse()?;
+
+        let mut bounds = Punctuated::new();
+        loop {
+            if input.peek(Token![where]) || input.peek(Token![;]) {
+                break;
+            }
+            bounds.push_value(input.parse()?);
+            if input.peek(Token![where]) || input.peek(Token![;]) {
+                break;
+            }
+            bounds.push_punct(input.parse()?);
+        }
+
+        generics.where_clause = input.parse()?;
+        let semi_token: Token![;] = input.parse()?;
+
+        Ok(ItemTraitAlias {
+            attrs,
+            vis,
+            trait_token,
+            ident,
+            generics,
+            eq_token,
+            bounds,
+            semi_token,
+        })
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitItem {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let defaultness: Option<Token![default]> = input.parse()?;
+            let ahead = input.fork();
+
+            let lookahead = ahead.lookahead1();
+            let mut item = if lookahead.peek(Token![fn]) || peek_signature(&ahead) {
+                input.parse().map(TraitItem::Fn)
+            } else if lookahead.peek(Token![const]) {
+                let const_token: Token![const] = ahead.parse()?;
+                let lookahead = ahead.lookahead1();
+                if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                    input.advance_to(&ahead);
+                    let ident = input.call(Ident::parse_any)?;
+                    let mut generics: Generics = input.parse()?;
+                    let colon_token: Token![:] = input.parse()?;
+                    let ty: Type = input.parse()?;
+                    let default = if let Some(eq_token) = input.parse::<Option<Token![=]>>()? {
+                        let expr: Expr = input.parse()?;
+                        Some((eq_token, expr))
+                    } else {
+                        None
+                    };
+                    generics.where_clause = input.parse()?;
+                    let semi_token: Token![;] = input.parse()?;
+                    if generics.lt_token.is_none() && generics.where_clause.is_none() {
+                        Ok(TraitItem::Const(TraitItemConst {
+                            attrs: Vec::new(),
+                            const_token,
+                            ident,
+                            generics,
+                            colon_token,
+                            ty,
+                            default,
+                            semi_token,
+                        }))
+                    } else {
+                        return Ok(TraitItem::Verbatim(verbatim::between(&begin, input)));
+                    }
+                } else if lookahead.peek(Token![async])
+                    || lookahead.peek(Token![unsafe])
+                    || lookahead.peek(Token![extern])
+                    || lookahead.peek(Token![fn])
+                {
+                    input.parse().map(TraitItem::Fn)
+                } else {
+                    Err(lookahead.error())
+                }
+            } else if lookahead.peek(Token![type]) {
+                parse_trait_item_type(begin.fork(), input)
+            } else if vis.is_inherited()
+                && defaultness.is_none()
+                && (lookahead.peek(Ident)
+                    || lookahead.peek(Token![self])
+                    || lookahead.peek(Token![super])
+                    || lookahead.peek(Token![crate])
+                    || lookahead.peek(Token![::]))
+            {
+                input.parse().map(TraitItem::Macro)
+            } else {
+                Err(lookahead.error())
+            }?;
+
+            match (vis, defaultness) {
+                (Visibility::Inherited, None) => {}
+                _ => return Ok(TraitItem::Verbatim(verbatim::between(&begin, input))),
+            }
+
+            let item_attrs = match &mut item {
+                TraitItem::Const(item) => &mut item.attrs,
+                TraitItem::Fn(item) => &mut item.attrs,
+                TraitItem::Type(item) => &mut item.attrs,
+                TraitItem::Macro(item) => &mut item.attrs,
+                TraitItem::Verbatim(_) => unreachable!(),
+            };
+            attrs.append(item_attrs);
+            *item_attrs = attrs;
+            Ok(item)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitItemConst {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let const_token: Token![const] = input.parse()?;
+
+            let lookahead = input.lookahead1();
+            let ident = if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                input.call(Ident::parse_any)?
+            } else {
+                return Err(lookahead.error());
+            };
+
+            let colon_token: Token![:] = input.parse()?;
+            let ty: Type = input.parse()?;
+            let default = if input.peek(Token![=]) {
+                let eq_token: Token![=] = input.parse()?;
+                let default: Expr = input.parse()?;
+                Some((eq_token, default))
+            } else {
+                None
+            };
+            let semi_token: Token![;] = input.parse()?;
+
+            Ok(TraitItemConst {
+                attrs,
+                const_token,
+                ident,
+                generics: Generics::default(),
+                colon_token,
+                ty,
+                default,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitItemFn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let sig: Signature = input.parse()?;
+
+            let lookahead = input.lookahead1();
+            let (brace_token, stmts, semi_token) = if lookahead.peek(token::Brace) {
+                let content;
+                let brace_token = braced!(content in input);
+                attr::parsing::parse_inner(&content, &mut attrs)?;
+                let stmts = content.call(Block::parse_within)?;
+                (Some(brace_token), stmts, None)
+            } else if lookahead.peek(Token![;]) {
+                let semi_token: Token![;] = input.parse()?;
+                (None, Vec::new(), Some(semi_token))
+            } else {
+                return Err(lookahead.error());
+            };
+
+            Ok(TraitItemFn {
+                attrs,
+                sig,
+                default: brace_token.map(|brace_token| Block { brace_token, stmts }),
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitItemType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let type_token: Token![type] = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let mut generics: Generics = input.parse()?;
+            let (colon_token, bounds) = FlexibleItemType::parse_optional_bounds(input)?;
+            let default = FlexibleItemType::parse_optional_definition(input)?;
+            generics.where_clause = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+            Ok(TraitItemType {
+                attrs,
+                type_token,
+                ident,
+                generics,
+                colon_token,
+                bounds,
+                default,
+                semi_token,
+            })
+        }
+    }
+
+    fn parse_trait_item_type(begin: ParseBuffer, input: ParseStream) -> Result<TraitItem> {
+        let FlexibleItemType {
+            vis,
+            defaultness: _,
+            type_token,
+            ident,
+            generics,
+            colon_token,
+            bounds,
+            ty,
+            semi_token,
+        } = FlexibleItemType::parse(
+            input,
+            TypeDefaultness::Disallowed,
+            WhereClauseLocation::AfterEq,
+        )?;
+
+        if vis.is_some() {
+            Ok(TraitItem::Verbatim(verbatim::between(&begin, input)))
+        } else {
+            Ok(TraitItem::Type(TraitItemType {
+                attrs: Vec::new(),
+                type_token,
+                ident,
+                generics,
+                colon_token,
+                bounds,
+                default: ty,
+                semi_token,
+            }))
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TraitItemMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let mac: Macro = input.parse()?;
+            let semi_token: Option<Token![;]> = if mac.delimiter.is_brace() {
+                None
+            } else {
+                Some(input.parse()?)
+            };
+            Ok(TraitItemMacro {
+                attrs,
+                mac,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ItemImpl {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_verbatim_impl = false;
+            parse_impl(input, allow_verbatim_impl).map(Option::unwrap)
+        }
+    }
+
+    fn parse_impl(input: ParseStream, allow_verbatim_impl: bool) -> Result<Option<ItemImpl>> {
+        let mut attrs = input.call(Attribute::parse_outer)?;
+        let has_visibility = allow_verbatim_impl && input.parse::<Visibility>()?.is_some();
+        let defaultness: Option<Token![default]> = input.parse()?;
+        let unsafety: Option<Token![unsafe]> = input.parse()?;
+        let impl_token: Token![impl] = input.parse()?;
+
+        let has_generics = input.peek(Token![<])
+            && (input.peek2(Token![>])
+                || input.peek2(Token![#])
+                || (input.peek2(Ident) || input.peek2(Lifetime))
+                    && (input.peek3(Token![:])
+                        || input.peek3(Token![,])
+                        || input.peek3(Token![>])
+                        || input.peek3(Token![=]))
+                || input.peek2(Token![const]));
+        let mut generics: Generics = if has_generics {
+            input.parse()?
+        } else {
+            Generics::default()
+        };
+
+        let is_const_impl = allow_verbatim_impl
+            && (input.peek(Token![const]) || input.peek(Token![?]) && input.peek2(Token![const]));
+        if is_const_impl {
+            input.parse::<Option<Token![?]>>()?;
+            input.parse::<Token![const]>()?;
+        }
+
+        let begin = input.fork();
+        let polarity = if input.peek(Token![!]) && !input.peek2(token::Brace) {
+            Some(input.parse::<Token![!]>()?)
+        } else {
+            None
+        };
+
+        #[cfg(not(feature = "printing"))]
+        let first_ty_span = input.span();
+        let mut first_ty: Type = input.parse()?;
+        let self_ty: Type;
+        let trait_;
+
+        let is_impl_for = input.peek(Token![for]);
+        if is_impl_for {
+            let for_token: Token![for] = input.parse()?;
+            let mut first_ty_ref = &first_ty;
+            while let Type::Group(ty) = first_ty_ref {
+                first_ty_ref = &ty.elem;
+            }
+            if let Type::Path(TypePath { qself: None, .. }) = first_ty_ref {
+                while let Type::Group(ty) = first_ty {
+                    first_ty = *ty.elem;
+                }
+                if let Type::Path(TypePath { qself: None, path }) = first_ty {
+                    trait_ = Some((polarity, path, for_token));
+                } else {
+                    unreachable!();
+                }
+            } else if !allow_verbatim_impl {
+                #[cfg(feature = "printing")]
+                return Err(Error::new_spanned(first_ty_ref, "expected trait path"));
+                #[cfg(not(feature = "printing"))]
+                return Err(Error::new(first_ty_span, "expected trait path"));
+            } else {
+                trait_ = None;
+            }
+            self_ty = input.parse()?;
+        } else {
+            trait_ = None;
+            self_ty = if polarity.is_none() {
+                first_ty
+            } else {
+                Type::Verbatim(verbatim::between(&begin, input))
+            };
+        }
+
+        generics.where_clause = input.parse()?;
+
+        let content;
+        let brace_token = braced!(content in input);
+        attr::parsing::parse_inner(&content, &mut attrs)?;
+
+        let mut items = Vec::new();
+        while !content.is_empty() {
+            items.push(content.parse()?);
+        }
+
+        if has_visibility || is_const_impl || is_impl_for && trait_.is_none() {
+            Ok(None)
+        } else {
+            Ok(Some(ItemImpl {
+                attrs,
+                defaultness,
+                unsafety,
+                impl_token,
+                generics,
+                trait_,
+                self_ty: Box::new(self_ty),
+                brace_token,
+                items,
+            }))
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ImplItem {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let mut attrs = input.call(Attribute::parse_outer)?;
+            let ahead = input.fork();
+            let vis: Visibility = ahead.parse()?;
+
+            let mut lookahead = ahead.lookahead1();
+            let defaultness = if lookahead.peek(Token![default]) && !ahead.peek2(Token![!]) {
+                let defaultness: Token![default] = ahead.parse()?;
+                lookahead = ahead.lookahead1();
+                Some(defaultness)
+            } else {
+                None
+            };
+
+            let mut item = if lookahead.peek(Token![fn]) || peek_signature(&ahead) {
+                let allow_omitted_body = true;
+                if let Some(item) = parse_impl_item_fn(input, allow_omitted_body)? {
+                    Ok(ImplItem::Fn(item))
+                } else {
+                    Ok(ImplItem::Verbatim(verbatim::between(&begin, input)))
+                }
+            } else if lookahead.peek(Token![const]) {
+                input.advance_to(&ahead);
+                let const_token: Token![const] = input.parse()?;
+                let lookahead = input.lookahead1();
+                let ident = if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                    input.call(Ident::parse_any)?
+                } else {
+                    return Err(lookahead.error());
+                };
+                let mut generics: Generics = input.parse()?;
+                let colon_token: Token![:] = input.parse()?;
+                let ty: Type = input.parse()?;
+                let value = if let Some(eq_token) = input.parse::<Option<Token![=]>>()? {
+                    let expr: Expr = input.parse()?;
+                    Some((eq_token, expr))
+                } else {
+                    None
+                };
+                generics.where_clause = input.parse()?;
+                let semi_token: Token![;] = input.parse()?;
+                return match value {
+                    Some((eq_token, expr))
+                        if generics.lt_token.is_none() && generics.where_clause.is_none() =>
+                    {
+                        Ok(ImplItem::Const(ImplItemConst {
+                            attrs,
+                            vis,
+                            defaultness,
+                            const_token,
+                            ident,
+                            generics,
+                            colon_token,
+                            ty,
+                            eq_token,
+                            expr,
+                            semi_token,
+                        }))
+                    }
+                    _ => Ok(ImplItem::Verbatim(verbatim::between(&begin, input))),
+                };
+            } else if lookahead.peek(Token![type]) {
+                parse_impl_item_type(begin, input)
+            } else if vis.is_inherited()
+                && defaultness.is_none()
+                && (lookahead.peek(Ident)
+                    || lookahead.peek(Token![self])
+                    || lookahead.peek(Token![super])
+                    || lookahead.peek(Token![crate])
+                    || lookahead.peek(Token![::]))
+            {
+                input.parse().map(ImplItem::Macro)
+            } else {
+                Err(lookahead.error())
+            }?;
+
+            {
+                let item_attrs = match &mut item {
+                    ImplItem::Const(item) => &mut item.attrs,
+                    ImplItem::Fn(item) => &mut item.attrs,
+                    ImplItem::Type(item) => &mut item.attrs,
+                    ImplItem::Macro(item) => &mut item.attrs,
+                    ImplItem::Verbatim(_) => return Ok(item),
+                };
+                attrs.append(item_attrs);
+                *item_attrs = attrs;
+            }
+
+            Ok(item)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ImplItemConst {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let defaultness: Option<Token![default]> = input.parse()?;
+            let const_token: Token![const] = input.parse()?;
+
+            let lookahead = input.lookahead1();
+            let ident = if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
+                input.call(Ident::parse_any)?
+            } else {
+                return Err(lookahead.error());
+            };
+
+            let colon_token: Token![:] = input.parse()?;
+            let ty: Type = input.parse()?;
+            let eq_token: Token![=] = input.parse()?;
+            let expr: Expr = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+
+            Ok(ImplItemConst {
+                attrs,
+                vis,
+                defaultness,
+                const_token,
+                ident,
+                generics: Generics::default(),
+                colon_token,
+                ty,
+                eq_token,
+                expr,
+                semi_token,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ImplItemFn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_omitted_body = false;
+            parse_impl_item_fn(input, allow_omitted_body).map(Option::unwrap)
+        }
+    }
+
+    fn parse_impl_item_fn(
+        input: ParseStream,
+        allow_omitted_body: bool,
+    ) -> Result<Option<ImplItemFn>> {
+        let mut attrs = input.call(Attribute::parse_outer)?;
+        let vis: Visibility = input.parse()?;
+        let defaultness: Option<Token![default]> = input.parse()?;
+        let sig: Signature = input.parse()?;
+
+        // Accept functions without a body in an impl block because rustc's
+        // *parser* does not reject them (the compilation error is emitted later
+        // than parsing) and it can be useful for macro DSLs.
+        if allow_omitted_body && input.parse::<Option<Token![;]>>()?.is_some() {
+            return Ok(None);
+        }
+
+        let content;
+        let brace_token = braced!(content in input);
+        attrs.extend(content.call(Attribute::parse_inner)?);
+        let block = Block {
+            brace_token,
+            stmts: content.call(Block::parse_within)?,
+        };
+
+        Ok(Some(ImplItemFn {
+            attrs,
+            vis,
+            defaultness,
+            sig,
+            block,
+        }))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ImplItemType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let vis: Visibility = input.parse()?;
+            let defaultness: Option<Token![default]> = input.parse()?;
+            let type_token: Token![type] = input.parse()?;
+            let ident: Ident = input.parse()?;
+            let mut generics: Generics = input.parse()?;
+            let eq_token: Token![=] = input.parse()?;
+            let ty: Type = input.parse()?;
+            generics.where_clause = input.parse()?;
+            let semi_token: Token![;] = input.parse()?;
+            Ok(ImplItemType {
+                attrs,
+                vis,
+                defaultness,
+                type_token,
+                ident,
+                generics,
+                eq_token,
+                ty,
+                semi_token,
+            })
+        }
+    }
+
+    fn parse_impl_item_type(begin: ParseBuffer, input: ParseStream) -> Result<ImplItem> {
+        let FlexibleItemType {
+            vis,
+            defaultness,
+            type_token,
+            ident,
+            generics,
+            colon_token,
+            bounds: _,
+            ty,
+            semi_token,
+        } = FlexibleItemType::parse(
+            input,
+            TypeDefaultness::Optional,
+            WhereClauseLocation::AfterEq,
+        )?;
+
+        let (eq_token, ty) = match ty {
+            Some(ty) if colon_token.is_none() => ty,
+            _ => return Ok(ImplItem::Verbatim(verbatim::between(&begin, input))),
+        };
+
+        Ok(ImplItem::Type(ImplItemType {
+            attrs: Vec::new(),
+            vis,
+            defaultness,
+            type_token,
+            ident,
+            generics,
+            eq_token,
+            ty,
+            semi_token,
+        }))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ImplItemMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+            let mac: Macro = input.parse()?;
+            let semi_token: Option<Token![;]> = if mac.delimiter.is_brace() {
+                None
+            } else {
+                Some(input.parse()?)
+            };
+            Ok(ImplItemMacro {
+                attrs,
+                mac,
+                semi_token,
+            })
+        }
+    }
+
+    impl Visibility {
+        fn is_inherited(&self) -> bool {
+            match self {
+                Visibility::Inherited => true,
+                _ => false,
+            }
+        }
+    }
+
+    impl MacroDelimiter {
+        pub(crate) fn is_brace(&self) -> bool {
+            match self {
+                MacroDelimiter::Brace(_) => true,
+                MacroDelimiter::Paren(_) | MacroDelimiter::Bracket(_) => false,
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for StaticMutability {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let mut_token: Option<Token![mut]> = input.parse()?;
+            Ok(mut_token.map_or(StaticMutability::None, StaticMutability::Mut))
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use crate::print::TokensOrDefault;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemExternCrate {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.extern_token.to_tokens(tokens);
+            self.crate_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            if let Some((as_token, rename)) = &self.rename {
+                as_token.to_tokens(tokens);
+                rename.to_tokens(tokens);
+            }
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemUse {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.use_token.to_tokens(tokens);
+            self.leading_colon.to_tokens(tokens);
+            self.tree.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemStatic {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.static_token.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemConst {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.const_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemFn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.sig.to_tokens(tokens);
+            self.block.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(self.attrs.inner());
+                tokens.append_all(&self.block.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemMod {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.unsafety.to_tokens(tokens);
+            self.mod_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            if let Some((brace, items)) = &self.content {
+                brace.surround(tokens, |tokens| {
+                    tokens.append_all(self.attrs.inner());
+                    tokens.append_all(items);
+                });
+            } else {
+                TokensOrDefault(&self.semi).to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemForeignMod {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.unsafety.to_tokens(tokens);
+            self.abi.to_tokens(tokens);
+            self.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(self.attrs.inner());
+                tokens.append_all(&self.items);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.type_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemEnum {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.enum_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.brace_token.surround(tokens, |tokens| {
+                self.variants.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.struct_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            match &self.fields {
+                Fields::Named(fields) => {
+                    self.generics.where_clause.to_tokens(tokens);
+                    fields.to_tokens(tokens);
+                }
+                Fields::Unnamed(fields) => {
+                    fields.to_tokens(tokens);
+                    self.generics.where_clause.to_tokens(tokens);
+                    TokensOrDefault(&self.semi_token).to_tokens(tokens);
+                }
+                Fields::Unit => {
+                    self.generics.where_clause.to_tokens(tokens);
+                    TokensOrDefault(&self.semi_token).to_tokens(tokens);
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemUnion {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.union_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.fields.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemTrait {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.unsafety.to_tokens(tokens);
+            self.auto_token.to_tokens(tokens);
+            self.trait_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            if !self.supertraits.is_empty() {
+                TokensOrDefault(&self.colon_token).to_tokens(tokens);
+                self.supertraits.to_tokens(tokens);
+            }
+            self.generics.where_clause.to_tokens(tokens);
+            self.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(self.attrs.inner());
+                tokens.append_all(&self.items);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemTraitAlias {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.trait_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemImpl {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.defaultness.to_tokens(tokens);
+            self.unsafety.to_tokens(tokens);
+            self.impl_token.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            if let Some((polarity, path, for_token)) = &self.trait_ {
+                polarity.to_tokens(tokens);
+                path.to_tokens(tokens);
+                for_token.to_tokens(tokens);
+            }
+            self.self_ty.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(self.attrs.inner());
+                tokens.append_all(&self.items);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ItemMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.mac.path.to_tokens(tokens);
+            self.mac.bang_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            match &self.mac.delimiter {
+                MacroDelimiter::Paren(paren) => {
+                    paren.surround(tokens, |tokens| self.mac.tokens.to_tokens(tokens));
+                }
+                MacroDelimiter::Brace(brace) => {
+                    brace.surround(tokens, |tokens| self.mac.tokens.to_tokens(tokens));
+                }
+                MacroDelimiter::Bracket(bracket) => {
+                    bracket.surround(tokens, |tokens| self.mac.tokens.to_tokens(tokens));
+                }
+            }
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UsePath {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.colon2_token.to_tokens(tokens);
+            self.tree.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UseName {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UseRename {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.as_token.to_tokens(tokens);
+            self.rename.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UseGlob {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.star_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UseGroup {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.brace_token.surround(tokens, |tokens| {
+                self.items.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitItemConst {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.const_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            if let Some((eq_token, default)) = &self.default {
+                eq_token.to_tokens(tokens);
+                default.to_tokens(tokens);
+            }
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitItemFn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.sig.to_tokens(tokens);
+            match &self.default {
+                Some(block) => {
+                    block.brace_token.surround(tokens, |tokens| {
+                        tokens.append_all(self.attrs.inner());
+                        tokens.append_all(&block.stmts);
+                    });
+                }
+                None => {
+                    TokensOrDefault(&self.semi_token).to_tokens(tokens);
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitItemType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.type_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            if !self.bounds.is_empty() {
+                TokensOrDefault(&self.colon_token).to_tokens(tokens);
+                self.bounds.to_tokens(tokens);
+            }
+            if let Some((eq_token, default)) = &self.default {
+                eq_token.to_tokens(tokens);
+                default.to_tokens(tokens);
+            }
+            self.generics.where_clause.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TraitItemMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.mac.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ImplItemConst {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.defaultness.to_tokens(tokens);
+            self.const_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.expr.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ImplItemFn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.defaultness.to_tokens(tokens);
+            self.sig.to_tokens(tokens);
+            self.block.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(self.attrs.inner());
+                tokens.append_all(&self.block.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ImplItemType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.defaultness.to_tokens(tokens);
+            self.type_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ImplItemMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.mac.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ForeignItemFn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.sig.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ForeignItemStatic {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.static_token.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ForeignItemType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.vis.to_tokens(tokens);
+            self.type_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ForeignItemMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.mac.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Signature {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.constness.to_tokens(tokens);
+            self.asyncness.to_tokens(tokens);
+            self.unsafety.to_tokens(tokens);
+            self.abi.to_tokens(tokens);
+            self.fn_token.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.inputs.to_tokens(tokens);
+                if let Some(variadic) = &self.variadic {
+                    if !self.inputs.empty_or_trailing() {
+                        <Token![,]>::default().to_tokens(tokens);
+                    }
+                    variadic.to_tokens(tokens);
+                }
+            });
+            self.output.to_tokens(tokens);
+            self.generics.where_clause.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Receiver {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some((ampersand, lifetime)) = &self.reference {
+                ampersand.to_tokens(tokens);
+                lifetime.to_tokens(tokens);
+            }
+            self.mutability.to_tokens(tokens);
+            self.self_token.to_tokens(tokens);
+            if let Some(colon_token) = &self.colon_token {
+                colon_token.to_tokens(tokens);
+                self.ty.to_tokens(tokens);
+            } else {
+                let consistent = match (&self.reference, &self.mutability, &*self.ty) {
+                    (Some(_), mutability, Type::Reference(ty)) => {
+                        mutability.is_some() == ty.mutability.is_some()
+                            && match &*ty.elem {
+                                Type::Path(ty) => ty.qself.is_none() && ty.path.is_ident("Self"),
+                                _ => false,
+                            }
+                    }
+                    (None, _, Type::Path(ty)) => ty.qself.is_none() && ty.path.is_ident("Self"),
+                    _ => false,
+                };
+                if !consistent {
+                    <Token![:]>::default().to_tokens(tokens);
+                    self.ty.to_tokens(tokens);
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Variadic {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some((pat, colon)) = &self.pat {
+                pat.to_tokens(tokens);
+                colon.to_tokens(tokens);
+            }
+            self.dots.to_tokens(tokens);
+            self.comma.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for StaticMutability {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                StaticMutability::None => {}
+                StaticMutability::Mut(mut_token) => mut_token.to_tokens(tokens),
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/lib.rs b/vendor/syn/src/lib.rs
new file mode 100644
index 0000000..a74d4b1
--- /dev/null
+++ b/vendor/syn/src/lib.rs
@@ -0,0 +1,970 @@
+//! [![github]](https://github.com/dtolnay/syn)&ensp;[![crates-io]](https://crates.io/crates/syn)&ensp;[![docs-rs]](crate)
+//!
+//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
+//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
+//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
+//!
+//! <br>
+//!
+//! Syn is a parsing library for parsing a stream of Rust tokens into a syntax
+//! tree of Rust source code.
+//!
+//! Currently this library is geared toward use in Rust procedural macros, but
+//! contains some APIs that may be useful more generally.
+//!
+//! - **Data structures** — Syn provides a complete syntax tree that can
+//!   represent any valid Rust source code. The syntax tree is rooted at
+//!   [`syn::File`] which represents a full source file, but there are other
+//!   entry points that may be useful to procedural macros including
+//!   [`syn::Item`], [`syn::Expr`] and [`syn::Type`].
+//!
+//! - **Derives** — Of particular interest to derive macros is
+//!   [`syn::DeriveInput`] which is any of the three legal input items to a
+//!   derive macro. An example below shows using this type in a library that can
+//!   derive implementations of a user-defined trait.
+//!
+//! - **Parsing** — Parsing in Syn is built around [parser functions] with the
+//!   signature `fn(ParseStream) -> Result<T>`. Every syntax tree node defined
+//!   by Syn is individually parsable and may be used as a building block for
+//!   custom syntaxes, or you may dream up your own brand new syntax without
+//!   involving any of our syntax tree types.
+//!
+//! - **Location information** — Every token parsed by Syn is associated with a
+//!   `Span` that tracks line and column information back to the source of that
+//!   token. These spans allow a procedural macro to display detailed error
+//!   messages pointing to all the right places in the user's code. There is an
+//!   example of this below.
+//!
+//! - **Feature flags** — Functionality is aggressively feature gated so your
+//!   procedural macros enable only what they need, and do not pay in compile
+//!   time for all the rest.
+//!
+//! [`syn::File`]: File
+//! [`syn::Item`]: Item
+//! [`syn::Expr`]: Expr
+//! [`syn::Type`]: Type
+//! [`syn::DeriveInput`]: DeriveInput
+//! [parser functions]: mod@parse
+//!
+//! <br>
+//!
+//! # Example of a derive macro
+//!
+//! The canonical derive macro using Syn looks like this. We write an ordinary
+//! Rust function tagged with a `proc_macro_derive` attribute and the name of
+//! the trait we are deriving. Any time that derive appears in the user's code,
+//! the Rust compiler passes their data structure as tokens into our macro. We
+//! get to execute arbitrary Rust code to figure out what to do with those
+//! tokens, then hand some tokens back to the compiler to compile into the
+//! user's crate.
+//!
+//! [`TokenStream`]: proc_macro::TokenStream
+//!
+//! ```toml
+//! [dependencies]
+//! syn = "2.0"
+//! quote = "1.0"
+//!
+//! [lib]
+//! proc-macro = true
+//! ```
+//!
+//! ```
+//! # extern crate proc_macro;
+//! #
+//! use proc_macro::TokenStream;
+//! use quote::quote;
+//! use syn::{parse_macro_input, DeriveInput};
+//!
+//! # const IGNORE_TOKENS: &str = stringify! {
+//! #[proc_macro_derive(MyMacro)]
+//! # };
+//! pub fn my_macro(input: TokenStream) -> TokenStream {
+//!     // Parse the input tokens into a syntax tree
+//!     let input = parse_macro_input!(input as DeriveInput);
+//!
+//!     // Build the output, possibly using quasi-quotation
+//!     let expanded = quote! {
+//!         // ...
+//!     };
+//!
+//!     // Hand the output tokens back to the compiler
+//!     TokenStream::from(expanded)
+//! }
+//! ```
+//!
+//! The [`heapsize`] example directory shows a complete working implementation
+//! of a derive macro. The example derives a `HeapSize` trait which computes an
+//! estimate of the amount of heap memory owned by a value.
+//!
+//! [`heapsize`]: https://github.com/dtolnay/syn/tree/master/examples/heapsize
+//!
+//! ```
+//! pub trait HeapSize {
+//!     /// Total number of bytes of heap memory owned by `self`.
+//!     fn heap_size_of_children(&self) -> usize;
+//! }
+//! ```
+//!
+//! The derive macro allows users to write `#[derive(HeapSize)]` on data
+//! structures in their program.
+//!
+//! ```
+//! # const IGNORE_TOKENS: &str = stringify! {
+//! #[derive(HeapSize)]
+//! # };
+//! struct Demo<'a, T: ?Sized> {
+//!     a: Box<T>,
+//!     b: u8,
+//!     c: &'a str,
+//!     d: String,
+//! }
+//! ```
+//!
+//! <p><br></p>
+//!
+//! # Spans and error reporting
+//!
+//! The token-based procedural macro API provides great control over where the
+//! compiler's error messages are displayed in user code. Consider the error the
+//! user sees if one of their field types does not implement `HeapSize`.
+//!
+//! ```
+//! # const IGNORE_TOKENS: &str = stringify! {
+//! #[derive(HeapSize)]
+//! # };
+//! struct Broken {
+//!     ok: String,
+//!     bad: std::thread::Thread,
+//! }
+//! ```
+//!
+//! By tracking span information all the way through the expansion of a
+//! procedural macro as shown in the `heapsize` example, token-based macros in
+//! Syn are able to trigger errors that directly pinpoint the source of the
+//! problem.
+//!
+//! ```text
+//! error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied
+//!  --> src/main.rs:7:5
+//!   |
+//! 7 |     bad: std::thread::Thread,
+//!   |     ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HeapSize` is not implemented for `Thread`
+//! ```
+//!
+//! <br>
+//!
+//! # Parsing a custom syntax
+//!
+//! The [`lazy-static`] example directory shows the implementation of a
+//! `functionlike!(...)` procedural macro in which the input tokens are parsed
+//! using Syn's parsing API.
+//!
+//! [`lazy-static`]: https://github.com/dtolnay/syn/tree/master/examples/lazy-static
+//!
+//! The example reimplements the popular `lazy_static` crate from crates.io as a
+//! procedural macro.
+//!
+//! ```
+//! # macro_rules! lazy_static {
+//! #     ($($tt:tt)*) => {}
+//! # }
+//! #
+//! lazy_static! {
+//!     static ref USERNAME: Regex = Regex::new("^[a-z0-9_-]{3,16}$").unwrap();
+//! }
+//! ```
+//!
+//! The implementation shows how to trigger custom warnings and error messages
+//! on the macro input.
+//!
+//! ```text
+//! warning: come on, pick a more creative name
+//!   --> src/main.rs:10:16
+//!    |
+//! 10 |     static ref FOO: String = "lazy_static".to_owned();
+//!    |                ^^^
+//! ```
+//!
+//! <br>
+//!
+//! # Testing
+//!
+//! When testing macros, we often care not just that the macro can be used
+//! successfully but also that when the macro is provided with invalid input it
+//! produces maximally helpful error messages. Consider using the [`trybuild`]
+//! crate to write tests for errors that are emitted by your macro or errors
+//! detected by the Rust compiler in the expanded code following misuse of the
+//! macro. Such tests help avoid regressions from later refactors that
+//! mistakenly make an error no longer trigger or be less helpful than it used
+//! to be.
+//!
+//! [`trybuild`]: https://github.com/dtolnay/trybuild
+//!
+//! <br>
+//!
+//! # Debugging
+//!
+//! When developing a procedural macro it can be helpful to look at what the
+//! generated code looks like. Use `cargo rustc -- -Zunstable-options
+//! --pretty=expanded` or the [`cargo expand`] subcommand.
+//!
+//! [`cargo expand`]: https://github.com/dtolnay/cargo-expand
+//!
+//! To show the expanded code for some crate that uses your procedural macro,
+//! run `cargo expand` from that crate. To show the expanded code for one of
+//! your own test cases, run `cargo expand --test the_test_case` where the last
+//! argument is the name of the test file without the `.rs` extension.
+//!
+//! This write-up by Brandon W Maister discusses debugging in more detail:
+//! [Debugging Rust's new Custom Derive system][debugging].
+//!
+//! [debugging]: https://quodlibetor.github.io/posts/debugging-rusts-new-custom-derive-system/
+//!
+//! <br>
+//!
+//! # Optional features
+//!
+//! Syn puts a lot of functionality behind optional features in order to
+//! optimize compile time for the most common use cases. The following features
+//! are available.
+//!
+//! - **`derive`** *(enabled by default)* — Data structures for representing the
+//!   possible input to a derive macro, including structs and enums and types.
+//! - **`full`** — Data structures for representing the syntax tree of all valid
+//!   Rust source code, including items and expressions.
+//! - **`parsing`** *(enabled by default)* — Ability to parse input tokens into
+//!   a syntax tree node of a chosen type.
+//! - **`printing`** *(enabled by default)* — Ability to print a syntax tree
+//!   node as tokens of Rust source code.
+//! - **`visit`** — Trait for traversing a syntax tree.
+//! - **`visit-mut`** — Trait for traversing and mutating in place a syntax
+//!   tree.
+//! - **`fold`** — Trait for transforming an owned syntax tree.
+//! - **`clone-impls`** *(enabled by default)* — Clone impls for all syntax tree
+//!   types.
+//! - **`extra-traits`** — Debug, Eq, PartialEq, Hash impls for all syntax tree
+//!   types.
+//! - **`proc-macro`** *(enabled by default)* — Runtime dependency on the
+//!   dynamic library libproc_macro from rustc toolchain.
+
+// Syn types in rustdoc of other crates get linked to here.
+#![doc(html_root_url = "https://docs.rs/syn/2.0.38")]
+#![cfg_attr(doc_cfg, feature(doc_cfg))]
+#![allow(non_camel_case_types)]
+#![allow(
+    clippy::bool_to_int_with_if,
+    clippy::cast_lossless,
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_ptr_alignment,
+    clippy::default_trait_access,
+    clippy::derivable_impls,
+    clippy::doc_markdown,
+    clippy::expl_impl_clone_on_copy,
+    clippy::explicit_auto_deref,
+    clippy::if_not_else,
+    clippy::inherent_to_string,
+    clippy::items_after_statements,
+    clippy::large_enum_variant,
+    clippy::let_underscore_untyped, // https://github.com/rust-lang/rust-clippy/issues/10410
+    clippy::manual_assert,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::match_on_vec_items,
+    clippy::match_same_arms,
+    clippy::match_wildcard_for_single_variants, // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6984
+    clippy::missing_errors_doc,
+    clippy::missing_panics_doc,
+    clippy::module_name_repetitions,
+    clippy::must_use_candidate,
+    clippy::needless_doctest_main,
+    clippy::needless_pass_by_value,
+    clippy::never_loop,
+    clippy::range_plus_one,
+    clippy::redundant_else,
+    clippy::return_self_not_must_use,
+    clippy::similar_names,
+    clippy::single_match_else,
+    clippy::too_many_arguments,
+    clippy::too_many_lines,
+    clippy::trivially_copy_pass_by_ref,
+    clippy::uninlined_format_args,
+    clippy::unnecessary_box_returns,
+    clippy::unnecessary_unwrap,
+    clippy::used_underscore_binding,
+    clippy::wildcard_imports,
+)]
+
+#[cfg(feature = "proc-macro")]
+extern crate proc_macro;
+
+#[macro_use]
+mod macros;
+
+#[cfg(feature = "parsing")]
+#[macro_use]
+mod group;
+
+#[macro_use]
+pub mod token;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod attr;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::attr::{AttrStyle, Attribute, Meta, MetaList, MetaNameValue};
+
+mod bigint;
+
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+pub mod buffer;
+
+mod custom_keyword;
+
+mod custom_punctuation;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod data;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::data::{Field, Fields, FieldsNamed, FieldsUnnamed, Variant};
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod derive;
+#[cfg(feature = "derive")]
+pub use crate::derive::{Data, DataEnum, DataStruct, DataUnion, DeriveInput};
+
+mod drops;
+
+mod error;
+pub use crate::error::{Error, Result};
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod expr;
+#[cfg(feature = "full")]
+pub use crate::expr::{Arm, FieldValue, Label, RangeLimits};
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::expr::{
+    Expr, ExprArray, ExprAssign, ExprAsync, ExprAwait, ExprBinary, ExprBlock, ExprBreak, ExprCall,
+    ExprCast, ExprClosure, ExprConst, ExprContinue, ExprField, ExprForLoop, ExprGroup, ExprIf,
+    ExprIndex, ExprInfer, ExprLet, ExprLit, ExprLoop, ExprMacro, ExprMatch, ExprMethodCall,
+    ExprParen, ExprPath, ExprRange, ExprReference, ExprRepeat, ExprReturn, ExprStruct, ExprTry,
+    ExprTryBlock, ExprTuple, ExprUnary, ExprUnsafe, ExprWhile, ExprYield, Index, Member,
+};
+
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+pub mod ext;
+
+#[cfg(feature = "full")]
+mod file;
+#[cfg(feature = "full")]
+pub use crate::file::File;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod generics;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::generics::{
+    BoundLifetimes, ConstParam, GenericParam, Generics, LifetimeParam, PredicateLifetime,
+    PredicateType, TraitBound, TraitBoundModifier, TypeParam, TypeParamBound, WhereClause,
+    WherePredicate,
+};
+#[cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))]
+pub use crate::generics::{ImplGenerics, Turbofish, TypeGenerics};
+
+mod ident;
+#[doc(inline)]
+pub use crate::ident::Ident;
+
+#[cfg(feature = "full")]
+mod item;
+#[cfg(feature = "full")]
+pub use crate::item::{
+    FnArg, ForeignItem, ForeignItemFn, ForeignItemMacro, ForeignItemStatic, ForeignItemType,
+    ImplItem, ImplItemConst, ImplItemFn, ImplItemMacro, ImplItemType, ImplRestriction, Item,
+    ItemConst, ItemEnum, ItemExternCrate, ItemFn, ItemForeignMod, ItemImpl, ItemMacro, ItemMod,
+    ItemStatic, ItemStruct, ItemTrait, ItemTraitAlias, ItemType, ItemUnion, ItemUse, Receiver,
+    Signature, StaticMutability, TraitItem, TraitItemConst, TraitItemFn, TraitItemMacro,
+    TraitItemType, UseGlob, UseGroup, UseName, UsePath, UseRename, UseTree, Variadic,
+};
+
+mod lifetime;
+#[doc(inline)]
+pub use crate::lifetime::Lifetime;
+
+mod lit;
+#[doc(inline)]
+pub use crate::lit::{
+    Lit, LitBool, LitByte, LitByteStr, LitChar, LitFloat, LitInt, LitStr, StrStyle,
+};
+
+#[cfg(feature = "parsing")]
+mod lookahead;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod mac;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::mac::{Macro, MacroDelimiter};
+
+#[cfg(all(feature = "parsing", any(feature = "full", feature = "derive")))]
+#[cfg_attr(
+    doc_cfg,
+    doc(cfg(all(feature = "parsing", any(feature = "full", feature = "derive"))))
+)]
+pub mod meta;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod op;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::op::{BinOp, UnOp};
+
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+pub mod parse;
+
+#[cfg(all(feature = "parsing", feature = "proc-macro"))]
+mod parse_macro_input;
+
+#[cfg(all(feature = "parsing", feature = "printing"))]
+mod parse_quote;
+
+#[cfg(feature = "full")]
+mod pat;
+#[cfg(feature = "full")]
+pub use crate::expr::{
+    ExprConst as PatConst, ExprLit as PatLit, ExprMacro as PatMacro, ExprPath as PatPath,
+    ExprRange as PatRange,
+};
+#[cfg(feature = "full")]
+pub use crate::pat::{
+    FieldPat, Pat, PatIdent, PatOr, PatParen, PatReference, PatRest, PatSlice, PatStruct, PatTuple,
+    PatTupleStruct, PatType, PatWild,
+};
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod path;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::path::{
+    AngleBracketedGenericArguments, AssocConst, AssocType, Constraint, GenericArgument,
+    ParenthesizedGenericArguments, Path, PathArguments, PathSegment, QSelf,
+};
+
+#[cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))]
+mod print;
+
+pub mod punctuated;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod restriction;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::restriction::{FieldMutability, VisRestricted, Visibility};
+
+mod sealed;
+
+mod span;
+
+#[cfg(all(feature = "parsing", feature = "printing"))]
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "printing"))))]
+pub mod spanned;
+
+#[cfg(feature = "full")]
+mod stmt;
+#[cfg(feature = "full")]
+pub use crate::stmt::{Block, Local, LocalInit, Stmt, StmtMacro};
+
+mod thread;
+
+#[cfg(all(any(feature = "full", feature = "derive"), feature = "extra-traits"))]
+mod tt;
+
+#[cfg(any(feature = "full", feature = "derive"))]
+mod ty;
+#[cfg(any(feature = "full", feature = "derive"))]
+pub use crate::ty::{
+    Abi, BareFnArg, BareVariadic, ReturnType, Type, TypeArray, TypeBareFn, TypeGroup,
+    TypeImplTrait, TypeInfer, TypeMacro, TypeNever, TypeParen, TypePath, TypePtr, TypeReference,
+    TypeSlice, TypeTraitObject, TypeTuple,
+};
+
+#[cfg(all(any(feature = "full", feature = "derive"), feature = "parsing"))]
+mod verbatim;
+
+#[cfg(all(feature = "parsing", feature = "full"))]
+mod whitespace;
+
+mod gen {
+    /// Syntax tree traversal to transform the nodes of an owned syntax tree.
+    ///
+    /// Each method of the [`Fold`] trait is a hook that can be overridden to
+    /// customize the behavior when transforming the corresponding type of node.
+    /// By default, every method recursively visits the substructure of the
+    /// input by invoking the right visitor method of each of its fields.
+    ///
+    /// [`Fold`]: fold::Fold
+    ///
+    /// ```
+    /// # use syn::{Attribute, BinOp, Expr, ExprBinary};
+    /// #
+    /// pub trait Fold {
+    ///     /* ... */
+    ///
+    ///     fn fold_expr_binary(&mut self, node: ExprBinary) -> ExprBinary {
+    ///         fold_expr_binary(self, node)
+    ///     }
+    ///
+    ///     /* ... */
+    ///     # fn fold_attribute(&mut self, node: Attribute) -> Attribute;
+    ///     # fn fold_expr(&mut self, node: Expr) -> Expr;
+    ///     # fn fold_bin_op(&mut self, node: BinOp) -> BinOp;
+    /// }
+    ///
+    /// pub fn fold_expr_binary<V>(v: &mut V, node: ExprBinary) -> ExprBinary
+    /// where
+    ///     V: Fold + ?Sized,
+    /// {
+    ///     ExprBinary {
+    ///         attrs: node
+    ///             .attrs
+    ///             .into_iter()
+    ///             .map(|attr| v.fold_attribute(attr))
+    ///             .collect(),
+    ///         left: Box::new(v.fold_expr(*node.left)),
+    ///         op: v.fold_bin_op(node.op),
+    ///         right: Box::new(v.fold_expr(*node.right)),
+    ///     }
+    /// }
+    ///
+    /// /* ... */
+    /// ```
+    ///
+    /// <br>
+    ///
+    /// # Example
+    ///
+    /// This fold inserts parentheses to fully parenthesizes any expression.
+    ///
+    /// ```
+    /// // [dependencies]
+    /// // quote = "1.0"
+    /// // syn = { version = "2.0", features = ["fold", "full"] }
+    ///
+    /// use quote::quote;
+    /// use syn::fold::{fold_expr, Fold};
+    /// use syn::{token, Expr, ExprParen};
+    ///
+    /// struct ParenthesizeEveryExpr;
+    ///
+    /// impl Fold for ParenthesizeEveryExpr {
+    ///     fn fold_expr(&mut self, expr: Expr) -> Expr {
+    ///         Expr::Paren(ExprParen {
+    ///             attrs: Vec::new(),
+    ///             expr: Box::new(fold_expr(self, expr)),
+    ///             paren_token: token::Paren::default(),
+    ///         })
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let code = quote! { a() + b(1) * c.d };
+    ///     let expr: Expr = syn::parse2(code).unwrap();
+    ///     let parenthesized = ParenthesizeEveryExpr.fold_expr(expr);
+    ///     println!("{}", quote!(#parenthesized));
+    ///
+    ///     // Output: (((a)()) + (((b)((1))) * ((c).d)))
+    /// }
+    /// ```
+    #[cfg(feature = "fold")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "fold")))]
+    #[rustfmt::skip]
+    pub mod fold;
+
+    /// Syntax tree traversal to walk a shared borrow of a syntax tree.
+    ///
+    /// Each method of the [`Visit`] trait is a hook that can be overridden to
+    /// customize the behavior when visiting the corresponding type of node. By
+    /// default, every method recursively visits the substructure of the input
+    /// by invoking the right visitor method of each of its fields.
+    ///
+    /// [`Visit`]: visit::Visit
+    ///
+    /// ```
+    /// # use syn::{Attribute, BinOp, Expr, ExprBinary};
+    /// #
+    /// pub trait Visit<'ast> {
+    ///     /* ... */
+    ///
+    ///     fn visit_expr_binary(&mut self, node: &'ast ExprBinary) {
+    ///         visit_expr_binary(self, node);
+    ///     }
+    ///
+    ///     /* ... */
+    ///     # fn visit_attribute(&mut self, node: &'ast Attribute);
+    ///     # fn visit_expr(&mut self, node: &'ast Expr);
+    ///     # fn visit_bin_op(&mut self, node: &'ast BinOp);
+    /// }
+    ///
+    /// pub fn visit_expr_binary<'ast, V>(v: &mut V, node: &'ast ExprBinary)
+    /// where
+    ///     V: Visit<'ast> + ?Sized,
+    /// {
+    ///     for attr in &node.attrs {
+    ///         v.visit_attribute(attr);
+    ///     }
+    ///     v.visit_expr(&*node.left);
+    ///     v.visit_bin_op(&node.op);
+    ///     v.visit_expr(&*node.right);
+    /// }
+    ///
+    /// /* ... */
+    /// ```
+    ///
+    /// <br>
+    ///
+    /// # Example
+    ///
+    /// This visitor will print the name of every freestanding function in the
+    /// syntax tree, including nested functions.
+    ///
+    /// ```
+    /// // [dependencies]
+    /// // quote = "1.0"
+    /// // syn = { version = "2.0", features = ["full", "visit"] }
+    ///
+    /// use quote::quote;
+    /// use syn::visit::{self, Visit};
+    /// use syn::{File, ItemFn};
+    ///
+    /// struct FnVisitor;
+    ///
+    /// impl<'ast> Visit<'ast> for FnVisitor {
+    ///     fn visit_item_fn(&mut self, node: &'ast ItemFn) {
+    ///         println!("Function with name={}", node.sig.ident);
+    ///
+    ///         // Delegate to the default impl to visit any nested functions.
+    ///         visit::visit_item_fn(self, node);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let code = quote! {
+    ///         pub fn f() {
+    ///             fn g() {}
+    ///         }
+    ///     };
+    ///
+    ///     let syntax_tree: File = syn::parse2(code).unwrap();
+    ///     FnVisitor.visit_file(&syntax_tree);
+    /// }
+    /// ```
+    ///
+    /// The `'ast` lifetime on the input references means that the syntax tree
+    /// outlives the complete recursive visit call, so the visitor is allowed to
+    /// hold on to references into the syntax tree.
+    ///
+    /// ```
+    /// use quote::quote;
+    /// use syn::visit::{self, Visit};
+    /// use syn::{File, ItemFn};
+    ///
+    /// struct FnVisitor<'ast> {
+    ///     functions: Vec<&'ast ItemFn>,
+    /// }
+    ///
+    /// impl<'ast> Visit<'ast> for FnVisitor<'ast> {
+    ///     fn visit_item_fn(&mut self, node: &'ast ItemFn) {
+    ///         self.functions.push(node);
+    ///         visit::visit_item_fn(self, node);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let code = quote! {
+    ///         pub fn f() {
+    ///             fn g() {}
+    ///         }
+    ///     };
+    ///
+    ///     let syntax_tree: File = syn::parse2(code).unwrap();
+    ///     let mut visitor = FnVisitor { functions: Vec::new() };
+    ///     visitor.visit_file(&syntax_tree);
+    ///     for f in visitor.functions {
+    ///         println!("Function with name={}", f.sig.ident);
+    ///     }
+    /// }
+    /// ```
+    #[cfg(feature = "visit")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "visit")))]
+    #[rustfmt::skip]
+    pub mod visit;
+
+    /// Syntax tree traversal to mutate an exclusive borrow of a syntax tree in
+    /// place.
+    ///
+    /// Each method of the [`VisitMut`] trait is a hook that can be overridden
+    /// to customize the behavior when mutating the corresponding type of node.
+    /// By default, every method recursively visits the substructure of the
+    /// input by invoking the right visitor method of each of its fields.
+    ///
+    /// [`VisitMut`]: visit_mut::VisitMut
+    ///
+    /// ```
+    /// # use syn::{Attribute, BinOp, Expr, ExprBinary};
+    /// #
+    /// pub trait VisitMut {
+    ///     /* ... */
+    ///
+    ///     fn visit_expr_binary_mut(&mut self, node: &mut ExprBinary) {
+    ///         visit_expr_binary_mut(self, node);
+    ///     }
+    ///
+    ///     /* ... */
+    ///     # fn visit_attribute_mut(&mut self, node: &mut Attribute);
+    ///     # fn visit_expr_mut(&mut self, node: &mut Expr);
+    ///     # fn visit_bin_op_mut(&mut self, node: &mut BinOp);
+    /// }
+    ///
+    /// pub fn visit_expr_binary_mut<V>(v: &mut V, node: &mut ExprBinary)
+    /// where
+    ///     V: VisitMut + ?Sized,
+    /// {
+    ///     for attr in &mut node.attrs {
+    ///         v.visit_attribute_mut(attr);
+    ///     }
+    ///     v.visit_expr_mut(&mut *node.left);
+    ///     v.visit_bin_op_mut(&mut node.op);
+    ///     v.visit_expr_mut(&mut *node.right);
+    /// }
+    ///
+    /// /* ... */
+    /// ```
+    ///
+    /// <br>
+    ///
+    /// # Example
+    ///
+    /// This mut visitor replace occurrences of u256 suffixed integer literals
+    /// like `999u256` with a macro invocation `bigint::u256!(999)`.
+    ///
+    /// ```
+    /// // [dependencies]
+    /// // quote = "1.0"
+    /// // syn = { version = "2.0", features = ["full", "visit-mut"] }
+    ///
+    /// use quote::quote;
+    /// use syn::visit_mut::{self, VisitMut};
+    /// use syn::{parse_quote, Expr, File, Lit, LitInt};
+    ///
+    /// struct BigintReplace;
+    ///
+    /// impl VisitMut for BigintReplace {
+    ///     fn visit_expr_mut(&mut self, node: &mut Expr) {
+    ///         if let Expr::Lit(expr) = &node {
+    ///             if let Lit::Int(int) = &expr.lit {
+    ///                 if int.suffix() == "u256" {
+    ///                     let digits = int.base10_digits();
+    ///                     let unsuffixed: LitInt = syn::parse_str(digits).unwrap();
+    ///                     *node = parse_quote!(bigint::u256!(#unsuffixed));
+    ///                     return;
+    ///                 }
+    ///             }
+    ///         }
+    ///
+    ///         // Delegate to the default impl to visit nested expressions.
+    ///         visit_mut::visit_expr_mut(self, node);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let code = quote! {
+    ///         fn main() {
+    ///             let _ = 999u256;
+    ///         }
+    ///     };
+    ///
+    ///     let mut syntax_tree: File = syn::parse2(code).unwrap();
+    ///     BigintReplace.visit_file_mut(&mut syntax_tree);
+    ///     println!("{}", quote!(#syntax_tree));
+    /// }
+    /// ```
+    #[cfg(feature = "visit-mut")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "visit-mut")))]
+    #[rustfmt::skip]
+    pub mod visit_mut;
+
+    #[cfg(feature = "clone-impls")]
+    #[rustfmt::skip]
+    mod clone;
+
+    #[cfg(feature = "extra-traits")]
+    #[rustfmt::skip]
+    mod debug;
+
+    #[cfg(feature = "extra-traits")]
+    #[rustfmt::skip]
+    mod eq;
+
+    #[cfg(feature = "extra-traits")]
+    #[rustfmt::skip]
+    mod hash;
+
+    #[cfg(any(feature = "full", feature = "derive"))]
+    #[path = "../gen_helper.rs"]
+    mod helper;
+}
+pub use crate::gen::*;
+
+// Not public API.
+#[doc(hidden)]
+#[path = "export.rs"]
+pub mod __private;
+
+/// Parse tokens of source code into the chosen syntax tree node.
+///
+/// This is preferred over parsing a string because tokens are able to preserve
+/// information about where in the user's code they were originally written (the
+/// "span" of the token), possibly allowing the compiler to produce better error
+/// messages.
+///
+/// This function parses a `proc_macro::TokenStream` which is the type used for
+/// interop with the compiler in a procedural macro. To parse a
+/// `proc_macro2::TokenStream`, use [`syn::parse2`] instead.
+///
+/// [`syn::parse2`]: parse2
+///
+/// # Examples
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use quote::quote;
+/// use syn::DeriveInput;
+///
+/// # const IGNORE_TOKENS: &str = stringify! {
+/// #[proc_macro_derive(MyMacro)]
+/// # };
+/// pub fn my_macro(input: TokenStream) -> TokenStream {
+///     // Parse the tokens into a syntax tree
+///     let ast: DeriveInput = syn::parse(input).unwrap();
+///
+///     // Build the output, possibly using quasi-quotation
+///     let expanded = quote! {
+///         /* ... */
+///     };
+///
+///     // Convert into a token stream and return it
+///     expanded.into()
+/// }
+/// ```
+#[cfg(all(feature = "parsing", feature = "proc-macro"))]
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "proc-macro"))))]
+pub fn parse<T: parse::Parse>(tokens: proc_macro::TokenStream) -> Result<T> {
+    parse::Parser::parse(T::parse, tokens)
+}
+
+/// Parse a proc-macro2 token stream into the chosen syntax tree node.
+///
+/// This function will check that the input is fully parsed. If there are
+/// any unparsed tokens at the end of the stream, an error is returned.
+///
+/// This function parses a `proc_macro2::TokenStream` which is commonly useful
+/// when the input comes from a node of the Syn syntax tree, for example the
+/// body tokens of a [`Macro`] node. When in a procedural macro parsing the
+/// `proc_macro::TokenStream` provided by the compiler, use [`syn::parse`]
+/// instead.
+///
+/// [`syn::parse`]: parse()
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+pub fn parse2<T: parse::Parse>(tokens: proc_macro2::TokenStream) -> Result<T> {
+    parse::Parser::parse2(T::parse, tokens)
+}
+
+/// Parse a string of Rust code into the chosen syntax tree node.
+///
+/// # Hygiene
+///
+/// Every span in the resulting syntax tree will be set to resolve at the macro
+/// call site.
+///
+/// # Examples
+///
+/// ```
+/// use syn::{Expr, Result};
+///
+/// fn run() -> Result<()> {
+///     let code = "assert_eq!(u8::max_value(), 255)";
+///     let expr = syn::parse_str::<Expr>(code)?;
+///     println!("{:#?}", expr);
+///     Ok(())
+/// }
+/// #
+/// # run().unwrap();
+/// ```
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+pub fn parse_str<T: parse::Parse>(s: &str) -> Result<T> {
+    parse::Parser::parse_str(T::parse, s)
+}
+
+// FIXME the name parse_file makes it sound like you might pass in a path to a
+// file, rather than the content.
+/// Parse the content of a file of Rust code.
+///
+/// This is different from `syn::parse_str::<File>(content)` in two ways:
+///
+/// - It discards a leading byte order mark `\u{FEFF}` if the file has one.
+/// - It preserves the shebang line of the file, such as `#!/usr/bin/env rustx`.
+///
+/// If present, either of these would be an error using `from_str`.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::error::Error;
+/// use std::fs::File;
+/// use std::io::Read;
+///
+/// fn run() -> Result<(), Box<dyn Error>> {
+///     let mut file = File::open("path/to/code.rs")?;
+///     let mut content = String::new();
+///     file.read_to_string(&mut content)?;
+///
+///     let ast = syn::parse_file(&content)?;
+///     if let Some(shebang) = ast.shebang {
+///         println!("{}", shebang);
+///     }
+///     println!("{} items", ast.items.len());
+///
+///     Ok(())
+/// }
+/// #
+/// # run().unwrap();
+/// ```
+#[cfg(all(feature = "parsing", feature = "full"))]
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "full"))))]
+pub fn parse_file(mut content: &str) -> Result<File> {
+    // Strip the BOM if it is present
+    const BOM: &str = "\u{feff}";
+    if content.starts_with(BOM) {
+        content = &content[BOM.len()..];
+    }
+
+    let mut shebang = None;
+    if content.starts_with("#!") {
+        let rest = whitespace::skip(&content[2..]);
+        if !rest.starts_with('[') {
+            if let Some(idx) = content.find('\n') {
+                shebang = Some(content[..idx].to_string());
+                content = &content[idx..];
+            } else {
+                shebang = Some(content.to_string());
+                content = "";
+            }
+        }
+    }
+
+    let mut file: File = parse_str(content)?;
+    file.shebang = shebang;
+    Ok(file)
+}
diff --git a/vendor/syn/src/lifetime.rs b/vendor/syn/src/lifetime.rs
new file mode 100644
index 0000000..29f4cfd
--- /dev/null
+++ b/vendor/syn/src/lifetime.rs
@@ -0,0 +1,156 @@
+use proc_macro2::{Ident, Span};
+use std::cmp::Ordering;
+use std::fmt::{self, Display};
+use std::hash::{Hash, Hasher};
+
+#[cfg(feature = "parsing")]
+use crate::lookahead;
+
+/// A Rust lifetime: `'a`.
+///
+/// Lifetime names must conform to the following rules:
+///
+/// - Must start with an apostrophe.
+/// - Must not consist of just an apostrophe: `'`.
+/// - Character after the apostrophe must be `_` or a Unicode code point with
+///   the XID_Start property.
+/// - All following characters must be Unicode code points with the XID_Continue
+///   property.
+pub struct Lifetime {
+    pub apostrophe: Span,
+    pub ident: Ident,
+}
+
+impl Lifetime {
+    /// # Panics
+    ///
+    /// Panics if the lifetime does not conform to the bulleted rules above.
+    ///
+    /// # Invocation
+    ///
+    /// ```
+    /// # use proc_macro2::Span;
+    /// # use syn::Lifetime;
+    /// #
+    /// # fn f() -> Lifetime {
+    /// Lifetime::new("'a", Span::call_site())
+    /// # }
+    /// ```
+    pub fn new(symbol: &str, span: Span) -> Self {
+        if !symbol.starts_with('\'') {
+            panic!(
+                "lifetime name must start with apostrophe as in \"'a\", got {:?}",
+                symbol
+            );
+        }
+
+        if symbol == "'" {
+            panic!("lifetime name must not be empty");
+        }
+
+        if !crate::ident::xid_ok(&symbol[1..]) {
+            panic!("{:?} is not a valid lifetime name", symbol);
+        }
+
+        Lifetime {
+            apostrophe: span,
+            ident: Ident::new(&symbol[1..], span),
+        }
+    }
+
+    pub fn span(&self) -> Span {
+        self.apostrophe
+            .join(self.ident.span())
+            .unwrap_or(self.apostrophe)
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.apostrophe = span;
+        self.ident.set_span(span);
+    }
+}
+
+impl Display for Lifetime {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        "'".fmt(formatter)?;
+        self.ident.fmt(formatter)
+    }
+}
+
+impl Clone for Lifetime {
+    fn clone(&self) -> Self {
+        Lifetime {
+            apostrophe: self.apostrophe,
+            ident: self.ident.clone(),
+        }
+    }
+}
+
+impl PartialEq for Lifetime {
+    fn eq(&self, other: &Lifetime) -> bool {
+        self.ident.eq(&other.ident)
+    }
+}
+
+impl Eq for Lifetime {}
+
+impl PartialOrd for Lifetime {
+    fn partial_cmp(&self, other: &Lifetime) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Lifetime {
+    fn cmp(&self, other: &Lifetime) -> Ordering {
+        self.ident.cmp(&other.ident)
+    }
+}
+
+impl Hash for Lifetime {
+    fn hash<H: Hasher>(&self, h: &mut H) {
+        self.ident.hash(h);
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub_if_not_doc! {
+    #[doc(hidden)]
+    #[allow(non_snake_case)]
+    pub fn Lifetime(marker: lookahead::TokenMarker) -> Lifetime {
+        match marker {}
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Lifetime {
+        fn parse(input: ParseStream) -> Result<Self> {
+            input.step(|cursor| {
+                cursor
+                    .lifetime()
+                    .ok_or_else(|| cursor.error("expected lifetime"))
+            })
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::{Punct, Spacing, TokenStream};
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Lifetime {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            let mut apostrophe = Punct::new('\'', Spacing::Joint);
+            apostrophe.set_span(self.apostrophe);
+            tokens.append(apostrophe);
+            self.ident.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/lit.rs b/vendor/syn/src/lit.rs
new file mode 100644
index 0000000..f7426ce
--- /dev/null
+++ b/vendor/syn/src/lit.rs
@@ -0,0 +1,1652 @@
+#[cfg(feature = "parsing")]
+use crate::lookahead;
+#[cfg(feature = "parsing")]
+use crate::parse::{Parse, Parser};
+use crate::{Error, Result};
+use proc_macro2::{Ident, Literal, Span};
+#[cfg(feature = "parsing")]
+use proc_macro2::{TokenStream, TokenTree};
+use std::fmt::{self, Display};
+#[cfg(feature = "extra-traits")]
+use std::hash::{Hash, Hasher};
+use std::str::{self, FromStr};
+
+ast_enum_of_structs! {
+    /// A Rust literal such as a string or integer or boolean.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: crate::Expr#syntax-tree-enums
+    #[non_exhaustive]
+    pub enum Lit {
+        /// A UTF-8 string literal: `"foo"`.
+        Str(LitStr),
+
+        /// A byte string literal: `b"foo"`.
+        ByteStr(LitByteStr),
+
+        /// A byte literal: `b'f'`.
+        Byte(LitByte),
+
+        /// A character literal: `'a'`.
+        Char(LitChar),
+
+        /// An integer literal: `1` or `1u16`.
+        Int(LitInt),
+
+        /// A floating point literal: `1f64` or `1.0e10f64`.
+        ///
+        /// Must be finite. May not be infinite or NaN.
+        Float(LitFloat),
+
+        /// A boolean literal: `true` or `false`.
+        Bool(LitBool),
+
+        /// A raw token literal not interpreted by Syn.
+        Verbatim(Literal),
+    }
+}
+
+ast_struct! {
+    /// A UTF-8 string literal: `"foo"`.
+    pub struct LitStr {
+        repr: Box<LitRepr>,
+    }
+}
+
+ast_struct! {
+    /// A byte string literal: `b"foo"`.
+    pub struct LitByteStr {
+        repr: Box<LitRepr>,
+    }
+}
+
+ast_struct! {
+    /// A byte literal: `b'f'`.
+    pub struct LitByte {
+        repr: Box<LitRepr>,
+    }
+}
+
+ast_struct! {
+    /// A character literal: `'a'`.
+    pub struct LitChar {
+        repr: Box<LitRepr>,
+    }
+}
+
+struct LitRepr {
+    token: Literal,
+    suffix: Box<str>,
+}
+
+ast_struct! {
+    /// An integer literal: `1` or `1u16`.
+    pub struct LitInt {
+        repr: Box<LitIntRepr>,
+    }
+}
+
+struct LitIntRepr {
+    token: Literal,
+    digits: Box<str>,
+    suffix: Box<str>,
+}
+
+ast_struct! {
+    /// A floating point literal: `1f64` or `1.0e10f64`.
+    ///
+    /// Must be finite. May not be infinite or NaN.
+    pub struct LitFloat {
+        repr: Box<LitFloatRepr>,
+    }
+}
+
+struct LitFloatRepr {
+    token: Literal,
+    digits: Box<str>,
+    suffix: Box<str>,
+}
+
+ast_struct! {
+    /// A boolean literal: `true` or `false`.
+    pub struct LitBool {
+        pub value: bool,
+        pub span: Span,
+    }
+}
+
+impl LitStr {
+    pub fn new(value: &str, span: Span) -> Self {
+        let mut token = Literal::string(value);
+        token.set_span(span);
+        LitStr {
+            repr: Box::new(LitRepr {
+                token,
+                suffix: Box::<str>::default(),
+            }),
+        }
+    }
+
+    pub fn value(&self) -> String {
+        let repr = self.repr.token.to_string();
+        let (value, _suffix) = value::parse_lit_str(&repr);
+        String::from(value)
+    }
+
+    /// Parse a syntax tree node from the content of this string literal.
+    ///
+    /// All spans in the syntax tree will point to the span of this `LitStr`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{Attribute, Error, Expr, Lit, Meta, Path, Result};
+    ///
+    /// // Parses the path from an attribute that looks like:
+    /// //
+    /// //     #[path = "a::b::c"]
+    /// //
+    /// // or returns `None` if the input is some other attribute.
+    /// fn get_path(attr: &Attribute) -> Result<Option<Path>> {
+    ///     if !attr.path().is_ident("path") {
+    ///         return Ok(None);
+    ///     }
+    ///
+    ///     if let Meta::NameValue(meta) = &attr.meta {
+    ///         if let Expr::Lit(expr) = &meta.value {
+    ///             if let Lit::Str(lit_str) = &expr.lit {
+    ///                 return lit_str.parse().map(Some);
+    ///             }
+    ///         }
+    ///     }
+    ///
+    ///     let message = "expected #[path = \"...\"]";
+    ///     Err(Error::new_spanned(attr, message))
+    /// }
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse<T: Parse>(&self) -> Result<T> {
+        self.parse_with(T::parse)
+    }
+
+    /// Invoke parser on the content of this string literal.
+    ///
+    /// All spans in the syntax tree will point to the span of this `LitStr`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use proc_macro2::Span;
+    /// # use syn::{LitStr, Result};
+    /// #
+    /// # fn main() -> Result<()> {
+    /// #     let lit_str = LitStr::new("a::b::c", Span::call_site());
+    /// #
+    /// #     const IGNORE: &str = stringify! {
+    /// let lit_str: LitStr = /* ... */;
+    /// #     };
+    ///
+    /// // Parse a string literal like "a::b::c" into a Path, not allowing
+    /// // generic arguments on any of the path segments.
+    /// let basic_path = lit_str.parse_with(syn::Path::parse_mod_style)?;
+    /// #
+    /// #     Ok(())
+    /// # }
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_with<F: Parser>(&self, parser: F) -> Result<F::Output> {
+        use proc_macro2::Group;
+
+        // Token stream with every span replaced by the given one.
+        fn respan_token_stream(stream: TokenStream, span: Span) -> TokenStream {
+            stream
+                .into_iter()
+                .map(|token| respan_token_tree(token, span))
+                .collect()
+        }
+
+        // Token tree with every span replaced by the given one.
+        fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree {
+            match &mut token {
+                TokenTree::Group(g) => {
+                    let stream = respan_token_stream(g.stream(), span);
+                    *g = Group::new(g.delimiter(), stream);
+                    g.set_span(span);
+                }
+                other => other.set_span(span),
+            }
+            token
+        }
+
+        // Parse string literal into a token stream with every span equal to the
+        // original literal's span.
+        let mut tokens = TokenStream::from_str(&self.value())?;
+        tokens = respan_token_stream(tokens, self.span());
+
+        let result = parser.parse2(tokens)?;
+
+        let suffix = self.suffix();
+        if !suffix.is_empty() {
+            return Err(Error::new(
+                self.span(),
+                format!("unexpected suffix `{}` on string literal", suffix),
+            ));
+        }
+
+        Ok(result)
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl LitByteStr {
+    pub fn new(value: &[u8], span: Span) -> Self {
+        let mut token = Literal::byte_string(value);
+        token.set_span(span);
+        LitByteStr {
+            repr: Box::new(LitRepr {
+                token,
+                suffix: Box::<str>::default(),
+            }),
+        }
+    }
+
+    pub fn value(&self) -> Vec<u8> {
+        let repr = self.repr.token.to_string();
+        let (value, _suffix) = value::parse_lit_byte_str(&repr);
+        value
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl LitByte {
+    pub fn new(value: u8, span: Span) -> Self {
+        let mut token = Literal::u8_suffixed(value);
+        token.set_span(span);
+        LitByte {
+            repr: Box::new(LitRepr {
+                token,
+                suffix: Box::<str>::default(),
+            }),
+        }
+    }
+
+    pub fn value(&self) -> u8 {
+        let repr = self.repr.token.to_string();
+        let (value, _suffix) = value::parse_lit_byte(&repr);
+        value
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl LitChar {
+    pub fn new(value: char, span: Span) -> Self {
+        let mut token = Literal::character(value);
+        token.set_span(span);
+        LitChar {
+            repr: Box::new(LitRepr {
+                token,
+                suffix: Box::<str>::default(),
+            }),
+        }
+    }
+
+    pub fn value(&self) -> char {
+        let repr = self.repr.token.to_string();
+        let (value, _suffix) = value::parse_lit_char(&repr);
+        value
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl LitInt {
+    pub fn new(repr: &str, span: Span) -> Self {
+        let (digits, suffix) = match value::parse_lit_int(repr) {
+            Some(parse) => parse,
+            None => panic!("Not an integer literal: `{}`", repr),
+        };
+
+        let mut token: Literal = repr.parse().unwrap();
+        token.set_span(span);
+        LitInt {
+            repr: Box::new(LitIntRepr {
+                token,
+                digits,
+                suffix,
+            }),
+        }
+    }
+
+    pub fn base10_digits(&self) -> &str {
+        &self.repr.digits
+    }
+
+    /// Parses the literal into a selected number type.
+    ///
+    /// This is equivalent to `lit.base10_digits().parse()` except that the
+    /// resulting errors will be correctly spanned to point to the literal token
+    /// in the macro input.
+    ///
+    /// ```
+    /// use syn::LitInt;
+    /// use syn::parse::{Parse, ParseStream, Result};
+    ///
+    /// struct Port {
+    ///     value: u16,
+    /// }
+    ///
+    /// impl Parse for Port {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let lit: LitInt = input.parse()?;
+    ///         let value = lit.base10_parse::<u16>()?;
+    ///         Ok(Port { value })
+    ///     }
+    /// }
+    /// ```
+    pub fn base10_parse<N>(&self) -> Result<N>
+    where
+        N: FromStr,
+        N::Err: Display,
+    {
+        self.base10_digits()
+            .parse()
+            .map_err(|err| Error::new(self.span(), err))
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl From<Literal> for LitInt {
+    fn from(token: Literal) -> Self {
+        let repr = token.to_string();
+        if let Some((digits, suffix)) = value::parse_lit_int(&repr) {
+            LitInt {
+                repr: Box::new(LitIntRepr {
+                    token,
+                    digits,
+                    suffix,
+                }),
+            }
+        } else {
+            panic!("Not an integer literal: `{}`", repr);
+        }
+    }
+}
+
+impl Display for LitInt {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        self.repr.token.fmt(formatter)
+    }
+}
+
+impl LitFloat {
+    pub fn new(repr: &str, span: Span) -> Self {
+        let (digits, suffix) = match value::parse_lit_float(repr) {
+            Some(parse) => parse,
+            None => panic!("Not a float literal: `{}`", repr),
+        };
+
+        let mut token: Literal = repr.parse().unwrap();
+        token.set_span(span);
+        LitFloat {
+            repr: Box::new(LitFloatRepr {
+                token,
+                digits,
+                suffix,
+            }),
+        }
+    }
+
+    pub fn base10_digits(&self) -> &str {
+        &self.repr.digits
+    }
+
+    pub fn base10_parse<N>(&self) -> Result<N>
+    where
+        N: FromStr,
+        N::Err: Display,
+    {
+        self.base10_digits()
+            .parse()
+            .map_err(|err| Error::new(self.span(), err))
+    }
+
+    pub fn suffix(&self) -> &str {
+        &self.repr.suffix
+    }
+
+    pub fn span(&self) -> Span {
+        self.repr.token.span()
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.repr.token.set_span(span);
+    }
+
+    pub fn token(&self) -> Literal {
+        self.repr.token.clone()
+    }
+}
+
+impl From<Literal> for LitFloat {
+    fn from(token: Literal) -> Self {
+        let repr = token.to_string();
+        if let Some((digits, suffix)) = value::parse_lit_float(&repr) {
+            LitFloat {
+                repr: Box::new(LitFloatRepr {
+                    token,
+                    digits,
+                    suffix,
+                }),
+            }
+        } else {
+            panic!("Not a float literal: `{}`", repr);
+        }
+    }
+}
+
+impl Display for LitFloat {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        self.repr.token.fmt(formatter)
+    }
+}
+
+impl LitBool {
+    pub fn new(value: bool, span: Span) -> Self {
+        LitBool { value, span }
+    }
+
+    pub fn value(&self) -> bool {
+        self.value
+    }
+
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+    }
+
+    pub fn token(&self) -> Ident {
+        let s = if self.value { "true" } else { "false" };
+        Ident::new(s, self.span)
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+mod debug_impls {
+    use super::*;
+    use std::fmt::{self, Debug};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitStr {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitStr {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitStr")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitByteStr {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitByteStr {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitByteStr")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitByte {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitByte {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitByte")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitChar {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitChar {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitChar")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitInt {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitInt {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitInt")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitFloat {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitFloat {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("token", &format_args!("{}", self.repr.token))
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitFloat")
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+    impl Debug for LitBool {
+        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            impl LitBool {
+                pub(crate) fn debug(
+                    &self,
+                    formatter: &mut fmt::Formatter,
+                    name: &str,
+                ) -> fmt::Result {
+                    formatter
+                        .debug_struct(name)
+                        .field("value", &self.value)
+                        .finish()
+                }
+            }
+            self.debug(formatter, "LitBool")
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LitRepr {
+    fn clone(&self) -> Self {
+        LitRepr {
+            token: self.token.clone(),
+            suffix: self.suffix.clone(),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LitIntRepr {
+    fn clone(&self) -> Self {
+        LitIntRepr {
+            token: self.token.clone(),
+            digits: self.digits.clone(),
+            suffix: self.suffix.clone(),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for LitFloatRepr {
+    fn clone(&self) -> Self {
+        LitFloatRepr {
+            token: self.token.clone(),
+            digits: self.digits.clone(),
+            suffix: self.suffix.clone(),
+        }
+    }
+}
+
+macro_rules! lit_extra_traits {
+    ($ty:ident) => {
+        #[cfg(feature = "clone-impls")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+        impl Clone for $ty {
+            fn clone(&self) -> Self {
+                $ty {
+                    repr: self.repr.clone(),
+                }
+            }
+        }
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl PartialEq for $ty {
+            fn eq(&self, other: &Self) -> bool {
+                self.repr.token.to_string() == other.repr.token.to_string()
+            }
+        }
+
+        #[cfg(feature = "extra-traits")]
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+        impl Hash for $ty {
+            fn hash<H>(&self, state: &mut H)
+            where
+                H: Hasher,
+            {
+                self.repr.token.to_string().hash(state);
+            }
+        }
+
+        #[cfg(feature = "parsing")]
+        pub_if_not_doc! {
+            #[doc(hidden)]
+            #[allow(non_snake_case)]
+            pub fn $ty(marker: lookahead::TokenMarker) -> $ty {
+                match marker {}
+            }
+        }
+    };
+}
+
+lit_extra_traits!(LitStr);
+lit_extra_traits!(LitByteStr);
+lit_extra_traits!(LitByte);
+lit_extra_traits!(LitChar);
+lit_extra_traits!(LitInt);
+lit_extra_traits!(LitFloat);
+
+#[cfg(feature = "parsing")]
+pub_if_not_doc! {
+    #[doc(hidden)]
+    #[allow(non_snake_case)]
+    pub fn LitBool(marker: lookahead::TokenMarker) -> LitBool {
+        match marker {}
+    }
+}
+
+ast_enum! {
+    /// The style of a string literal, either plain quoted or a raw string like
+    /// `r##"data"##`.
+    pub enum StrStyle #no_visit {
+        /// An ordinary string like `"data"`.
+        Cooked,
+        /// A raw string like `r##"data"##`.
+        ///
+        /// The unsigned integer is the number of `#` symbols used.
+        Raw(usize),
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub_if_not_doc! {
+    #[doc(hidden)]
+    #[allow(non_snake_case)]
+    pub fn Lit(marker: lookahead::TokenMarker) -> Lit {
+        match marker {}
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::buffer::Cursor;
+    use crate::parse::{Parse, ParseStream, Result};
+    use proc_macro2::Punct;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Lit {
+        fn parse(input: ParseStream) -> Result<Self> {
+            input.step(|cursor| {
+                if let Some((lit, rest)) = cursor.literal() {
+                    return Ok((Lit::new(lit), rest));
+                }
+
+                if let Some((ident, rest)) = cursor.ident() {
+                    let value = ident == "true";
+                    if value || ident == "false" {
+                        let lit_bool = LitBool {
+                            value,
+                            span: ident.span(),
+                        };
+                        return Ok((Lit::Bool(lit_bool), rest));
+                    }
+                }
+
+                if let Some((punct, rest)) = cursor.punct() {
+                    if punct.as_char() == '-' {
+                        if let Some((lit, rest)) = parse_negative_lit(punct, rest) {
+                            return Ok((lit, rest));
+                        }
+                    }
+                }
+
+                Err(cursor.error("expected literal"))
+            })
+        }
+    }
+
+    fn parse_negative_lit(neg: Punct, cursor: Cursor) -> Option<(Lit, Cursor)> {
+        let (lit, rest) = cursor.literal()?;
+
+        let mut span = neg.span();
+        span = span.join(lit.span()).unwrap_or(span);
+
+        let mut repr = lit.to_string();
+        repr.insert(0, '-');
+
+        if let Some((digits, suffix)) = value::parse_lit_int(&repr) {
+            let mut token: Literal = repr.parse().unwrap();
+            token.set_span(span);
+            return Some((
+                Lit::Int(LitInt {
+                    repr: Box::new(LitIntRepr {
+                        token,
+                        digits,
+                        suffix,
+                    }),
+                }),
+                rest,
+            ));
+        }
+
+        let (digits, suffix) = value::parse_lit_float(&repr)?;
+        let mut token: Literal = repr.parse().unwrap();
+        token.set_span(span);
+        Some((
+            Lit::Float(LitFloat {
+                repr: Box::new(LitFloatRepr {
+                    token,
+                    digits,
+                    suffix,
+                }),
+            }),
+            rest,
+        ))
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitStr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Str(lit)) => Ok(lit),
+                _ => Err(head.error("expected string literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitByteStr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::ByteStr(lit)) => Ok(lit),
+                _ => Err(head.error("expected byte string literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitByte {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Byte(lit)) => Ok(lit),
+                _ => Err(head.error("expected byte literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitChar {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Char(lit)) => Ok(lit),
+                _ => Err(head.error("expected character literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitInt {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Int(lit)) => Ok(lit),
+                _ => Err(head.error("expected integer literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitFloat {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Float(lit)) => Ok(lit),
+                _ => Err(head.error("expected floating point literal")),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for LitBool {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let head = input.fork();
+            match input.parse() {
+                Ok(Lit::Bool(lit)) => Ok(lit),
+                _ => Err(head.error("expected boolean literal")),
+            }
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitStr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitByteStr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitByte {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitChar {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitInt {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitFloat {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.repr.token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for LitBool {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append(self.token());
+        }
+    }
+}
+
+mod value {
+    use super::*;
+    use crate::bigint::BigInt;
+    use std::char;
+    use std::ops::{Index, RangeFrom};
+
+    impl Lit {
+        /// Interpret a Syn literal from a proc-macro2 literal.
+        pub fn new(token: Literal) -> Self {
+            let repr = token.to_string();
+
+            match byte(&repr, 0) {
+                // "...", r"...", r#"..."#
+                b'"' | b'r' => {
+                    let (_, suffix) = parse_lit_str(&repr);
+                    return Lit::Str(LitStr {
+                        repr: Box::new(LitRepr { token, suffix }),
+                    });
+                }
+                b'b' => match byte(&repr, 1) {
+                    // b"...", br"...", br#"...#"
+                    b'"' | b'r' => {
+                        let (_, suffix) = parse_lit_byte_str(&repr);
+                        return Lit::ByteStr(LitByteStr {
+                            repr: Box::new(LitRepr { token, suffix }),
+                        });
+                    }
+                    // b'...'
+                    b'\'' => {
+                        let (_, suffix) = parse_lit_byte(&repr);
+                        return Lit::Byte(LitByte {
+                            repr: Box::new(LitRepr { token, suffix }),
+                        });
+                    }
+                    _ => {}
+                },
+                // '...'
+                b'\'' => {
+                    let (_, suffix) = parse_lit_char(&repr);
+                    return Lit::Char(LitChar {
+                        repr: Box::new(LitRepr { token, suffix }),
+                    });
+                }
+                b'0'..=b'9' | b'-' => {
+                    // 0, 123, 0xFF, 0o77, 0b11
+                    if let Some((digits, suffix)) = parse_lit_int(&repr) {
+                        return Lit::Int(LitInt {
+                            repr: Box::new(LitIntRepr {
+                                token,
+                                digits,
+                                suffix,
+                            }),
+                        });
+                    }
+                    // 1.0, 1e-1, 1e+1
+                    if let Some((digits, suffix)) = parse_lit_float(&repr) {
+                        return Lit::Float(LitFloat {
+                            repr: Box::new(LitFloatRepr {
+                                token,
+                                digits,
+                                suffix,
+                            }),
+                        });
+                    }
+                }
+                // true, false
+                b't' | b'f' => {
+                    if repr == "true" || repr == "false" {
+                        return Lit::Bool(LitBool {
+                            value: repr == "true",
+                            span: token.span(),
+                        });
+                    }
+                }
+                // c"...", cr"...", cr#"..."#
+                // TODO: add a Lit::CStr variant?
+                b'c' => return Lit::Verbatim(token),
+                b'(' if repr == "(/*ERROR*/)" => return Lit::Verbatim(token),
+                _ => {}
+            }
+
+            panic!("Unrecognized literal: `{}`", repr);
+        }
+
+        pub fn suffix(&self) -> &str {
+            match self {
+                Lit::Str(lit) => lit.suffix(),
+                Lit::ByteStr(lit) => lit.suffix(),
+                Lit::Byte(lit) => lit.suffix(),
+                Lit::Char(lit) => lit.suffix(),
+                Lit::Int(lit) => lit.suffix(),
+                Lit::Float(lit) => lit.suffix(),
+                Lit::Bool(_) | Lit::Verbatim(_) => "",
+            }
+        }
+
+        pub fn span(&self) -> Span {
+            match self {
+                Lit::Str(lit) => lit.span(),
+                Lit::ByteStr(lit) => lit.span(),
+                Lit::Byte(lit) => lit.span(),
+                Lit::Char(lit) => lit.span(),
+                Lit::Int(lit) => lit.span(),
+                Lit::Float(lit) => lit.span(),
+                Lit::Bool(lit) => lit.span,
+                Lit::Verbatim(lit) => lit.span(),
+            }
+        }
+
+        pub fn set_span(&mut self, span: Span) {
+            match self {
+                Lit::Str(lit) => lit.set_span(span),
+                Lit::ByteStr(lit) => lit.set_span(span),
+                Lit::Byte(lit) => lit.set_span(span),
+                Lit::Char(lit) => lit.set_span(span),
+                Lit::Int(lit) => lit.set_span(span),
+                Lit::Float(lit) => lit.set_span(span),
+                Lit::Bool(lit) => lit.span = span,
+                Lit::Verbatim(lit) => lit.set_span(span),
+            }
+        }
+    }
+
+    /// Get the byte at offset idx, or a default of `b'\0'` if we're looking
+    /// past the end of the input buffer.
+    pub(crate) fn byte<S: AsRef<[u8]> + ?Sized>(s: &S, idx: usize) -> u8 {
+        let s = s.as_ref();
+        if idx < s.len() {
+            s[idx]
+        } else {
+            0
+        }
+    }
+
+    fn next_chr(s: &str) -> char {
+        s.chars().next().unwrap_or('\0')
+    }
+
+    // Returns (content, suffix).
+    pub(crate) fn parse_lit_str(s: &str) -> (Box<str>, Box<str>) {
+        match byte(s, 0) {
+            b'"' => parse_lit_str_cooked(s),
+            b'r' => parse_lit_str_raw(s),
+            _ => unreachable!(),
+        }
+    }
+
+    // Clippy false positive
+    // https://github.com/rust-lang-nursery/rust-clippy/issues/2329
+    #[allow(clippy::needless_continue)]
+    fn parse_lit_str_cooked(mut s: &str) -> (Box<str>, Box<str>) {
+        assert_eq!(byte(s, 0), b'"');
+        s = &s[1..];
+
+        let mut content = String::new();
+        'outer: loop {
+            let ch = match byte(s, 0) {
+                b'"' => break,
+                b'\\' => {
+                    let b = byte(s, 1);
+                    s = &s[2..];
+                    match b {
+                        b'x' => {
+                            let (byte, rest) = backslash_x(s);
+                            s = rest;
+                            assert!(byte <= 0x7F, "Invalid \\x byte in string literal");
+                            char::from_u32(u32::from(byte)).unwrap()
+                        }
+                        b'u' => {
+                            let (chr, rest) = backslash_u(s);
+                            s = rest;
+                            chr
+                        }
+                        b'n' => '\n',
+                        b'r' => '\r',
+                        b't' => '\t',
+                        b'\\' => '\\',
+                        b'0' => '\0',
+                        b'\'' => '\'',
+                        b'"' => '"',
+                        b'\r' | b'\n' => loop {
+                            let b = byte(s, 0);
+                            match b {
+                                b' ' | b'\t' | b'\n' | b'\r' => s = &s[1..],
+                                _ => continue 'outer,
+                            }
+                        },
+                        b => panic!("unexpected byte {:?} after \\ character in byte literal", b),
+                    }
+                }
+                b'\r' => {
+                    assert_eq!(byte(s, 1), b'\n', "Bare CR not allowed in string");
+                    s = &s[2..];
+                    '\n'
+                }
+                _ => {
+                    let ch = next_chr(s);
+                    s = &s[ch.len_utf8()..];
+                    ch
+                }
+            };
+            content.push(ch);
+        }
+
+        assert!(s.starts_with('"'));
+        let content = content.into_boxed_str();
+        let suffix = s[1..].to_owned().into_boxed_str();
+        (content, suffix)
+    }
+
+    fn parse_lit_str_raw(mut s: &str) -> (Box<str>, Box<str>) {
+        assert_eq!(byte(s, 0), b'r');
+        s = &s[1..];
+
+        let mut pounds = 0;
+        while byte(s, pounds) == b'#' {
+            pounds += 1;
+        }
+        assert_eq!(byte(s, pounds), b'"');
+        let close = s.rfind('"').unwrap();
+        for end in s[close + 1..close + 1 + pounds].bytes() {
+            assert_eq!(end, b'#');
+        }
+
+        let content = s[pounds + 1..close].to_owned().into_boxed_str();
+        let suffix = s[close + 1 + pounds..].to_owned().into_boxed_str();
+        (content, suffix)
+    }
+
+    // Returns (content, suffix).
+    pub(crate) fn parse_lit_byte_str(s: &str) -> (Vec<u8>, Box<str>) {
+        assert_eq!(byte(s, 0), b'b');
+        match byte(s, 1) {
+            b'"' => parse_lit_byte_str_cooked(s),
+            b'r' => parse_lit_byte_str_raw(s),
+            _ => unreachable!(),
+        }
+    }
+
+    // Clippy false positive
+    // https://github.com/rust-lang-nursery/rust-clippy/issues/2329
+    #[allow(clippy::needless_continue)]
+    fn parse_lit_byte_str_cooked(mut s: &str) -> (Vec<u8>, Box<str>) {
+        assert_eq!(byte(s, 0), b'b');
+        assert_eq!(byte(s, 1), b'"');
+        s = &s[2..];
+
+        // We're going to want to have slices which don't respect codepoint boundaries.
+        let mut v = s.as_bytes();
+
+        let mut out = Vec::new();
+        'outer: loop {
+            let byte = match byte(v, 0) {
+                b'"' => break,
+                b'\\' => {
+                    let b = byte(v, 1);
+                    v = &v[2..];
+                    match b {
+                        b'x' => {
+                            let (b, rest) = backslash_x(v);
+                            v = rest;
+                            b
+                        }
+                        b'n' => b'\n',
+                        b'r' => b'\r',
+                        b't' => b'\t',
+                        b'\\' => b'\\',
+                        b'0' => b'\0',
+                        b'\'' => b'\'',
+                        b'"' => b'"',
+                        b'\r' | b'\n' => loop {
+                            let byte = byte(v, 0);
+                            if matches!(byte, b' ' | b'\t' | b'\n' | b'\r') {
+                                v = &v[1..];
+                            } else {
+                                continue 'outer;
+                            }
+                        },
+                        b => panic!("unexpected byte {:?} after \\ character in byte literal", b),
+                    }
+                }
+                b'\r' => {
+                    assert_eq!(byte(v, 1), b'\n', "Bare CR not allowed in string");
+                    v = &v[2..];
+                    b'\n'
+                }
+                b => {
+                    v = &v[1..];
+                    b
+                }
+            };
+            out.push(byte);
+        }
+
+        assert_eq!(byte(v, 0), b'"');
+        let suffix = s[s.len() - v.len() + 1..].to_owned().into_boxed_str();
+        (out, suffix)
+    }
+
+    fn parse_lit_byte_str_raw(s: &str) -> (Vec<u8>, Box<str>) {
+        assert_eq!(byte(s, 0), b'b');
+        let (value, suffix) = parse_lit_str_raw(&s[1..]);
+        (String::from(value).into_bytes(), suffix)
+    }
+
+    // Returns (value, suffix).
+    pub(crate) fn parse_lit_byte(s: &str) -> (u8, Box<str>) {
+        assert_eq!(byte(s, 0), b'b');
+        assert_eq!(byte(s, 1), b'\'');
+
+        // We're going to want to have slices which don't respect codepoint boundaries.
+        let mut v = s[2..].as_bytes();
+
+        let b = match byte(v, 0) {
+            b'\\' => {
+                let b = byte(v, 1);
+                v = &v[2..];
+                match b {
+                    b'x' => {
+                        let (b, rest) = backslash_x(v);
+                        v = rest;
+                        b
+                    }
+                    b'n' => b'\n',
+                    b'r' => b'\r',
+                    b't' => b'\t',
+                    b'\\' => b'\\',
+                    b'0' => b'\0',
+                    b'\'' => b'\'',
+                    b'"' => b'"',
+                    b => panic!("unexpected byte {:?} after \\ character in byte literal", b),
+                }
+            }
+            b => {
+                v = &v[1..];
+                b
+            }
+        };
+
+        assert_eq!(byte(v, 0), b'\'');
+        let suffix = s[s.len() - v.len() + 1..].to_owned().into_boxed_str();
+        (b, suffix)
+    }
+
+    // Returns (value, suffix).
+    pub(crate) fn parse_lit_char(mut s: &str) -> (char, Box<str>) {
+        assert_eq!(byte(s, 0), b'\'');
+        s = &s[1..];
+
+        let ch = match byte(s, 0) {
+            b'\\' => {
+                let b = byte(s, 1);
+                s = &s[2..];
+                match b {
+                    b'x' => {
+                        let (byte, rest) = backslash_x(s);
+                        s = rest;
+                        assert!(byte <= 0x80, "Invalid \\x byte in string literal");
+                        char::from_u32(u32::from(byte)).unwrap()
+                    }
+                    b'u' => {
+                        let (chr, rest) = backslash_u(s);
+                        s = rest;
+                        chr
+                    }
+                    b'n' => '\n',
+                    b'r' => '\r',
+                    b't' => '\t',
+                    b'\\' => '\\',
+                    b'0' => '\0',
+                    b'\'' => '\'',
+                    b'"' => '"',
+                    b => panic!("unexpected byte {:?} after \\ character in byte literal", b),
+                }
+            }
+            _ => {
+                let ch = next_chr(s);
+                s = &s[ch.len_utf8()..];
+                ch
+            }
+        };
+        assert_eq!(byte(s, 0), b'\'');
+        let suffix = s[1..].to_owned().into_boxed_str();
+        (ch, suffix)
+    }
+
+    fn backslash_x<S>(s: &S) -> (u8, &S)
+    where
+        S: Index<RangeFrom<usize>, Output = S> + AsRef<[u8]> + ?Sized,
+    {
+        let mut ch = 0;
+        let b0 = byte(s, 0);
+        let b1 = byte(s, 1);
+        ch += 0x10
+            * match b0 {
+                b'0'..=b'9' => b0 - b'0',
+                b'a'..=b'f' => 10 + (b0 - b'a'),
+                b'A'..=b'F' => 10 + (b0 - b'A'),
+                _ => panic!("unexpected non-hex character after \\x"),
+            };
+        ch += match b1 {
+            b'0'..=b'9' => b1 - b'0',
+            b'a'..=b'f' => 10 + (b1 - b'a'),
+            b'A'..=b'F' => 10 + (b1 - b'A'),
+            _ => panic!("unexpected non-hex character after \\x"),
+        };
+        (ch, &s[2..])
+    }
+
+    fn backslash_u(mut s: &str) -> (char, &str) {
+        if byte(s, 0) != b'{' {
+            panic!("{}", "expected { after \\u");
+        }
+        s = &s[1..];
+
+        let mut ch = 0;
+        let mut digits = 0;
+        loop {
+            let b = byte(s, 0);
+            let digit = match b {
+                b'0'..=b'9' => b - b'0',
+                b'a'..=b'f' => 10 + b - b'a',
+                b'A'..=b'F' => 10 + b - b'A',
+                b'_' if digits > 0 => {
+                    s = &s[1..];
+                    continue;
+                }
+                b'}' if digits == 0 => panic!("invalid empty unicode escape"),
+                b'}' => break,
+                _ => panic!("unexpected non-hex character after \\u"),
+            };
+            if digits == 6 {
+                panic!("overlong unicode escape (must have at most 6 hex digits)");
+            }
+            ch *= 0x10;
+            ch += u32::from(digit);
+            digits += 1;
+            s = &s[1..];
+        }
+        assert!(byte(s, 0) == b'}');
+        s = &s[1..];
+
+        if let Some(ch) = char::from_u32(ch) {
+            (ch, s)
+        } else {
+            panic!("character code {:x} is not a valid unicode character", ch);
+        }
+    }
+
+    // Returns base 10 digits and suffix.
+    pub(crate) fn parse_lit_int(mut s: &str) -> Option<(Box<str>, Box<str>)> {
+        let negative = byte(s, 0) == b'-';
+        if negative {
+            s = &s[1..];
+        }
+
+        let base = match (byte(s, 0), byte(s, 1)) {
+            (b'0', b'x') => {
+                s = &s[2..];
+                16
+            }
+            (b'0', b'o') => {
+                s = &s[2..];
+                8
+            }
+            (b'0', b'b') => {
+                s = &s[2..];
+                2
+            }
+            (b'0'..=b'9', _) => 10,
+            _ => return None,
+        };
+
+        let mut value = BigInt::new();
+        let mut has_digit = false;
+        'outer: loop {
+            let b = byte(s, 0);
+            let digit = match b {
+                b'0'..=b'9' => b - b'0',
+                b'a'..=b'f' if base > 10 => b - b'a' + 10,
+                b'A'..=b'F' if base > 10 => b - b'A' + 10,
+                b'_' => {
+                    s = &s[1..];
+                    continue;
+                }
+                // If looking at a floating point literal, we don't want to
+                // consider it an integer.
+                b'.' if base == 10 => return None,
+                b'e' | b'E' if base == 10 => {
+                    let mut has_exp = false;
+                    for (i, b) in s[1..].bytes().enumerate() {
+                        match b {
+                            b'_' => {}
+                            b'-' | b'+' => return None,
+                            b'0'..=b'9' => has_exp = true,
+                            _ => {
+                                let suffix = &s[1 + i..];
+                                if has_exp && crate::ident::xid_ok(suffix) {
+                                    return None;
+                                } else {
+                                    break 'outer;
+                                }
+                            }
+                        }
+                    }
+                    if has_exp {
+                        return None;
+                    } else {
+                        break;
+                    }
+                }
+                _ => break,
+            };
+
+            if digit >= base {
+                return None;
+            }
+
+            has_digit = true;
+            value *= base;
+            value += digit;
+            s = &s[1..];
+        }
+
+        if !has_digit {
+            return None;
+        }
+
+        let suffix = s;
+        if suffix.is_empty() || crate::ident::xid_ok(suffix) {
+            let mut repr = value.to_string();
+            if negative {
+                repr.insert(0, '-');
+            }
+            Some((repr.into_boxed_str(), suffix.to_owned().into_boxed_str()))
+        } else {
+            None
+        }
+    }
+
+    // Returns base 10 digits and suffix.
+    pub(crate) fn parse_lit_float(input: &str) -> Option<(Box<str>, Box<str>)> {
+        // Rust's floating point literals are very similar to the ones parsed by
+        // the standard library, except that rust's literals can contain
+        // ignorable underscores. Let's remove those underscores.
+
+        let mut bytes = input.to_owned().into_bytes();
+
+        let start = (*bytes.first()? == b'-') as usize;
+        match bytes.get(start)? {
+            b'0'..=b'9' => {}
+            _ => return None,
+        }
+
+        let mut read = start;
+        let mut write = start;
+        let mut has_dot = false;
+        let mut has_e = false;
+        let mut has_sign = false;
+        let mut has_exponent = false;
+        while read < bytes.len() {
+            match bytes[read] {
+                b'_' => {
+                    // Don't increase write
+                    read += 1;
+                    continue;
+                }
+                b'0'..=b'9' => {
+                    if has_e {
+                        has_exponent = true;
+                    }
+                    bytes[write] = bytes[read];
+                }
+                b'.' => {
+                    if has_e || has_dot {
+                        return None;
+                    }
+                    has_dot = true;
+                    bytes[write] = b'.';
+                }
+                b'e' | b'E' => {
+                    match bytes[read + 1..]
+                        .iter()
+                        .find(|b| **b != b'_')
+                        .unwrap_or(&b'\0')
+                    {
+                        b'-' | b'+' | b'0'..=b'9' => {}
+                        _ => break,
+                    }
+                    if has_e {
+                        if has_exponent {
+                            break;
+                        } else {
+                            return None;
+                        }
+                    }
+                    has_e = true;
+                    bytes[write] = b'e';
+                }
+                b'-' | b'+' => {
+                    if has_sign || has_exponent || !has_e {
+                        return None;
+                    }
+                    has_sign = true;
+                    if bytes[read] == b'-' {
+                        bytes[write] = bytes[read];
+                    } else {
+                        // Omit '+'
+                        read += 1;
+                        continue;
+                    }
+                }
+                _ => break,
+            }
+            read += 1;
+            write += 1;
+        }
+
+        if has_e && !has_exponent {
+            return None;
+        }
+
+        let mut digits = String::from_utf8(bytes).unwrap();
+        let suffix = digits.split_off(read);
+        digits.truncate(write);
+        if suffix.is_empty() || crate::ident::xid_ok(&suffix) {
+            Some((digits.into_boxed_str(), suffix.into_boxed_str()))
+        } else {
+            None
+        }
+    }
+}
diff --git a/vendor/syn/src/lookahead.rs b/vendor/syn/src/lookahead.rs
new file mode 100644
index 0000000..e89a4c7
--- /dev/null
+++ b/vendor/syn/src/lookahead.rs
@@ -0,0 +1,169 @@
+use crate::buffer::Cursor;
+use crate::error::{self, Error};
+use crate::sealed::lookahead::Sealed;
+use crate::span::IntoSpans;
+use crate::token::Token;
+use proc_macro2::{Delimiter, Span};
+use std::cell::RefCell;
+
+/// Support for checking the next token in a stream to decide how to parse.
+///
+/// An important advantage over [`ParseStream::peek`] is that here we
+/// automatically construct an appropriate error message based on the token
+/// alternatives that get peeked. If you are producing your own error message,
+/// go ahead and use `ParseStream::peek` instead.
+///
+/// Use [`ParseStream::lookahead1`] to construct this object.
+///
+/// [`ParseStream::peek`]: crate::parse::ParseBuffer::peek
+/// [`ParseStream::lookahead1`]: crate::parse::ParseBuffer::lookahead1
+///
+/// Consuming tokens from the source stream after constructing a lookahead
+/// object does not also advance the lookahead object.
+///
+/// # Example
+///
+/// ```
+/// use syn::{ConstParam, Ident, Lifetime, LifetimeParam, Result, Token, TypeParam};
+/// use syn::parse::{Parse, ParseStream};
+///
+/// // A generic parameter, a single one of the comma-separated elements inside
+/// // angle brackets in:
+/// //
+/// //     fn f<T: Clone, 'a, 'b: 'a, const N: usize>() { ... }
+/// //
+/// // On invalid input, lookahead gives us a reasonable error message.
+/// //
+/// //     error: expected one of: identifier, lifetime, `const`
+/// //       |
+/// //     5 |     fn f<!Sized>() {}
+/// //       |          ^
+/// enum GenericParam {
+///     Type(TypeParam),
+///     Lifetime(LifetimeParam),
+///     Const(ConstParam),
+/// }
+///
+/// impl Parse for GenericParam {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let lookahead = input.lookahead1();
+///         if lookahead.peek(Ident) {
+///             input.parse().map(GenericParam::Type)
+///         } else if lookahead.peek(Lifetime) {
+///             input.parse().map(GenericParam::Lifetime)
+///         } else if lookahead.peek(Token![const]) {
+///             input.parse().map(GenericParam::Const)
+///         } else {
+///             Err(lookahead.error())
+///         }
+///     }
+/// }
+/// ```
+pub struct Lookahead1<'a> {
+    scope: Span,
+    cursor: Cursor<'a>,
+    comparisons: RefCell<Vec<&'static str>>,
+}
+
+pub(crate) fn new(scope: Span, cursor: Cursor) -> Lookahead1 {
+    Lookahead1 {
+        scope,
+        cursor,
+        comparisons: RefCell::new(Vec::new()),
+    }
+}
+
+fn peek_impl(
+    lookahead: &Lookahead1,
+    peek: fn(Cursor) -> bool,
+    display: fn() -> &'static str,
+) -> bool {
+    if peek(lookahead.cursor) {
+        return true;
+    }
+    lookahead.comparisons.borrow_mut().push(display());
+    false
+}
+
+impl<'a> Lookahead1<'a> {
+    /// Looks at the next token in the parse stream to determine whether it
+    /// matches the requested type of token.
+    ///
+    /// # Syntax
+    ///
+    /// Note that this method does not use turbofish syntax. Pass the peek type
+    /// inside of parentheses.
+    ///
+    /// - `input.peek(Token![struct])`
+    /// - `input.peek(Token![==])`
+    /// - `input.peek(Ident)`&emsp;*(does not accept keywords)*
+    /// - `input.peek(Ident::peek_any)`
+    /// - `input.peek(Lifetime)`
+    /// - `input.peek(token::Brace)`
+    pub fn peek<T: Peek>(&self, token: T) -> bool {
+        let _ = token;
+        peek_impl(self, T::Token::peek, T::Token::display)
+    }
+
+    /// Triggers an error at the current position of the parse stream.
+    ///
+    /// The error message will identify all of the expected token types that
+    /// have been peeked against this lookahead instance.
+    pub fn error(self) -> Error {
+        let comparisons = self.comparisons.borrow();
+        match comparisons.len() {
+            0 => {
+                if self.cursor.eof() {
+                    Error::new(self.scope, "unexpected end of input")
+                } else {
+                    Error::new(self.cursor.span(), "unexpected token")
+                }
+            }
+            1 => {
+                let message = format!("expected {}", comparisons[0]);
+                error::new_at(self.scope, self.cursor, message)
+            }
+            2 => {
+                let message = format!("expected {} or {}", comparisons[0], comparisons[1]);
+                error::new_at(self.scope, self.cursor, message)
+            }
+            _ => {
+                let join = comparisons.join(", ");
+                let message = format!("expected one of: {}", join);
+                error::new_at(self.scope, self.cursor, message)
+            }
+        }
+    }
+}
+
+/// Types that can be parsed by looking at just one token.
+///
+/// Use [`ParseStream::peek`] to peek one of these types in a parse stream
+/// without consuming it from the stream.
+///
+/// This trait is sealed and cannot be implemented for types outside of Syn.
+///
+/// [`ParseStream::peek`]: crate::parse::ParseBuffer::peek
+pub trait Peek: Sealed {
+    // Not public API.
+    #[doc(hidden)]
+    type Token: Token;
+}
+
+impl<F: Copy + FnOnce(TokenMarker) -> T, T: Token> Peek for F {
+    type Token = T;
+}
+
+pub enum TokenMarker {}
+
+impl<S> IntoSpans<S> for TokenMarker {
+    fn into_spans(self) -> S {
+        match self {}
+    }
+}
+
+pub(crate) fn is_delimiter(cursor: Cursor, delimiter: Delimiter) -> bool {
+    cursor.group(delimiter).is_some()
+}
+
+impl<F: Copy + FnOnce(TokenMarker) -> T, T: Token> Sealed for F {}
diff --git a/vendor/syn/src/mac.rs b/vendor/syn/src/mac.rs
new file mode 100644
index 0000000..8f687cc
--- /dev/null
+++ b/vendor/syn/src/mac.rs
@@ -0,0 +1,211 @@
+use super::*;
+use crate::token::{Brace, Bracket, Paren};
+use proc_macro2::extra::DelimSpan;
+#[cfg(any(feature = "parsing", feature = "printing"))]
+use proc_macro2::Delimiter;
+use proc_macro2::TokenStream;
+#[cfg(feature = "parsing")]
+use proc_macro2::TokenTree;
+
+#[cfg(feature = "parsing")]
+use crate::parse::{Parse, ParseStream, Parser, Result};
+
+ast_struct! {
+    /// A macro invocation: `println!("{}", mac)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Macro {
+        pub path: Path,
+        pub bang_token: Token![!],
+        pub delimiter: MacroDelimiter,
+        pub tokens: TokenStream,
+    }
+}
+
+ast_enum! {
+    /// A grouping token that surrounds a macro body: `m!(...)` or `m!{...}` or `m![...]`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum MacroDelimiter {
+        Paren(Paren),
+        Brace(Brace),
+        Bracket(Bracket),
+    }
+}
+
+impl MacroDelimiter {
+    pub fn span(&self) -> &DelimSpan {
+        match self {
+            MacroDelimiter::Paren(token) => &token.span,
+            MacroDelimiter::Brace(token) => &token.span,
+            MacroDelimiter::Bracket(token) => &token.span,
+        }
+    }
+}
+
+impl Macro {
+    /// Parse the tokens within the macro invocation's delimiters into a syntax
+    /// tree.
+    ///
+    /// This is equivalent to `syn::parse2::<T>(mac.tokens)` except that it
+    /// produces a more useful span when `tokens` is empty.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{parse_quote, Expr, ExprLit, Ident, Lit, LitStr, Macro, Token};
+    /// use syn::ext::IdentExt;
+    /// use syn::parse::{Error, Parse, ParseStream, Result};
+    /// use syn::punctuated::Punctuated;
+    ///
+    /// // The arguments expected by libcore's format_args macro, and as a
+    /// // result most other formatting and printing macros like println.
+    /// //
+    /// //     println!("{} is {number:.prec$}", "x", prec=5, number=0.01)
+    /// struct FormatArgs {
+    ///     format_string: Expr,
+    ///     positional_args: Vec<Expr>,
+    ///     named_args: Vec<(Ident, Expr)>,
+    /// }
+    ///
+    /// impl Parse for FormatArgs {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let format_string: Expr;
+    ///         let mut positional_args = Vec::new();
+    ///         let mut named_args = Vec::new();
+    ///
+    ///         format_string = input.parse()?;
+    ///         while !input.is_empty() {
+    ///             input.parse::<Token![,]>()?;
+    ///             if input.is_empty() {
+    ///                 break;
+    ///             }
+    ///             if input.peek(Ident::peek_any) && input.peek2(Token![=]) {
+    ///                 while !input.is_empty() {
+    ///                     let name: Ident = input.call(Ident::parse_any)?;
+    ///                     input.parse::<Token![=]>()?;
+    ///                     let value: Expr = input.parse()?;
+    ///                     named_args.push((name, value));
+    ///                     if input.is_empty() {
+    ///                         break;
+    ///                     }
+    ///                     input.parse::<Token![,]>()?;
+    ///                 }
+    ///                 break;
+    ///             }
+    ///             positional_args.push(input.parse()?);
+    ///         }
+    ///
+    ///         Ok(FormatArgs {
+    ///             format_string,
+    ///             positional_args,
+    ///             named_args,
+    ///         })
+    ///     }
+    /// }
+    ///
+    /// // Extract the first argument, the format string literal, from an
+    /// // invocation of a formatting or printing macro.
+    /// fn get_format_string(m: &Macro) -> Result<LitStr> {
+    ///     let args: FormatArgs = m.parse_body()?;
+    ///     match args.format_string {
+    ///         Expr::Lit(ExprLit { lit: Lit::Str(lit), .. }) => Ok(lit),
+    ///         other => {
+    ///             // First argument was not a string literal expression.
+    ///             // Maybe something like: println!(concat!(...), ...)
+    ///             Err(Error::new_spanned(other, "format string must be a string literal"))
+    ///         }
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let invocation = parse_quote! {
+    ///         println!("{:?}", Instant::now())
+    ///     };
+    ///     let lit = get_format_string(&invocation).unwrap();
+    ///     assert_eq!(lit.value(), "{:?}");
+    /// }
+    /// ```
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_body<T: Parse>(&self) -> Result<T> {
+        self.parse_body_with(T::parse)
+    }
+
+    /// Parse the tokens within the macro invocation's delimiters using the
+    /// given parser.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_body_with<F: Parser>(&self, parser: F) -> Result<F::Output> {
+        let scope = self.delimiter.span().close();
+        crate::parse::parse_scoped(parser, scope, self.tokens.clone())
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) fn parse_delimiter(input: ParseStream) -> Result<(MacroDelimiter, TokenStream)> {
+    input.step(|cursor| {
+        if let Some((TokenTree::Group(g), rest)) = cursor.token_tree() {
+            let span = g.delim_span();
+            let delimiter = match g.delimiter() {
+                Delimiter::Parenthesis => MacroDelimiter::Paren(Paren(span)),
+                Delimiter::Brace => MacroDelimiter::Brace(Brace(span)),
+                Delimiter::Bracket => MacroDelimiter::Bracket(Bracket(span)),
+                Delimiter::None => {
+                    return Err(cursor.error("expected delimiter"));
+                }
+            };
+            Ok(((delimiter, g.stream()), rest))
+        } else {
+            Err(cursor.error("expected delimiter"))
+        }
+    })
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Macro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let tokens;
+            Ok(Macro {
+                path: input.call(Path::parse_mod_style)?,
+                bang_token: input.parse()?,
+                delimiter: {
+                    let (delimiter, content) = parse_delimiter(input)?;
+                    tokens = content;
+                    delimiter
+                },
+                tokens,
+            })
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+
+    impl MacroDelimiter {
+        pub(crate) fn surround(&self, tokens: &mut TokenStream, inner: TokenStream) {
+            let (delim, span) = match self {
+                MacroDelimiter::Paren(paren) => (Delimiter::Parenthesis, paren.span),
+                MacroDelimiter::Brace(brace) => (Delimiter::Brace, brace.span),
+                MacroDelimiter::Bracket(bracket) => (Delimiter::Bracket, bracket.span),
+            };
+            token::printing::delim(delim, span.join(), tokens, inner);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Macro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.path.to_tokens(tokens);
+            self.bang_token.to_tokens(tokens);
+            self.delimiter.surround(tokens, self.tokens.clone());
+        }
+    }
+}
diff --git a/vendor/syn/src/macros.rs b/vendor/syn/src/macros.rs
new file mode 100644
index 0000000..06ceb54
--- /dev/null
+++ b/vendor/syn/src/macros.rs
@@ -0,0 +1,185 @@
+#[cfg_attr(
+    not(any(feature = "full", feature = "derive")),
+    allow(unknown_lints, unused_macro_rules)
+)]
+macro_rules! ast_struct {
+    (
+        [$($attrs_pub:tt)*]
+        struct $name:ident #full $($rest:tt)*
+    ) => {
+        #[cfg(feature = "full")]
+        $($attrs_pub)* struct $name $($rest)*
+
+        #[cfg(not(feature = "full"))]
+        $($attrs_pub)* struct $name {
+            _noconstruct: ::std::marker::PhantomData<::proc_macro2::Span>,
+        }
+
+        #[cfg(all(not(feature = "full"), feature = "printing"))]
+        impl ::quote::ToTokens for $name {
+            fn to_tokens(&self, _: &mut ::proc_macro2::TokenStream) {
+                unreachable!()
+            }
+        }
+    };
+
+    (
+        [$($attrs_pub:tt)*]
+        struct $name:ident $($rest:tt)*
+    ) => {
+        $($attrs_pub)* struct $name $($rest)*
+    };
+
+    ($($t:tt)*) => {
+        strip_attrs_pub!(ast_struct!($($t)*));
+    };
+}
+
+macro_rules! ast_enum {
+    // Drop the `#no_visit` attribute, if present.
+    (
+        [$($attrs_pub:tt)*]
+        enum $name:ident #no_visit $($rest:tt)*
+    ) => (
+        ast_enum!([$($attrs_pub)*] enum $name $($rest)*);
+    );
+
+    (
+        [$($attrs_pub:tt)*]
+        enum $name:ident $($rest:tt)*
+    ) => (
+        $($attrs_pub)* enum $name $($rest)*
+    );
+
+    ($($t:tt)*) => {
+        strip_attrs_pub!(ast_enum!($($t)*));
+    };
+}
+
+macro_rules! ast_enum_of_structs {
+    (
+        $(#[$enum_attr:meta])*
+        $pub:ident $enum:ident $name:ident $body:tt
+        $($remaining:tt)*
+    ) => {
+        ast_enum!($(#[$enum_attr])* $pub $enum $name $body);
+        ast_enum_of_structs_impl!($pub $enum $name $body $($remaining)*);
+    };
+}
+
+macro_rules! ast_enum_of_structs_impl {
+    (
+        $pub:ident $enum:ident $name:ident {
+            $(
+                $(#[cfg $cfg_attr:tt])*
+                $(#[doc $($doc_attr:tt)*])*
+                $variant:ident $( ($($member:ident)::+) )*,
+            )*
+        }
+    ) => {
+        check_keyword_matches!(pub $pub);
+        check_keyword_matches!(enum $enum);
+
+        $($(
+            ast_enum_from_struct!($name::$variant, $($member)::+);
+        )*)*
+
+        #[cfg(feature = "printing")]
+        generate_to_tokens! {
+            ()
+            tokens
+            $name {
+                $(
+                    $(#[cfg $cfg_attr])*
+                    $(#[doc $($doc_attr)*])*
+                    $variant $($($member)::+)*,
+                )*
+            }
+        }
+    };
+}
+
+macro_rules! ast_enum_from_struct {
+    // No From<TokenStream> for verbatim variants.
+    ($name:ident::Verbatim, $member:ident) => {};
+
+    ($name:ident::$variant:ident, $member:ident) => {
+        impl From<$member> for $name {
+            fn from(e: $member) -> $name {
+                $name::$variant(e)
+            }
+        }
+    };
+}
+
+#[cfg(feature = "printing")]
+macro_rules! generate_to_tokens {
+    (
+        ($($arms:tt)*) $tokens:ident $name:ident {
+            $(#[cfg $cfg_attr:tt])*
+            $(#[doc $($doc_attr:tt)*])*
+            $variant:ident,
+            $($next:tt)*
+        }
+    ) => {
+        generate_to_tokens!(
+            ($($arms)* $(#[cfg $cfg_attr])* $name::$variant => {})
+            $tokens $name { $($next)* }
+        );
+    };
+
+    (
+        ($($arms:tt)*) $tokens:ident $name:ident {
+            $(#[cfg $cfg_attr:tt])*
+            $(#[doc $($doc_attr:tt)*])*
+            $variant:ident $member:ident,
+            $($next:tt)*
+        }
+    ) => {
+        generate_to_tokens!(
+            ($($arms)* $(#[cfg $cfg_attr])* $name::$variant(_e) => _e.to_tokens($tokens),)
+            $tokens $name { $($next)* }
+        );
+    };
+
+    (($($arms:tt)*) $tokens:ident $name:ident {}) => {
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+        impl ::quote::ToTokens for $name {
+            fn to_tokens(&self, $tokens: &mut ::proc_macro2::TokenStream) {
+                match self {
+                    $($arms)*
+                }
+            }
+        }
+    };
+}
+
+macro_rules! strip_attrs_pub {
+    ($mac:ident!($(#[$m:meta])* $pub:ident $($t:tt)*)) => {
+        check_keyword_matches!(pub $pub);
+
+        $mac!([$(#[$m])* $pub] $($t)*);
+    };
+}
+
+macro_rules! check_keyword_matches {
+    (enum enum) => {};
+    (pub pub) => {};
+}
+
+// Rustdoc bug: does not respect the doc(hidden) on some items.
+#[cfg(all(doc, feature = "parsing"))]
+macro_rules! pub_if_not_doc {
+    ($(#[$m:meta])* pub $($item:tt)*) => {
+        $(#[$m])*
+        pub(crate) $($item)*
+    };
+}
+
+#[cfg(all(not(doc), feature = "parsing"))]
+macro_rules! pub_if_not_doc {
+    ($(#[$m:meta])* pub $($item:tt)*) => {
+        $(#[$m])*
+        pub $($item)*
+    };
+}
diff --git a/vendor/syn/src/meta.rs b/vendor/syn/src/meta.rs
new file mode 100644
index 0000000..f17b280
--- /dev/null
+++ b/vendor/syn/src/meta.rs
@@ -0,0 +1,426 @@
+//! Facility for interpreting structured content inside of an `Attribute`.
+
+use crate::ext::IdentExt;
+use crate::lit::Lit;
+use crate::parse::{Error, ParseStream, Parser, Result};
+use crate::path::{Path, PathSegment};
+use crate::punctuated::Punctuated;
+use proc_macro2::Ident;
+use std::fmt::Display;
+
+/// Make a parser that is usable with `parse_macro_input!` in a
+/// `#[proc_macro_attribute]` macro.
+///
+/// *Warning:* When parsing attribute args **other than** the
+/// `proc_macro::TokenStream` input of a `proc_macro_attribute`, you do **not**
+/// need this function. In several cases your callers will get worse error
+/// messages if you use this function, because the surrounding delimiter's span
+/// is concealed from attribute macros by rustc. Use
+/// [`Attribute::parse_nested_meta`] instead.
+///
+/// [`Attribute::parse_nested_meta`]: crate::Attribute::parse_nested_meta
+///
+/// # Example
+///
+/// This example implements an attribute macro whose invocations look like this:
+///
+/// ```
+/// # const IGNORE: &str = stringify! {
+/// #[tea(kind = "EarlGrey", hot)]
+/// struct Picard {...}
+/// # };
+/// ```
+///
+/// The "parameters" supported by the attribute are:
+///
+/// - `kind = "..."`
+/// - `hot`
+/// - `with(sugar, milk, ...)`, a comma-separated list of ingredients
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use syn::{parse_macro_input, LitStr, Path};
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro_attribute]
+/// # };
+/// pub fn tea(args: TokenStream, input: TokenStream) -> TokenStream {
+///     let mut kind: Option<LitStr> = None;
+///     let mut hot: bool = false;
+///     let mut with: Vec<Path> = Vec::new();
+///     let tea_parser = syn::meta::parser(|meta| {
+///         if meta.path.is_ident("kind") {
+///             kind = Some(meta.value()?.parse()?);
+///             Ok(())
+///         } else if meta.path.is_ident("hot") {
+///             hot = true;
+///             Ok(())
+///         } else if meta.path.is_ident("with") {
+///             meta.parse_nested_meta(|meta| {
+///                 with.push(meta.path);
+///                 Ok(())
+///             })
+///         } else {
+///             Err(meta.error("unsupported tea property"))
+///         }
+///     });
+///
+///     parse_macro_input!(args with tea_parser);
+///     eprintln!("kind={kind:?} hot={hot} with={with:?}");
+///
+///     /* ... */
+/// #   TokenStream::new()
+/// }
+/// ```
+///
+/// The `syn::meta` library will take care of dealing with the commas including
+/// trailing commas, and producing sensible error messages on unexpected input.
+///
+/// ```console
+/// error: expected `,`
+///  --> src/main.rs:3:37
+///   |
+/// 3 | #[tea(kind = "EarlGrey", with(sugar = "lol", milk))]
+///   |                                     ^
+/// ```
+///
+/// # Example
+///
+/// Same as above but we factor out most of the logic into a separate function.
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use syn::meta::ParseNestedMeta;
+/// use syn::parse::{Parser, Result};
+/// use syn::{parse_macro_input, LitStr, Path};
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro_attribute]
+/// # };
+/// pub fn tea(args: TokenStream, input: TokenStream) -> TokenStream {
+///     let mut attrs = TeaAttributes::default();
+///     let tea_parser = syn::meta::parser(|meta| attrs.parse(meta));
+///     parse_macro_input!(args with tea_parser);
+///
+///     /* ... */
+/// #   TokenStream::new()
+/// }
+///
+/// #[derive(Default)]
+/// struct TeaAttributes {
+///     kind: Option<LitStr>,
+///     hot: bool,
+///     with: Vec<Path>,
+/// }
+///
+/// impl TeaAttributes {
+///     fn parse(&mut self, meta: ParseNestedMeta) -> Result<()> {
+///         if meta.path.is_ident("kind") {
+///             self.kind = Some(meta.value()?.parse()?);
+///             Ok(())
+///         } else /* just like in last example */
+/// #           { unimplemented!() }
+///
+///     }
+/// }
+/// ```
+pub fn parser(logic: impl FnMut(ParseNestedMeta) -> Result<()>) -> impl Parser<Output = ()> {
+    |input: ParseStream| {
+        if input.is_empty() {
+            Ok(())
+        } else {
+            parse_nested_meta(input, logic)
+        }
+    }
+}
+
+/// Context for parsing a single property in the conventional syntax for
+/// structured attributes.
+///
+/// # Examples
+///
+/// Refer to usage examples on the following two entry-points:
+///
+/// - [`Attribute::parse_nested_meta`] if you have an entire `Attribute` to
+///   parse. Always use this if possible. Generally this is able to produce
+///   better error messages because `Attribute` holds span information for all
+///   of the delimiters therein.
+///
+/// - [`syn::meta::parser`] if you are implementing a `proc_macro_attribute`
+///   macro and parsing the arguments to the attribute macro, i.e. the ones
+///   written in the same attribute that dispatched the macro invocation. Rustc
+///   does not pass span information for the surrounding delimiters into the
+///   attribute macro invocation in this situation, so error messages might be
+///   less precise.
+///
+/// [`Attribute::parse_nested_meta`]: crate::Attribute::parse_nested_meta
+/// [`syn::meta::parser`]: crate::meta::parser
+#[non_exhaustive]
+pub struct ParseNestedMeta<'a> {
+    pub path: Path,
+    pub input: ParseStream<'a>,
+}
+
+impl<'a> ParseNestedMeta<'a> {
+    /// Used when parsing `key = "value"` syntax.
+    ///
+    /// All it does is advance `meta.input` past the `=` sign in the input. You
+    /// could accomplish the same effect by writing
+    /// `meta.parse::<Token![=]>()?`, so at most it is a minor convenience to
+    /// use `meta.value()?`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{parse_quote, Attribute, LitStr};
+    ///
+    /// let attr: Attribute = parse_quote! {
+    ///     #[tea(kind = "EarlGrey")]
+    /// };
+    ///                                          // conceptually:
+    /// if attr.path().is_ident("tea") {         // this parses the `tea`
+    ///     attr.parse_nested_meta(|meta| {      // this parses the `(`
+    ///         if meta.path.is_ident("kind") {  // this parses the `kind`
+    ///             let value = meta.value()?;   // this parses the `=`
+    ///             let s: LitStr = value.parse()?;  // this parses `"EarlGrey"`
+    ///             if s.value() == "EarlGrey" {
+    ///                 // ...
+    ///             }
+    ///             Ok(())
+    ///         } else {
+    ///             Err(meta.error("unsupported attribute"))
+    ///         }
+    ///     })?;
+    /// }
+    /// # anyhow::Ok(())
+    /// ```
+    pub fn value(&self) -> Result<ParseStream<'a>> {
+        self.input.parse::<Token![=]>()?;
+        Ok(self.input)
+    }
+
+    /// Used when parsing `list(...)` syntax **if** the content inside the
+    /// nested parentheses is also expected to conform to Rust's structured
+    /// attribute convention.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{parse_quote, Attribute};
+    ///
+    /// let attr: Attribute = parse_quote! {
+    ///     #[tea(with(sugar, milk))]
+    /// };
+    ///
+    /// if attr.path().is_ident("tea") {
+    ///     attr.parse_nested_meta(|meta| {
+    ///         if meta.path.is_ident("with") {
+    ///             meta.parse_nested_meta(|meta| {  // <---
+    ///                 if meta.path.is_ident("sugar") {
+    ///                     // Here we can go even deeper if needed.
+    ///                     Ok(())
+    ///                 } else if meta.path.is_ident("milk") {
+    ///                     Ok(())
+    ///                 } else {
+    ///                     Err(meta.error("unsupported ingredient"))
+    ///                 }
+    ///             })
+    ///         } else {
+    ///             Err(meta.error("unsupported tea property"))
+    ///         }
+    ///     })?;
+    /// }
+    /// # anyhow::Ok(())
+    /// ```
+    ///
+    /// # Counterexample
+    ///
+    /// If you don't need `parse_nested_meta`'s help in parsing the content
+    /// written within the nested parentheses, keep in mind that you can always
+    /// just parse it yourself from the exposed ParseStream. Rust syntax permits
+    /// arbitrary tokens within those parentheses so for the crazier stuff,
+    /// `parse_nested_meta` is not what you want.
+    ///
+    /// ```
+    /// use syn::{parenthesized, parse_quote, Attribute, LitInt};
+    ///
+    /// let attr: Attribute = parse_quote! {
+    ///     #[repr(align(32))]
+    /// };
+    ///
+    /// let mut align: Option<LitInt> = None;
+    /// if attr.path().is_ident("repr") {
+    ///     attr.parse_nested_meta(|meta| {
+    ///         if meta.path.is_ident("align") {
+    ///             let content;
+    ///             parenthesized!(content in meta.input);
+    ///             align = Some(content.parse()?);
+    ///             Ok(())
+    ///         } else {
+    ///             Err(meta.error("unsupported repr"))
+    ///         }
+    ///     })?;
+    /// }
+    /// # anyhow::Ok(())
+    /// ```
+    pub fn parse_nested_meta(
+        &self,
+        logic: impl FnMut(ParseNestedMeta) -> Result<()>,
+    ) -> Result<()> {
+        let content;
+        parenthesized!(content in self.input);
+        parse_nested_meta(&content, logic)
+    }
+
+    /// Report that the attribute's content did not conform to expectations.
+    ///
+    /// The span of the resulting error will cover `meta.path` *and* everything
+    /// that has been parsed so far since it.
+    ///
+    /// There are 2 ways you might call this. First, if `meta.path` is not
+    /// something you recognize:
+    ///
+    /// ```
+    /// # use syn::Attribute;
+    /// #
+    /// # fn example(attr: &Attribute) -> syn::Result<()> {
+    /// attr.parse_nested_meta(|meta| {
+    ///     if meta.path.is_ident("kind") {
+    ///         // ...
+    ///         Ok(())
+    ///     } else {
+    ///         Err(meta.error("unsupported tea property"))
+    ///     }
+    /// })?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// In this case, it behaves exactly like
+    /// `syn::Error::new_spanned(&meta.path, "message...")`.
+    ///
+    /// ```console
+    /// error: unsupported tea property
+    ///  --> src/main.rs:3:26
+    ///   |
+    /// 3 | #[tea(kind = "EarlGrey", wat = "foo")]
+    ///   |                          ^^^
+    /// ```
+    ///
+    /// More usefully, the second place is if you've already parsed a value but
+    /// have decided not to accept the value:
+    ///
+    /// ```
+    /// # use syn::Attribute;
+    /// #
+    /// # fn example(attr: &Attribute) -> syn::Result<()> {
+    /// use syn::Expr;
+    ///
+    /// attr.parse_nested_meta(|meta| {
+    ///     if meta.path.is_ident("kind") {
+    ///         let expr: Expr = meta.value()?.parse()?;
+    ///         match expr {
+    ///             Expr::Lit(expr) => /* ... */
+    /// #               unimplemented!(),
+    ///             Expr::Path(expr) => /* ... */
+    /// #               unimplemented!(),
+    ///             Expr::Macro(expr) => /* ... */
+    /// #               unimplemented!(),
+    ///             _ => Err(meta.error("tea kind must be a string literal, path, or macro")),
+    ///         }
+    ///     } else /* as above */
+    /// #       { unimplemented!() }
+    ///
+    /// })?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// ```console
+    /// error: tea kind must be a string literal, path, or macro
+    ///  --> src/main.rs:3:7
+    ///   |
+    /// 3 | #[tea(kind = async { replicator.await })]
+    ///   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+    /// ```
+    ///
+    /// Often you may want to use `syn::Error::new_spanned` even in this
+    /// situation. In the above code, that would be:
+    ///
+    /// ```
+    /// # use syn::{Error, Expr};
+    /// #
+    /// # fn example(expr: Expr) -> syn::Result<()> {
+    ///     match expr {
+    ///         Expr::Lit(expr) => /* ... */
+    /// #           unimplemented!(),
+    ///         Expr::Path(expr) => /* ... */
+    /// #           unimplemented!(),
+    ///         Expr::Macro(expr) => /* ... */
+    /// #           unimplemented!(),
+    ///         _ => Err(Error::new_spanned(expr, "unsupported expression type for `kind`")),
+    ///     }
+    /// # }
+    /// ```
+    ///
+    /// ```console
+    /// error: unsupported expression type for `kind`
+    ///  --> src/main.rs:3:14
+    ///   |
+    /// 3 | #[tea(kind = async { replicator.await })]
+    ///   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+    /// ```
+    pub fn error(&self, msg: impl Display) -> Error {
+        let start_span = self.path.segments[0].ident.span();
+        let end_span = self.input.cursor().prev_span();
+        crate::error::new2(start_span, end_span, msg)
+    }
+}
+
+pub(crate) fn parse_nested_meta(
+    input: ParseStream,
+    mut logic: impl FnMut(ParseNestedMeta) -> Result<()>,
+) -> Result<()> {
+    loop {
+        let path = input.call(parse_meta_path)?;
+        logic(ParseNestedMeta { path, input })?;
+        if input.is_empty() {
+            return Ok(());
+        }
+        input.parse::<Token![,]>()?;
+        if input.is_empty() {
+            return Ok(());
+        }
+    }
+}
+
+// Like Path::parse_mod_style, but accepts keywords in the path.
+fn parse_meta_path(input: ParseStream) -> Result<Path> {
+    Ok(Path {
+        leading_colon: input.parse()?,
+        segments: {
+            let mut segments = Punctuated::new();
+            if input.peek(Ident::peek_any) {
+                let ident = Ident::parse_any(input)?;
+                segments.push_value(PathSegment::from(ident));
+            } else if input.is_empty() {
+                return Err(input.error("expected nested attribute"));
+            } else if input.peek(Lit) {
+                return Err(input.error("unexpected literal in nested attribute, expected ident"));
+            } else {
+                return Err(input.error("unexpected token in nested attribute, expected ident"));
+            }
+            while input.peek(Token![::]) {
+                let punct = input.parse()?;
+                segments.push_punct(punct);
+                let ident = Ident::parse_any(input)?;
+                segments.push_value(PathSegment::from(ident));
+            }
+            segments
+        },
+    })
+}
diff --git a/vendor/syn/src/op.rs b/vendor/syn/src/op.rs
new file mode 100644
index 0000000..bff72c8
--- /dev/null
+++ b/vendor/syn/src/op.rs
@@ -0,0 +1,230 @@
+ast_enum! {
+    /// A binary operator: `+`, `+=`, `&`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum BinOp {
+        /// The `+` operator (addition)
+        Add(Token![+]),
+        /// The `-` operator (subtraction)
+        Sub(Token![-]),
+        /// The `*` operator (multiplication)
+        Mul(Token![*]),
+        /// The `/` operator (division)
+        Div(Token![/]),
+        /// The `%` operator (modulus)
+        Rem(Token![%]),
+        /// The `&&` operator (logical and)
+        And(Token![&&]),
+        /// The `||` operator (logical or)
+        Or(Token![||]),
+        /// The `^` operator (bitwise xor)
+        BitXor(Token![^]),
+        /// The `&` operator (bitwise and)
+        BitAnd(Token![&]),
+        /// The `|` operator (bitwise or)
+        BitOr(Token![|]),
+        /// The `<<` operator (shift left)
+        Shl(Token![<<]),
+        /// The `>>` operator (shift right)
+        Shr(Token![>>]),
+        /// The `==` operator (equality)
+        Eq(Token![==]),
+        /// The `<` operator (less than)
+        Lt(Token![<]),
+        /// The `<=` operator (less than or equal to)
+        Le(Token![<=]),
+        /// The `!=` operator (not equal to)
+        Ne(Token![!=]),
+        /// The `>=` operator (greater than or equal to)
+        Ge(Token![>=]),
+        /// The `>` operator (greater than)
+        Gt(Token![>]),
+        /// The `+=` operator
+        AddAssign(Token![+=]),
+        /// The `-=` operator
+        SubAssign(Token![-=]),
+        /// The `*=` operator
+        MulAssign(Token![*=]),
+        /// The `/=` operator
+        DivAssign(Token![/=]),
+        /// The `%=` operator
+        RemAssign(Token![%=]),
+        /// The `^=` operator
+        BitXorAssign(Token![^=]),
+        /// The `&=` operator
+        BitAndAssign(Token![&=]),
+        /// The `|=` operator
+        BitOrAssign(Token![|=]),
+        /// The `<<=` operator
+        ShlAssign(Token![<<=]),
+        /// The `>>=` operator
+        ShrAssign(Token![>>=]),
+    }
+}
+
+ast_enum! {
+    /// A unary operator: `*`, `!`, `-`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum UnOp {
+        /// The `*` operator for dereferencing
+        Deref(Token![*]),
+        /// The `!` operator for logical inversion
+        Not(Token![!]),
+        /// The `-` operator for negation
+        Neg(Token![-]),
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    fn parse_binop(input: ParseStream) -> Result<BinOp> {
+        if input.peek(Token![&&]) {
+            input.parse().map(BinOp::And)
+        } else if input.peek(Token![||]) {
+            input.parse().map(BinOp::Or)
+        } else if input.peek(Token![<<]) {
+            input.parse().map(BinOp::Shl)
+        } else if input.peek(Token![>>]) {
+            input.parse().map(BinOp::Shr)
+        } else if input.peek(Token![==]) {
+            input.parse().map(BinOp::Eq)
+        } else if input.peek(Token![<=]) {
+            input.parse().map(BinOp::Le)
+        } else if input.peek(Token![!=]) {
+            input.parse().map(BinOp::Ne)
+        } else if input.peek(Token![>=]) {
+            input.parse().map(BinOp::Ge)
+        } else if input.peek(Token![+]) {
+            input.parse().map(BinOp::Add)
+        } else if input.peek(Token![-]) {
+            input.parse().map(BinOp::Sub)
+        } else if input.peek(Token![*]) {
+            input.parse().map(BinOp::Mul)
+        } else if input.peek(Token![/]) {
+            input.parse().map(BinOp::Div)
+        } else if input.peek(Token![%]) {
+            input.parse().map(BinOp::Rem)
+        } else if input.peek(Token![^]) {
+            input.parse().map(BinOp::BitXor)
+        } else if input.peek(Token![&]) {
+            input.parse().map(BinOp::BitAnd)
+        } else if input.peek(Token![|]) {
+            input.parse().map(BinOp::BitOr)
+        } else if input.peek(Token![<]) {
+            input.parse().map(BinOp::Lt)
+        } else if input.peek(Token![>]) {
+            input.parse().map(BinOp::Gt)
+        } else {
+            Err(input.error("expected binary operator"))
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for BinOp {
+        #[cfg(not(feature = "full"))]
+        fn parse(input: ParseStream) -> Result<Self> {
+            parse_binop(input)
+        }
+
+        #[cfg(feature = "full")]
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Token![+=]) {
+                input.parse().map(BinOp::AddAssign)
+            } else if input.peek(Token![-=]) {
+                input.parse().map(BinOp::SubAssign)
+            } else if input.peek(Token![*=]) {
+                input.parse().map(BinOp::MulAssign)
+            } else if input.peek(Token![/=]) {
+                input.parse().map(BinOp::DivAssign)
+            } else if input.peek(Token![%=]) {
+                input.parse().map(BinOp::RemAssign)
+            } else if input.peek(Token![^=]) {
+                input.parse().map(BinOp::BitXorAssign)
+            } else if input.peek(Token![&=]) {
+                input.parse().map(BinOp::BitAndAssign)
+            } else if input.peek(Token![|=]) {
+                input.parse().map(BinOp::BitOrAssign)
+            } else if input.peek(Token![<<=]) {
+                input.parse().map(BinOp::ShlAssign)
+            } else if input.peek(Token![>>=]) {
+                input.parse().map(BinOp::ShrAssign)
+            } else {
+                parse_binop(input)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for UnOp {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Token![*]) {
+                input.parse().map(UnOp::Deref)
+            } else if lookahead.peek(Token![!]) {
+                input.parse().map(UnOp::Not)
+            } else if lookahead.peek(Token![-]) {
+                input.parse().map(UnOp::Neg)
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for BinOp {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                BinOp::Add(t) => t.to_tokens(tokens),
+                BinOp::Sub(t) => t.to_tokens(tokens),
+                BinOp::Mul(t) => t.to_tokens(tokens),
+                BinOp::Div(t) => t.to_tokens(tokens),
+                BinOp::Rem(t) => t.to_tokens(tokens),
+                BinOp::And(t) => t.to_tokens(tokens),
+                BinOp::Or(t) => t.to_tokens(tokens),
+                BinOp::BitXor(t) => t.to_tokens(tokens),
+                BinOp::BitAnd(t) => t.to_tokens(tokens),
+                BinOp::BitOr(t) => t.to_tokens(tokens),
+                BinOp::Shl(t) => t.to_tokens(tokens),
+                BinOp::Shr(t) => t.to_tokens(tokens),
+                BinOp::Eq(t) => t.to_tokens(tokens),
+                BinOp::Lt(t) => t.to_tokens(tokens),
+                BinOp::Le(t) => t.to_tokens(tokens),
+                BinOp::Ne(t) => t.to_tokens(tokens),
+                BinOp::Ge(t) => t.to_tokens(tokens),
+                BinOp::Gt(t) => t.to_tokens(tokens),
+                BinOp::AddAssign(t) => t.to_tokens(tokens),
+                BinOp::SubAssign(t) => t.to_tokens(tokens),
+                BinOp::MulAssign(t) => t.to_tokens(tokens),
+                BinOp::DivAssign(t) => t.to_tokens(tokens),
+                BinOp::RemAssign(t) => t.to_tokens(tokens),
+                BinOp::BitXorAssign(t) => t.to_tokens(tokens),
+                BinOp::BitAndAssign(t) => t.to_tokens(tokens),
+                BinOp::BitOrAssign(t) => t.to_tokens(tokens),
+                BinOp::ShlAssign(t) => t.to_tokens(tokens),
+                BinOp::ShrAssign(t) => t.to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for UnOp {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                UnOp::Deref(t) => t.to_tokens(tokens),
+                UnOp::Not(t) => t.to_tokens(tokens),
+                UnOp::Neg(t) => t.to_tokens(tokens),
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/parse.rs b/vendor/syn/src/parse.rs
new file mode 100644
index 0000000..5a2aeb6
--- /dev/null
+++ b/vendor/syn/src/parse.rs
@@ -0,0 +1,1334 @@
+//! Parsing interface for parsing a token stream into a syntax tree node.
+//!
+//! Parsing in Syn is built on parser functions that take in a [`ParseStream`]
+//! and produce a [`Result<T>`] where `T` is some syntax tree node. Underlying
+//! these parser functions is a lower level mechanism built around the
+//! [`Cursor`] type. `Cursor` is a cheaply copyable cursor over a range of
+//! tokens in a token stream.
+//!
+//! [`Result<T>`]: Result
+//! [`Cursor`]: crate::buffer::Cursor
+//!
+//! # Example
+//!
+//! Here is a snippet of parsing code to get a feel for the style of the
+//! library. We define data structures for a subset of Rust syntax including
+//! enums (not shown) and structs, then provide implementations of the [`Parse`]
+//! trait to parse these syntax tree data structures from a token stream.
+//!
+//! Once `Parse` impls have been defined, they can be called conveniently from a
+//! procedural macro through [`parse_macro_input!`] as shown at the bottom of
+//! the snippet. If the caller provides syntactically invalid input to the
+//! procedural macro, they will receive a helpful compiler error message
+//! pointing out the exact token that triggered the failure to parse.
+//!
+//! [`parse_macro_input!`]: crate::parse_macro_input!
+//!
+//! ```
+//! # extern crate proc_macro;
+//! #
+//! use proc_macro::TokenStream;
+//! use syn::{braced, parse_macro_input, token, Field, Ident, Result, Token};
+//! use syn::parse::{Parse, ParseStream};
+//! use syn::punctuated::Punctuated;
+//!
+//! enum Item {
+//!     Struct(ItemStruct),
+//!     Enum(ItemEnum),
+//! }
+//!
+//! struct ItemStruct {
+//!     struct_token: Token![struct],
+//!     ident: Ident,
+//!     brace_token: token::Brace,
+//!     fields: Punctuated<Field, Token![,]>,
+//! }
+//! #
+//! # enum ItemEnum {}
+//!
+//! impl Parse for Item {
+//!     fn parse(input: ParseStream) -> Result<Self> {
+//!         let lookahead = input.lookahead1();
+//!         if lookahead.peek(Token![struct]) {
+//!             input.parse().map(Item::Struct)
+//!         } else if lookahead.peek(Token![enum]) {
+//!             input.parse().map(Item::Enum)
+//!         } else {
+//!             Err(lookahead.error())
+//!         }
+//!     }
+//! }
+//!
+//! impl Parse for ItemStruct {
+//!     fn parse(input: ParseStream) -> Result<Self> {
+//!         let content;
+//!         Ok(ItemStruct {
+//!             struct_token: input.parse()?,
+//!             ident: input.parse()?,
+//!             brace_token: braced!(content in input),
+//!             fields: content.parse_terminated(Field::parse_named, Token![,])?,
+//!         })
+//!     }
+//! }
+//! #
+//! # impl Parse for ItemEnum {
+//! #     fn parse(input: ParseStream) -> Result<Self> {
+//! #         unimplemented!()
+//! #     }
+//! # }
+//!
+//! # const IGNORE: &str = stringify! {
+//! #[proc_macro]
+//! # };
+//! pub fn my_macro(tokens: TokenStream) -> TokenStream {
+//!     let input = parse_macro_input!(tokens as Item);
+//!
+//!     /* ... */
+//! #   TokenStream::new()
+//! }
+//! ```
+//!
+//! # The `syn::parse*` functions
+//!
+//! The [`syn::parse`], [`syn::parse2`], and [`syn::parse_str`] functions serve
+//! as an entry point for parsing syntax tree nodes that can be parsed in an
+//! obvious default way. These functions can return any syntax tree node that
+//! implements the [`Parse`] trait, which includes most types in Syn.
+//!
+//! [`syn::parse`]: crate::parse()
+//! [`syn::parse2`]: crate::parse2()
+//! [`syn::parse_str`]: crate::parse_str()
+//!
+//! ```
+//! use syn::Type;
+//!
+//! # fn run_parser() -> syn::Result<()> {
+//! let t: Type = syn::parse_str("std::collections::HashMap<String, Value>")?;
+//! #     Ok(())
+//! # }
+//! #
+//! # run_parser().unwrap();
+//! ```
+//!
+//! The [`parse_quote!`] macro also uses this approach.
+//!
+//! [`parse_quote!`]: crate::parse_quote!
+//!
+//! # The `Parser` trait
+//!
+//! Some types can be parsed in several ways depending on context. For example
+//! an [`Attribute`] can be either "outer" like `#[...]` or "inner" like
+//! `#![...]` and parsing the wrong one would be a bug. Similarly [`Punctuated`]
+//! may or may not allow trailing punctuation, and parsing it the wrong way
+//! would either reject valid input or accept invalid input.
+//!
+//! [`Attribute`]: crate::Attribute
+//! [`Punctuated`]: crate::punctuated
+//!
+//! The `Parse` trait is not implemented in these cases because there is no good
+//! behavior to consider the default.
+//!
+//! ```compile_fail
+//! # extern crate proc_macro;
+//! #
+//! # use syn::punctuated::Punctuated;
+//! # use syn::{PathSegment, Result, Token};
+//! #
+//! # fn f(tokens: proc_macro::TokenStream) -> Result<()> {
+//! #
+//! // Can't parse `Punctuated` without knowing whether trailing punctuation
+//! // should be allowed in this context.
+//! let path: Punctuated<PathSegment, Token![::]> = syn::parse(tokens)?;
+//! #
+//! #     Ok(())
+//! # }
+//! ```
+//!
+//! In these cases the types provide a choice of parser functions rather than a
+//! single `Parse` implementation, and those parser functions can be invoked
+//! through the [`Parser`] trait.
+//!
+//!
+//! ```
+//! # extern crate proc_macro;
+//! #
+//! use proc_macro::TokenStream;
+//! use syn::parse::Parser;
+//! use syn::punctuated::Punctuated;
+//! use syn::{Attribute, Expr, PathSegment, Result, Token};
+//!
+//! fn call_some_parser_methods(input: TokenStream) -> Result<()> {
+//!     // Parse a nonempty sequence of path segments separated by `::` punctuation
+//!     // with no trailing punctuation.
+//!     let tokens = input.clone();
+//!     let parser = Punctuated::<PathSegment, Token![::]>::parse_separated_nonempty;
+//!     let _path = parser.parse(tokens)?;
+//!
+//!     // Parse a possibly empty sequence of expressions terminated by commas with
+//!     // an optional trailing punctuation.
+//!     let tokens = input.clone();
+//!     let parser = Punctuated::<Expr, Token![,]>::parse_terminated;
+//!     let _args = parser.parse(tokens)?;
+//!
+//!     // Parse zero or more outer attributes but not inner attributes.
+//!     let tokens = input.clone();
+//!     let parser = Attribute::parse_outer;
+//!     let _attrs = parser.parse(tokens)?;
+//!
+//!     Ok(())
+//! }
+//! ```
+
+#[path = "discouraged.rs"]
+pub mod discouraged;
+
+use crate::buffer::{Cursor, TokenBuffer};
+use crate::error;
+use crate::lookahead;
+#[cfg(feature = "proc-macro")]
+use crate::proc_macro;
+use crate::punctuated::Punctuated;
+use crate::token::Token;
+use proc_macro2::{self, Delimiter, Group, Literal, Punct, Span, TokenStream, TokenTree};
+use std::cell::Cell;
+use std::fmt::{self, Debug, Display};
+#[cfg(feature = "extra-traits")]
+use std::hash::{Hash, Hasher};
+use std::marker::PhantomData;
+use std::mem;
+use std::ops::Deref;
+use std::rc::Rc;
+use std::str::FromStr;
+
+pub use crate::error::{Error, Result};
+pub use crate::lookahead::{Lookahead1, Peek};
+
+/// Parsing interface implemented by all types that can be parsed in a default
+/// way from a token stream.
+///
+/// Refer to the [module documentation] for details about implementing and using
+/// the `Parse` trait.
+///
+/// [module documentation]: self
+pub trait Parse: Sized {
+    fn parse(input: ParseStream) -> Result<Self>;
+}
+
+/// Input to a Syn parser function.
+///
+/// See the methods of this type under the documentation of [`ParseBuffer`]. For
+/// an overview of parsing in Syn, refer to the [module documentation].
+///
+/// [module documentation]: self
+pub type ParseStream<'a> = &'a ParseBuffer<'a>;
+
+/// Cursor position within a buffered token stream.
+///
+/// This type is more commonly used through the type alias [`ParseStream`] which
+/// is an alias for `&ParseBuffer`.
+///
+/// `ParseStream` is the input type for all parser functions in Syn. They have
+/// the signature `fn(ParseStream) -> Result<T>`.
+///
+/// ## Calling a parser function
+///
+/// There is no public way to construct a `ParseBuffer`. Instead, if you are
+/// looking to invoke a parser function that requires `ParseStream` as input,
+/// you will need to go through one of the public parsing entry points.
+///
+/// - The [`parse_macro_input!`] macro if parsing input of a procedural macro;
+/// - One of [the `syn::parse*` functions][syn-parse]; or
+/// - A method of the [`Parser`] trait.
+///
+/// [`parse_macro_input!`]: crate::parse_macro_input!
+/// [syn-parse]: self#the-synparse-functions
+pub struct ParseBuffer<'a> {
+    scope: Span,
+    // Instead of Cell<Cursor<'a>> so that ParseBuffer<'a> is covariant in 'a.
+    // The rest of the code in this module needs to be careful that only a
+    // cursor derived from this `cell` is ever assigned to this `cell`.
+    //
+    // Cell<Cursor<'a>> cannot be covariant in 'a because then we could take a
+    // ParseBuffer<'a>, upcast to ParseBuffer<'short> for some lifetime shorter
+    // than 'a, and then assign a Cursor<'short> into the Cell.
+    //
+    // By extension, it would not be safe to expose an API that accepts a
+    // Cursor<'a> and trusts that it lives as long as the cursor currently in
+    // the cell.
+    cell: Cell<Cursor<'static>>,
+    marker: PhantomData<Cursor<'a>>,
+    unexpected: Cell<Option<Rc<Cell<Unexpected>>>>,
+}
+
+impl<'a> Drop for ParseBuffer<'a> {
+    fn drop(&mut self) {
+        if let Some(unexpected_span) = span_of_unexpected_ignoring_nones(self.cursor()) {
+            let (inner, old_span) = inner_unexpected(self);
+            if old_span.is_none() {
+                inner.set(Unexpected::Some(unexpected_span));
+            }
+        }
+    }
+}
+
+impl<'a> Display for ParseBuffer<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.cursor().token_stream(), f)
+    }
+}
+
+impl<'a> Debug for ParseBuffer<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.cursor().token_stream(), f)
+    }
+}
+
+/// Cursor state associated with speculative parsing.
+///
+/// This type is the input of the closure provided to [`ParseStream::step`].
+///
+/// [`ParseStream::step`]: ParseBuffer::step
+///
+/// # Example
+///
+/// ```
+/// use proc_macro2::TokenTree;
+/// use syn::Result;
+/// use syn::parse::ParseStream;
+///
+/// // This function advances the stream past the next occurrence of `@`. If
+/// // no `@` is present in the stream, the stream position is unchanged and
+/// // an error is returned.
+/// fn skip_past_next_at(input: ParseStream) -> Result<()> {
+///     input.step(|cursor| {
+///         let mut rest = *cursor;
+///         while let Some((tt, next)) = rest.token_tree() {
+///             match &tt {
+///                 TokenTree::Punct(punct) if punct.as_char() == '@' => {
+///                     return Ok(((), next));
+///                 }
+///                 _ => rest = next,
+///             }
+///         }
+///         Err(cursor.error("no `@` was found after this point"))
+///     })
+/// }
+/// #
+/// # fn remainder_after_skipping_past_next_at(
+/// #     input: ParseStream,
+/// # ) -> Result<proc_macro2::TokenStream> {
+/// #     skip_past_next_at(input)?;
+/// #     input.parse()
+/// # }
+/// #
+/// # use syn::parse::Parser;
+/// # let remainder = remainder_after_skipping_past_next_at
+/// #     .parse_str("a @ b c")
+/// #     .unwrap();
+/// # assert_eq!(remainder.to_string(), "b c");
+/// ```
+pub struct StepCursor<'c, 'a> {
+    scope: Span,
+    // This field is covariant in 'c.
+    cursor: Cursor<'c>,
+    // This field is contravariant in 'c. Together these make StepCursor
+    // invariant in 'c. Also covariant in 'a. The user cannot cast 'c to a
+    // different lifetime but can upcast into a StepCursor with a shorter
+    // lifetime 'a.
+    //
+    // As long as we only ever construct a StepCursor for which 'c outlives 'a,
+    // this means if ever a StepCursor<'c, 'a> exists we are guaranteed that 'c
+    // outlives 'a.
+    marker: PhantomData<fn(Cursor<'c>) -> Cursor<'a>>,
+}
+
+impl<'c, 'a> Deref for StepCursor<'c, 'a> {
+    type Target = Cursor<'c>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.cursor
+    }
+}
+
+impl<'c, 'a> Copy for StepCursor<'c, 'a> {}
+
+impl<'c, 'a> Clone for StepCursor<'c, 'a> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<'c, 'a> StepCursor<'c, 'a> {
+    /// Triggers an error at the current position of the parse stream.
+    ///
+    /// The `ParseStream::step` invocation will return this same error without
+    /// advancing the stream state.
+    pub fn error<T: Display>(self, message: T) -> Error {
+        error::new_at(self.scope, self.cursor, message)
+    }
+}
+
+pub(crate) fn advance_step_cursor<'c, 'a>(proof: StepCursor<'c, 'a>, to: Cursor<'c>) -> Cursor<'a> {
+    // Refer to the comments within the StepCursor definition. We use the
+    // fact that a StepCursor<'c, 'a> exists as proof that 'c outlives 'a.
+    // Cursor is covariant in its lifetime parameter so we can cast a
+    // Cursor<'c> to one with the shorter lifetime Cursor<'a>.
+    let _ = proof;
+    unsafe { mem::transmute::<Cursor<'c>, Cursor<'a>>(to) }
+}
+
+pub(crate) fn new_parse_buffer(
+    scope: Span,
+    cursor: Cursor,
+    unexpected: Rc<Cell<Unexpected>>,
+) -> ParseBuffer {
+    ParseBuffer {
+        scope,
+        // See comment on `cell` in the struct definition.
+        cell: Cell::new(unsafe { mem::transmute::<Cursor, Cursor<'static>>(cursor) }),
+        marker: PhantomData,
+        unexpected: Cell::new(Some(unexpected)),
+    }
+}
+
+pub(crate) enum Unexpected {
+    None,
+    Some(Span),
+    Chain(Rc<Cell<Unexpected>>),
+}
+
+impl Default for Unexpected {
+    fn default() -> Self {
+        Unexpected::None
+    }
+}
+
+impl Clone for Unexpected {
+    fn clone(&self) -> Self {
+        match self {
+            Unexpected::None => Unexpected::None,
+            Unexpected::Some(span) => Unexpected::Some(*span),
+            Unexpected::Chain(next) => Unexpected::Chain(next.clone()),
+        }
+    }
+}
+
+// We call this on Cell<Unexpected> and Cell<Option<T>> where temporarily
+// swapping in a None is cheap.
+fn cell_clone<T: Default + Clone>(cell: &Cell<T>) -> T {
+    let prev = cell.take();
+    let ret = prev.clone();
+    cell.set(prev);
+    ret
+}
+
+fn inner_unexpected(buffer: &ParseBuffer) -> (Rc<Cell<Unexpected>>, Option<Span>) {
+    let mut unexpected = get_unexpected(buffer);
+    loop {
+        match cell_clone(&unexpected) {
+            Unexpected::None => return (unexpected, None),
+            Unexpected::Some(span) => return (unexpected, Some(span)),
+            Unexpected::Chain(next) => unexpected = next,
+        }
+    }
+}
+
+pub(crate) fn get_unexpected(buffer: &ParseBuffer) -> Rc<Cell<Unexpected>> {
+    cell_clone(&buffer.unexpected).unwrap()
+}
+
+fn span_of_unexpected_ignoring_nones(mut cursor: Cursor) -> Option<Span> {
+    if cursor.eof() {
+        return None;
+    }
+    while let Some((inner, _span, rest)) = cursor.group(Delimiter::None) {
+        if let Some(unexpected) = span_of_unexpected_ignoring_nones(inner) {
+            return Some(unexpected);
+        }
+        cursor = rest;
+    }
+    if cursor.eof() {
+        None
+    } else {
+        Some(cursor.span())
+    }
+}
+
+impl<'a> ParseBuffer<'a> {
+    /// Parses a syntax tree node of type `T`, advancing the position of our
+    /// parse stream past it.
+    pub fn parse<T: Parse>(&self) -> Result<T> {
+        T::parse(self)
+    }
+
+    /// Calls the given parser function to parse a syntax tree node of type `T`
+    /// from this stream.
+    ///
+    /// # Example
+    ///
+    /// The parser below invokes [`Attribute::parse_outer`] to parse a vector of
+    /// zero or more outer attributes.
+    ///
+    /// [`Attribute::parse_outer`]: crate::Attribute::parse_outer
+    ///
+    /// ```
+    /// use syn::{Attribute, Ident, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // Parses a unit struct with attributes.
+    /// //
+    /// //     #[path = "s.tmpl"]
+    /// //     struct S;
+    /// struct UnitStruct {
+    ///     attrs: Vec<Attribute>,
+    ///     struct_token: Token![struct],
+    ///     name: Ident,
+    ///     semi_token: Token![;],
+    /// }
+    ///
+    /// impl Parse for UnitStruct {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         Ok(UnitStruct {
+    ///             attrs: input.call(Attribute::parse_outer)?,
+    ///             struct_token: input.parse()?,
+    ///             name: input.parse()?,
+    ///             semi_token: input.parse()?,
+    ///         })
+    ///     }
+    /// }
+    /// ```
+    pub fn call<T>(&self, function: fn(ParseStream) -> Result<T>) -> Result<T> {
+        function(self)
+    }
+
+    /// Looks at the next token in the parse stream to determine whether it
+    /// matches the requested type of token.
+    ///
+    /// Does not advance the position of the parse stream.
+    ///
+    /// # Syntax
+    ///
+    /// Note that this method does not use turbofish syntax. Pass the peek type
+    /// inside of parentheses.
+    ///
+    /// - `input.peek(Token![struct])`
+    /// - `input.peek(Token![==])`
+    /// - `input.peek(Ident)`&emsp;*(does not accept keywords)*
+    /// - `input.peek(Ident::peek_any)`
+    /// - `input.peek(Lifetime)`
+    /// - `input.peek(token::Brace)`
+    ///
+    /// # Example
+    ///
+    /// In this example we finish parsing the list of supertraits when the next
+    /// token in the input is either `where` or an opening curly brace.
+    ///
+    /// ```
+    /// use syn::{braced, token, Generics, Ident, Result, Token, TypeParamBound};
+    /// use syn::parse::{Parse, ParseStream};
+    /// use syn::punctuated::Punctuated;
+    ///
+    /// // Parses a trait definition containing no associated items.
+    /// //
+    /// //     trait Marker<'de, T>: A + B<'de> where Box<T>: Clone {}
+    /// struct MarkerTrait {
+    ///     trait_token: Token![trait],
+    ///     ident: Ident,
+    ///     generics: Generics,
+    ///     colon_token: Option<Token![:]>,
+    ///     supertraits: Punctuated<TypeParamBound, Token![+]>,
+    ///     brace_token: token::Brace,
+    /// }
+    ///
+    /// impl Parse for MarkerTrait {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let trait_token: Token![trait] = input.parse()?;
+    ///         let ident: Ident = input.parse()?;
+    ///         let mut generics: Generics = input.parse()?;
+    ///         let colon_token: Option<Token![:]> = input.parse()?;
+    ///
+    ///         let mut supertraits = Punctuated::new();
+    ///         if colon_token.is_some() {
+    ///             loop {
+    ///                 supertraits.push_value(input.parse()?);
+    ///                 if input.peek(Token![where]) || input.peek(token::Brace) {
+    ///                     break;
+    ///                 }
+    ///                 supertraits.push_punct(input.parse()?);
+    ///             }
+    ///         }
+    ///
+    ///         generics.where_clause = input.parse()?;
+    ///         let content;
+    ///         let empty_brace_token = braced!(content in input);
+    ///
+    ///         Ok(MarkerTrait {
+    ///             trait_token,
+    ///             ident,
+    ///             generics,
+    ///             colon_token,
+    ///             supertraits,
+    ///             brace_token: empty_brace_token,
+    ///         })
+    ///     }
+    /// }
+    /// ```
+    pub fn peek<T: Peek>(&self, token: T) -> bool {
+        let _ = token;
+        T::Token::peek(self.cursor())
+    }
+
+    /// Looks at the second-next token in the parse stream.
+    ///
+    /// This is commonly useful as a way to implement contextual keywords.
+    ///
+    /// # Example
+    ///
+    /// This example needs to use `peek2` because the symbol `union` is not a
+    /// keyword in Rust. We can't use just `peek` and decide to parse a union if
+    /// the very next token is `union`, because someone is free to write a `mod
+    /// union` and a macro invocation that looks like `union::some_macro! { ...
+    /// }`. In other words `union` is a contextual keyword.
+    ///
+    /// ```
+    /// use syn::{Ident, ItemUnion, Macro, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // Parses either a union or a macro invocation.
+    /// enum UnionOrMacro {
+    ///     // union MaybeUninit<T> { uninit: (), value: T }
+    ///     Union(ItemUnion),
+    ///     // lazy_static! { ... }
+    ///     Macro(Macro),
+    /// }
+    ///
+    /// impl Parse for UnionOrMacro {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         if input.peek(Token![union]) && input.peek2(Ident) {
+    ///             input.parse().map(UnionOrMacro::Union)
+    ///         } else {
+    ///             input.parse().map(UnionOrMacro::Macro)
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    pub fn peek2<T: Peek>(&self, token: T) -> bool {
+        fn peek2(buffer: &ParseBuffer, peek: fn(Cursor) -> bool) -> bool {
+            if let Some(group) = buffer.cursor().group(Delimiter::None) {
+                if group.0.skip().map_or(false, peek) {
+                    return true;
+                }
+            }
+            buffer.cursor().skip().map_or(false, peek)
+        }
+
+        let _ = token;
+        peek2(self, T::Token::peek)
+    }
+
+    /// Looks at the third-next token in the parse stream.
+    pub fn peek3<T: Peek>(&self, token: T) -> bool {
+        fn peek3(buffer: &ParseBuffer, peek: fn(Cursor) -> bool) -> bool {
+            if let Some(group) = buffer.cursor().group(Delimiter::None) {
+                if group.0.skip().and_then(Cursor::skip).map_or(false, peek) {
+                    return true;
+                }
+            }
+            buffer
+                .cursor()
+                .skip()
+                .and_then(Cursor::skip)
+                .map_or(false, peek)
+        }
+
+        let _ = token;
+        peek3(self, T::Token::peek)
+    }
+
+    /// Parses zero or more occurrences of `T` separated by punctuation of type
+    /// `P`, with optional trailing punctuation.
+    ///
+    /// Parsing continues until the end of this parse stream. The entire content
+    /// of this parse stream must consist of `T` and `P`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use quote::quote;
+    /// #
+    /// use syn::{parenthesized, token, Ident, Result, Token, Type};
+    /// use syn::parse::{Parse, ParseStream};
+    /// use syn::punctuated::Punctuated;
+    ///
+    /// // Parse a simplified tuple struct syntax like:
+    /// //
+    /// //     struct S(A, B);
+    /// struct TupleStruct {
+    ///     struct_token: Token![struct],
+    ///     ident: Ident,
+    ///     paren_token: token::Paren,
+    ///     fields: Punctuated<Type, Token![,]>,
+    ///     semi_token: Token![;],
+    /// }
+    ///
+    /// impl Parse for TupleStruct {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let content;
+    ///         Ok(TupleStruct {
+    ///             struct_token: input.parse()?,
+    ///             ident: input.parse()?,
+    ///             paren_token: parenthesized!(content in input),
+    ///             fields: content.parse_terminated(Type::parse, Token![,])?,
+    ///             semi_token: input.parse()?,
+    ///         })
+    ///     }
+    /// }
+    /// #
+    /// # let input = quote! {
+    /// #     struct S(A, B);
+    /// # };
+    /// # syn::parse2::<TupleStruct>(input).unwrap();
+    /// ```
+    ///
+    /// # See also
+    ///
+    /// If your separator is anything more complicated than an invocation of the
+    /// `Token!` macro, this method won't be applicable and you can instead
+    /// directly use `Punctuated`'s parser functions: [`parse_terminated`],
+    /// [`parse_separated_nonempty`] etc.
+    ///
+    /// [`parse_terminated`]: Punctuated::parse_terminated
+    /// [`parse_separated_nonempty`]: Punctuated::parse_separated_nonempty
+    ///
+    /// ```
+    /// use syn::{custom_keyword, Expr, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    /// use syn::punctuated::Punctuated;
+    ///
+    /// mod kw {
+    ///     syn::custom_keyword!(fin);
+    /// }
+    ///
+    /// struct Fin(kw::fin, Token![;]);
+    ///
+    /// impl Parse for Fin {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         Ok(Self(input.parse()?, input.parse()?))
+    ///     }
+    /// }
+    ///
+    /// struct Thing {
+    ///     steps: Punctuated<Expr, Fin>,
+    /// }
+    ///
+    /// impl Parse for Thing {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    /// # if true {
+    ///         Ok(Thing {
+    ///             steps: Punctuated::parse_terminated(input)?,
+    ///         })
+    /// # } else {
+    ///         // or equivalently, this means the same thing:
+    /// #       Ok(Thing {
+    ///             steps: input.call(Punctuated::parse_terminated)?,
+    /// #       })
+    /// # }
+    ///     }
+    /// }
+    /// ```
+    pub fn parse_terminated<T, P>(
+        &self,
+        parser: fn(ParseStream) -> Result<T>,
+        separator: P,
+    ) -> Result<Punctuated<T, P::Token>>
+    where
+        P: Peek,
+        P::Token: Parse,
+    {
+        let _ = separator;
+        Punctuated::parse_terminated_with(self, parser)
+    }
+
+    /// Returns whether there are tokens remaining in this stream.
+    ///
+    /// This method returns true at the end of the content of a set of
+    /// delimiters, as well as at the very end of the complete macro input.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{braced, token, Ident, Item, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // Parses a Rust `mod m { ... }` containing zero or more items.
+    /// struct Mod {
+    ///     mod_token: Token![mod],
+    ///     name: Ident,
+    ///     brace_token: token::Brace,
+    ///     items: Vec<Item>,
+    /// }
+    ///
+    /// impl Parse for Mod {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let content;
+    ///         Ok(Mod {
+    ///             mod_token: input.parse()?,
+    ///             name: input.parse()?,
+    ///             brace_token: braced!(content in input),
+    ///             items: {
+    ///                 let mut items = Vec::new();
+    ///                 while !content.is_empty() {
+    ///                     items.push(content.parse()?);
+    ///                 }
+    ///                 items
+    ///             },
+    ///         })
+    ///     }
+    /// }
+    /// ```
+    pub fn is_empty(&self) -> bool {
+        self.cursor().eof()
+    }
+
+    /// Constructs a helper for peeking at the next token in this stream and
+    /// building an error message if it is not one of a set of expected tokens.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{ConstParam, Ident, Lifetime, LifetimeParam, Result, Token, TypeParam};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // A generic parameter, a single one of the comma-separated elements inside
+    /// // angle brackets in:
+    /// //
+    /// //     fn f<T: Clone, 'a, 'b: 'a, const N: usize>() { ... }
+    /// //
+    /// // On invalid input, lookahead gives us a reasonable error message.
+    /// //
+    /// //     error: expected one of: identifier, lifetime, `const`
+    /// //       |
+    /// //     5 |     fn f<!Sized>() {}
+    /// //       |          ^
+    /// enum GenericParam {
+    ///     Type(TypeParam),
+    ///     Lifetime(LifetimeParam),
+    ///     Const(ConstParam),
+    /// }
+    ///
+    /// impl Parse for GenericParam {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let lookahead = input.lookahead1();
+    ///         if lookahead.peek(Ident) {
+    ///             input.parse().map(GenericParam::Type)
+    ///         } else if lookahead.peek(Lifetime) {
+    ///             input.parse().map(GenericParam::Lifetime)
+    ///         } else if lookahead.peek(Token![const]) {
+    ///             input.parse().map(GenericParam::Const)
+    ///         } else {
+    ///             Err(lookahead.error())
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    pub fn lookahead1(&self) -> Lookahead1<'a> {
+        lookahead::new(self.scope, self.cursor())
+    }
+
+    /// Forks a parse stream so that parsing tokens out of either the original
+    /// or the fork does not advance the position of the other.
+    ///
+    /// # Performance
+    ///
+    /// Forking a parse stream is a cheap fixed amount of work and does not
+    /// involve copying token buffers. Where you might hit performance problems
+    /// is if your macro ends up parsing a large amount of content more than
+    /// once.
+    ///
+    /// ```
+    /// # use syn::{Expr, Result};
+    /// # use syn::parse::ParseStream;
+    /// #
+    /// # fn bad(input: ParseStream) -> Result<Expr> {
+    /// // Do not do this.
+    /// if input.fork().parse::<Expr>().is_ok() {
+    ///     return input.parse::<Expr>();
+    /// }
+    /// # unimplemented!()
+    /// # }
+    /// ```
+    ///
+    /// As a rule, avoid parsing an unbounded amount of tokens out of a forked
+    /// parse stream. Only use a fork when the amount of work performed against
+    /// the fork is small and bounded.
+    ///
+    /// When complex speculative parsing against the forked stream is
+    /// unavoidable, use [`parse::discouraged::Speculative`] to advance the
+    /// original stream once the fork's parse is determined to have been
+    /// successful.
+    ///
+    /// For a lower level way to perform speculative parsing at the token level,
+    /// consider using [`ParseStream::step`] instead.
+    ///
+    /// [`parse::discouraged::Speculative`]: discouraged::Speculative
+    /// [`ParseStream::step`]: ParseBuffer::step
+    ///
+    /// # Example
+    ///
+    /// The parse implementation shown here parses possibly restricted `pub`
+    /// visibilities.
+    ///
+    /// - `pub`
+    /// - `pub(crate)`
+    /// - `pub(self)`
+    /// - `pub(super)`
+    /// - `pub(in some::path)`
+    ///
+    /// To handle the case of visibilities inside of tuple structs, the parser
+    /// needs to distinguish parentheses that specify visibility restrictions
+    /// from parentheses that form part of a tuple type.
+    ///
+    /// ```
+    /// # struct A;
+    /// # struct B;
+    /// # struct C;
+    /// #
+    /// struct S(pub(crate) A, pub (B, C));
+    /// ```
+    ///
+    /// In this example input the first tuple struct element of `S` has
+    /// `pub(crate)` visibility while the second tuple struct element has `pub`
+    /// visibility; the parentheses around `(B, C)` are part of the type rather
+    /// than part of a visibility restriction.
+    ///
+    /// The parser uses a forked parse stream to check the first token inside of
+    /// parentheses after the `pub` keyword. This is a small bounded amount of
+    /// work performed against the forked parse stream.
+    ///
+    /// ```
+    /// use syn::{parenthesized, token, Ident, Path, Result, Token};
+    /// use syn::ext::IdentExt;
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// struct PubVisibility {
+    ///     pub_token: Token![pub],
+    ///     restricted: Option<Restricted>,
+    /// }
+    ///
+    /// struct Restricted {
+    ///     paren_token: token::Paren,
+    ///     in_token: Option<Token![in]>,
+    ///     path: Path,
+    /// }
+    ///
+    /// impl Parse for PubVisibility {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         let pub_token: Token![pub] = input.parse()?;
+    ///
+    ///         if input.peek(token::Paren) {
+    ///             let ahead = input.fork();
+    ///             let mut content;
+    ///             parenthesized!(content in ahead);
+    ///
+    ///             if content.peek(Token![crate])
+    ///                 || content.peek(Token![self])
+    ///                 || content.peek(Token![super])
+    ///             {
+    ///                 return Ok(PubVisibility {
+    ///                     pub_token,
+    ///                     restricted: Some(Restricted {
+    ///                         paren_token: parenthesized!(content in input),
+    ///                         in_token: None,
+    ///                         path: Path::from(content.call(Ident::parse_any)?),
+    ///                     }),
+    ///                 });
+    ///             } else if content.peek(Token![in]) {
+    ///                 return Ok(PubVisibility {
+    ///                     pub_token,
+    ///                     restricted: Some(Restricted {
+    ///                         paren_token: parenthesized!(content in input),
+    ///                         in_token: Some(content.parse()?),
+    ///                         path: content.call(Path::parse_mod_style)?,
+    ///                     }),
+    ///                 });
+    ///             }
+    ///         }
+    ///
+    ///         Ok(PubVisibility {
+    ///             pub_token,
+    ///             restricted: None,
+    ///         })
+    ///     }
+    /// }
+    /// ```
+    pub fn fork(&self) -> Self {
+        ParseBuffer {
+            scope: self.scope,
+            cell: self.cell.clone(),
+            marker: PhantomData,
+            // Not the parent's unexpected. Nothing cares whether the clone
+            // parses all the way unless we `advance_to`.
+            unexpected: Cell::new(Some(Rc::new(Cell::new(Unexpected::None)))),
+        }
+    }
+
+    /// Triggers an error at the current position of the parse stream.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use syn::{Expr, Result, Token};
+    /// use syn::parse::{Parse, ParseStream};
+    ///
+    /// // Some kind of loop: `while` or `for` or `loop`.
+    /// struct Loop {
+    ///     expr: Expr,
+    /// }
+    ///
+    /// impl Parse for Loop {
+    ///     fn parse(input: ParseStream) -> Result<Self> {
+    ///         if input.peek(Token![while])
+    ///             || input.peek(Token![for])
+    ///             || input.peek(Token![loop])
+    ///         {
+    ///             Ok(Loop {
+    ///                 expr: input.parse()?,
+    ///             })
+    ///         } else {
+    ///             Err(input.error("expected some kind of loop"))
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    pub fn error<T: Display>(&self, message: T) -> Error {
+        error::new_at(self.scope, self.cursor(), message)
+    }
+
+    /// Speculatively parses tokens from this parse stream, advancing the
+    /// position of this stream only if parsing succeeds.
+    ///
+    /// This is a powerful low-level API used for defining the `Parse` impls of
+    /// the basic built-in token types. It is not something that will be used
+    /// widely outside of the Syn codebase.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use proc_macro2::TokenTree;
+    /// use syn::Result;
+    /// use syn::parse::ParseStream;
+    ///
+    /// // This function advances the stream past the next occurrence of `@`. If
+    /// // no `@` is present in the stream, the stream position is unchanged and
+    /// // an error is returned.
+    /// fn skip_past_next_at(input: ParseStream) -> Result<()> {
+    ///     input.step(|cursor| {
+    ///         let mut rest = *cursor;
+    ///         while let Some((tt, next)) = rest.token_tree() {
+    ///             match &tt {
+    ///                 TokenTree::Punct(punct) if punct.as_char() == '@' => {
+    ///                     return Ok(((), next));
+    ///                 }
+    ///                 _ => rest = next,
+    ///             }
+    ///         }
+    ///         Err(cursor.error("no `@` was found after this point"))
+    ///     })
+    /// }
+    /// #
+    /// # fn remainder_after_skipping_past_next_at(
+    /// #     input: ParseStream,
+    /// # ) -> Result<proc_macro2::TokenStream> {
+    /// #     skip_past_next_at(input)?;
+    /// #     input.parse()
+    /// # }
+    /// #
+    /// # use syn::parse::Parser;
+    /// # let remainder = remainder_after_skipping_past_next_at
+    /// #     .parse_str("a @ b c")
+    /// #     .unwrap();
+    /// # assert_eq!(remainder.to_string(), "b c");
+    /// ```
+    pub fn step<F, R>(&self, function: F) -> Result<R>
+    where
+        F: for<'c> FnOnce(StepCursor<'c, 'a>) -> Result<(R, Cursor<'c>)>,
+    {
+        // Since the user's function is required to work for any 'c, we know
+        // that the Cursor<'c> they return is either derived from the input
+        // StepCursor<'c, 'a> or from a Cursor<'static>.
+        //
+        // It would not be legal to write this function without the invariant
+        // lifetime 'c in StepCursor<'c, 'a>. If this function were written only
+        // in terms of 'a, the user could take our ParseBuffer<'a>, upcast it to
+        // a ParseBuffer<'short> which some shorter lifetime than 'a, invoke
+        // `step` on their ParseBuffer<'short> with a closure that returns
+        // Cursor<'short>, and we would wrongly write that Cursor<'short> into
+        // the Cell intended to hold Cursor<'a>.
+        //
+        // In some cases it may be necessary for R to contain a Cursor<'a>.
+        // Within Syn we solve this using `advance_step_cursor` which uses the
+        // existence of a StepCursor<'c, 'a> as proof that it is safe to cast
+        // from Cursor<'c> to Cursor<'a>. If needed outside of Syn, it would be
+        // safe to expose that API as a method on StepCursor.
+        let (node, rest) = function(StepCursor {
+            scope: self.scope,
+            cursor: self.cell.get(),
+            marker: PhantomData,
+        })?;
+        self.cell.set(rest);
+        Ok(node)
+    }
+
+    /// Returns the `Span` of the next token in the parse stream, or
+    /// `Span::call_site()` if this parse stream has completely exhausted its
+    /// input `TokenStream`.
+    pub fn span(&self) -> Span {
+        let cursor = self.cursor();
+        if cursor.eof() {
+            self.scope
+        } else {
+            crate::buffer::open_span_of_group(cursor)
+        }
+    }
+
+    /// Provides low-level access to the token representation underlying this
+    /// parse stream.
+    ///
+    /// Cursors are immutable so no operations you perform against the cursor
+    /// will affect the state of this parse stream.
+    pub fn cursor(&self) -> Cursor<'a> {
+        self.cell.get()
+    }
+
+    fn check_unexpected(&self) -> Result<()> {
+        match inner_unexpected(self).1 {
+            Some(span) => Err(Error::new(span, "unexpected token")),
+            None => Ok(()),
+        }
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl<T: Parse> Parse for Box<T> {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.parse().map(Box::new)
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl<T: Parse + Token> Parse for Option<T> {
+    fn parse(input: ParseStream) -> Result<Self> {
+        if T::peek(input.cursor()) {
+            Ok(Some(input.parse()?))
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for TokenStream {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| Ok((cursor.token_stream(), Cursor::empty())))
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for TokenTree {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| match cursor.token_tree() {
+            Some((tt, rest)) => Ok((tt, rest)),
+            None => Err(cursor.error("expected token tree")),
+        })
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for Group {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| {
+            if let Some((group, rest)) = cursor.any_group_token() {
+                if group.delimiter() != Delimiter::None {
+                    return Ok((group, rest));
+                }
+            }
+            Err(cursor.error("expected group token"))
+        })
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for Punct {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| match cursor.punct() {
+            Some((punct, rest)) => Ok((punct, rest)),
+            None => Err(cursor.error("expected punctuation token")),
+        })
+    }
+}
+
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for Literal {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| match cursor.literal() {
+            Some((literal, rest)) => Ok((literal, rest)),
+            None => Err(cursor.error("expected literal token")),
+        })
+    }
+}
+
+/// Parser that can parse Rust tokens into a particular syntax tree node.
+///
+/// Refer to the [module documentation] for details about parsing in Syn.
+///
+/// [module documentation]: self
+pub trait Parser: Sized {
+    type Output;
+
+    /// Parse a proc-macro2 token stream into the chosen syntax tree node.
+    ///
+    /// This function will check that the input is fully parsed. If there are
+    /// any unparsed tokens at the end of the stream, an error is returned.
+    fn parse2(self, tokens: TokenStream) -> Result<Self::Output>;
+
+    /// Parse tokens of source code into the chosen syntax tree node.
+    ///
+    /// This function will check that the input is fully parsed. If there are
+    /// any unparsed tokens at the end of the stream, an error is returned.
+    #[cfg(feature = "proc-macro")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "proc-macro")))]
+    fn parse(self, tokens: proc_macro::TokenStream) -> Result<Self::Output> {
+        self.parse2(proc_macro2::TokenStream::from(tokens))
+    }
+
+    /// Parse a string of Rust code into the chosen syntax tree node.
+    ///
+    /// This function will check that the input is fully parsed. If there are
+    /// any unparsed tokens at the end of the string, an error is returned.
+    ///
+    /// # Hygiene
+    ///
+    /// Every span in the resulting syntax tree will be set to resolve at the
+    /// macro call site.
+    fn parse_str(self, s: &str) -> Result<Self::Output> {
+        self.parse2(proc_macro2::TokenStream::from_str(s)?)
+    }
+
+    // Not public API.
+    #[doc(hidden)]
+    #[cfg(any(feature = "full", feature = "derive"))]
+    fn __parse_scoped(self, scope: Span, tokens: TokenStream) -> Result<Self::Output> {
+        let _ = scope;
+        self.parse2(tokens)
+    }
+}
+
+fn tokens_to_parse_buffer(tokens: &TokenBuffer) -> ParseBuffer {
+    let scope = Span::call_site();
+    let cursor = tokens.begin();
+    let unexpected = Rc::new(Cell::new(Unexpected::None));
+    new_parse_buffer(scope, cursor, unexpected)
+}
+
+impl<F, T> Parser for F
+where
+    F: FnOnce(ParseStream) -> Result<T>,
+{
+    type Output = T;
+
+    fn parse2(self, tokens: TokenStream) -> Result<T> {
+        let buf = TokenBuffer::new2(tokens);
+        let state = tokens_to_parse_buffer(&buf);
+        let node = self(&state)?;
+        state.check_unexpected()?;
+        if let Some(unexpected_span) = span_of_unexpected_ignoring_nones(state.cursor()) {
+            Err(Error::new(unexpected_span, "unexpected token"))
+        } else {
+            Ok(node)
+        }
+    }
+
+    #[cfg(any(feature = "full", feature = "derive"))]
+    fn __parse_scoped(self, scope: Span, tokens: TokenStream) -> Result<Self::Output> {
+        let buf = TokenBuffer::new2(tokens);
+        let cursor = buf.begin();
+        let unexpected = Rc::new(Cell::new(Unexpected::None));
+        let state = new_parse_buffer(scope, cursor, unexpected);
+        let node = self(&state)?;
+        state.check_unexpected()?;
+        if let Some(unexpected_span) = span_of_unexpected_ignoring_nones(state.cursor()) {
+            Err(Error::new(unexpected_span, "unexpected token"))
+        } else {
+            Ok(node)
+        }
+    }
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn parse_scoped<F: Parser>(f: F, scope: Span, tokens: TokenStream) -> Result<F::Output> {
+    f.__parse_scoped(scope, tokens)
+}
+
+/// An empty syntax tree node that consumes no tokens when parsed.
+///
+/// This is useful for attribute macros that want to ensure they are not
+/// provided any attribute args.
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use syn::parse_macro_input;
+/// use syn::parse::Nothing;
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro_attribute]
+/// # };
+/// pub fn my_attr(args: TokenStream, input: TokenStream) -> TokenStream {
+///     parse_macro_input!(args as Nothing);
+///
+///     /* ... */
+/// #   TokenStream::new()
+/// }
+/// ```
+///
+/// ```text
+/// error: unexpected token
+///  --> src/main.rs:3:19
+///   |
+/// 3 | #[my_attr(asdf)]
+///   |           ^^^^
+/// ```
+pub struct Nothing;
+
+impl Parse for Nothing {
+    fn parse(_input: ParseStream) -> Result<Self> {
+        Ok(Nothing)
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Nothing {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str("Nothing")
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Eq for Nothing {}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Nothing {
+    fn eq(&self, _other: &Self) -> bool {
+        true
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Nothing {
+    fn hash<H: Hasher>(&self, _state: &mut H) {}
+}
diff --git a/vendor/syn/src/parse_macro_input.rs b/vendor/syn/src/parse_macro_input.rs
new file mode 100644
index 0000000..6f1562f
--- /dev/null
+++ b/vendor/syn/src/parse_macro_input.rs
@@ -0,0 +1,128 @@
+/// Parse the input TokenStream of a macro, triggering a compile error if the
+/// tokens fail to parse.
+///
+/// Refer to the [`parse` module] documentation for more details about parsing
+/// in Syn.
+///
+/// [`parse` module]: mod@crate::parse
+///
+/// <br>
+///
+/// # Intended usage
+///
+/// This macro must be called from a function that returns
+/// `proc_macro::TokenStream`. Usually this will be your proc macro entry point,
+/// the function that has the #\[proc_macro\] / #\[proc_macro_derive\] /
+/// #\[proc_macro_attribute\] attribute.
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// use proc_macro::TokenStream;
+/// use syn::{parse_macro_input, Result};
+/// use syn::parse::{Parse, ParseStream};
+///
+/// struct MyMacroInput {
+///     /* ... */
+/// }
+///
+/// impl Parse for MyMacroInput {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         /* ... */
+/// #       Ok(MyMacroInput {})
+///     }
+/// }
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro]
+/// # };
+/// pub fn my_macro(tokens: TokenStream) -> TokenStream {
+///     let input = parse_macro_input!(tokens as MyMacroInput);
+///
+///     /* ... */
+/// #   TokenStream::new()
+/// }
+/// ```
+///
+/// <br>
+///
+/// # Usage with Parser
+///
+/// This macro can also be used with the [`Parser` trait] for types that have
+/// multiple ways that they can be parsed.
+///
+/// [`Parser` trait]: crate::parse::Parser
+///
+/// ```
+/// # extern crate proc_macro;
+/// #
+/// # use proc_macro::TokenStream;
+/// # use syn::{parse_macro_input, Result};
+/// # use syn::parse::ParseStream;
+/// #
+/// # struct MyMacroInput {}
+/// #
+/// impl MyMacroInput {
+///     fn parse_alternate(input: ParseStream) -> Result<Self> {
+///         /* ... */
+/// #       Ok(MyMacroInput {})
+///     }
+/// }
+///
+/// # const IGNORE: &str = stringify! {
+/// #[proc_macro]
+/// # };
+/// pub fn my_macro(tokens: TokenStream) -> TokenStream {
+///     let input = parse_macro_input!(tokens with MyMacroInput::parse_alternate);
+///
+///     /* ... */
+/// #   TokenStream::new()
+/// }
+/// ```
+///
+/// <br>
+///
+/// # Expansion
+///
+/// `parse_macro_input!($variable as $Type)` expands to something like:
+///
+/// ```no_run
+/// # extern crate proc_macro;
+/// #
+/// # macro_rules! doc_test {
+/// #     ($variable:ident as $Type:ty) => {
+/// match syn::parse::<$Type>($variable) {
+///     Ok(syntax_tree) => syntax_tree,
+///     Err(err) => return proc_macro::TokenStream::from(err.to_compile_error()),
+/// }
+/// #     };
+/// # }
+/// #
+/// # fn test(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+/// #     let _ = doc_test!(input as syn::Ident);
+/// #     proc_macro::TokenStream::new()
+/// # }
+/// ```
+#[macro_export]
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "proc-macro"))))]
+macro_rules! parse_macro_input {
+    ($tokenstream:ident as $ty:ty) => {
+        match $crate::parse::<$ty>($tokenstream) {
+            $crate::__private::Ok(data) => data,
+            $crate::__private::Err(err) => {
+                return $crate::__private::TokenStream::from(err.to_compile_error());
+            }
+        }
+    };
+    ($tokenstream:ident with $parser:path) => {
+        match $crate::parse::Parser::parse($parser, $tokenstream) {
+            $crate::__private::Ok(data) => data,
+            $crate::__private::Err(err) => {
+                return $crate::__private::TokenStream::from(err.to_compile_error());
+            }
+        }
+    };
+    ($tokenstream:ident) => {
+        $crate::parse_macro_input!($tokenstream as _)
+    };
+}
diff --git a/vendor/syn/src/parse_quote.rs b/vendor/syn/src/parse_quote.rs
new file mode 100644
index 0000000..59e51b4
--- /dev/null
+++ b/vendor/syn/src/parse_quote.rs
@@ -0,0 +1,179 @@
+/// Quasi-quotation macro that accepts input like the [`quote!`] macro but uses
+/// type inference to figure out a return type for those tokens.
+///
+/// [`quote!`]: https://docs.rs/quote/1.0/quote/index.html
+///
+/// The return type can be any syntax tree node that implements the [`Parse`]
+/// trait.
+///
+/// [`Parse`]: crate::parse::Parse
+///
+/// ```
+/// use quote::quote;
+/// use syn::{parse_quote, Stmt};
+///
+/// fn main() {
+///     let name = quote!(v);
+///     let ty = quote!(u8);
+///
+///     let stmt: Stmt = parse_quote! {
+///         let #name: #ty = Default::default();
+///     };
+///
+///     println!("{:#?}", stmt);
+/// }
+/// ```
+///
+/// *This macro is available only if Syn is built with both the `"parsing"` and
+/// `"printing"` features.*
+///
+/// # Example
+///
+/// The following helper function adds a bound `T: HeapSize` to every type
+/// parameter `T` in the input generics.
+///
+/// ```
+/// use syn::{parse_quote, Generics, GenericParam};
+///
+/// // Add a bound `T: HeapSize` to every type parameter T.
+/// fn add_trait_bounds(mut generics: Generics) -> Generics {
+///     for param in &mut generics.params {
+///         if let GenericParam::Type(type_param) = param {
+///             type_param.bounds.push(parse_quote!(HeapSize));
+///         }
+///     }
+///     generics
+/// }
+/// ```
+///
+/// # Special cases
+///
+/// This macro can parse the following additional types as a special case even
+/// though they do not implement the `Parse` trait.
+///
+/// - [`Attribute`] — parses one attribute, allowing either outer like `#[...]`
+///   or inner like `#![...]`
+/// - [`Punctuated<T, P>`] — parses zero or more `T` separated by punctuation
+///   `P` with optional trailing punctuation
+/// - [`Vec<Stmt>`] — parses the same as `Block::parse_within`
+///
+/// [`Vec<Stmt>`]: Block::parse_within
+///
+/// # Panics
+///
+/// Panics if the tokens fail to parse as the expected syntax tree type. The
+/// caller is responsible for ensuring that the input tokens are syntactically
+/// valid.
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "printing"))))]
+#[macro_export]
+macro_rules! parse_quote {
+    ($($tt:tt)*) => {
+        $crate::__private::parse_quote($crate::__private::quote::quote!($($tt)*))
+    };
+}
+
+/// This macro is [`parse_quote!`] + [`quote_spanned!`][quote::quote_spanned].
+///
+/// Please refer to each of their documentation.
+///
+/// # Example
+///
+/// ```
+/// use quote::{quote, quote_spanned};
+/// use syn::spanned::Spanned;
+/// use syn::{parse_quote_spanned, ReturnType, Signature};
+///
+/// // Changes `fn()` to `fn() -> Pin<Box<dyn Future<Output = ()>>>`,
+/// // and `fn() -> T` to `fn() -> Pin<Box<dyn Future<Output = T>>>`,
+/// // without introducing any call_site() spans.
+/// fn make_ret_pinned_future(sig: &mut Signature) {
+///     let ret = match &sig.output {
+///         ReturnType::Default => quote_spanned!(sig.paren_token.span=> ()),
+///         ReturnType::Type(_, ret) => quote!(#ret),
+///     };
+///     sig.output = parse_quote_spanned! {ret.span()=>
+///         -> ::std::pin::Pin<::std::boxed::Box<dyn ::std::future::Future<Output = #ret>>>
+///     };
+/// }
+/// ```
+#[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "printing"))))]
+#[macro_export]
+macro_rules! parse_quote_spanned {
+    ($span:expr=> $($tt:tt)*) => {
+        $crate::__private::parse_quote($crate::__private::quote::quote_spanned!($span=> $($tt)*))
+    };
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Can parse any type that implements Parse.
+
+use crate::parse::{Parse, ParseStream, Parser, Result};
+use proc_macro2::TokenStream;
+
+// Not public API.
+#[doc(hidden)]
+pub fn parse<T: ParseQuote>(token_stream: TokenStream) -> T {
+    let parser = T::parse;
+    match parser.parse2(token_stream) {
+        Ok(t) => t,
+        Err(err) => panic!("{}", err),
+    }
+}
+
+#[doc(hidden)]
+pub trait ParseQuote: Sized {
+    fn parse(input: ParseStream) -> Result<Self>;
+}
+
+impl<T: Parse> ParseQuote for T {
+    fn parse(input: ParseStream) -> Result<Self> {
+        <T as Parse>::parse(input)
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Any other types that we want `parse_quote!` to be able to parse.
+
+use crate::punctuated::Punctuated;
+#[cfg(any(feature = "full", feature = "derive"))]
+use crate::{attr, Attribute};
+#[cfg(feature = "full")]
+use crate::{Block, Pat, Stmt};
+
+#[cfg(any(feature = "full", feature = "derive"))]
+impl ParseQuote for Attribute {
+    fn parse(input: ParseStream) -> Result<Self> {
+        if input.peek(Token![#]) && input.peek2(Token![!]) {
+            attr::parsing::single_parse_inner(input)
+        } else {
+            attr::parsing::single_parse_outer(input)
+        }
+    }
+}
+
+#[cfg(feature = "full")]
+impl ParseQuote for Pat {
+    fn parse(input: ParseStream) -> Result<Self> {
+        Pat::parse_multi_with_leading_vert(input)
+    }
+}
+
+#[cfg(feature = "full")]
+impl ParseQuote for Box<Pat> {
+    fn parse(input: ParseStream) -> Result<Self> {
+        <Pat as ParseQuote>::parse(input).map(Box::new)
+    }
+}
+
+impl<T: Parse, P: Parse> ParseQuote for Punctuated<T, P> {
+    fn parse(input: ParseStream) -> Result<Self> {
+        Self::parse_terminated(input)
+    }
+}
+
+#[cfg(feature = "full")]
+impl ParseQuote for Vec<Stmt> {
+    fn parse(input: ParseStream) -> Result<Self> {
+        Block::parse_within(input)
+    }
+}
diff --git a/vendor/syn/src/pat.rs b/vendor/syn/src/pat.rs
new file mode 100644
index 0000000..df7da5b
--- /dev/null
+++ b/vendor/syn/src/pat.rs
@@ -0,0 +1,903 @@
+use super::*;
+use crate::punctuated::Punctuated;
+use proc_macro2::TokenStream;
+
+ast_enum_of_structs! {
+    /// A pattern in a local binding, function signature, match expression, or
+    /// various other places.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum Pat {
+        /// A const block: `const { ... }`.
+        Const(PatConst),
+
+        /// A pattern that binds a new variable: `ref mut binding @ SUBPATTERN`.
+        Ident(PatIdent),
+
+        /// A literal pattern: `0`.
+        Lit(PatLit),
+
+        /// A macro in pattern position.
+        Macro(PatMacro),
+
+        /// A pattern that matches any one of a set of cases.
+        Or(PatOr),
+
+        /// A parenthesized pattern: `(A | B)`.
+        Paren(PatParen),
+
+        /// A path pattern like `Color::Red`, optionally qualified with a
+        /// self-type.
+        ///
+        /// Unqualified path patterns can legally refer to variants, structs,
+        /// constants or associated constants. Qualified path patterns like
+        /// `<A>::B::C` and `<A as Trait>::B::C` can only legally refer to
+        /// associated constants.
+        Path(PatPath),
+
+        /// A range pattern: `1..=2`.
+        Range(PatRange),
+
+        /// A reference pattern: `&mut var`.
+        Reference(PatReference),
+
+        /// The dots in a tuple or slice pattern: `[0, 1, ..]`.
+        Rest(PatRest),
+
+        /// A dynamically sized slice pattern: `[a, b, ref i @ .., y, z]`.
+        Slice(PatSlice),
+
+        /// A struct or struct variant pattern: `Variant { x, y, .. }`.
+        Struct(PatStruct),
+
+        /// A tuple pattern: `(a, b)`.
+        Tuple(PatTuple),
+
+        /// A tuple struct or tuple variant pattern: `Variant(x, y, .., z)`.
+        TupleStruct(PatTupleStruct),
+
+        /// A type ascription pattern: `foo: f64`.
+        Type(PatType),
+
+        /// Tokens in pattern position not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        /// A pattern that matches any value: `_`.
+        Wild(PatWild),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match pat {
+        //         Pat::Box(pat) => {...}
+        //         Pat::Ident(pat) => {...}
+        //         ...
+        //         Pat::Wild(pat) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A pattern that binds a new variable: `ref mut binding @ SUBPATTERN`.
+    ///
+    /// It may also be a unit struct or struct variant (e.g. `None`), or a
+    /// constant; these cannot be distinguished syntactically.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatIdent {
+        pub attrs: Vec<Attribute>,
+        pub by_ref: Option<Token![ref]>,
+        pub mutability: Option<Token![mut]>,
+        pub ident: Ident,
+        pub subpat: Option<(Token![@], Box<Pat>)>,
+    }
+}
+
+ast_struct! {
+    /// A pattern that matches any one of a set of cases.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatOr {
+        pub attrs: Vec<Attribute>,
+        pub leading_vert: Option<Token![|]>,
+        pub cases: Punctuated<Pat, Token![|]>,
+    }
+}
+
+ast_struct! {
+    /// A parenthesized pattern: `(A | B)`.
+    pub struct PatParen {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub pat: Box<Pat>,
+    }
+}
+
+ast_struct! {
+    /// A reference pattern: `&mut var`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatReference {
+        pub attrs: Vec<Attribute>,
+        pub and_token: Token![&],
+        pub mutability: Option<Token![mut]>,
+        pub pat: Box<Pat>,
+    }
+}
+
+ast_struct! {
+    /// The dots in a tuple or slice pattern: `[0, 1, ..]`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatRest {
+        pub attrs: Vec<Attribute>,
+        pub dot2_token: Token![..],
+    }
+}
+
+ast_struct! {
+    /// A dynamically sized slice pattern: `[a, b, ref i @ .., y, z]`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatSlice {
+        pub attrs: Vec<Attribute>,
+        pub bracket_token: token::Bracket,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A struct or struct variant pattern: `Variant { x, y, .. }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatStruct {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+        pub brace_token: token::Brace,
+        pub fields: Punctuated<FieldPat, Token![,]>,
+        pub rest: Option<PatRest>,
+    }
+}
+
+ast_struct! {
+    /// A tuple pattern: `(a, b)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatTuple {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A tuple struct or tuple variant pattern: `Variant(x, y, .., z)`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatTupleStruct {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A type ascription pattern: `foo: f64`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatType {
+        pub attrs: Vec<Attribute>,
+        pub pat: Box<Pat>,
+        pub colon_token: Token![:],
+        pub ty: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A pattern that matches any value: `_`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct PatWild {
+        pub attrs: Vec<Attribute>,
+        pub underscore_token: Token![_],
+    }
+}
+
+ast_struct! {
+    /// A single field in a struct pattern.
+    ///
+    /// Patterns like the fields of Foo `{ x, ref y, ref mut z }` are treated
+    /// the same as `x: x, y: ref y, z: ref mut z` but there is no colon token.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct FieldPat {
+        pub attrs: Vec<Attribute>,
+        pub member: Member,
+        pub colon_token: Option<Token![:]>,
+        pub pat: Box<Pat>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::{ParseBuffer, ParseStream, Result};
+    use crate::path;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Pat {
+        /// Parse a pattern that does _not_ involve `|` at the top level.
+        ///
+        /// This parser matches the behavior of the `$:pat_param` macro_rules
+        /// matcher, and on editions prior to Rust 2021, the behavior of
+        /// `$:pat`.
+        ///
+        /// In Rust syntax, some examples of where this syntax would occur are
+        /// in the argument pattern of functions and closures. Patterns using
+        /// `|` are not allowed to occur in these positions.
+        ///
+        /// ```compile_fail
+        /// fn f(Some(_) | None: Option<T>) {
+        ///     let _ = |Some(_) | None: Option<T>| {};
+        ///     //       ^^^^^^^^^^^^^^^^^^^^^^^^^??? :(
+        /// }
+        /// ```
+        ///
+        /// ```console
+        /// error: top-level or-patterns are not allowed in function parameters
+        ///  --> src/main.rs:1:6
+        ///   |
+        /// 1 | fn f(Some(_) | None: Option<T>) {
+        ///   |      ^^^^^^^^^^^^^^ help: wrap the pattern in parentheses: `(Some(_) | None)`
+        /// ```
+        pub fn parse_single(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Ident)
+                && (input.peek2(Token![::])
+                    || input.peek2(Token![!])
+                    || input.peek2(token::Brace)
+                    || input.peek2(token::Paren)
+                    || input.peek2(Token![..]))
+                || input.peek(Token![self]) && input.peek2(Token![::])
+                || lookahead.peek(Token![::])
+                || lookahead.peek(Token![<])
+                || input.peek(Token![Self])
+                || input.peek(Token![super])
+                || input.peek(Token![crate])
+            {
+                pat_path_or_macro_or_struct_or_range(input)
+            } else if lookahead.peek(Token![_]) {
+                input.call(pat_wild).map(Pat::Wild)
+            } else if input.peek(Token![box]) {
+                pat_box(begin, input)
+            } else if input.peek(Token![-]) || lookahead.peek(Lit) || lookahead.peek(Token![const])
+            {
+                pat_lit_or_range(input)
+            } else if lookahead.peek(Token![ref])
+                || lookahead.peek(Token![mut])
+                || input.peek(Token![self])
+                || input.peek(Ident)
+            {
+                input.call(pat_ident).map(Pat::Ident)
+            } else if lookahead.peek(Token![&]) {
+                input.call(pat_reference).map(Pat::Reference)
+            } else if lookahead.peek(token::Paren) {
+                input.call(pat_paren_or_tuple)
+            } else if lookahead.peek(token::Bracket) {
+                input.call(pat_slice).map(Pat::Slice)
+            } else if lookahead.peek(Token![..]) && !input.peek(Token![...]) {
+                pat_range_half_open(input)
+            } else if lookahead.peek(Token![const]) {
+                input.call(pat_const).map(Pat::Verbatim)
+            } else {
+                Err(lookahead.error())
+            }
+        }
+
+        /// Parse a pattern, possibly involving `|`, but not a leading `|`.
+        pub fn parse_multi(input: ParseStream) -> Result<Self> {
+            multi_pat_impl(input, None)
+        }
+
+        /// Parse a pattern, possibly involving `|`, possibly including a
+        /// leading `|`.
+        ///
+        /// This parser matches the behavior of the Rust 2021 edition's `$:pat`
+        /// macro_rules matcher.
+        ///
+        /// In Rust syntax, an example of where this syntax would occur is in
+        /// the pattern of a `match` arm, where the language permits an optional
+        /// leading `|`, although it is not idiomatic to write one there in
+        /// handwritten code.
+        ///
+        /// ```
+        /// # let wat = None;
+        /// match wat {
+        ///     | None | Some(false) => {}
+        ///     | Some(true) => {}
+        /// }
+        /// ```
+        ///
+        /// The compiler accepts it only to facilitate some situations in
+        /// macro-generated code where a macro author might need to write:
+        ///
+        /// ```
+        /// # macro_rules! doc {
+        /// #     ($value:expr, ($($conditions1:pat),*), ($($conditions2:pat),*), $then:expr) => {
+        /// match $value {
+        ///     $(| $conditions1)* $(| $conditions2)* => $then
+        /// }
+        /// #     };
+        /// # }
+        /// #
+        /// # doc!(true, (true), (false), {});
+        /// # doc!(true, (), (true, false), {});
+        /// # doc!(true, (true, false), (), {});
+        /// ```
+        ///
+        /// Expressing the same thing correctly in the case that either one (but
+        /// not both) of `$conditions1` and `$conditions2` might be empty,
+        /// without leading `|`, is complex.
+        ///
+        /// Use [`Pat::parse_multi`] instead if you are not intending to support
+        /// macro-generated macro input.
+        pub fn parse_multi_with_leading_vert(input: ParseStream) -> Result<Self> {
+            let leading_vert: Option<Token![|]> = input.parse()?;
+            multi_pat_impl(input, leading_vert)
+        }
+    }
+
+    fn multi_pat_impl(input: ParseStream, leading_vert: Option<Token![|]>) -> Result<Pat> {
+        let mut pat = Pat::parse_single(input)?;
+        if leading_vert.is_some()
+            || input.peek(Token![|]) && !input.peek(Token![||]) && !input.peek(Token![|=])
+        {
+            let mut cases = Punctuated::new();
+            cases.push_value(pat);
+            while input.peek(Token![|]) && !input.peek(Token![||]) && !input.peek(Token![|=]) {
+                let punct = input.parse()?;
+                cases.push_punct(punct);
+                let pat = Pat::parse_single(input)?;
+                cases.push_value(pat);
+            }
+            pat = Pat::Or(PatOr {
+                attrs: Vec::new(),
+                leading_vert,
+                cases,
+            });
+        }
+        Ok(pat)
+    }
+
+    fn pat_path_or_macro_or_struct_or_range(input: ParseStream) -> Result<Pat> {
+        let (qself, path) = path::parsing::qpath(input, true)?;
+
+        if qself.is_none()
+            && input.peek(Token![!])
+            && !input.peek(Token![!=])
+            && path.is_mod_style()
+        {
+            let bang_token: Token![!] = input.parse()?;
+            let (delimiter, tokens) = mac::parse_delimiter(input)?;
+            return Ok(Pat::Macro(ExprMacro {
+                attrs: Vec::new(),
+                mac: Macro {
+                    path,
+                    bang_token,
+                    delimiter,
+                    tokens,
+                },
+            }));
+        }
+
+        if input.peek(token::Brace) {
+            pat_struct(input, qself, path).map(Pat::Struct)
+        } else if input.peek(token::Paren) {
+            pat_tuple_struct(input, qself, path).map(Pat::TupleStruct)
+        } else if input.peek(Token![..]) {
+            pat_range(input, qself, path)
+        } else {
+            Ok(Pat::Path(ExprPath {
+                attrs: Vec::new(),
+                qself,
+                path,
+            }))
+        }
+    }
+
+    fn pat_wild(input: ParseStream) -> Result<PatWild> {
+        Ok(PatWild {
+            attrs: Vec::new(),
+            underscore_token: input.parse()?,
+        })
+    }
+
+    fn pat_box(begin: ParseBuffer, input: ParseStream) -> Result<Pat> {
+        input.parse::<Token![box]>()?;
+        Pat::parse_single(input)?;
+        Ok(Pat::Verbatim(verbatim::between(&begin, input)))
+    }
+
+    fn pat_ident(input: ParseStream) -> Result<PatIdent> {
+        Ok(PatIdent {
+            attrs: Vec::new(),
+            by_ref: input.parse()?,
+            mutability: input.parse()?,
+            ident: input.call(Ident::parse_any)?,
+            subpat: {
+                if input.peek(Token![@]) {
+                    let at_token: Token![@] = input.parse()?;
+                    let subpat = Pat::parse_single(input)?;
+                    Some((at_token, Box::new(subpat)))
+                } else {
+                    None
+                }
+            },
+        })
+    }
+
+    fn pat_tuple_struct(
+        input: ParseStream,
+        qself: Option<QSelf>,
+        path: Path,
+    ) -> Result<PatTupleStruct> {
+        let content;
+        let paren_token = parenthesized!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            elems.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(PatTupleStruct {
+            attrs: Vec::new(),
+            qself,
+            path,
+            paren_token,
+            elems,
+        })
+    }
+
+    fn pat_struct(input: ParseStream, qself: Option<QSelf>, path: Path) -> Result<PatStruct> {
+        let content;
+        let brace_token = braced!(content in input);
+
+        let mut fields = Punctuated::new();
+        let mut rest = None;
+        while !content.is_empty() {
+            let attrs = content.call(Attribute::parse_outer)?;
+            if content.peek(Token![..]) {
+                rest = Some(PatRest {
+                    attrs,
+                    dot2_token: content.parse()?,
+                });
+                break;
+            }
+            let mut value = content.call(field_pat)?;
+            value.attrs = attrs;
+            fields.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct: Token![,] = content.parse()?;
+            fields.push_punct(punct);
+        }
+
+        Ok(PatStruct {
+            attrs: Vec::new(),
+            qself,
+            path,
+            brace_token,
+            fields,
+            rest,
+        })
+    }
+
+    impl Member {
+        fn is_unnamed(&self) -> bool {
+            match self {
+                Member::Named(_) => false,
+                Member::Unnamed(_) => true,
+            }
+        }
+    }
+
+    fn field_pat(input: ParseStream) -> Result<FieldPat> {
+        let begin = input.fork();
+        let boxed: Option<Token![box]> = input.parse()?;
+        let by_ref: Option<Token![ref]> = input.parse()?;
+        let mutability: Option<Token![mut]> = input.parse()?;
+
+        let member = if boxed.is_some() || by_ref.is_some() || mutability.is_some() {
+            input.parse().map(Member::Named)
+        } else {
+            input.parse()
+        }?;
+
+        if boxed.is_none() && by_ref.is_none() && mutability.is_none() && input.peek(Token![:])
+            || member.is_unnamed()
+        {
+            return Ok(FieldPat {
+                attrs: Vec::new(),
+                member,
+                colon_token: Some(input.parse()?),
+                pat: Box::new(Pat::parse_multi_with_leading_vert(input)?),
+            });
+        }
+
+        let ident = match member {
+            Member::Named(ident) => ident,
+            Member::Unnamed(_) => unreachable!(),
+        };
+
+        let pat = if boxed.is_some() {
+            Pat::Verbatim(verbatim::between(&begin, input))
+        } else {
+            Pat::Ident(PatIdent {
+                attrs: Vec::new(),
+                by_ref,
+                mutability,
+                ident: ident.clone(),
+                subpat: None,
+            })
+        };
+
+        Ok(FieldPat {
+            attrs: Vec::new(),
+            member: Member::Named(ident),
+            colon_token: None,
+            pat: Box::new(pat),
+        })
+    }
+
+    fn pat_range(input: ParseStream, qself: Option<QSelf>, path: Path) -> Result<Pat> {
+        let limits = RangeLimits::parse_obsolete(input)?;
+        let end = input.call(pat_range_bound)?;
+        if let (RangeLimits::Closed(_), None) = (&limits, &end) {
+            return Err(input.error("expected range upper bound"));
+        }
+        Ok(Pat::Range(ExprRange {
+            attrs: Vec::new(),
+            start: Some(Box::new(Expr::Path(ExprPath {
+                attrs: Vec::new(),
+                qself,
+                path,
+            }))),
+            limits,
+            end: end.map(PatRangeBound::into_expr),
+        }))
+    }
+
+    fn pat_range_half_open(input: ParseStream) -> Result<Pat> {
+        let limits: RangeLimits = input.parse()?;
+        let end = input.call(pat_range_bound)?;
+        if end.is_some() {
+            Ok(Pat::Range(ExprRange {
+                attrs: Vec::new(),
+                start: None,
+                limits,
+                end: end.map(PatRangeBound::into_expr),
+            }))
+        } else {
+            match limits {
+                RangeLimits::HalfOpen(dot2_token) => Ok(Pat::Rest(PatRest {
+                    attrs: Vec::new(),
+                    dot2_token,
+                })),
+                RangeLimits::Closed(_) => Err(input.error("expected range upper bound")),
+            }
+        }
+    }
+
+    fn pat_paren_or_tuple(input: ParseStream) -> Result<Pat> {
+        let content;
+        let paren_token = parenthesized!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            if content.is_empty() {
+                if elems.is_empty() && !matches!(value, Pat::Rest(_)) {
+                    return Ok(Pat::Paren(PatParen {
+                        attrs: Vec::new(),
+                        paren_token,
+                        pat: Box::new(value),
+                    }));
+                }
+                elems.push_value(value);
+                break;
+            }
+            elems.push_value(value);
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(Pat::Tuple(PatTuple {
+            attrs: Vec::new(),
+            paren_token,
+            elems,
+        }))
+    }
+
+    fn pat_reference(input: ParseStream) -> Result<PatReference> {
+        Ok(PatReference {
+            attrs: Vec::new(),
+            and_token: input.parse()?,
+            mutability: input.parse()?,
+            pat: Box::new(Pat::parse_single(input)?),
+        })
+    }
+
+    fn pat_lit_or_range(input: ParseStream) -> Result<Pat> {
+        let start = input.call(pat_range_bound)?.unwrap();
+        if input.peek(Token![..]) {
+            let limits = RangeLimits::parse_obsolete(input)?;
+            let end = input.call(pat_range_bound)?;
+            if let (RangeLimits::Closed(_), None) = (&limits, &end) {
+                return Err(input.error("expected range upper bound"));
+            }
+            Ok(Pat::Range(ExprRange {
+                attrs: Vec::new(),
+                start: Some(start.into_expr()),
+                limits,
+                end: end.map(PatRangeBound::into_expr),
+            }))
+        } else {
+            Ok(start.into_pat())
+        }
+    }
+
+    // Patterns that can appear on either side of a range pattern.
+    enum PatRangeBound {
+        Const(ExprConst),
+        Lit(ExprLit),
+        Path(ExprPath),
+    }
+
+    impl PatRangeBound {
+        fn into_expr(self) -> Box<Expr> {
+            Box::new(match self {
+                PatRangeBound::Const(pat) => Expr::Const(pat),
+                PatRangeBound::Lit(pat) => Expr::Lit(pat),
+                PatRangeBound::Path(pat) => Expr::Path(pat),
+            })
+        }
+
+        fn into_pat(self) -> Pat {
+            match self {
+                PatRangeBound::Const(pat) => Pat::Const(pat),
+                PatRangeBound::Lit(pat) => Pat::Lit(pat),
+                PatRangeBound::Path(pat) => Pat::Path(pat),
+            }
+        }
+    }
+
+    fn pat_range_bound(input: ParseStream) -> Result<Option<PatRangeBound>> {
+        if input.is_empty()
+            || input.peek(Token![|])
+            || input.peek(Token![=])
+            || input.peek(Token![:]) && !input.peek(Token![::])
+            || input.peek(Token![,])
+            || input.peek(Token![;])
+            || input.peek(Token![if])
+        {
+            return Ok(None);
+        }
+
+        let lookahead = input.lookahead1();
+        let expr = if lookahead.peek(Lit) {
+            PatRangeBound::Lit(input.parse()?)
+        } else if lookahead.peek(Ident)
+            || lookahead.peek(Token![::])
+            || lookahead.peek(Token![<])
+            || lookahead.peek(Token![self])
+            || lookahead.peek(Token![Self])
+            || lookahead.peek(Token![super])
+            || lookahead.peek(Token![crate])
+        {
+            PatRangeBound::Path(input.parse()?)
+        } else if lookahead.peek(Token![const]) {
+            PatRangeBound::Const(input.parse()?)
+        } else {
+            return Err(lookahead.error());
+        };
+
+        Ok(Some(expr))
+    }
+
+    fn pat_slice(input: ParseStream) -> Result<PatSlice> {
+        let content;
+        let bracket_token = bracketed!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            match value {
+                Pat::Range(pat) if pat.start.is_none() || pat.end.is_none() => {
+                    let (start, end) = match pat.limits {
+                        RangeLimits::HalfOpen(dot_dot) => (dot_dot.spans[0], dot_dot.spans[1]),
+                        RangeLimits::Closed(dot_dot_eq) => {
+                            (dot_dot_eq.spans[0], dot_dot_eq.spans[2])
+                        }
+                    };
+                    let msg = "range pattern is not allowed unparenthesized inside slice pattern";
+                    return Err(error::new2(start, end, msg));
+                }
+                _ => {}
+            }
+            elems.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(PatSlice {
+            attrs: Vec::new(),
+            bracket_token,
+            elems,
+        })
+    }
+
+    fn pat_const(input: ParseStream) -> Result<TokenStream> {
+        let begin = input.fork();
+        input.parse::<Token![const]>()?;
+
+        let content;
+        braced!(content in input);
+        content.call(Attribute::parse_inner)?;
+        content.call(Block::parse_within)?;
+
+        Ok(verbatim::between(&begin, input))
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatIdent {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.by_ref.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            if let Some((at_token, subpat)) = &self.subpat {
+                at_token.to_tokens(tokens);
+                subpat.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatOr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.leading_vert.to_tokens(tokens);
+            self.cases.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatParen {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.paren_token.surround(tokens, |tokens| {
+                self.pat.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatReference {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.and_token.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.pat.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatRest {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.dot2_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatSlice {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.bracket_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            path::printing::print_path(tokens, &self.qself, &self.path);
+            self.brace_token.surround(tokens, |tokens| {
+                self.fields.to_tokens(tokens);
+                // NOTE: We need a comma before the dot2 token if it is present.
+                if !self.fields.empty_or_trailing() && self.rest.is_some() {
+                    <Token![,]>::default().to_tokens(tokens);
+                }
+                self.rest.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatTuple {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatTupleStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            path::printing::print_path(tokens, &self.qself, &self.path);
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.pat.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatWild {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.underscore_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for FieldPat {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some(colon_token) = &self.colon_token {
+                self.member.to_tokens(tokens);
+                colon_token.to_tokens(tokens);
+            }
+            self.pat.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/path.rs b/vendor/syn/src/path.rs
new file mode 100644
index 0000000..b9d96e6
--- /dev/null
+++ b/vendor/syn/src/path.rs
@@ -0,0 +1,874 @@
+use super::*;
+use crate::punctuated::Punctuated;
+
+ast_struct! {
+    /// A path at which a named item is exported (e.g. `std::collections::HashMap`).
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Path {
+        pub leading_colon: Option<Token![::]>,
+        pub segments: Punctuated<PathSegment, Token![::]>,
+    }
+}
+
+impl<T> From<T> for Path
+where
+    T: Into<PathSegment>,
+{
+    fn from(segment: T) -> Self {
+        let mut path = Path {
+            leading_colon: None,
+            segments: Punctuated::new(),
+        };
+        path.segments.push_value(segment.into());
+        path
+    }
+}
+
+impl Path {
+    /// Determines whether this is a path of length 1 equal to the given
+    /// ident.
+    ///
+    /// For them to compare equal, it must be the case that:
+    ///
+    /// - the path has no leading colon,
+    /// - the number of path segments is 1,
+    /// - the first path segment has no angle bracketed or parenthesized
+    ///   path arguments, and
+    /// - the ident of the first path segment is equal to the given one.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use proc_macro2::TokenStream;
+    /// use syn::{Attribute, Error, Meta, Result};
+    ///
+    /// fn get_serde_meta_item(attr: &Attribute) -> Result<Option<&TokenStream>> {
+    ///     if attr.path().is_ident("serde") {
+    ///         match &attr.meta {
+    ///             Meta::List(meta) => Ok(Some(&meta.tokens)),
+    ///             bad => Err(Error::new_spanned(bad, "unrecognized attribute")),
+    ///         }
+    ///     } else {
+    ///         Ok(None)
+    ///     }
+    /// }
+    /// ```
+    pub fn is_ident<I>(&self, ident: &I) -> bool
+    where
+        I: ?Sized,
+        Ident: PartialEq<I>,
+    {
+        match self.get_ident() {
+            Some(id) => id == ident,
+            None => false,
+        }
+    }
+
+    /// If this path consists of a single ident, returns the ident.
+    ///
+    /// A path is considered an ident if:
+    ///
+    /// - the path has no leading colon,
+    /// - the number of path segments is 1, and
+    /// - the first path segment has no angle bracketed or parenthesized
+    ///   path arguments.
+    pub fn get_ident(&self) -> Option<&Ident> {
+        if self.leading_colon.is_none()
+            && self.segments.len() == 1
+            && self.segments[0].arguments.is_none()
+        {
+            Some(&self.segments[0].ident)
+        } else {
+            None
+        }
+    }
+
+    /// An error if this path is not a single ident, as defined in `get_ident`.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn require_ident(&self) -> Result<&Ident> {
+        self.get_ident().ok_or_else(|| {
+            crate::error::new2(
+                self.segments.first().unwrap().ident.span(),
+                self.segments.last().unwrap().ident.span(),
+                "expected this path to be an identifier",
+            )
+        })
+    }
+}
+
+ast_struct! {
+    /// A segment of a path together with any path arguments on that segment.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct PathSegment {
+        pub ident: Ident,
+        pub arguments: PathArguments,
+    }
+}
+
+impl<T> From<T> for PathSegment
+where
+    T: Into<Ident>,
+{
+    fn from(ident: T) -> Self {
+        PathSegment {
+            ident: ident.into(),
+            arguments: PathArguments::None,
+        }
+    }
+}
+
+ast_enum! {
+    /// Angle bracketed or parenthesized arguments of a path segment.
+    ///
+    /// ## Angle bracketed
+    ///
+    /// The `<'a, T>` in `std::slice::iter<'a, T>`.
+    ///
+    /// ## Parenthesized
+    ///
+    /// The `(A, B) -> C` in `Fn(A, B) -> C`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum PathArguments {
+        None,
+        /// The `<'a, T>` in `std::slice::iter<'a, T>`.
+        AngleBracketed(AngleBracketedGenericArguments),
+        /// The `(A, B) -> C` in `Fn(A, B) -> C`.
+        Parenthesized(ParenthesizedGenericArguments),
+    }
+}
+
+impl Default for PathArguments {
+    fn default() -> Self {
+        PathArguments::None
+    }
+}
+
+impl PathArguments {
+    pub fn is_empty(&self) -> bool {
+        match self {
+            PathArguments::None => true,
+            PathArguments::AngleBracketed(bracketed) => bracketed.args.is_empty(),
+            PathArguments::Parenthesized(_) => false,
+        }
+    }
+
+    pub fn is_none(&self) -> bool {
+        match self {
+            PathArguments::None => true,
+            PathArguments::AngleBracketed(_) | PathArguments::Parenthesized(_) => false,
+        }
+    }
+}
+
+ast_enum! {
+    /// An individual generic argument, like `'a`, `T`, or `Item = T`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum GenericArgument {
+        /// A lifetime argument.
+        Lifetime(Lifetime),
+        /// A type argument.
+        Type(Type),
+        /// A const expression. Must be inside of a block.
+        ///
+        /// NOTE: Identity expressions are represented as Type arguments, as
+        /// they are indistinguishable syntactically.
+        Const(Expr),
+        /// A binding (equality constraint) on an associated type: the `Item =
+        /// u8` in `Iterator<Item = u8>`.
+        AssocType(AssocType),
+        /// An equality constraint on an associated constant: the `PANIC =
+        /// false` in `Trait<PANIC = false>`.
+        AssocConst(AssocConst),
+        /// An associated type bound: `Iterator<Item: Display>`.
+        Constraint(Constraint),
+    }
+}
+
+ast_struct! {
+    /// Angle bracketed arguments of a path segment: the `<K, V>` in `HashMap<K,
+    /// V>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct AngleBracketedGenericArguments {
+        pub colon2_token: Option<Token![::]>,
+        pub lt_token: Token![<],
+        pub args: Punctuated<GenericArgument, Token![,]>,
+        pub gt_token: Token![>],
+    }
+}
+
+ast_struct! {
+    /// A binding (equality constraint) on an associated type: the `Item = u8`
+    /// in `Iterator<Item = u8>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct AssocType {
+        pub ident: Ident,
+        pub generics: Option<AngleBracketedGenericArguments>,
+        pub eq_token: Token![=],
+        pub ty: Type,
+    }
+}
+
+ast_struct! {
+    /// An equality constraint on an associated constant: the `PANIC = false` in
+    /// `Trait<PANIC = false>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct AssocConst {
+        pub ident: Ident,
+        pub generics: Option<AngleBracketedGenericArguments>,
+        pub eq_token: Token![=],
+        pub value: Expr,
+    }
+}
+
+ast_struct! {
+    /// An associated type bound: `Iterator<Item: Display>`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Constraint {
+        pub ident: Ident,
+        pub generics: Option<AngleBracketedGenericArguments>,
+        pub colon_token: Token![:],
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+    }
+}
+
+ast_struct! {
+    /// Arguments of a function path segment: the `(A, B) -> C` in `Fn(A,B) ->
+    /// C`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ParenthesizedGenericArguments {
+        pub paren_token: token::Paren,
+        /// `(A, B)`
+        pub inputs: Punctuated<Type, Token![,]>,
+        /// `C`
+        pub output: ReturnType,
+    }
+}
+
+ast_struct! {
+    /// The explicit Self type in a qualified path: the `T` in `<T as
+    /// Display>::fmt`.
+    ///
+    /// The actual path, including the trait and the associated item, is stored
+    /// separately. The `position` field represents the index of the associated
+    /// item qualified with this Self type.
+    ///
+    /// ```text
+    /// <Vec<T> as a::b::Trait>::AssociatedItem
+    ///  ^~~~~~    ~~~~~~~~~~~~~~^
+    ///  ty        position = 3
+    ///
+    /// <Vec<T>>::AssociatedItem
+    ///  ^~~~~~   ^
+    ///  ty       position = 0
+    /// ```
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct QSelf {
+        pub lt_token: Token![<],
+        pub ty: Box<Type>,
+        pub position: usize,
+        pub as_token: Option<Token![as]>,
+        pub gt_token: Token![>],
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+
+    use crate::ext::IdentExt;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Path {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Self::parse_helper(input, false)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for GenericArgument {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Lifetime) && !input.peek2(Token![+]) {
+                return Ok(GenericArgument::Lifetime(input.parse()?));
+            }
+
+            if input.peek(Lit) || input.peek(token::Brace) {
+                return const_argument(input).map(GenericArgument::Const);
+            }
+
+            let mut argument: Type = input.parse()?;
+
+            match argument {
+                Type::Path(mut ty)
+                    if ty.qself.is_none()
+                        && ty.path.leading_colon.is_none()
+                        && ty.path.segments.len() == 1
+                        && match &ty.path.segments[0].arguments {
+                            PathArguments::None | PathArguments::AngleBracketed(_) => true,
+                            PathArguments::Parenthesized(_) => false,
+                        } =>
+                {
+                    if let Some(eq_token) = input.parse::<Option<Token![=]>>()? {
+                        let segment = ty.path.segments.pop().unwrap().into_value();
+                        let ident = segment.ident;
+                        let generics = match segment.arguments {
+                            PathArguments::None => None,
+                            PathArguments::AngleBracketed(arguments) => Some(arguments),
+                            PathArguments::Parenthesized(_) => unreachable!(),
+                        };
+                        return if input.peek(Lit) || input.peek(token::Brace) {
+                            Ok(GenericArgument::AssocConst(AssocConst {
+                                ident,
+                                generics,
+                                eq_token,
+                                value: const_argument(input)?,
+                            }))
+                        } else {
+                            Ok(GenericArgument::AssocType(AssocType {
+                                ident,
+                                generics,
+                                eq_token,
+                                ty: input.parse()?,
+                            }))
+                        };
+                    }
+
+                    #[cfg(feature = "full")]
+                    if let Some(colon_token) = input.parse::<Option<Token![:]>>()? {
+                        let segment = ty.path.segments.pop().unwrap().into_value();
+                        return Ok(GenericArgument::Constraint(Constraint {
+                            ident: segment.ident,
+                            generics: match segment.arguments {
+                                PathArguments::None => None,
+                                PathArguments::AngleBracketed(arguments) => Some(arguments),
+                                PathArguments::Parenthesized(_) => unreachable!(),
+                            },
+                            colon_token,
+                            bounds: {
+                                let mut bounds = Punctuated::new();
+                                loop {
+                                    if input.peek(Token![,]) || input.peek(Token![>]) {
+                                        break;
+                                    }
+                                    let value: TypeParamBound = input.parse()?;
+                                    bounds.push_value(value);
+                                    if !input.peek(Token![+]) {
+                                        break;
+                                    }
+                                    let punct: Token![+] = input.parse()?;
+                                    bounds.push_punct(punct);
+                                }
+                                bounds
+                            },
+                        }));
+                    }
+
+                    argument = Type::Path(ty);
+                }
+                _ => {}
+            }
+
+            Ok(GenericArgument::Type(argument))
+        }
+    }
+
+    pub(crate) fn const_argument(input: ParseStream) -> Result<Expr> {
+        let lookahead = input.lookahead1();
+
+        if input.peek(Lit) {
+            let lit = input.parse()?;
+            return Ok(Expr::Lit(lit));
+        }
+
+        if input.peek(Ident) {
+            let ident: Ident = input.parse()?;
+            return Ok(Expr::Path(ExprPath {
+                attrs: Vec::new(),
+                qself: None,
+                path: Path::from(ident),
+            }));
+        }
+
+        if input.peek(token::Brace) {
+            #[cfg(feature = "full")]
+            {
+                let block: ExprBlock = input.parse()?;
+                return Ok(Expr::Block(block));
+            }
+
+            #[cfg(not(feature = "full"))]
+            {
+                let begin = input.fork();
+                let content;
+                braced!(content in input);
+                content.parse::<Expr>()?;
+                let verbatim = verbatim::between(&begin, input);
+                return Ok(Expr::Verbatim(verbatim));
+            }
+        }
+
+        Err(lookahead.error())
+    }
+
+    impl AngleBracketedGenericArguments {
+        /// Parse `::<…>` with mandatory leading `::`.
+        ///
+        /// The ordinary [`Parse`] impl for `AngleBracketedGenericArguments`
+        /// parses optional leading `::`.
+        #[cfg(feature = "full")]
+        #[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "full"))))]
+        pub fn parse_turbofish(input: ParseStream) -> Result<Self> {
+            let colon2_token: Token![::] = input.parse()?;
+            Self::do_parse(Some(colon2_token), input)
+        }
+
+        fn do_parse(colon2_token: Option<Token![::]>, input: ParseStream) -> Result<Self> {
+            Ok(AngleBracketedGenericArguments {
+                colon2_token,
+                lt_token: input.parse()?,
+                args: {
+                    let mut args = Punctuated::new();
+                    loop {
+                        if input.peek(Token![>]) {
+                            break;
+                        }
+                        let value: GenericArgument = input.parse()?;
+                        args.push_value(value);
+                        if input.peek(Token![>]) {
+                            break;
+                        }
+                        let punct: Token![,] = input.parse()?;
+                        args.push_punct(punct);
+                    }
+                    args
+                },
+                gt_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for AngleBracketedGenericArguments {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let colon2_token: Option<Token![::]> = input.parse()?;
+            Self::do_parse(colon2_token, input)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ParenthesizedGenericArguments {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(ParenthesizedGenericArguments {
+                paren_token: parenthesized!(content in input),
+                inputs: content.parse_terminated(Type::parse, Token![,])?,
+                output: input.call(ReturnType::without_plus)?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for PathSegment {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Self::parse_helper(input, false)
+        }
+    }
+
+    impl PathSegment {
+        fn parse_helper(input: ParseStream, expr_style: bool) -> Result<Self> {
+            if input.peek(Token![super])
+                || input.peek(Token![self])
+                || input.peek(Token![crate])
+                || cfg!(feature = "full") && input.peek(Token![try])
+            {
+                let ident = input.call(Ident::parse_any)?;
+                return Ok(PathSegment::from(ident));
+            }
+
+            let ident = if input.peek(Token![Self]) {
+                input.call(Ident::parse_any)?
+            } else {
+                input.parse()?
+            };
+
+            if !expr_style && input.peek(Token![<]) && !input.peek(Token![<=])
+                || input.peek(Token![::]) && input.peek3(Token![<])
+            {
+                Ok(PathSegment {
+                    ident,
+                    arguments: PathArguments::AngleBracketed(input.parse()?),
+                })
+            } else {
+                Ok(PathSegment::from(ident))
+            }
+        }
+    }
+
+    impl Path {
+        /// Parse a `Path` containing no path arguments on any of its segments.
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// use syn::{Path, Result, Token};
+        /// use syn::parse::{Parse, ParseStream};
+        ///
+        /// // A simplified single `use` statement like:
+        /// //
+        /// //     use std::collections::HashMap;
+        /// //
+        /// // Note that generic parameters are not allowed in a `use` statement
+        /// // so the following must not be accepted.
+        /// //
+        /// //     use a::<b>::c;
+        /// struct SingleUse {
+        ///     use_token: Token![use],
+        ///     path: Path,
+        /// }
+        ///
+        /// impl Parse for SingleUse {
+        ///     fn parse(input: ParseStream) -> Result<Self> {
+        ///         Ok(SingleUse {
+        ///             use_token: input.parse()?,
+        ///             path: input.call(Path::parse_mod_style)?,
+        ///         })
+        ///     }
+        /// }
+        /// ```
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn parse_mod_style(input: ParseStream) -> Result<Self> {
+            Ok(Path {
+                leading_colon: input.parse()?,
+                segments: {
+                    let mut segments = Punctuated::new();
+                    loop {
+                        if !input.peek(Ident)
+                            && !input.peek(Token![super])
+                            && !input.peek(Token![self])
+                            && !input.peek(Token![Self])
+                            && !input.peek(Token![crate])
+                        {
+                            break;
+                        }
+                        let ident = Ident::parse_any(input)?;
+                        segments.push_value(PathSegment::from(ident));
+                        if !input.peek(Token![::]) {
+                            break;
+                        }
+                        let punct = input.parse()?;
+                        segments.push_punct(punct);
+                    }
+                    if segments.is_empty() {
+                        return Err(input.parse::<Ident>().unwrap_err());
+                    } else if segments.trailing_punct() {
+                        return Err(input.error("expected path segment after `::`"));
+                    }
+                    segments
+                },
+            })
+        }
+
+        pub(crate) fn parse_helper(input: ParseStream, expr_style: bool) -> Result<Self> {
+            let mut path = Path {
+                leading_colon: input.parse()?,
+                segments: {
+                    let mut segments = Punctuated::new();
+                    let value = PathSegment::parse_helper(input, expr_style)?;
+                    segments.push_value(value);
+                    segments
+                },
+            };
+            Path::parse_rest(input, &mut path, expr_style)?;
+            Ok(path)
+        }
+
+        pub(crate) fn parse_rest(
+            input: ParseStream,
+            path: &mut Self,
+            expr_style: bool,
+        ) -> Result<()> {
+            while input.peek(Token![::]) && !input.peek3(token::Paren) {
+                let punct: Token![::] = input.parse()?;
+                path.segments.push_punct(punct);
+                let value = PathSegment::parse_helper(input, expr_style)?;
+                path.segments.push_value(value);
+            }
+            Ok(())
+        }
+
+        pub(crate) fn is_mod_style(&self) -> bool {
+            self.segments
+                .iter()
+                .all(|segment| segment.arguments.is_none())
+        }
+    }
+
+    pub(crate) fn qpath(input: ParseStream, expr_style: bool) -> Result<(Option<QSelf>, Path)> {
+        if input.peek(Token![<]) {
+            let lt_token: Token![<] = input.parse()?;
+            let this: Type = input.parse()?;
+            let path = if input.peek(Token![as]) {
+                let as_token: Token![as] = input.parse()?;
+                let path: Path = input.parse()?;
+                Some((as_token, path))
+            } else {
+                None
+            };
+            let gt_token: Token![>] = input.parse()?;
+            let colon2_token: Token![::] = input.parse()?;
+            let mut rest = Punctuated::new();
+            loop {
+                let path = PathSegment::parse_helper(input, expr_style)?;
+                rest.push_value(path);
+                if !input.peek(Token![::]) {
+                    break;
+                }
+                let punct: Token![::] = input.parse()?;
+                rest.push_punct(punct);
+            }
+            let (position, as_token, path) = match path {
+                Some((as_token, mut path)) => {
+                    let pos = path.segments.len();
+                    path.segments.push_punct(colon2_token);
+                    path.segments.extend(rest.into_pairs());
+                    (pos, Some(as_token), path)
+                }
+                None => {
+                    let path = Path {
+                        leading_colon: Some(colon2_token),
+                        segments: rest,
+                    };
+                    (0, None, path)
+                }
+            };
+            let qself = QSelf {
+                lt_token,
+                ty: Box::new(this),
+                position,
+                as_token,
+                gt_token,
+            };
+            Ok((Some(qself), path))
+        } else {
+            let path = Path::parse_helper(input, expr_style)?;
+            Ok((None, path))
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+pub(crate) mod printing {
+    use super::*;
+    use crate::print::TokensOrDefault;
+    #[cfg(feature = "parsing")]
+    use crate::spanned::Spanned;
+    #[cfg(feature = "parsing")]
+    use proc_macro2::Span;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+    use std::cmp;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Path {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.leading_colon.to_tokens(tokens);
+            self.segments.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PathSegment {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.arguments.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for PathArguments {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                PathArguments::None => {}
+                PathArguments::AngleBracketed(arguments) => {
+                    arguments.to_tokens(tokens);
+                }
+                PathArguments::Parenthesized(arguments) => {
+                    arguments.to_tokens(tokens);
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for GenericArgument {
+        #[allow(clippy::match_same_arms)]
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                GenericArgument::Lifetime(lt) => lt.to_tokens(tokens),
+                GenericArgument::Type(ty) => ty.to_tokens(tokens),
+                GenericArgument::Const(expr) => match expr {
+                    Expr::Lit(expr) => expr.to_tokens(tokens),
+
+                    Expr::Path(expr)
+                        if expr.attrs.is_empty()
+                            && expr.qself.is_none()
+                            && expr.path.get_ident().is_some() =>
+                    {
+                        expr.to_tokens(tokens);
+                    }
+
+                    #[cfg(feature = "full")]
+                    Expr::Block(expr) => expr.to_tokens(tokens),
+
+                    #[cfg(not(feature = "full"))]
+                    Expr::Verbatim(expr) => expr.to_tokens(tokens),
+
+                    // ERROR CORRECTION: Add braces to make sure that the
+                    // generated code is valid.
+                    _ => token::Brace::default().surround(tokens, |tokens| {
+                        expr.to_tokens(tokens);
+                    }),
+                },
+                GenericArgument::AssocType(assoc) => assoc.to_tokens(tokens),
+                GenericArgument::AssocConst(assoc) => assoc.to_tokens(tokens),
+                GenericArgument::Constraint(constraint) => constraint.to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for AngleBracketedGenericArguments {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.colon2_token.to_tokens(tokens);
+            self.lt_token.to_tokens(tokens);
+
+            // Print lifetimes before types/consts/bindings, regardless of their
+            // order in self.args.
+            let mut trailing_or_empty = true;
+            for param in self.args.pairs() {
+                match param.value() {
+                    GenericArgument::Lifetime(_) => {
+                        param.to_tokens(tokens);
+                        trailing_or_empty = param.punct().is_some();
+                    }
+                    GenericArgument::Type(_)
+                    | GenericArgument::Const(_)
+                    | GenericArgument::AssocType(_)
+                    | GenericArgument::AssocConst(_)
+                    | GenericArgument::Constraint(_) => {}
+                }
+            }
+            for param in self.args.pairs() {
+                match param.value() {
+                    GenericArgument::Type(_)
+                    | GenericArgument::Const(_)
+                    | GenericArgument::AssocType(_)
+                    | GenericArgument::AssocConst(_)
+                    | GenericArgument::Constraint(_) => {
+                        if !trailing_or_empty {
+                            <Token![,]>::default().to_tokens(tokens);
+                        }
+                        param.to_tokens(tokens);
+                        trailing_or_empty = param.punct().is_some();
+                    }
+                    GenericArgument::Lifetime(_) => {}
+                }
+            }
+
+            self.gt_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for AssocType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for AssocConst {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.eq_token.to_tokens(tokens);
+            self.value.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Constraint {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.ident.to_tokens(tokens);
+            self.generics.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ParenthesizedGenericArguments {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.paren_token.surround(tokens, |tokens| {
+                self.inputs.to_tokens(tokens);
+            });
+            self.output.to_tokens(tokens);
+        }
+    }
+
+    pub(crate) fn print_path(tokens: &mut TokenStream, qself: &Option<QSelf>, path: &Path) {
+        let qself = match qself {
+            Some(qself) => qself,
+            None => {
+                path.to_tokens(tokens);
+                return;
+            }
+        };
+        qself.lt_token.to_tokens(tokens);
+        qself.ty.to_tokens(tokens);
+
+        let pos = cmp::min(qself.position, path.segments.len());
+        let mut segments = path.segments.pairs();
+        if pos > 0 {
+            TokensOrDefault(&qself.as_token).to_tokens(tokens);
+            path.leading_colon.to_tokens(tokens);
+            for (i, segment) in segments.by_ref().take(pos).enumerate() {
+                if i + 1 == pos {
+                    segment.value().to_tokens(tokens);
+                    qself.gt_token.to_tokens(tokens);
+                    segment.punct().to_tokens(tokens);
+                } else {
+                    segment.to_tokens(tokens);
+                }
+            }
+        } else {
+            qself.gt_token.to_tokens(tokens);
+            path.leading_colon.to_tokens(tokens);
+        }
+        for segment in segments {
+            segment.to_tokens(tokens);
+        }
+    }
+
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(all(feature = "parsing", feature = "printing"))))]
+    impl Spanned for QSelf {
+        fn span(&self) -> Span {
+            struct QSelfDelimiters<'a>(&'a QSelf);
+
+            impl<'a> ToTokens for QSelfDelimiters<'a> {
+                fn to_tokens(&self, tokens: &mut TokenStream) {
+                    self.0.lt_token.to_tokens(tokens);
+                    self.0.gt_token.to_tokens(tokens);
+                }
+            }
+
+            QSelfDelimiters(self).span()
+        }
+    }
+}
diff --git a/vendor/syn/src/print.rs b/vendor/syn/src/print.rs
new file mode 100644
index 0000000..0740993
--- /dev/null
+++ b/vendor/syn/src/print.rs
@@ -0,0 +1,16 @@
+use proc_macro2::TokenStream;
+use quote::ToTokens;
+
+pub(crate) struct TokensOrDefault<'a, T: 'a>(pub &'a Option<T>);
+
+impl<'a, T> ToTokens for TokensOrDefault<'a, T>
+where
+    T: ToTokens + Default,
+{
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        match self.0 {
+            Some(t) => t.to_tokens(tokens),
+            None => T::default().to_tokens(tokens),
+        }
+    }
+}
diff --git a/vendor/syn/src/punctuated.rs b/vendor/syn/src/punctuated.rs
new file mode 100644
index 0000000..3ea8a1d
--- /dev/null
+++ b/vendor/syn/src/punctuated.rs
@@ -0,0 +1,1108 @@
+//! A punctuated sequence of syntax tree nodes separated by punctuation.
+//!
+//! Lots of things in Rust are punctuated sequences.
+//!
+//! - The fields of a struct are `Punctuated<Field, Token![,]>`.
+//! - The segments of a path are `Punctuated<PathSegment, Token![::]>`.
+//! - The bounds on a generic parameter are `Punctuated<TypeParamBound,
+//!   Token![+]>`.
+//! - The arguments to a function call are `Punctuated<Expr, Token![,]>`.
+//!
+//! This module provides a common representation for these punctuated sequences
+//! in the form of the [`Punctuated<T, P>`] type. We store a vector of pairs of
+//! syntax tree node + punctuation, where every node in the sequence is followed
+//! by punctuation except for possibly the final one.
+//!
+//! [`Punctuated<T, P>`]: Punctuated
+//!
+//! ```text
+//! a_function_call(arg1, arg2, arg3);
+//!                 ~~~~^ ~~~~^ ~~~~
+//! ```
+
+#[cfg(feature = "extra-traits")]
+use std::fmt::{self, Debug};
+#[cfg(feature = "extra-traits")]
+use std::hash::{Hash, Hasher};
+#[cfg(any(feature = "full", feature = "derive"))]
+use std::iter;
+use std::ops::{Index, IndexMut};
+use std::option;
+use std::slice;
+use std::vec;
+
+use crate::drops::{NoDrop, TrivialDrop};
+#[cfg(feature = "parsing")]
+use crate::parse::{Parse, ParseStream, Result};
+#[cfg(feature = "parsing")]
+use crate::token::Token;
+
+/// **A punctuated sequence of syntax tree nodes of type `T` separated by
+/// punctuation of type `P`.**
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct Punctuated<T, P> {
+    inner: Vec<(T, P)>,
+    last: Option<Box<T>>,
+}
+
+impl<T, P> Punctuated<T, P> {
+    /// Creates an empty punctuated sequence.
+    pub const fn new() -> Self {
+        Punctuated {
+            inner: Vec::new(),
+            last: None,
+        }
+    }
+
+    /// Determines whether this punctuated sequence is empty, meaning it
+    /// contains no syntax tree nodes or punctuation.
+    pub fn is_empty(&self) -> bool {
+        self.inner.len() == 0 && self.last.is_none()
+    }
+
+    /// Returns the number of syntax tree nodes in this punctuated sequence.
+    ///
+    /// This is the number of nodes of type `T`, not counting the punctuation of
+    /// type `P`.
+    pub fn len(&self) -> usize {
+        self.inner.len() + if self.last.is_some() { 1 } else { 0 }
+    }
+
+    /// Borrows the first element in this sequence.
+    pub fn first(&self) -> Option<&T> {
+        self.iter().next()
+    }
+
+    /// Mutably borrows the first element in this sequence.
+    pub fn first_mut(&mut self) -> Option<&mut T> {
+        self.iter_mut().next()
+    }
+
+    /// Borrows the last element in this sequence.
+    pub fn last(&self) -> Option<&T> {
+        self.iter().next_back()
+    }
+
+    /// Mutably borrows the last element in this sequence.
+    pub fn last_mut(&mut self) -> Option<&mut T> {
+        self.iter_mut().next_back()
+    }
+
+    /// Returns an iterator over borrowed syntax tree nodes of type `&T`.
+    pub fn iter(&self) -> Iter<T> {
+        Iter {
+            inner: Box::new(NoDrop::new(PrivateIter {
+                inner: self.inner.iter(),
+                last: self.last.as_ref().map(Box::as_ref).into_iter(),
+            })),
+        }
+    }
+
+    /// Returns an iterator over mutably borrowed syntax tree nodes of type
+    /// `&mut T`.
+    pub fn iter_mut(&mut self) -> IterMut<T> {
+        IterMut {
+            inner: Box::new(NoDrop::new(PrivateIterMut {
+                inner: self.inner.iter_mut(),
+                last: self.last.as_mut().map(Box::as_mut).into_iter(),
+            })),
+        }
+    }
+
+    /// Returns an iterator over the contents of this sequence as borrowed
+    /// punctuated pairs.
+    pub fn pairs(&self) -> Pairs<T, P> {
+        Pairs {
+            inner: self.inner.iter(),
+            last: self.last.as_ref().map(Box::as_ref).into_iter(),
+        }
+    }
+
+    /// Returns an iterator over the contents of this sequence as mutably
+    /// borrowed punctuated pairs.
+    pub fn pairs_mut(&mut self) -> PairsMut<T, P> {
+        PairsMut {
+            inner: self.inner.iter_mut(),
+            last: self.last.as_mut().map(Box::as_mut).into_iter(),
+        }
+    }
+
+    /// Returns an iterator over the contents of this sequence as owned
+    /// punctuated pairs.
+    pub fn into_pairs(self) -> IntoPairs<T, P> {
+        IntoPairs {
+            inner: self.inner.into_iter(),
+            last: self.last.map(|t| *t).into_iter(),
+        }
+    }
+
+    /// Appends a syntax tree node onto the end of this punctuated sequence. The
+    /// sequence must already have a trailing punctuation, or be empty.
+    ///
+    /// Use [`push`] instead if the punctuated sequence may or may not already
+    /// have trailing punctuation.
+    ///
+    /// [`push`]: Punctuated::push
+    ///
+    /// # Panics
+    ///
+    /// Panics if the sequence is nonempty and does not already have a trailing
+    /// punctuation.
+    pub fn push_value(&mut self, value: T) {
+        assert!(
+            self.empty_or_trailing(),
+            "Punctuated::push_value: cannot push value if Punctuated is missing trailing punctuation",
+        );
+
+        self.last = Some(Box::new(value));
+    }
+
+    /// Appends a trailing punctuation onto the end of this punctuated sequence.
+    /// The sequence must be non-empty and must not already have trailing
+    /// punctuation.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the sequence is empty or already has a trailing punctuation.
+    pub fn push_punct(&mut self, punctuation: P) {
+        assert!(
+            self.last.is_some(),
+            "Punctuated::push_punct: cannot push punctuation if Punctuated is empty or already has trailing punctuation",
+        );
+
+        let last = self.last.take().unwrap();
+        self.inner.push((*last, punctuation));
+    }
+
+    /// Removes the last punctuated pair from this sequence, or `None` if the
+    /// sequence is empty.
+    pub fn pop(&mut self) -> Option<Pair<T, P>> {
+        if self.last.is_some() {
+            self.last.take().map(|t| Pair::End(*t))
+        } else {
+            self.inner.pop().map(|(t, p)| Pair::Punctuated(t, p))
+        }
+    }
+
+    /// Removes the trailing punctuation from this punctuated sequence, or
+    /// `None` if there isn't any.
+    pub fn pop_punct(&mut self) -> Option<P> {
+        if self.last.is_some() {
+            None
+        } else {
+            let (t, p) = self.inner.pop()?;
+            self.last = Some(Box::new(t));
+            Some(p)
+        }
+    }
+
+    /// Determines whether this punctuated sequence ends with a trailing
+    /// punctuation.
+    pub fn trailing_punct(&self) -> bool {
+        self.last.is_none() && !self.is_empty()
+    }
+
+    /// Returns true if either this `Punctuated` is empty, or it has a trailing
+    /// punctuation.
+    ///
+    /// Equivalent to `punctuated.is_empty() || punctuated.trailing_punct()`.
+    pub fn empty_or_trailing(&self) -> bool {
+        self.last.is_none()
+    }
+
+    /// Appends a syntax tree node onto the end of this punctuated sequence.
+    ///
+    /// If there is not a trailing punctuation in this sequence when this method
+    /// is called, the default value of punctuation type `P` is inserted before
+    /// the given value of type `T`.
+    pub fn push(&mut self, value: T)
+    where
+        P: Default,
+    {
+        if !self.empty_or_trailing() {
+            self.push_punct(Default::default());
+        }
+        self.push_value(value);
+    }
+
+    /// Inserts an element at position `index`.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `index` is greater than the number of elements previously in
+    /// this punctuated sequence.
+    pub fn insert(&mut self, index: usize, value: T)
+    where
+        P: Default,
+    {
+        assert!(
+            index <= self.len(),
+            "Punctuated::insert: index out of range",
+        );
+
+        if index == self.len() {
+            self.push(value);
+        } else {
+            self.inner.insert(index, (value, Default::default()));
+        }
+    }
+
+    /// Clears the sequence of all values and punctuation, making it empty.
+    pub fn clear(&mut self) {
+        self.inner.clear();
+        self.last = None;
+    }
+
+    /// Parses zero or more occurrences of `T` separated by punctuation of type
+    /// `P`, with optional trailing punctuation.
+    ///
+    /// Parsing continues until the end of this parse stream. The entire content
+    /// of this parse stream must consist of `T` and `P`.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_terminated(input: ParseStream) -> Result<Self>
+    where
+        T: Parse,
+        P: Parse,
+    {
+        Self::parse_terminated_with(input, T::parse)
+    }
+
+    /// Parses zero or more occurrences of `T` using the given parse function,
+    /// separated by punctuation of type `P`, with optional trailing
+    /// punctuation.
+    ///
+    /// Like [`parse_terminated`], the entire content of this stream is expected
+    /// to be parsed.
+    ///
+    /// [`parse_terminated`]: Punctuated::parse_terminated
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_terminated_with(
+        input: ParseStream,
+        parser: fn(ParseStream) -> Result<T>,
+    ) -> Result<Self>
+    where
+        P: Parse,
+    {
+        let mut punctuated = Punctuated::new();
+
+        loop {
+            if input.is_empty() {
+                break;
+            }
+            let value = parser(input)?;
+            punctuated.push_value(value);
+            if input.is_empty() {
+                break;
+            }
+            let punct = input.parse()?;
+            punctuated.push_punct(punct);
+        }
+
+        Ok(punctuated)
+    }
+
+    /// Parses one or more occurrences of `T` separated by punctuation of type
+    /// `P`, not accepting trailing punctuation.
+    ///
+    /// Parsing continues as long as punctuation `P` is present at the head of
+    /// the stream. This method returns upon parsing a `T` and observing that it
+    /// is not followed by a `P`, even if there are remaining tokens in the
+    /// stream.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_separated_nonempty(input: ParseStream) -> Result<Self>
+    where
+        T: Parse,
+        P: Token + Parse,
+    {
+        Self::parse_separated_nonempty_with(input, T::parse)
+    }
+
+    /// Parses one or more occurrences of `T` using the given parse function,
+    /// separated by punctuation of type `P`, not accepting trailing
+    /// punctuation.
+    ///
+    /// Like [`parse_separated_nonempty`], may complete early without parsing
+    /// the entire content of this stream.
+    ///
+    /// [`parse_separated_nonempty`]: Punctuated::parse_separated_nonempty
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    pub fn parse_separated_nonempty_with(
+        input: ParseStream,
+        parser: fn(ParseStream) -> Result<T>,
+    ) -> Result<Self>
+    where
+        P: Token + Parse,
+    {
+        let mut punctuated = Punctuated::new();
+
+        loop {
+            let value = parser(input)?;
+            punctuated.push_value(value);
+            if !P::peek(input.cursor()) {
+                break;
+            }
+            let punct = input.parse()?;
+            punctuated.push_punct(punct);
+        }
+
+        Ok(punctuated)
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl<T, P> Clone for Punctuated<T, P>
+where
+    T: Clone,
+    P: Clone,
+{
+    fn clone(&self) -> Self {
+        Punctuated {
+            inner: self.inner.clone(),
+            last: self.last.clone(),
+        }
+    }
+
+    fn clone_from(&mut self, other: &Self) {
+        self.inner.clone_from(&other.inner);
+        self.last.clone_from(&other.last);
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl<T, P> Eq for Punctuated<T, P>
+where
+    T: Eq,
+    P: Eq,
+{
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl<T, P> PartialEq for Punctuated<T, P>
+where
+    T: PartialEq,
+    P: PartialEq,
+{
+    fn eq(&self, other: &Self) -> bool {
+        let Punctuated { inner, last } = self;
+        *inner == other.inner && *last == other.last
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl<T, P> Hash for Punctuated<T, P>
+where
+    T: Hash,
+    P: Hash,
+{
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        let Punctuated { inner, last } = self;
+        inner.hash(state);
+        last.hash(state);
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl<T: Debug, P: Debug> Debug for Punctuated<T, P> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut list = f.debug_list();
+        for (t, p) in &self.inner {
+            list.entry(t);
+            list.entry(p);
+        }
+        if let Some(last) = &self.last {
+            list.entry(last);
+        }
+        list.finish()
+    }
+}
+
+impl<T, P> FromIterator<T> for Punctuated<T, P>
+where
+    P: Default,
+{
+    fn from_iter<I: IntoIterator<Item = T>>(i: I) -> Self {
+        let mut ret = Punctuated::new();
+        ret.extend(i);
+        ret
+    }
+}
+
+impl<T, P> Extend<T> for Punctuated<T, P>
+where
+    P: Default,
+{
+    fn extend<I: IntoIterator<Item = T>>(&mut self, i: I) {
+        for value in i {
+            self.push(value);
+        }
+    }
+}
+
+impl<T, P> FromIterator<Pair<T, P>> for Punctuated<T, P> {
+    fn from_iter<I: IntoIterator<Item = Pair<T, P>>>(i: I) -> Self {
+        let mut ret = Punctuated::new();
+        do_extend(&mut ret, i.into_iter());
+        ret
+    }
+}
+
+impl<T, P> Extend<Pair<T, P>> for Punctuated<T, P>
+where
+    P: Default,
+{
+    fn extend<I: IntoIterator<Item = Pair<T, P>>>(&mut self, i: I) {
+        if !self.empty_or_trailing() {
+            self.push_punct(P::default());
+        }
+        do_extend(self, i.into_iter());
+    }
+}
+
+fn do_extend<T, P, I>(punctuated: &mut Punctuated<T, P>, i: I)
+where
+    I: Iterator<Item = Pair<T, P>>,
+{
+    let mut nomore = false;
+    for pair in i {
+        if nomore {
+            panic!("Punctuated extended with items after a Pair::End");
+        }
+        match pair {
+            Pair::Punctuated(a, b) => punctuated.inner.push((a, b)),
+            Pair::End(a) => {
+                punctuated.last = Some(Box::new(a));
+                nomore = true;
+            }
+        }
+    }
+}
+
+impl<T, P> IntoIterator for Punctuated<T, P> {
+    type Item = T;
+    type IntoIter = IntoIter<T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        let mut elements = Vec::with_capacity(self.len());
+        elements.extend(self.inner.into_iter().map(|pair| pair.0));
+        elements.extend(self.last.map(|t| *t));
+
+        IntoIter {
+            inner: elements.into_iter(),
+        }
+    }
+}
+
+impl<'a, T, P> IntoIterator for &'a Punctuated<T, P> {
+    type Item = &'a T;
+    type IntoIter = Iter<'a, T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Punctuated::iter(self)
+    }
+}
+
+impl<'a, T, P> IntoIterator for &'a mut Punctuated<T, P> {
+    type Item = &'a mut T;
+    type IntoIter = IterMut<'a, T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Punctuated::iter_mut(self)
+    }
+}
+
+impl<T, P> Default for Punctuated<T, P> {
+    fn default() -> Self {
+        Punctuated::new()
+    }
+}
+
+/// An iterator over borrowed pairs of type `Pair<&T, &P>`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct Pairs<'a, T: 'a, P: 'a> {
+    inner: slice::Iter<'a, (T, P)>,
+    last: option::IntoIter<&'a T>,
+}
+
+impl<'a, T, P> Iterator for Pairs<'a, T, P> {
+    type Item = Pair<&'a T, &'a P>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner
+            .next()
+            .map(|(t, p)| Pair::Punctuated(t, p))
+            .or_else(|| self.last.next().map(Pair::End))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<'a, T, P> DoubleEndedIterator for Pairs<'a, T, P> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.last
+            .next()
+            .map(Pair::End)
+            .or_else(|| self.inner.next_back().map(|(t, p)| Pair::Punctuated(t, p)))
+    }
+}
+
+impl<'a, T, P> ExactSizeIterator for Pairs<'a, T, P> {
+    fn len(&self) -> usize {
+        self.inner.len() + self.last.len()
+    }
+}
+
+// No Clone bound on T or P.
+impl<'a, T, P> Clone for Pairs<'a, T, P> {
+    fn clone(&self) -> Self {
+        Pairs {
+            inner: self.inner.clone(),
+            last: self.last.clone(),
+        }
+    }
+}
+
+/// An iterator over mutably borrowed pairs of type `Pair<&mut T, &mut P>`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct PairsMut<'a, T: 'a, P: 'a> {
+    inner: slice::IterMut<'a, (T, P)>,
+    last: option::IntoIter<&'a mut T>,
+}
+
+impl<'a, T, P> Iterator for PairsMut<'a, T, P> {
+    type Item = Pair<&'a mut T, &'a mut P>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner
+            .next()
+            .map(|(t, p)| Pair::Punctuated(t, p))
+            .or_else(|| self.last.next().map(Pair::End))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<'a, T, P> DoubleEndedIterator for PairsMut<'a, T, P> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.last
+            .next()
+            .map(Pair::End)
+            .or_else(|| self.inner.next_back().map(|(t, p)| Pair::Punctuated(t, p)))
+    }
+}
+
+impl<'a, T, P> ExactSizeIterator for PairsMut<'a, T, P> {
+    fn len(&self) -> usize {
+        self.inner.len() + self.last.len()
+    }
+}
+
+/// An iterator over owned pairs of type `Pair<T, P>`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct IntoPairs<T, P> {
+    inner: vec::IntoIter<(T, P)>,
+    last: option::IntoIter<T>,
+}
+
+impl<T, P> Iterator for IntoPairs<T, P> {
+    type Item = Pair<T, P>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner
+            .next()
+            .map(|(t, p)| Pair::Punctuated(t, p))
+            .or_else(|| self.last.next().map(Pair::End))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<T, P> DoubleEndedIterator for IntoPairs<T, P> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.last
+            .next()
+            .map(Pair::End)
+            .or_else(|| self.inner.next_back().map(|(t, p)| Pair::Punctuated(t, p)))
+    }
+}
+
+impl<T, P> ExactSizeIterator for IntoPairs<T, P> {
+    fn len(&self) -> usize {
+        self.inner.len() + self.last.len()
+    }
+}
+
+impl<T, P> Clone for IntoPairs<T, P>
+where
+    T: Clone,
+    P: Clone,
+{
+    fn clone(&self) -> Self {
+        IntoPairs {
+            inner: self.inner.clone(),
+            last: self.last.clone(),
+        }
+    }
+}
+
+/// An iterator over owned values of type `T`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct IntoIter<T> {
+    inner: vec::IntoIter<T>,
+}
+
+impl<T> Iterator for IntoIter<T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<T> DoubleEndedIterator for IntoIter<T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.inner.next_back()
+    }
+}
+
+impl<T> ExactSizeIterator for IntoIter<T> {
+    fn len(&self) -> usize {
+        self.inner.len()
+    }
+}
+
+impl<T> Clone for IntoIter<T>
+where
+    T: Clone,
+{
+    fn clone(&self) -> Self {
+        IntoIter {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+/// An iterator over borrowed values of type `&T`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct Iter<'a, T: 'a> {
+    inner: Box<NoDrop<dyn IterTrait<'a, T> + 'a>>,
+}
+
+trait IterTrait<'a, T: 'a>: Iterator<Item = &'a T> + DoubleEndedIterator + ExactSizeIterator {
+    fn clone_box(&self) -> Box<NoDrop<dyn IterTrait<'a, T> + 'a>>;
+}
+
+struct PrivateIter<'a, T: 'a, P: 'a> {
+    inner: slice::Iter<'a, (T, P)>,
+    last: option::IntoIter<&'a T>,
+}
+
+impl<'a, T, P> TrivialDrop for PrivateIter<'a, T, P>
+where
+    slice::Iter<'a, (T, P)>: TrivialDrop,
+    option::IntoIter<&'a T>: TrivialDrop,
+{
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn empty_punctuated_iter<'a, T>() -> Iter<'a, T> {
+    Iter {
+        inner: Box::new(NoDrop::new(iter::empty())),
+    }
+}
+
+// No Clone bound on T.
+impl<'a, T> Clone for Iter<'a, T> {
+    fn clone(&self) -> Self {
+        Iter {
+            inner: self.inner.clone_box(),
+        }
+    }
+}
+
+impl<'a, T> Iterator for Iter<'a, T> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.inner.next_back()
+    }
+}
+
+impl<'a, T> ExactSizeIterator for Iter<'a, T> {
+    fn len(&self) -> usize {
+        self.inner.len()
+    }
+}
+
+impl<'a, T, P> Iterator for PrivateIter<'a, T, P> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner
+            .next()
+            .map(|pair| &pair.0)
+            .or_else(|| self.last.next())
+    }
+}
+
+impl<'a, T, P> DoubleEndedIterator for PrivateIter<'a, T, P> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.last
+            .next()
+            .or_else(|| self.inner.next_back().map(|pair| &pair.0))
+    }
+}
+
+impl<'a, T, P> ExactSizeIterator for PrivateIter<'a, T, P> {
+    fn len(&self) -> usize {
+        self.inner.len() + self.last.len()
+    }
+}
+
+// No Clone bound on T or P.
+impl<'a, T, P> Clone for PrivateIter<'a, T, P> {
+    fn clone(&self) -> Self {
+        PrivateIter {
+            inner: self.inner.clone(),
+            last: self.last.clone(),
+        }
+    }
+}
+
+impl<'a, T, I> IterTrait<'a, T> for I
+where
+    T: 'a,
+    I: DoubleEndedIterator<Item = &'a T>
+        + ExactSizeIterator<Item = &'a T>
+        + Clone
+        + TrivialDrop
+        + 'a,
+{
+    fn clone_box(&self) -> Box<NoDrop<dyn IterTrait<'a, T> + 'a>> {
+        Box::new(NoDrop::new(self.clone()))
+    }
+}
+
+/// An iterator over mutably borrowed values of type `&mut T`.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub struct IterMut<'a, T: 'a> {
+    inner: Box<NoDrop<dyn IterMutTrait<'a, T, Item = &'a mut T> + 'a>>,
+}
+
+trait IterMutTrait<'a, T: 'a>:
+    DoubleEndedIterator<Item = &'a mut T> + ExactSizeIterator<Item = &'a mut T>
+{
+}
+
+struct PrivateIterMut<'a, T: 'a, P: 'a> {
+    inner: slice::IterMut<'a, (T, P)>,
+    last: option::IntoIter<&'a mut T>,
+}
+
+impl<'a, T, P> TrivialDrop for PrivateIterMut<'a, T, P>
+where
+    slice::IterMut<'a, (T, P)>: TrivialDrop,
+    option::IntoIter<&'a mut T>: TrivialDrop,
+{
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn empty_punctuated_iter_mut<'a, T>() -> IterMut<'a, T> {
+    IterMut {
+        inner: Box::new(NoDrop::new(iter::empty())),
+    }
+}
+
+impl<'a, T> Iterator for IterMut<'a, T> {
+    type Item = &'a mut T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(), Some(self.len()))
+    }
+}
+
+impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.inner.next_back()
+    }
+}
+
+impl<'a, T> ExactSizeIterator for IterMut<'a, T> {
+    fn len(&self) -> usize {
+        self.inner.len()
+    }
+}
+
+impl<'a, T, P> Iterator for PrivateIterMut<'a, T, P> {
+    type Item = &'a mut T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner
+            .next()
+            .map(|pair| &mut pair.0)
+            .or_else(|| self.last.next())
+    }
+}
+
+impl<'a, T, P> DoubleEndedIterator for PrivateIterMut<'a, T, P> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.last
+            .next()
+            .or_else(|| self.inner.next_back().map(|pair| &mut pair.0))
+    }
+}
+
+impl<'a, T, P> ExactSizeIterator for PrivateIterMut<'a, T, P> {
+    fn len(&self) -> usize {
+        self.inner.len() + self.last.len()
+    }
+}
+
+impl<'a, T, I> IterMutTrait<'a, T> for I
+where
+    T: 'a,
+    I: DoubleEndedIterator<Item = &'a mut T> + ExactSizeIterator<Item = &'a mut T> + 'a,
+{
+}
+
+/// A single syntax tree node of type `T` followed by its trailing punctuation
+/// of type `P` if any.
+///
+/// Refer to the [module documentation] for details about punctuated sequences.
+///
+/// [module documentation]: self
+pub enum Pair<T, P> {
+    Punctuated(T, P),
+    End(T),
+}
+
+impl<T, P> Pair<T, P> {
+    /// Extracts the syntax tree node from this punctuated pair, discarding the
+    /// following punctuation.
+    pub fn into_value(self) -> T {
+        match self {
+            Pair::Punctuated(t, _) | Pair::End(t) => t,
+        }
+    }
+
+    /// Borrows the syntax tree node from this punctuated pair.
+    pub fn value(&self) -> &T {
+        match self {
+            Pair::Punctuated(t, _) | Pair::End(t) => t,
+        }
+    }
+
+    /// Mutably borrows the syntax tree node from this punctuated pair.
+    pub fn value_mut(&mut self) -> &mut T {
+        match self {
+            Pair::Punctuated(t, _) | Pair::End(t) => t,
+        }
+    }
+
+    /// Borrows the punctuation from this punctuated pair, unless this pair is
+    /// the final one and there is no trailing punctuation.
+    pub fn punct(&self) -> Option<&P> {
+        match self {
+            Pair::Punctuated(_, p) => Some(p),
+            Pair::End(_) => None,
+        }
+    }
+
+    /// Mutably borrows the punctuation from this punctuated pair, unless the
+    /// pair is the final one and there is no trailing punctuation.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use proc_macro2::Span;
+    /// # use syn::punctuated::Punctuated;
+    /// # use syn::{parse_quote, Token, TypeParamBound};
+    /// #
+    /// # let mut punctuated = Punctuated::<TypeParamBound, Token![+]>::new();
+    /// # let span = Span::call_site();
+    /// #
+    /// punctuated.insert(0, parse_quote!('lifetime));
+    /// if let Some(punct) = punctuated.pairs_mut().next().unwrap().punct_mut() {
+    ///     punct.span = span;
+    /// }
+    /// ```
+    pub fn punct_mut(&mut self) -> Option<&mut P> {
+        match self {
+            Pair::Punctuated(_, p) => Some(p),
+            Pair::End(_) => None,
+        }
+    }
+
+    /// Creates a punctuated pair out of a syntax tree node and an optional
+    /// following punctuation.
+    pub fn new(t: T, p: Option<P>) -> Self {
+        match p {
+            Some(p) => Pair::Punctuated(t, p),
+            None => Pair::End(t),
+        }
+    }
+
+    /// Produces this punctuated pair as a tuple of syntax tree node and
+    /// optional following punctuation.
+    pub fn into_tuple(self) -> (T, Option<P>) {
+        match self {
+            Pair::Punctuated(t, p) => (t, Some(p)),
+            Pair::End(t) => (t, None),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl<T, P> Pair<&T, &P> {
+    pub fn cloned(self) -> Pair<T, P>
+    where
+        T: Clone,
+        P: Clone,
+    {
+        match self {
+            Pair::Punctuated(t, p) => Pair::Punctuated(t.clone(), p.clone()),
+            Pair::End(t) => Pair::End(t.clone()),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl<T, P> Clone for Pair<T, P>
+where
+    T: Clone,
+    P: Clone,
+{
+    fn clone(&self) -> Self {
+        match self {
+            Pair::Punctuated(t, p) => Pair::Punctuated(t.clone(), p.clone()),
+            Pair::End(t) => Pair::End(t.clone()),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl<T, P> Copy for Pair<T, P>
+where
+    T: Copy,
+    P: Copy,
+{
+}
+
+impl<T, P> Index<usize> for Punctuated<T, P> {
+    type Output = T;
+
+    fn index(&self, index: usize) -> &Self::Output {
+        if index == self.len() - 1 {
+            match &self.last {
+                Some(t) => t,
+                None => &self.inner[index].0,
+            }
+        } else {
+            &self.inner[index].0
+        }
+    }
+}
+
+impl<T, P> IndexMut<usize> for Punctuated<T, P> {
+    fn index_mut(&mut self, index: usize) -> &mut Self::Output {
+        if index == self.len() - 1 {
+            match &mut self.last {
+                Some(t) => t,
+                None => &mut self.inner[index].0,
+            }
+        } else {
+            &mut self.inner[index].0
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl<T, P> ToTokens for Punctuated<T, P>
+    where
+        T: ToTokens,
+        P: ToTokens,
+    {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.pairs());
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl<T, P> ToTokens for Pair<T, P>
+    where
+        T: ToTokens,
+        P: ToTokens,
+    {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                Pair::Punctuated(a, b) => {
+                    a.to_tokens(tokens);
+                    b.to_tokens(tokens);
+                }
+                Pair::End(a) => a.to_tokens(tokens),
+            }
+        }
+    }
+}
diff --git a/vendor/syn/src/restriction.rs b/vendor/syn/src/restriction.rs
new file mode 100644
index 0000000..97c7f5a
--- /dev/null
+++ b/vendor/syn/src/restriction.rs
@@ -0,0 +1,171 @@
+use super::*;
+
+ast_enum! {
+    /// The visibility level of an item: inherited or `pub` or
+    /// `pub(restricted)`.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum Visibility {
+        /// A public visibility level: `pub`.
+        Public(Token![pub]),
+
+        /// A visibility level restricted to some path: `pub(self)` or
+        /// `pub(super)` or `pub(crate)` or `pub(in some::module)`.
+        Restricted(VisRestricted),
+
+        /// An inherited visibility, which usually means private.
+        Inherited,
+    }
+}
+
+ast_struct! {
+    /// A visibility level restricted to some path: `pub(self)` or
+    /// `pub(super)` or `pub(crate)` or `pub(in some::module)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct VisRestricted {
+        pub pub_token: Token![pub],
+        pub paren_token: token::Paren,
+        pub in_token: Option<Token![in]>,
+        pub path: Box<Path>,
+    }
+}
+
+ast_enum! {
+    /// Unused, but reserved for RFC 3323 restrictions.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum FieldMutability {
+        None,
+
+        // TODO: https://rust-lang.github.io/rfcs/3323-restrictions.html
+        //
+        // FieldMutability::Restricted(MutRestricted)
+        //
+        // pub struct MutRestricted {
+        //     pub mut_token: Token![mut],
+        //     pub paren_token: token::Paren,
+        //     pub in_token: Option<Token![in]>,
+        //     pub path: Box<Path>,
+        // }
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::discouraged::Speculative;
+    use crate::parse::{Parse, ParseStream, Result};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Visibility {
+        fn parse(input: ParseStream) -> Result<Self> {
+            // Recognize an empty None-delimited group, as produced by a $:vis
+            // matcher that matched no tokens.
+            if input.peek(token::Group) {
+                let ahead = input.fork();
+                let group = crate::group::parse_group(&ahead)?;
+                if group.content.is_empty() {
+                    input.advance_to(&ahead);
+                    return Ok(Visibility::Inherited);
+                }
+            }
+
+            if input.peek(Token![pub]) {
+                Self::parse_pub(input)
+            } else {
+                Ok(Visibility::Inherited)
+            }
+        }
+    }
+
+    impl Visibility {
+        fn parse_pub(input: ParseStream) -> Result<Self> {
+            let pub_token = input.parse::<Token![pub]>()?;
+
+            if input.peek(token::Paren) {
+                let ahead = input.fork();
+
+                let content;
+                let paren_token = parenthesized!(content in ahead);
+                if content.peek(Token![crate])
+                    || content.peek(Token![self])
+                    || content.peek(Token![super])
+                {
+                    let path = content.call(Ident::parse_any)?;
+
+                    // Ensure there are no additional tokens within `content`.
+                    // Without explicitly checking, we may misinterpret a tuple
+                    // field as a restricted visibility, causing a parse error.
+                    // e.g. `pub (crate::A, crate::B)` (Issue #720).
+                    if content.is_empty() {
+                        input.advance_to(&ahead);
+                        return Ok(Visibility::Restricted(VisRestricted {
+                            pub_token,
+                            paren_token,
+                            in_token: None,
+                            path: Box::new(Path::from(path)),
+                        }));
+                    }
+                } else if content.peek(Token![in]) {
+                    let in_token: Token![in] = content.parse()?;
+                    let path = content.call(Path::parse_mod_style)?;
+
+                    input.advance_to(&ahead);
+                    return Ok(Visibility::Restricted(VisRestricted {
+                        pub_token,
+                        paren_token,
+                        in_token: Some(in_token),
+                        path: Box::new(path),
+                    }));
+                }
+            }
+
+            Ok(Visibility::Public(pub_token))
+        }
+
+        #[cfg(feature = "full")]
+        pub(crate) fn is_some(&self) -> bool {
+            match self {
+                Visibility::Inherited => false,
+                _ => true,
+            }
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::ToTokens;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Visibility {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                Visibility::Public(pub_token) => pub_token.to_tokens(tokens),
+                Visibility::Restricted(vis_restricted) => vis_restricted.to_tokens(tokens),
+                Visibility::Inherited => {}
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for VisRestricted {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.pub_token.to_tokens(tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                // TODO: If we have a path which is not "self" or "super" or
+                // "crate", automatically add the "in" token.
+                self.in_token.to_tokens(tokens);
+                self.path.to_tokens(tokens);
+            });
+        }
+    }
+}
diff --git a/vendor/syn/src/sealed.rs b/vendor/syn/src/sealed.rs
new file mode 100644
index 0000000..dc80474
--- /dev/null
+++ b/vendor/syn/src/sealed.rs
@@ -0,0 +1,4 @@
+#[cfg(feature = "parsing")]
+pub(crate) mod lookahead {
+    pub trait Sealed: Copy {}
+}
diff --git a/vendor/syn/src/span.rs b/vendor/syn/src/span.rs
new file mode 100644
index 0000000..eb27794
--- /dev/null
+++ b/vendor/syn/src/span.rs
@@ -0,0 +1,63 @@
+use proc_macro2::extra::DelimSpan;
+use proc_macro2::{Delimiter, Group, Span, TokenStream};
+
+#[doc(hidden)]
+pub trait IntoSpans<S> {
+    fn into_spans(self) -> S;
+}
+
+impl IntoSpans<Span> for Span {
+    fn into_spans(self) -> Span {
+        self
+    }
+}
+
+impl IntoSpans<[Span; 1]> for Span {
+    fn into_spans(self) -> [Span; 1] {
+        [self]
+    }
+}
+
+impl IntoSpans<[Span; 2]> for Span {
+    fn into_spans(self) -> [Span; 2] {
+        [self, self]
+    }
+}
+
+impl IntoSpans<[Span; 3]> for Span {
+    fn into_spans(self) -> [Span; 3] {
+        [self, self, self]
+    }
+}
+
+impl IntoSpans<[Span; 1]> for [Span; 1] {
+    fn into_spans(self) -> [Span; 1] {
+        self
+    }
+}
+
+impl IntoSpans<[Span; 2]> for [Span; 2] {
+    fn into_spans(self) -> [Span; 2] {
+        self
+    }
+}
+
+impl IntoSpans<[Span; 3]> for [Span; 3] {
+    fn into_spans(self) -> [Span; 3] {
+        self
+    }
+}
+
+impl IntoSpans<DelimSpan> for Span {
+    fn into_spans(self) -> DelimSpan {
+        let mut group = Group::new(Delimiter::None, TokenStream::new());
+        group.set_span(self);
+        group.delim_span()
+    }
+}
+
+impl IntoSpans<DelimSpan> for DelimSpan {
+    fn into_spans(self) -> DelimSpan {
+        self
+    }
+}
diff --git a/vendor/syn/src/spanned.rs b/vendor/syn/src/spanned.rs
new file mode 100644
index 0000000..98aa0aa
--- /dev/null
+++ b/vendor/syn/src/spanned.rs
@@ -0,0 +1,118 @@
+//! A trait that can provide the `Span` of the complete contents of a syntax
+//! tree node.
+//!
+//! <br>
+//!
+//! # Example
+//!
+//! Suppose in a procedural macro we have a [`Type`] that we want to assert
+//! implements the [`Sync`] trait. Maybe this is the type of one of the fields
+//! of a struct for which we are deriving a trait implementation, and we need to
+//! be able to pass a reference to one of those fields across threads.
+//!
+//! [`Type`]: crate::Type
+//! [`Sync`]: std::marker::Sync
+//!
+//! If the field type does *not* implement `Sync` as required, we want the
+//! compiler to report an error pointing out exactly which type it was.
+//!
+//! The following macro code takes a variable `ty` of type `Type` and produces a
+//! static assertion that `Sync` is implemented for that type.
+//!
+//! ```
+//! # extern crate proc_macro;
+//! #
+//! use proc_macro::TokenStream;
+//! use proc_macro2::Span;
+//! use quote::quote_spanned;
+//! use syn::Type;
+//! use syn::spanned::Spanned;
+//!
+//! # const IGNORE_TOKENS: &str = stringify! {
+//! #[proc_macro_derive(MyMacro)]
+//! # };
+//! pub fn my_macro(input: TokenStream) -> TokenStream {
+//!     # let ty = get_a_type();
+//!     /* ... */
+//!
+//!     let assert_sync = quote_spanned! {ty.span()=>
+//!         struct _AssertSync where #ty: Sync;
+//!     };
+//!
+//!     /* ... */
+//!     # input
+//! }
+//! #
+//! # fn get_a_type() -> Type {
+//! #     unimplemented!()
+//! # }
+//! ```
+//!
+//! By inserting this `assert_sync` fragment into the output code generated by
+//! our macro, the user's code will fail to compile if `ty` does not implement
+//! `Sync`. The errors they would see look like the following.
+//!
+//! ```text
+//! error[E0277]: the trait bound `*const i32: std::marker::Sync` is not satisfied
+//!   --> src/main.rs:10:21
+//!    |
+//! 10 |     bad_field: *const i32,
+//!    |                ^^^^^^^^^^ `*const i32` cannot be shared between threads safely
+//! ```
+//!
+//! In this technique, using the `Type`'s span for the error message makes the
+//! error appear in the correct place underlining the right type.
+//!
+//! <br>
+//!
+//! # Limitations
+//!
+//! The underlying [`proc_macro::Span::join`] method is nightly-only. When
+//! called from within a procedural macro in a nightly compiler, `Spanned` will
+//! use `join` to produce the intended span. When not using a nightly compiler,
+//! only the span of the *first token* of the syntax tree node is returned.
+//!
+//! In the common case of wanting to use the joined span as the span of a
+//! `syn::Error`, consider instead using [`syn::Error::new_spanned`] which is
+//! able to span the error correctly under the complete syntax tree node without
+//! needing the unstable `join`.
+//!
+//! [`syn::Error::new_spanned`]: crate::Error::new_spanned
+
+use proc_macro2::Span;
+use quote::spanned::Spanned as ToTokens;
+
+/// A trait that can provide the `Span` of the complete contents of a syntax
+/// tree node.
+///
+/// This trait is automatically implemented for all types that implement
+/// [`ToTokens`] from the `quote` crate, as well as for `Span` itself.
+///
+/// [`ToTokens`]: quote::ToTokens
+///
+/// See the [module documentation] for an example.
+///
+/// [module documentation]: self
+pub trait Spanned: private::Sealed {
+    /// Returns a `Span` covering the complete contents of this syntax tree
+    /// node, or [`Span::call_site()`] if this node is empty.
+    ///
+    /// [`Span::call_site()`]: proc_macro2::Span::call_site
+    fn span(&self) -> Span;
+}
+
+impl<T: ?Sized + ToTokens> Spanned for T {
+    fn span(&self) -> Span {
+        self.__span()
+    }
+}
+
+mod private {
+    use super::*;
+
+    pub trait Sealed {}
+    impl<T: ?Sized + ToTokens> Sealed for T {}
+
+    #[cfg(any(feature = "full", feature = "derive"))]
+    impl Sealed for crate::QSelf {}
+}
diff --git a/vendor/syn/src/stmt.rs b/vendor/syn/src/stmt.rs
new file mode 100644
index 0000000..fb67fec
--- /dev/null
+++ b/vendor/syn/src/stmt.rs
@@ -0,0 +1,452 @@
+use super::*;
+
+ast_struct! {
+    /// A braced block containing Rust statements.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Block {
+        pub brace_token: token::Brace,
+        /// Statements in a block
+        pub stmts: Vec<Stmt>,
+    }
+}
+
+ast_enum! {
+    /// A statement, usually ending in a semicolon.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub enum Stmt {
+        /// A local (let) binding.
+        Local(Local),
+
+        /// An item definition.
+        Item(Item),
+
+        /// Expression, with or without trailing semicolon.
+        Expr(Expr, Option<Token![;]>),
+
+        /// A macro invocation in statement position.
+        ///
+        /// Syntactically it's ambiguous which other kind of statement this
+        /// macro would expand to. It can be any of local variable (`let`),
+        /// item, or expression.
+        Macro(StmtMacro),
+    }
+}
+
+ast_struct! {
+    /// A local `let` binding: `let x: u64 = s.parse()?`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct Local {
+        pub attrs: Vec<Attribute>,
+        pub let_token: Token![let],
+        pub pat: Pat,
+        pub init: Option<LocalInit>,
+        pub semi_token: Token![;],
+    }
+}
+
+ast_struct! {
+    /// The expression assigned in a local `let` binding, including optional
+    /// diverging `else` block.
+    ///
+    /// `LocalInit` represents `= s.parse()?` in `let x: u64 = s.parse()?` and
+    /// `= r else { return }` in `let Ok(x) = r else { return }`.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct LocalInit {
+        pub eq_token: Token![=],
+        pub expr: Box<Expr>,
+        pub diverge: Option<(Token![else], Box<Expr>)>,
+    }
+}
+
+ast_struct! {
+    /// A macro invocation in statement position.
+    ///
+    /// Syntactically it's ambiguous which other kind of statement this macro
+    /// would expand to. It can be any of local variable (`let`), item, or
+    /// expression.
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
+    pub struct StmtMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+        pub semi_token: Option<Token![;]>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::parse::discouraged::Speculative;
+    use crate::parse::{Parse, ParseStream, Result};
+    use proc_macro2::TokenStream;
+
+    struct AllowNoSemi(bool);
+
+    impl Block {
+        /// Parse the body of a block as zero or more statements, possibly
+        /// including one trailing expression.
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// use syn::{braced, token, Attribute, Block, Ident, Result, Stmt, Token};
+        /// use syn::parse::{Parse, ParseStream};
+        ///
+        /// // Parse a function with no generics or parameter list.
+        /// //
+        /// //     fn playground {
+        /// //         let mut x = 1;
+        /// //         x += 1;
+        /// //         println!("{}", x);
+        /// //     }
+        /// struct MiniFunction {
+        ///     attrs: Vec<Attribute>,
+        ///     fn_token: Token![fn],
+        ///     name: Ident,
+        ///     brace_token: token::Brace,
+        ///     stmts: Vec<Stmt>,
+        /// }
+        ///
+        /// impl Parse for MiniFunction {
+        ///     fn parse(input: ParseStream) -> Result<Self> {
+        ///         let outer_attrs = input.call(Attribute::parse_outer)?;
+        ///         let fn_token: Token![fn] = input.parse()?;
+        ///         let name: Ident = input.parse()?;
+        ///
+        ///         let content;
+        ///         let brace_token = braced!(content in input);
+        ///         let inner_attrs = content.call(Attribute::parse_inner)?;
+        ///         let stmts = content.call(Block::parse_within)?;
+        ///
+        ///         Ok(MiniFunction {
+        ///             attrs: {
+        ///                 let mut attrs = outer_attrs;
+        ///                 attrs.extend(inner_attrs);
+        ///                 attrs
+        ///             },
+        ///             fn_token,
+        ///             name,
+        ///             brace_token,
+        ///             stmts,
+        ///         })
+        ///     }
+        /// }
+        /// ```
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn parse_within(input: ParseStream) -> Result<Vec<Stmt>> {
+            let mut stmts = Vec::new();
+            loop {
+                while let semi @ Some(_) = input.parse()? {
+                    stmts.push(Stmt::Expr(Expr::Verbatim(TokenStream::new()), semi));
+                }
+                if input.is_empty() {
+                    break;
+                }
+                let stmt = parse_stmt(input, AllowNoSemi(true))?;
+                let requires_semicolon = match &stmt {
+                    Stmt::Expr(stmt, None) => expr::requires_terminator(stmt),
+                    Stmt::Macro(stmt) => {
+                        stmt.semi_token.is_none() && !stmt.mac.delimiter.is_brace()
+                    }
+                    Stmt::Local(_) | Stmt::Item(_) | Stmt::Expr(_, Some(_)) => false,
+                };
+                stmts.push(stmt);
+                if input.is_empty() {
+                    break;
+                } else if requires_semicolon {
+                    return Err(input.error("unexpected token, expected `;`"));
+                }
+            }
+            Ok(stmts)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Block {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(Block {
+                brace_token: braced!(content in input),
+                stmts: content.call(Block::parse_within)?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Stmt {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_nosemi = AllowNoSemi(false);
+            parse_stmt(input, allow_nosemi)
+        }
+    }
+
+    fn parse_stmt(input: ParseStream, allow_nosemi: AllowNoSemi) -> Result<Stmt> {
+        let begin = input.fork();
+        let attrs = input.call(Attribute::parse_outer)?;
+
+        // brace-style macros; paren and bracket macros get parsed as
+        // expression statements.
+        let ahead = input.fork();
+        let mut is_item_macro = false;
+        if let Ok(path) = ahead.call(Path::parse_mod_style) {
+            if ahead.peek(Token![!]) {
+                if ahead.peek2(Ident) || ahead.peek2(Token![try]) {
+                    is_item_macro = true;
+                } else if ahead.peek2(token::Brace)
+                    && !(ahead.peek3(Token![.]) || ahead.peek3(Token![?]))
+                {
+                    input.advance_to(&ahead);
+                    return stmt_mac(input, attrs, path).map(Stmt::Macro);
+                }
+            }
+        }
+
+        if input.peek(Token![let]) {
+            stmt_local(input, attrs).map(Stmt::Local)
+        } else if input.peek(Token![pub])
+            || input.peek(Token![crate]) && !input.peek2(Token![::])
+            || input.peek(Token![extern])
+            || input.peek(Token![use])
+            || input.peek(Token![static])
+                && (input.peek2(Token![mut])
+                    || input.peek2(Ident)
+                        && !(input.peek2(Token![async])
+                            && (input.peek3(Token![move]) || input.peek3(Token![|]))))
+            || input.peek(Token![const])
+                && !(input.peek2(token::Brace)
+                    || input.peek2(Token![static])
+                    || input.peek2(Token![async])
+                        && !(input.peek3(Token![unsafe])
+                            || input.peek3(Token![extern])
+                            || input.peek3(Token![fn]))
+                    || input.peek2(Token![move])
+                    || input.peek2(Token![|]))
+            || input.peek(Token![unsafe]) && !input.peek2(token::Brace)
+            || input.peek(Token![async])
+                && (input.peek2(Token![unsafe])
+                    || input.peek2(Token![extern])
+                    || input.peek2(Token![fn]))
+            || input.peek(Token![fn])
+            || input.peek(Token![mod])
+            || input.peek(Token![type])
+            || input.peek(Token![struct])
+            || input.peek(Token![enum])
+            || input.peek(Token![union]) && input.peek2(Ident)
+            || input.peek(Token![auto]) && input.peek2(Token![trait])
+            || input.peek(Token![trait])
+            || input.peek(Token![default])
+                && (input.peek2(Token![unsafe]) || input.peek2(Token![impl]))
+            || input.peek(Token![impl])
+            || input.peek(Token![macro])
+            || is_item_macro
+        {
+            let item = item::parsing::parse_rest_of_item(begin, attrs, input)?;
+            Ok(Stmt::Item(item))
+        } else {
+            stmt_expr(input, allow_nosemi, attrs)
+        }
+    }
+
+    fn stmt_mac(input: ParseStream, attrs: Vec<Attribute>, path: Path) -> Result<StmtMacro> {
+        let bang_token: Token![!] = input.parse()?;
+        let (delimiter, tokens) = mac::parse_delimiter(input)?;
+        let semi_token: Option<Token![;]> = input.parse()?;
+
+        Ok(StmtMacro {
+            attrs,
+            mac: Macro {
+                path,
+                bang_token,
+                delimiter,
+                tokens,
+            },
+            semi_token,
+        })
+    }
+
+    fn stmt_local(input: ParseStream, attrs: Vec<Attribute>) -> Result<Local> {
+        let let_token: Token![let] = input.parse()?;
+
+        let mut pat = Pat::parse_single(input)?;
+        if input.peek(Token![:]) {
+            let colon_token: Token![:] = input.parse()?;
+            let ty: Type = input.parse()?;
+            pat = Pat::Type(PatType {
+                attrs: Vec::new(),
+                pat: Box::new(pat),
+                colon_token,
+                ty: Box::new(ty),
+            });
+        }
+
+        let init = if let Some(eq_token) = input.parse()? {
+            let eq_token: Token![=] = eq_token;
+            let expr: Expr = input.parse()?;
+
+            let diverge = if let Some(else_token) = input.parse()? {
+                let else_token: Token![else] = else_token;
+                let diverge = ExprBlock {
+                    attrs: Vec::new(),
+                    label: None,
+                    block: input.parse()?,
+                };
+                Some((else_token, Box::new(Expr::Block(diverge))))
+            } else {
+                None
+            };
+
+            Some(LocalInit {
+                eq_token,
+                expr: Box::new(expr),
+                diverge,
+            })
+        } else {
+            None
+        };
+
+        let semi_token: Token![;] = input.parse()?;
+
+        Ok(Local {
+            attrs,
+            let_token,
+            pat,
+            init,
+            semi_token,
+        })
+    }
+
+    fn stmt_expr(
+        input: ParseStream,
+        allow_nosemi: AllowNoSemi,
+        mut attrs: Vec<Attribute>,
+    ) -> Result<Stmt> {
+        let mut e = expr::parsing::expr_early(input)?;
+
+        let mut attr_target = &mut e;
+        loop {
+            attr_target = match attr_target {
+                Expr::Assign(e) => &mut e.left,
+                Expr::Binary(e) => &mut e.left,
+                Expr::Cast(e) => &mut e.expr,
+                Expr::Array(_)
+                | Expr::Async(_)
+                | Expr::Await(_)
+                | Expr::Block(_)
+                | Expr::Break(_)
+                | Expr::Call(_)
+                | Expr::Closure(_)
+                | Expr::Const(_)
+                | Expr::Continue(_)
+                | Expr::Field(_)
+                | Expr::ForLoop(_)
+                | Expr::Group(_)
+                | Expr::If(_)
+                | Expr::Index(_)
+                | Expr::Infer(_)
+                | Expr::Let(_)
+                | Expr::Lit(_)
+                | Expr::Loop(_)
+                | Expr::Macro(_)
+                | Expr::Match(_)
+                | Expr::MethodCall(_)
+                | Expr::Paren(_)
+                | Expr::Path(_)
+                | Expr::Range(_)
+                | Expr::Reference(_)
+                | Expr::Repeat(_)
+                | Expr::Return(_)
+                | Expr::Struct(_)
+                | Expr::Try(_)
+                | Expr::TryBlock(_)
+                | Expr::Tuple(_)
+                | Expr::Unary(_)
+                | Expr::Unsafe(_)
+                | Expr::While(_)
+                | Expr::Yield(_)
+                | Expr::Verbatim(_) => break,
+            };
+        }
+        attrs.extend(attr_target.replace_attrs(Vec::new()));
+        attr_target.replace_attrs(attrs);
+
+        let semi_token: Option<Token![;]> = input.parse()?;
+
+        match e {
+            Expr::Macro(ExprMacro { attrs, mac })
+                if semi_token.is_some() || mac.delimiter.is_brace() =>
+            {
+                return Ok(Stmt::Macro(StmtMacro {
+                    attrs,
+                    mac,
+                    semi_token,
+                }));
+            }
+            _ => {}
+        }
+
+        if semi_token.is_some() {
+            Ok(Stmt::Expr(e, semi_token))
+        } else if allow_nosemi.0 || !expr::requires_terminator(&e) {
+            Ok(Stmt::Expr(e, None))
+        } else {
+            Err(input.error("expected semicolon"))
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Block {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.brace_token.surround(tokens, |tokens| {
+                tokens.append_all(&self.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Stmt {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                Stmt::Local(local) => local.to_tokens(tokens),
+                Stmt::Item(item) => item.to_tokens(tokens),
+                Stmt::Expr(expr, semi) => {
+                    expr.to_tokens(tokens);
+                    semi.to_tokens(tokens);
+                }
+                Stmt::Macro(mac) => mac.to_tokens(tokens),
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Local {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            expr::printing::outer_attrs_to_tokens(&self.attrs, tokens);
+            self.let_token.to_tokens(tokens);
+            self.pat.to_tokens(tokens);
+            if let Some(init) = &self.init {
+                init.eq_token.to_tokens(tokens);
+                init.expr.to_tokens(tokens);
+                if let Some((else_token, diverge)) = &init.diverge {
+                    else_token.to_tokens(tokens);
+                    diverge.to_tokens(tokens);
+                }
+            }
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for StmtMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            expr::printing::outer_attrs_to_tokens(&self.attrs, tokens);
+            self.mac.to_tokens(tokens);
+            self.semi_token.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/thread.rs b/vendor/syn/src/thread.rs
new file mode 100644
index 0000000..b33d248
--- /dev/null
+++ b/vendor/syn/src/thread.rs
@@ -0,0 +1,60 @@
+use std::fmt::{self, Debug};
+use std::thread::{self, ThreadId};
+
+/// ThreadBound is a Sync-maker and Send-maker that allows accessing a value
+/// of type T only from the original thread on which the ThreadBound was
+/// constructed.
+pub(crate) struct ThreadBound<T> {
+    value: T,
+    thread_id: ThreadId,
+}
+
+unsafe impl<T> Sync for ThreadBound<T> {}
+
+// Send bound requires Copy, as otherwise Drop could run in the wrong place.
+//
+// Today Copy and Drop are mutually exclusive so `T: Copy` implies `T: !Drop`.
+// This impl needs to be revisited if that restriction is relaxed in the future.
+unsafe impl<T: Copy> Send for ThreadBound<T> {}
+
+impl<T> ThreadBound<T> {
+    pub(crate) fn new(value: T) -> Self {
+        ThreadBound {
+            value,
+            thread_id: thread::current().id(),
+        }
+    }
+
+    pub(crate) fn get(&self) -> Option<&T> {
+        if thread::current().id() == self.thread_id {
+            Some(&self.value)
+        } else {
+            None
+        }
+    }
+}
+
+impl<T: Debug> Debug for ThreadBound<T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match self.get() {
+            Some(value) => Debug::fmt(value, formatter),
+            None => formatter.write_str("unknown"),
+        }
+    }
+}
+
+// Copy the bytes of T, even if the currently running thread is the "wrong"
+// thread. This is fine as long as the original thread is not simultaneously
+// mutating this value via interior mutability, which would be a data race.
+//
+// Currently `T: Copy` is sufficient to guarantee that T contains no interior
+// mutability, because _all_ interior mutability in Rust is built on
+// std::cell::UnsafeCell, which has no Copy impl. This impl needs to be
+// revisited if that restriction is relaxed in the future.
+impl<T: Copy> Copy for ThreadBound<T> {}
+
+impl<T: Copy> Clone for ThreadBound<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
diff --git a/vendor/syn/src/token.rs b/vendor/syn/src/token.rs
new file mode 100644
index 0000000..af7f25c
--- /dev/null
+++ b/vendor/syn/src/token.rs
@@ -0,0 +1,1134 @@
+//! Tokens representing Rust punctuation, keywords, and delimiters.
+//!
+//! The type names in this module can be difficult to keep straight, so we
+//! prefer to use the [`Token!`] macro instead. This is a type-macro that
+//! expands to the token type of the given token.
+//!
+//! [`Token!`]: crate::Token
+//!
+//! # Example
+//!
+//! The [`ItemStatic`] syntax tree node is defined like this.
+//!
+//! [`ItemStatic`]: crate::ItemStatic
+//!
+//! ```
+//! # use syn::{Attribute, Expr, Ident, Token, Type, Visibility};
+//! #
+//! pub struct ItemStatic {
+//!     pub attrs: Vec<Attribute>,
+//!     pub vis: Visibility,
+//!     pub static_token: Token![static],
+//!     pub mutability: Option<Token![mut]>,
+//!     pub ident: Ident,
+//!     pub colon_token: Token![:],
+//!     pub ty: Box<Type>,
+//!     pub eq_token: Token![=],
+//!     pub expr: Box<Expr>,
+//!     pub semi_token: Token![;],
+//! }
+//! ```
+//!
+//! # Parsing
+//!
+//! Keywords and punctuation can be parsed through the [`ParseStream::parse`]
+//! method. Delimiter tokens are parsed using the [`parenthesized!`],
+//! [`bracketed!`] and [`braced!`] macros.
+//!
+//! [`ParseStream::parse`]: crate::parse::ParseBuffer::parse()
+//! [`parenthesized!`]: crate::parenthesized!
+//! [`bracketed!`]: crate::bracketed!
+//! [`braced!`]: crate::braced!
+//!
+//! ```
+//! use syn::{Attribute, Result};
+//! use syn::parse::{Parse, ParseStream};
+//! #
+//! # enum ItemStatic {}
+//!
+//! // Parse the ItemStatic struct shown above.
+//! impl Parse for ItemStatic {
+//!     fn parse(input: ParseStream) -> Result<Self> {
+//!         # use syn::ItemStatic;
+//!         # fn parse(input: ParseStream) -> Result<ItemStatic> {
+//!         Ok(ItemStatic {
+//!             attrs: input.call(Attribute::parse_outer)?,
+//!             vis: input.parse()?,
+//!             static_token: input.parse()?,
+//!             mutability: input.parse()?,
+//!             ident: input.parse()?,
+//!             colon_token: input.parse()?,
+//!             ty: input.parse()?,
+//!             eq_token: input.parse()?,
+//!             expr: input.parse()?,
+//!             semi_token: input.parse()?,
+//!         })
+//!         # }
+//!         # unimplemented!()
+//!     }
+//! }
+//! ```
+//!
+//! # Other operations
+//!
+//! Every keyword and punctuation token supports the following operations.
+//!
+//! - [Peeking] — `input.peek(Token![...])`
+//!
+//! - [Parsing] — `input.parse::<Token![...]>()?`
+//!
+//! - [Printing] — `quote!( ... #the_token ... )`
+//!
+//! - Construction from a [`Span`] — `let the_token = Token![...](sp)`
+//!
+//! - Field access to its span — `let sp = the_token.span`
+//!
+//! [Peeking]: crate::parse::ParseBuffer::peek()
+//! [Parsing]: crate::parse::ParseBuffer::parse()
+//! [Printing]: https://docs.rs/quote/1.0/quote/trait.ToTokens.html
+//! [`Span`]: https://docs.rs/proc-macro2/1.0/proc_macro2/struct.Span.html
+
+use self::private::WithSpan;
+#[cfg(feature = "parsing")]
+use crate::buffer::Cursor;
+#[cfg(feature = "parsing")]
+use crate::error::Result;
+#[cfg(feature = "parsing")]
+use crate::lifetime::Lifetime;
+#[cfg(feature = "parsing")]
+use crate::lit::{Lit, LitBool, LitByte, LitByteStr, LitChar, LitFloat, LitInt, LitStr};
+#[cfg(feature = "parsing")]
+use crate::lookahead;
+#[cfg(feature = "parsing")]
+use crate::parse::{Parse, ParseStream};
+use crate::span::IntoSpans;
+use proc_macro2::extra::DelimSpan;
+use proc_macro2::Span;
+#[cfg(feature = "printing")]
+use proc_macro2::TokenStream;
+#[cfg(any(feature = "parsing", feature = "printing"))]
+use proc_macro2::{Delimiter, Ident};
+#[cfg(feature = "parsing")]
+use proc_macro2::{Literal, Punct, TokenTree};
+#[cfg(feature = "printing")]
+use quote::{ToTokens, TokenStreamExt};
+#[cfg(feature = "extra-traits")]
+use std::cmp;
+#[cfg(feature = "extra-traits")]
+use std::fmt::{self, Debug};
+#[cfg(feature = "extra-traits")]
+use std::hash::{Hash, Hasher};
+use std::ops::{Deref, DerefMut};
+
+/// Marker trait for types that represent single tokens.
+///
+/// This trait is sealed and cannot be implemented for types outside of Syn.
+#[cfg(feature = "parsing")]
+pub trait Token: private::Sealed {
+    // Not public API.
+    #[doc(hidden)]
+    fn peek(cursor: Cursor) -> bool;
+
+    // Not public API.
+    #[doc(hidden)]
+    fn display() -> &'static str;
+}
+
+mod private {
+    use proc_macro2::Span;
+
+    #[cfg(feature = "parsing")]
+    pub trait Sealed {}
+
+    /// Support writing `token.span` rather than `token.spans[0]` on tokens that
+    /// hold a single span.
+    #[repr(transparent)]
+    #[allow(unknown_lints, repr_transparent_external_private_fields)] // False positive: https://github.com/rust-lang/rust/issues/78586#issuecomment-1722680482
+    pub struct WithSpan {
+        pub span: Span,
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl private::Sealed for Ident {}
+
+#[cfg(feature = "parsing")]
+fn peek_impl(cursor: Cursor, peek: fn(ParseStream) -> bool) -> bool {
+    use crate::parse::Unexpected;
+    use std::cell::Cell;
+    use std::rc::Rc;
+
+    let scope = Span::call_site();
+    let unexpected = Rc::new(Cell::new(Unexpected::None));
+    let buffer = crate::parse::new_parse_buffer(scope, cursor, unexpected);
+    peek(&buffer)
+}
+
+macro_rules! impl_token {
+    ($display:literal $name:ty) => {
+        #[cfg(feature = "parsing")]
+        impl Token for $name {
+            fn peek(cursor: Cursor) -> bool {
+                fn peek(input: ParseStream) -> bool {
+                    <$name as Parse>::parse(input).is_ok()
+                }
+                peek_impl(cursor, peek)
+            }
+
+            fn display() -> &'static str {
+                $display
+            }
+        }
+
+        #[cfg(feature = "parsing")]
+        impl private::Sealed for $name {}
+    };
+}
+
+impl_token!("lifetime" Lifetime);
+impl_token!("literal" Lit);
+impl_token!("string literal" LitStr);
+impl_token!("byte string literal" LitByteStr);
+impl_token!("byte literal" LitByte);
+impl_token!("character literal" LitChar);
+impl_token!("integer literal" LitInt);
+impl_token!("floating point literal" LitFloat);
+impl_token!("boolean literal" LitBool);
+impl_token!("group token" proc_macro2::Group);
+
+macro_rules! impl_low_level_token {
+    ($display:literal $ty:ident $get:ident) => {
+        #[cfg(feature = "parsing")]
+        impl Token for $ty {
+            fn peek(cursor: Cursor) -> bool {
+                cursor.$get().is_some()
+            }
+
+            fn display() -> &'static str {
+                $display
+            }
+        }
+
+        #[cfg(feature = "parsing")]
+        impl private::Sealed for $ty {}
+    };
+}
+
+impl_low_level_token!("punctuation token" Punct punct);
+impl_low_level_token!("literal" Literal literal);
+impl_low_level_token!("token" TokenTree token_tree);
+
+// Not public API.
+#[doc(hidden)]
+#[cfg(feature = "parsing")]
+pub trait CustomToken {
+    fn peek(cursor: Cursor) -> bool;
+    fn display() -> &'static str;
+}
+
+#[cfg(feature = "parsing")]
+impl<T: CustomToken> private::Sealed for T {}
+
+#[cfg(feature = "parsing")]
+impl<T: CustomToken> Token for T {
+    fn peek(cursor: Cursor) -> bool {
+        <Self as CustomToken>::peek(cursor)
+    }
+
+    fn display() -> &'static str {
+        <Self as CustomToken>::display()
+    }
+}
+
+macro_rules! define_keywords {
+    ($($token:literal pub struct $name:ident)*) => {
+        $(
+            #[doc = concat!('`', $token, '`')]
+            ///
+            /// Don't try to remember the name of this type &mdash; use the
+            /// [`Token!`] macro instead.
+            ///
+            /// [`Token!`]: crate::token
+            pub struct $name {
+                pub span: Span,
+            }
+
+            #[doc(hidden)]
+            #[allow(non_snake_case)]
+            pub fn $name<S: IntoSpans<Span>>(span: S) -> $name {
+                $name {
+                    span: span.into_spans(),
+                }
+            }
+
+            impl std::default::Default for $name {
+                fn default() -> Self {
+                    $name {
+                        span: Span::call_site(),
+                    }
+                }
+            }
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Copy for $name {}
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Clone for $name {
+                fn clone(&self) -> Self {
+                    *self
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Debug for $name {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    f.write_str(stringify!($name))
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl cmp::Eq for $name {}
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl PartialEq for $name {
+                fn eq(&self, _other: &$name) -> bool {
+                    true
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Hash for $name {
+                fn hash<H: Hasher>(&self, _state: &mut H) {}
+            }
+
+            #[cfg(feature = "printing")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+            impl ToTokens for $name {
+                fn to_tokens(&self, tokens: &mut TokenStream) {
+                    printing::keyword($token, self.span, tokens);
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+            impl Parse for $name {
+                fn parse(input: ParseStream) -> Result<Self> {
+                    Ok($name {
+                        span: parsing::keyword(input, $token)?,
+                    })
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            impl Token for $name {
+                fn peek(cursor: Cursor) -> bool {
+                    parsing::peek_keyword(cursor, $token)
+                }
+
+                fn display() -> &'static str {
+                    concat!("`", $token, "`")
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            impl private::Sealed for $name {}
+        )*
+    };
+}
+
+macro_rules! impl_deref_if_len_is_1 {
+    ($name:ident/1) => {
+        impl Deref for $name {
+            type Target = WithSpan;
+
+            fn deref(&self) -> &Self::Target {
+                unsafe { &*(self as *const Self).cast::<WithSpan>() }
+            }
+        }
+
+        impl DerefMut for $name {
+            fn deref_mut(&mut self) -> &mut Self::Target {
+                unsafe { &mut *(self as *mut Self).cast::<WithSpan>() }
+            }
+        }
+    };
+
+    ($name:ident/$len:literal) => {};
+}
+
+macro_rules! define_punctuation_structs {
+    ($($token:literal pub struct $name:ident/$len:tt #[doc = $usage:literal])*) => {
+        $(
+            #[cfg_attr(not(doc), repr(transparent))]
+            #[allow(unknown_lints, repr_transparent_external_private_fields)] // False positive: https://github.com/rust-lang/rust/issues/78586#issuecomment-1722680482
+            #[doc = concat!('`', $token, '`')]
+            ///
+            /// Usage:
+            #[doc = concat!($usage, '.')]
+            ///
+            /// Don't try to remember the name of this type &mdash; use the
+            /// [`Token!`] macro instead.
+            ///
+            /// [`Token!`]: crate::token
+            pub struct $name {
+                pub spans: [Span; $len],
+            }
+
+            #[doc(hidden)]
+            #[allow(non_snake_case)]
+            pub fn $name<S: IntoSpans<[Span; $len]>>(spans: S) -> $name {
+                $name {
+                    spans: spans.into_spans(),
+                }
+            }
+
+            impl std::default::Default for $name {
+                fn default() -> Self {
+                    $name {
+                        spans: [Span::call_site(); $len],
+                    }
+                }
+            }
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Copy for $name {}
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Clone for $name {
+                fn clone(&self) -> Self {
+                    *self
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Debug for $name {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    f.write_str(stringify!($name))
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl cmp::Eq for $name {}
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl PartialEq for $name {
+                fn eq(&self, _other: &$name) -> bool {
+                    true
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Hash for $name {
+                fn hash<H: Hasher>(&self, _state: &mut H) {}
+            }
+
+            impl_deref_if_len_is_1!($name/$len);
+        )*
+    };
+}
+
+macro_rules! define_punctuation {
+    ($($token:literal pub struct $name:ident/$len:tt #[doc = $usage:literal])*) => {
+        $(
+            define_punctuation_structs! {
+                $token pub struct $name/$len #[doc = $usage]
+            }
+
+            #[cfg(feature = "printing")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+            impl ToTokens for $name {
+                fn to_tokens(&self, tokens: &mut TokenStream) {
+                    printing::punct($token, &self.spans, tokens);
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+            impl Parse for $name {
+                fn parse(input: ParseStream) -> Result<Self> {
+                    Ok($name {
+                        spans: parsing::punct(input, $token)?,
+                    })
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            impl Token for $name {
+                fn peek(cursor: Cursor) -> bool {
+                    parsing::peek_punct(cursor, $token)
+                }
+
+                fn display() -> &'static str {
+                    concat!("`", $token, "`")
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            impl private::Sealed for $name {}
+        )*
+    };
+}
+
+macro_rules! define_delimiters {
+    ($($delim:ident pub struct $name:ident #[$doc:meta])*) => {
+        $(
+            #[$doc]
+            pub struct $name {
+                pub span: DelimSpan,
+            }
+
+            #[doc(hidden)]
+            #[allow(non_snake_case)]
+            pub fn $name<S: IntoSpans<DelimSpan>>(span: S) -> $name {
+                $name {
+                    span: span.into_spans(),
+                }
+            }
+
+            impl std::default::Default for $name {
+                fn default() -> Self {
+                    $name(Span::call_site())
+                }
+            }
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Copy for $name {}
+
+            #[cfg(feature = "clone-impls")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+            impl Clone for $name {
+                fn clone(&self) -> Self {
+                    *self
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Debug for $name {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    f.write_str(stringify!($name))
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl cmp::Eq for $name {}
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl PartialEq for $name {
+                fn eq(&self, _other: &$name) -> bool {
+                    true
+                }
+            }
+
+            #[cfg(feature = "extra-traits")]
+            #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+            impl Hash for $name {
+                fn hash<H: Hasher>(&self, _state: &mut H) {}
+            }
+
+            impl $name {
+                #[cfg(feature = "printing")]
+                pub fn surround<F>(&self, tokens: &mut TokenStream, f: F)
+                where
+                    F: FnOnce(&mut TokenStream),
+                {
+                    let mut inner = TokenStream::new();
+                    f(&mut inner);
+                    printing::delim(Delimiter::$delim, self.span.join(), tokens, inner);
+                }
+            }
+
+            #[cfg(feature = "parsing")]
+            impl private::Sealed for $name {}
+        )*
+    };
+}
+
+define_punctuation_structs! {
+    "_" pub struct Underscore/1 /// wildcard patterns, inferred types, unnamed items in constants, extern crates, use declarations, and destructuring assignment
+}
+
+#[cfg(feature = "printing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+impl ToTokens for Underscore {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.append(Ident::new("_", self.span));
+    }
+}
+
+#[cfg(feature = "parsing")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+impl Parse for Underscore {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.step(|cursor| {
+            if let Some((ident, rest)) = cursor.ident() {
+                if ident == "_" {
+                    return Ok((Underscore(ident.span()), rest));
+                }
+            }
+            if let Some((punct, rest)) = cursor.punct() {
+                if punct.as_char() == '_' {
+                    return Ok((Underscore(punct.span()), rest));
+                }
+            }
+            Err(cursor.error("expected `_`"))
+        })
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl Token for Underscore {
+    fn peek(cursor: Cursor) -> bool {
+        if let Some((ident, _rest)) = cursor.ident() {
+            return ident == "_";
+        }
+        if let Some((punct, _rest)) = cursor.punct() {
+            return punct.as_char() == '_';
+        }
+        false
+    }
+
+    fn display() -> &'static str {
+        "`_`"
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl private::Sealed for Underscore {}
+
+/// None-delimited group
+pub struct Group {
+    pub span: Span,
+}
+
+#[doc(hidden)]
+#[allow(non_snake_case)]
+pub fn Group<S: IntoSpans<Span>>(span: S) -> Group {
+    Group {
+        span: span.into_spans(),
+    }
+}
+
+impl std::default::Default for Group {
+    fn default() -> Self {
+        Group {
+            span: Span::call_site(),
+        }
+    }
+}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Copy for Group {}
+
+#[cfg(feature = "clone-impls")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))]
+impl Clone for Group {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Debug for Group {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str("Group")
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl cmp::Eq for Group {}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl PartialEq for Group {
+    fn eq(&self, _other: &Group) -> bool {
+        true
+    }
+}
+
+#[cfg(feature = "extra-traits")]
+#[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))]
+impl Hash for Group {
+    fn hash<H: Hasher>(&self, _state: &mut H) {}
+}
+
+impl Group {
+    #[cfg(feature = "printing")]
+    pub fn surround<F>(&self, tokens: &mut TokenStream, f: F)
+    where
+        F: FnOnce(&mut TokenStream),
+    {
+        let mut inner = TokenStream::new();
+        f(&mut inner);
+        printing::delim(Delimiter::None, self.span, tokens, inner);
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl private::Sealed for Group {}
+
+#[cfg(feature = "parsing")]
+impl Token for Paren {
+    fn peek(cursor: Cursor) -> bool {
+        lookahead::is_delimiter(cursor, Delimiter::Parenthesis)
+    }
+
+    fn display() -> &'static str {
+        "parentheses"
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl Token for Brace {
+    fn peek(cursor: Cursor) -> bool {
+        lookahead::is_delimiter(cursor, Delimiter::Brace)
+    }
+
+    fn display() -> &'static str {
+        "curly braces"
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl Token for Bracket {
+    fn peek(cursor: Cursor) -> bool {
+        lookahead::is_delimiter(cursor, Delimiter::Bracket)
+    }
+
+    fn display() -> &'static str {
+        "square brackets"
+    }
+}
+
+#[cfg(feature = "parsing")]
+impl Token for Group {
+    fn peek(cursor: Cursor) -> bool {
+        lookahead::is_delimiter(cursor, Delimiter::None)
+    }
+
+    fn display() -> &'static str {
+        "invisible group"
+    }
+}
+
+define_keywords! {
+    "abstract"    pub struct Abstract
+    "as"          pub struct As
+    "async"       pub struct Async
+    "auto"        pub struct Auto
+    "await"       pub struct Await
+    "become"      pub struct Become
+    "box"         pub struct Box
+    "break"       pub struct Break
+    "const"       pub struct Const
+    "continue"    pub struct Continue
+    "crate"       pub struct Crate
+    "default"     pub struct Default
+    "do"          pub struct Do
+    "dyn"         pub struct Dyn
+    "else"        pub struct Else
+    "enum"        pub struct Enum
+    "extern"      pub struct Extern
+    "final"       pub struct Final
+    "fn"          pub struct Fn
+    "for"         pub struct For
+    "if"          pub struct If
+    "impl"        pub struct Impl
+    "in"          pub struct In
+    "let"         pub struct Let
+    "loop"        pub struct Loop
+    "macro"       pub struct Macro
+    "match"       pub struct Match
+    "mod"         pub struct Mod
+    "move"        pub struct Move
+    "mut"         pub struct Mut
+    "override"    pub struct Override
+    "priv"        pub struct Priv
+    "pub"         pub struct Pub
+    "ref"         pub struct Ref
+    "return"      pub struct Return
+    "Self"        pub struct SelfType
+    "self"        pub struct SelfValue
+    "static"      pub struct Static
+    "struct"      pub struct Struct
+    "super"       pub struct Super
+    "trait"       pub struct Trait
+    "try"         pub struct Try
+    "type"        pub struct Type
+    "typeof"      pub struct Typeof
+    "union"       pub struct Union
+    "unsafe"      pub struct Unsafe
+    "unsized"     pub struct Unsized
+    "use"         pub struct Use
+    "virtual"     pub struct Virtual
+    "where"       pub struct Where
+    "while"       pub struct While
+    "yield"       pub struct Yield
+}
+
+define_punctuation! {
+    "&"           pub struct And/1        /// bitwise and logical AND, borrow, references, reference patterns
+    "&&"          pub struct AndAnd/2     /// lazy AND, borrow, references, reference patterns
+    "&="          pub struct AndEq/2      /// bitwise AND assignment
+    "@"           pub struct At/1         /// subpattern binding
+    "^"           pub struct Caret/1      /// bitwise and logical XOR
+    "^="          pub struct CaretEq/2    /// bitwise XOR assignment
+    ":"           pub struct Colon/1      /// various separators
+    ","           pub struct Comma/1      /// various separators
+    "$"           pub struct Dollar/1     /// macros
+    "."           pub struct Dot/1        /// field access, tuple index
+    ".."          pub struct DotDot/2     /// range, struct expressions, patterns, range patterns
+    "..."         pub struct DotDotDot/3  /// variadic functions, range patterns
+    "..="         pub struct DotDotEq/3   /// inclusive range, range patterns
+    "="           pub struct Eq/1         /// assignment, attributes, various type definitions
+    "=="          pub struct EqEq/2       /// equal
+    "=>"          pub struct FatArrow/2   /// match arms, macros
+    ">="          pub struct Ge/2         /// greater than or equal to, generics
+    ">"           pub struct Gt/1         /// greater than, generics, paths
+    "<-"          pub struct LArrow/2     /// unused
+    "<="          pub struct Le/2         /// less than or equal to
+    "<"           pub struct Lt/1         /// less than, generics, paths
+    "-"           pub struct Minus/1      /// subtraction, negation
+    "-="          pub struct MinusEq/2    /// subtraction assignment
+    "!="          pub struct Ne/2         /// not equal
+    "!"           pub struct Not/1        /// bitwise and logical NOT, macro calls, inner attributes, never type, negative impls
+    "|"           pub struct Or/1         /// bitwise and logical OR, closures, patterns in match, if let, and while let
+    "|="          pub struct OrEq/2       /// bitwise OR assignment
+    "||"          pub struct OrOr/2       /// lazy OR, closures
+    "::"          pub struct PathSep/2    /// path separator
+    "%"           pub struct Percent/1    /// remainder
+    "%="          pub struct PercentEq/2  /// remainder assignment
+    "+"           pub struct Plus/1       /// addition, trait bounds, macro Kleene matcher
+    "+="          pub struct PlusEq/2     /// addition assignment
+    "#"           pub struct Pound/1      /// attributes
+    "?"           pub struct Question/1   /// question mark operator, questionably sized, macro Kleene matcher
+    "->"          pub struct RArrow/2     /// function return type, closure return type, function pointer type
+    ";"           pub struct Semi/1       /// terminator for various items and statements, array types
+    "<<"          pub struct Shl/2        /// shift left, nested generics
+    "<<="         pub struct ShlEq/3      /// shift left assignment
+    ">>"          pub struct Shr/2        /// shift right, nested generics
+    ">>="         pub struct ShrEq/3      /// shift right assignment, nested generics
+    "/"           pub struct Slash/1      /// division
+    "/="          pub struct SlashEq/2    /// division assignment
+    "*"           pub struct Star/1       /// multiplication, dereference, raw pointers, macro Kleene matcher, use wildcards
+    "*="          pub struct StarEq/2     /// multiplication assignment
+    "~"           pub struct Tilde/1      /// unused since before Rust 1.0
+}
+
+define_delimiters! {
+    Brace         pub struct Brace        /// `{`&hellip;`}`
+    Bracket       pub struct Bracket      /// `[`&hellip;`]`
+    Parenthesis   pub struct Paren        /// `(`&hellip;`)`
+}
+
+/// A type-macro that expands to the name of the Rust type representation of a
+/// given token.
+///
+/// As a type, `Token!` is commonly used in the type of struct fields, the type
+/// of a `let` statement, or in turbofish for a `parse` function.
+///
+/// ```
+/// use syn::{Ident, Token};
+/// use syn::parse::{Parse, ParseStream, Result};
+///
+/// // `struct Foo;`
+/// pub struct UnitStruct {
+///     struct_token: Token![struct],
+///     ident: Ident,
+///     semi_token: Token![;],
+/// }
+///
+/// impl Parse for UnitStruct {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let struct_token: Token![struct] = input.parse()?;
+///         let ident: Ident = input.parse()?;
+///         let semi_token = input.parse::<Token![;]>()?;
+///         Ok(UnitStruct { struct_token, ident, semi_token })
+///     }
+/// }
+/// ```
+///
+/// As an expression, `Token!` is used for peeking tokens or instantiating
+/// tokens from a span.
+///
+/// ```
+/// # use syn::{Ident, Token};
+/// # use syn::parse::{Parse, ParseStream, Result};
+/// #
+/// # struct UnitStruct {
+/// #     struct_token: Token![struct],
+/// #     ident: Ident,
+/// #     semi_token: Token![;],
+/// # }
+/// #
+/// # impl Parse for UnitStruct {
+/// #     fn parse(input: ParseStream) -> Result<Self> {
+/// #         unimplemented!()
+/// #     }
+/// # }
+/// #
+/// fn make_unit_struct(name: Ident) -> UnitStruct {
+///     let span = name.span();
+///     UnitStruct {
+///         struct_token: Token![struct](span),
+///         ident: name,
+///         semi_token: Token![;](span),
+///     }
+/// }
+///
+/// # fn parse(input: ParseStream) -> Result<()> {
+/// if input.peek(Token![struct]) {
+///     let unit_struct: UnitStruct = input.parse()?;
+///     /* ... */
+/// }
+/// # Ok(())
+/// # }
+/// ```
+///
+/// See the [token module] documentation for details and examples.
+///
+/// [token module]: crate::token
+#[macro_export]
+macro_rules! Token {
+    [abstract]    => { $crate::token::Abstract };
+    [as]          => { $crate::token::As };
+    [async]       => { $crate::token::Async };
+    [auto]        => { $crate::token::Auto };
+    [await]       => { $crate::token::Await };
+    [become]      => { $crate::token::Become };
+    [box]         => { $crate::token::Box };
+    [break]       => { $crate::token::Break };
+    [const]       => { $crate::token::Const };
+    [continue]    => { $crate::token::Continue };
+    [crate]       => { $crate::token::Crate };
+    [default]     => { $crate::token::Default };
+    [do]          => { $crate::token::Do };
+    [dyn]         => { $crate::token::Dyn };
+    [else]        => { $crate::token::Else };
+    [enum]        => { $crate::token::Enum };
+    [extern]      => { $crate::token::Extern };
+    [final]       => { $crate::token::Final };
+    [fn]          => { $crate::token::Fn };
+    [for]         => { $crate::token::For };
+    [if]          => { $crate::token::If };
+    [impl]        => { $crate::token::Impl };
+    [in]          => { $crate::token::In };
+    [let]         => { $crate::token::Let };
+    [loop]        => { $crate::token::Loop };
+    [macro]       => { $crate::token::Macro };
+    [match]       => { $crate::token::Match };
+    [mod]         => { $crate::token::Mod };
+    [move]        => { $crate::token::Move };
+    [mut]         => { $crate::token::Mut };
+    [override]    => { $crate::token::Override };
+    [priv]        => { $crate::token::Priv };
+    [pub]         => { $crate::token::Pub };
+    [ref]         => { $crate::token::Ref };
+    [return]      => { $crate::token::Return };
+    [Self]        => { $crate::token::SelfType };
+    [self]        => { $crate::token::SelfValue };
+    [static]      => { $crate::token::Static };
+    [struct]      => { $crate::token::Struct };
+    [super]       => { $crate::token::Super };
+    [trait]       => { $crate::token::Trait };
+    [try]         => { $crate::token::Try };
+    [type]        => { $crate::token::Type };
+    [typeof]      => { $crate::token::Typeof };
+    [union]       => { $crate::token::Union };
+    [unsafe]      => { $crate::token::Unsafe };
+    [unsized]     => { $crate::token::Unsized };
+    [use]         => { $crate::token::Use };
+    [virtual]     => { $crate::token::Virtual };
+    [where]       => { $crate::token::Where };
+    [while]       => { $crate::token::While };
+    [yield]       => { $crate::token::Yield };
+    [&]           => { $crate::token::And };
+    [&&]          => { $crate::token::AndAnd };
+    [&=]          => { $crate::token::AndEq };
+    [@]           => { $crate::token::At };
+    [^]           => { $crate::token::Caret };
+    [^=]          => { $crate::token::CaretEq };
+    [:]           => { $crate::token::Colon };
+    [,]           => { $crate::token::Comma };
+    [$]           => { $crate::token::Dollar };
+    [.]           => { $crate::token::Dot };
+    [..]          => { $crate::token::DotDot };
+    [...]         => { $crate::token::DotDotDot };
+    [..=]         => { $crate::token::DotDotEq };
+    [=]           => { $crate::token::Eq };
+    [==]          => { $crate::token::EqEq };
+    [=>]          => { $crate::token::FatArrow };
+    [>=]          => { $crate::token::Ge };
+    [>]           => { $crate::token::Gt };
+    [<-]          => { $crate::token::LArrow };
+    [<=]          => { $crate::token::Le };
+    [<]           => { $crate::token::Lt };
+    [-]           => { $crate::token::Minus };
+    [-=]          => { $crate::token::MinusEq };
+    [!=]          => { $crate::token::Ne };
+    [!]           => { $crate::token::Not };
+    [|]           => { $crate::token::Or };
+    [|=]          => { $crate::token::OrEq };
+    [||]          => { $crate::token::OrOr };
+    [::]          => { $crate::token::PathSep };
+    [%]           => { $crate::token::Percent };
+    [%=]          => { $crate::token::PercentEq };
+    [+]           => { $crate::token::Plus };
+    [+=]          => { $crate::token::PlusEq };
+    [#]           => { $crate::token::Pound };
+    [?]           => { $crate::token::Question };
+    [->]          => { $crate::token::RArrow };
+    [;]           => { $crate::token::Semi };
+    [<<]          => { $crate::token::Shl };
+    [<<=]         => { $crate::token::ShlEq };
+    [>>]          => { $crate::token::Shr };
+    [>>=]         => { $crate::token::ShrEq };
+    [/]           => { $crate::token::Slash };
+    [/=]          => { $crate::token::SlashEq };
+    [*]           => { $crate::token::Star };
+    [*=]          => { $crate::token::StarEq };
+    [~]           => { $crate::token::Tilde };
+    [_]           => { $crate::token::Underscore };
+}
+
+// Not public API.
+#[doc(hidden)]
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use crate::buffer::Cursor;
+    use crate::error::{Error, Result};
+    use crate::parse::ParseStream;
+    use proc_macro2::{Spacing, Span};
+
+    pub(crate) fn keyword(input: ParseStream, token: &str) -> Result<Span> {
+        input.step(|cursor| {
+            if let Some((ident, rest)) = cursor.ident() {
+                if ident == token {
+                    return Ok((ident.span(), rest));
+                }
+            }
+            Err(cursor.error(format!("expected `{}`", token)))
+        })
+    }
+
+    pub(crate) fn peek_keyword(cursor: Cursor, token: &str) -> bool {
+        if let Some((ident, _rest)) = cursor.ident() {
+            ident == token
+        } else {
+            false
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn punct<const N: usize>(input: ParseStream, token: &str) -> Result<[Span; N]> {
+        let mut spans = [input.span(); N];
+        punct_helper(input, token, &mut spans)?;
+        Ok(spans)
+    }
+
+    fn punct_helper(input: ParseStream, token: &str, spans: &mut [Span]) -> Result<()> {
+        input.step(|cursor| {
+            let mut cursor = *cursor;
+            assert_eq!(token.len(), spans.len());
+
+            for (i, ch) in token.chars().enumerate() {
+                match cursor.punct() {
+                    Some((punct, rest)) => {
+                        spans[i] = punct.span();
+                        if punct.as_char() != ch {
+                            break;
+                        } else if i == token.len() - 1 {
+                            return Ok(((), rest));
+                        } else if punct.spacing() != Spacing::Joint {
+                            break;
+                        }
+                        cursor = rest;
+                    }
+                    None => break,
+                }
+            }
+
+            Err(Error::new(spans[0], format!("expected `{}`", token)))
+        })
+    }
+
+    #[doc(hidden)]
+    pub fn peek_punct(mut cursor: Cursor, token: &str) -> bool {
+        for (i, ch) in token.chars().enumerate() {
+            match cursor.punct() {
+                Some((punct, rest)) => {
+                    if punct.as_char() != ch {
+                        break;
+                    } else if i == token.len() - 1 {
+                        return true;
+                    } else if punct.spacing() != Spacing::Joint {
+                        break;
+                    }
+                    cursor = rest;
+                }
+                None => break,
+            }
+        }
+        false
+    }
+}
+
+// Not public API.
+#[doc(hidden)]
+#[cfg(feature = "printing")]
+pub(crate) mod printing {
+    use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream};
+    use quote::TokenStreamExt;
+
+    #[doc(hidden)]
+    pub fn punct(s: &str, spans: &[Span], tokens: &mut TokenStream) {
+        assert_eq!(s.len(), spans.len());
+
+        let mut chars = s.chars();
+        let mut spans = spans.iter();
+        let ch = chars.next_back().unwrap();
+        let span = spans.next_back().unwrap();
+        for (ch, span) in chars.zip(spans) {
+            let mut op = Punct::new(ch, Spacing::Joint);
+            op.set_span(*span);
+            tokens.append(op);
+        }
+
+        let mut op = Punct::new(ch, Spacing::Alone);
+        op.set_span(*span);
+        tokens.append(op);
+    }
+
+    pub(crate) fn keyword(s: &str, span: Span, tokens: &mut TokenStream) {
+        tokens.append(Ident::new(s, span));
+    }
+
+    pub(crate) fn delim(
+        delim: Delimiter,
+        span: Span,
+        tokens: &mut TokenStream,
+        inner: TokenStream,
+    ) {
+        let mut g = Group::new(delim, inner);
+        g.set_span(span);
+        tokens.append(g);
+    }
+}
diff --git a/vendor/syn/src/tt.rs b/vendor/syn/src/tt.rs
new file mode 100644
index 0000000..d8dc9aa
--- /dev/null
+++ b/vendor/syn/src/tt.rs
@@ -0,0 +1,107 @@
+use proc_macro2::{Delimiter, TokenStream, TokenTree};
+use std::hash::{Hash, Hasher};
+
+pub(crate) struct TokenTreeHelper<'a>(pub &'a TokenTree);
+
+impl<'a> PartialEq for TokenTreeHelper<'a> {
+    fn eq(&self, other: &Self) -> bool {
+        use proc_macro2::Spacing;
+
+        match (self.0, other.0) {
+            (TokenTree::Group(g1), TokenTree::Group(g2)) => {
+                match (g1.delimiter(), g2.delimiter()) {
+                    (Delimiter::Parenthesis, Delimiter::Parenthesis)
+                    | (Delimiter::Brace, Delimiter::Brace)
+                    | (Delimiter::Bracket, Delimiter::Bracket)
+                    | (Delimiter::None, Delimiter::None) => {}
+                    _ => return false,
+                }
+
+                let s1 = g1.stream().into_iter();
+                let mut s2 = g2.stream().into_iter();
+
+                for item1 in s1 {
+                    let item2 = match s2.next() {
+                        Some(item) => item,
+                        None => return false,
+                    };
+                    if TokenTreeHelper(&item1) != TokenTreeHelper(&item2) {
+                        return false;
+                    }
+                }
+                s2.next().is_none()
+            }
+            (TokenTree::Punct(o1), TokenTree::Punct(o2)) => {
+                o1.as_char() == o2.as_char()
+                    && match (o1.spacing(), o2.spacing()) {
+                        (Spacing::Alone, Spacing::Alone) | (Spacing::Joint, Spacing::Joint) => true,
+                        _ => false,
+                    }
+            }
+            (TokenTree::Literal(l1), TokenTree::Literal(l2)) => l1.to_string() == l2.to_string(),
+            (TokenTree::Ident(s1), TokenTree::Ident(s2)) => s1 == s2,
+            _ => false,
+        }
+    }
+}
+
+impl<'a> Hash for TokenTreeHelper<'a> {
+    fn hash<H: Hasher>(&self, h: &mut H) {
+        use proc_macro2::Spacing;
+
+        match self.0 {
+            TokenTree::Group(g) => {
+                0u8.hash(h);
+                match g.delimiter() {
+                    Delimiter::Parenthesis => 0u8.hash(h),
+                    Delimiter::Brace => 1u8.hash(h),
+                    Delimiter::Bracket => 2u8.hash(h),
+                    Delimiter::None => 3u8.hash(h),
+                }
+
+                for item in g.stream() {
+                    TokenTreeHelper(&item).hash(h);
+                }
+                0xffu8.hash(h); // terminator w/ a variant we don't normally hash
+            }
+            TokenTree::Punct(op) => {
+                1u8.hash(h);
+                op.as_char().hash(h);
+                match op.spacing() {
+                    Spacing::Alone => 0u8.hash(h),
+                    Spacing::Joint => 1u8.hash(h),
+                }
+            }
+            TokenTree::Literal(lit) => (2u8, lit.to_string()).hash(h),
+            TokenTree::Ident(word) => (3u8, word).hash(h),
+        }
+    }
+}
+
+pub(crate) struct TokenStreamHelper<'a>(pub &'a TokenStream);
+
+impl<'a> PartialEq for TokenStreamHelper<'a> {
+    fn eq(&self, other: &Self) -> bool {
+        let left = self.0.clone().into_iter().collect::<Vec<_>>();
+        let right = other.0.clone().into_iter().collect::<Vec<_>>();
+        if left.len() != right.len() {
+            return false;
+        }
+        for (a, b) in left.into_iter().zip(right) {
+            if TokenTreeHelper(&a) != TokenTreeHelper(&b) {
+                return false;
+            }
+        }
+        true
+    }
+}
+
+impl<'a> Hash for TokenStreamHelper<'a> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        let tts = self.0.clone().into_iter().collect::<Vec<_>>();
+        tts.len().hash(state);
+        for tt in tts {
+            TokenTreeHelper(&tt).hash(state);
+        }
+    }
+}
diff --git a/vendor/syn/src/ty.rs b/vendor/syn/src/ty.rs
new file mode 100644
index 0000000..0f41fe4
--- /dev/null
+++ b/vendor/syn/src/ty.rs
@@ -0,0 +1,1188 @@
+use super::*;
+use crate::punctuated::Punctuated;
+use proc_macro2::TokenStream;
+
+ast_enum_of_structs! {
+    /// The possible types that a Rust value could have.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: Expr#syntax-tree-enums
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    #[non_exhaustive]
+    pub enum Type {
+        /// A fixed size array type: `[T; n]`.
+        Array(TypeArray),
+
+        /// A bare function type: `fn(usize) -> bool`.
+        BareFn(TypeBareFn),
+
+        /// A type contained within invisible delimiters.
+        Group(TypeGroup),
+
+        /// An `impl Bound1 + Bound2 + Bound3` type where `Bound` is a trait or
+        /// a lifetime.
+        ImplTrait(TypeImplTrait),
+
+        /// Indication that a type should be inferred by the compiler: `_`.
+        Infer(TypeInfer),
+
+        /// A macro in the type position.
+        Macro(TypeMacro),
+
+        /// The never type: `!`.
+        Never(TypeNever),
+
+        /// A parenthesized type equivalent to the inner type.
+        Paren(TypeParen),
+
+        /// A path like `std::slice::Iter`, optionally qualified with a
+        /// self-type as in `<Vec<T> as SomeTrait>::Associated`.
+        Path(TypePath),
+
+        /// A raw pointer type: `*const T` or `*mut T`.
+        Ptr(TypePtr),
+
+        /// A reference type: `&'a T` or `&'a mut T`.
+        Reference(TypeReference),
+
+        /// A dynamically sized slice type: `[T]`.
+        Slice(TypeSlice),
+
+        /// A trait object type `dyn Bound1 + Bound2 + Bound3` where `Bound` is a
+        /// trait or a lifetime.
+        TraitObject(TypeTraitObject),
+
+        /// A tuple type: `(A, B, C, String)`.
+        Tuple(TypeTuple),
+
+        /// Tokens in type position not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match ty {
+        //         Type::Array(ty) => {...}
+        //         Type::BareFn(ty) => {...}
+        //         ...
+        //         Type::Verbatim(ty) => {...}
+        //
+        //         #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A fixed size array type: `[T; n]`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeArray {
+        pub bracket_token: token::Bracket,
+        pub elem: Box<Type>,
+        pub semi_token: Token![;],
+        pub len: Expr,
+    }
+}
+
+ast_struct! {
+    /// A bare function type: `fn(usize) -> bool`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeBareFn {
+        pub lifetimes: Option<BoundLifetimes>,
+        pub unsafety: Option<Token![unsafe]>,
+        pub abi: Option<Abi>,
+        pub fn_token: Token![fn],
+        pub paren_token: token::Paren,
+        pub inputs: Punctuated<BareFnArg, Token![,]>,
+        pub variadic: Option<BareVariadic>,
+        pub output: ReturnType,
+    }
+}
+
+ast_struct! {
+    /// A type contained within invisible delimiters.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeGroup {
+        pub group_token: token::Group,
+        pub elem: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// An `impl Bound1 + Bound2 + Bound3` type where `Bound` is a trait or
+    /// a lifetime.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeImplTrait {
+        pub impl_token: Token![impl],
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+    }
+}
+
+ast_struct! {
+    /// Indication that a type should be inferred by the compiler: `_`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeInfer {
+        pub underscore_token: Token![_],
+    }
+}
+
+ast_struct! {
+    /// A macro in the type position.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeMacro {
+        pub mac: Macro,
+    }
+}
+
+ast_struct! {
+    /// The never type: `!`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeNever {
+        pub bang_token: Token![!],
+    }
+}
+
+ast_struct! {
+    /// A parenthesized type equivalent to the inner type.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeParen {
+        pub paren_token: token::Paren,
+        pub elem: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A path like `std::slice::Iter`, optionally qualified with a
+    /// self-type as in `<Vec<T> as SomeTrait>::Associated`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypePath {
+        pub qself: Option<QSelf>,
+        pub path: Path,
+    }
+}
+
+ast_struct! {
+    /// A raw pointer type: `*const T` or `*mut T`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypePtr {
+        pub star_token: Token![*],
+        pub const_token: Option<Token![const]>,
+        pub mutability: Option<Token![mut]>,
+        pub elem: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A reference type: `&'a T` or `&'a mut T`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeReference {
+        pub and_token: Token![&],
+        pub lifetime: Option<Lifetime>,
+        pub mutability: Option<Token![mut]>,
+        pub elem: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A dynamically sized slice type: `[T]`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeSlice {
+        pub bracket_token: token::Bracket,
+        pub elem: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A trait object type `dyn Bound1 + Bound2 + Bound3` where `Bound` is a
+    /// trait or a lifetime.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeTraitObject {
+        pub dyn_token: Option<Token![dyn]>,
+        pub bounds: Punctuated<TypeParamBound, Token![+]>,
+    }
+}
+
+ast_struct! {
+    /// A tuple type: `(A, B, C, String)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct TypeTuple {
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Type, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// The binary interface of a function: `extern "C"`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct Abi {
+        pub extern_token: Token![extern],
+        pub name: Option<LitStr>,
+    }
+}
+
+ast_struct! {
+    /// An argument in a function type: the `usize` in `fn(usize) -> bool`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct BareFnArg {
+        pub attrs: Vec<Attribute>,
+        pub name: Option<(Ident, Token![:])>,
+        pub ty: Type,
+    }
+}
+
+ast_struct! {
+    /// The variadic argument of a function pointer like `fn(usize, ...)`.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct BareVariadic {
+        pub attrs: Vec<Attribute>,
+        pub name: Option<(Ident, Token![:])>,
+        pub dots: Token![...],
+        pub comma: Option<Token![,]>,
+    }
+}
+
+ast_enum! {
+    /// Return type of a function signature.
+    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub enum ReturnType {
+        /// Return type is not specified.
+        ///
+        /// Functions default to `()` and closures default to type inference.
+        Default,
+        /// A particular type is returned.
+        Type(Token![->], Box<Type>),
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use super::*;
+    use crate::ext::IdentExt;
+    use crate::parse::{Parse, ParseStream, Result};
+    use crate::path;
+    use proc_macro2::Span;
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Type {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_plus = true;
+            let allow_group_generic = true;
+            ambig_ty(input, allow_plus, allow_group_generic)
+        }
+    }
+
+    impl Type {
+        /// In some positions, types may not contain the `+` character, to
+        /// disambiguate them. For example in the expression `1 as T`, T may not
+        /// contain a `+` character.
+        ///
+        /// This parser does not allow a `+`, while the default parser does.
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn without_plus(input: ParseStream) -> Result<Self> {
+            let allow_plus = false;
+            let allow_group_generic = true;
+            ambig_ty(input, allow_plus, allow_group_generic)
+        }
+    }
+
+    pub(crate) fn ambig_ty(
+        input: ParseStream,
+        allow_plus: bool,
+        allow_group_generic: bool,
+    ) -> Result<Type> {
+        let begin = input.fork();
+
+        if input.peek(token::Group) {
+            let mut group: TypeGroup = input.parse()?;
+            if input.peek(Token![::]) && input.peek3(Ident::peek_any) {
+                if let Type::Path(mut ty) = *group.elem {
+                    Path::parse_rest(input, &mut ty.path, false)?;
+                    return Ok(Type::Path(ty));
+                } else {
+                    return Ok(Type::Path(TypePath {
+                        qself: Some(QSelf {
+                            lt_token: Token![<](group.group_token.span),
+                            position: 0,
+                            as_token: None,
+                            gt_token: Token![>](group.group_token.span),
+                            ty: group.elem,
+                        }),
+                        path: Path::parse_helper(input, false)?,
+                    }));
+                }
+            } else if input.peek(Token![<]) && allow_group_generic
+                || input.peek(Token![::]) && input.peek3(Token![<])
+            {
+                if let Type::Path(mut ty) = *group.elem {
+                    let arguments = &mut ty.path.segments.last_mut().unwrap().arguments;
+                    if arguments.is_none() {
+                        *arguments = PathArguments::AngleBracketed(input.parse()?);
+                        Path::parse_rest(input, &mut ty.path, false)?;
+                        return Ok(Type::Path(ty));
+                    } else {
+                        group.elem = Box::new(Type::Path(ty));
+                    }
+                }
+            }
+            return Ok(Type::Group(group));
+        }
+
+        let mut lifetimes = None::<BoundLifetimes>;
+        let mut lookahead = input.lookahead1();
+        if lookahead.peek(Token![for]) {
+            lifetimes = input.parse()?;
+            lookahead = input.lookahead1();
+            if !lookahead.peek(Ident)
+                && !lookahead.peek(Token![fn])
+                && !lookahead.peek(Token![unsafe])
+                && !lookahead.peek(Token![extern])
+                && !lookahead.peek(Token![super])
+                && !lookahead.peek(Token![self])
+                && !lookahead.peek(Token![Self])
+                && !lookahead.peek(Token![crate])
+                || input.peek(Token![dyn])
+            {
+                return Err(lookahead.error());
+            }
+        }
+
+        if lookahead.peek(token::Paren) {
+            let content;
+            let paren_token = parenthesized!(content in input);
+            if content.is_empty() {
+                return Ok(Type::Tuple(TypeTuple {
+                    paren_token,
+                    elems: Punctuated::new(),
+                }));
+            }
+            if content.peek(Lifetime) {
+                return Ok(Type::Paren(TypeParen {
+                    paren_token,
+                    elem: Box::new(Type::TraitObject(content.parse()?)),
+                }));
+            }
+            if content.peek(Token![?]) {
+                return Ok(Type::TraitObject(TypeTraitObject {
+                    dyn_token: None,
+                    bounds: {
+                        let mut bounds = Punctuated::new();
+                        bounds.push_value(TypeParamBound::Trait(TraitBound {
+                            paren_token: Some(paren_token),
+                            ..content.parse()?
+                        }));
+                        while let Some(plus) = input.parse()? {
+                            bounds.push_punct(plus);
+                            bounds.push_value(input.parse()?);
+                        }
+                        bounds
+                    },
+                }));
+            }
+            let mut first: Type = content.parse()?;
+            if content.peek(Token![,]) {
+                return Ok(Type::Tuple(TypeTuple {
+                    paren_token,
+                    elems: {
+                        let mut elems = Punctuated::new();
+                        elems.push_value(first);
+                        elems.push_punct(content.parse()?);
+                        while !content.is_empty() {
+                            elems.push_value(content.parse()?);
+                            if content.is_empty() {
+                                break;
+                            }
+                            elems.push_punct(content.parse()?);
+                        }
+                        elems
+                    },
+                }));
+            }
+            if allow_plus && input.peek(Token![+]) {
+                loop {
+                    let first = match first {
+                        Type::Path(TypePath { qself: None, path }) => {
+                            TypeParamBound::Trait(TraitBound {
+                                paren_token: Some(paren_token),
+                                modifier: TraitBoundModifier::None,
+                                lifetimes: None,
+                                path,
+                            })
+                        }
+                        Type::TraitObject(TypeTraitObject {
+                            dyn_token: None,
+                            bounds,
+                        }) => {
+                            if bounds.len() > 1 || bounds.trailing_punct() {
+                                first = Type::TraitObject(TypeTraitObject {
+                                    dyn_token: None,
+                                    bounds,
+                                });
+                                break;
+                            }
+                            match bounds.into_iter().next().unwrap() {
+                                TypeParamBound::Trait(trait_bound) => {
+                                    TypeParamBound::Trait(TraitBound {
+                                        paren_token: Some(paren_token),
+                                        ..trait_bound
+                                    })
+                                }
+                                other @ (TypeParamBound::Lifetime(_)
+                                | TypeParamBound::Verbatim(_)) => other,
+                            }
+                        }
+                        _ => break,
+                    };
+                    return Ok(Type::TraitObject(TypeTraitObject {
+                        dyn_token: None,
+                        bounds: {
+                            let mut bounds = Punctuated::new();
+                            bounds.push_value(first);
+                            while let Some(plus) = input.parse()? {
+                                bounds.push_punct(plus);
+                                bounds.push_value(input.parse()?);
+                            }
+                            bounds
+                        },
+                    }));
+                }
+            }
+            Ok(Type::Paren(TypeParen {
+                paren_token,
+                elem: Box::new(first),
+            }))
+        } else if lookahead.peek(Token![fn])
+            || lookahead.peek(Token![unsafe])
+            || lookahead.peek(Token![extern])
+        {
+            let mut bare_fn: TypeBareFn = input.parse()?;
+            bare_fn.lifetimes = lifetimes;
+            Ok(Type::BareFn(bare_fn))
+        } else if lookahead.peek(Ident)
+            || input.peek(Token![super])
+            || input.peek(Token![self])
+            || input.peek(Token![Self])
+            || input.peek(Token![crate])
+            || lookahead.peek(Token![::])
+            || lookahead.peek(Token![<])
+        {
+            let ty: TypePath = input.parse()?;
+            if ty.qself.is_some() {
+                return Ok(Type::Path(ty));
+            }
+
+            if input.peek(Token![!]) && !input.peek(Token![!=]) && ty.path.is_mod_style() {
+                let bang_token: Token![!] = input.parse()?;
+                let (delimiter, tokens) = mac::parse_delimiter(input)?;
+                return Ok(Type::Macro(TypeMacro {
+                    mac: Macro {
+                        path: ty.path,
+                        bang_token,
+                        delimiter,
+                        tokens,
+                    },
+                }));
+            }
+
+            if lifetimes.is_some() || allow_plus && input.peek(Token![+]) {
+                let mut bounds = Punctuated::new();
+                bounds.push_value(TypeParamBound::Trait(TraitBound {
+                    paren_token: None,
+                    modifier: TraitBoundModifier::None,
+                    lifetimes,
+                    path: ty.path,
+                }));
+                if allow_plus {
+                    while input.peek(Token![+]) {
+                        bounds.push_punct(input.parse()?);
+                        if !(input.peek(Ident::peek_any)
+                            || input.peek(Token![::])
+                            || input.peek(Token![?])
+                            || input.peek(Lifetime)
+                            || input.peek(token::Paren))
+                        {
+                            break;
+                        }
+                        bounds.push_value(input.parse()?);
+                    }
+                }
+                return Ok(Type::TraitObject(TypeTraitObject {
+                    dyn_token: None,
+                    bounds,
+                }));
+            }
+
+            Ok(Type::Path(ty))
+        } else if lookahead.peek(Token![dyn]) {
+            let dyn_token: Token![dyn] = input.parse()?;
+            let dyn_span = dyn_token.span;
+            let star_token: Option<Token![*]> = input.parse()?;
+            let bounds = TypeTraitObject::parse_bounds(dyn_span, input, allow_plus)?;
+            return Ok(if star_token.is_some() {
+                Type::Verbatim(verbatim::between(&begin, input))
+            } else {
+                Type::TraitObject(TypeTraitObject {
+                    dyn_token: Some(dyn_token),
+                    bounds,
+                })
+            });
+        } else if lookahead.peek(token::Bracket) {
+            let content;
+            let bracket_token = bracketed!(content in input);
+            let elem: Type = content.parse()?;
+            if content.peek(Token![;]) {
+                Ok(Type::Array(TypeArray {
+                    bracket_token,
+                    elem: Box::new(elem),
+                    semi_token: content.parse()?,
+                    len: content.parse()?,
+                }))
+            } else {
+                Ok(Type::Slice(TypeSlice {
+                    bracket_token,
+                    elem: Box::new(elem),
+                }))
+            }
+        } else if lookahead.peek(Token![*]) {
+            input.parse().map(Type::Ptr)
+        } else if lookahead.peek(Token![&]) {
+            input.parse().map(Type::Reference)
+        } else if lookahead.peek(Token![!]) && !input.peek(Token![=]) {
+            input.parse().map(Type::Never)
+        } else if lookahead.peek(Token![impl]) {
+            TypeImplTrait::parse(input, allow_plus).map(Type::ImplTrait)
+        } else if lookahead.peek(Token![_]) {
+            input.parse().map(Type::Infer)
+        } else if lookahead.peek(Lifetime) {
+            input.parse().map(Type::TraitObject)
+        } else {
+            Err(lookahead.error())
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeSlice {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(TypeSlice {
+                bracket_token: bracketed!(content in input),
+                elem: content.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeArray {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(TypeArray {
+                bracket_token: bracketed!(content in input),
+                elem: content.parse()?,
+                semi_token: content.parse()?,
+                len: content.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypePtr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let star_token: Token![*] = input.parse()?;
+
+            let lookahead = input.lookahead1();
+            let (const_token, mutability) = if lookahead.peek(Token![const]) {
+                (Some(input.parse()?), None)
+            } else if lookahead.peek(Token![mut]) {
+                (None, Some(input.parse()?))
+            } else {
+                return Err(lookahead.error());
+            };
+
+            Ok(TypePtr {
+                star_token,
+                const_token,
+                mutability,
+                elem: Box::new(input.call(Type::without_plus)?),
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeReference {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(TypeReference {
+                and_token: input.parse()?,
+                lifetime: input.parse()?,
+                mutability: input.parse()?,
+                // & binds tighter than +, so we don't allow + here.
+                elem: Box::new(input.call(Type::without_plus)?),
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeBareFn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let args;
+            let mut variadic = None;
+
+            Ok(TypeBareFn {
+                lifetimes: input.parse()?,
+                unsafety: input.parse()?,
+                abi: input.parse()?,
+                fn_token: input.parse()?,
+                paren_token: parenthesized!(args in input),
+                inputs: {
+                    let mut inputs = Punctuated::new();
+
+                    while !args.is_empty() {
+                        let attrs = args.call(Attribute::parse_outer)?;
+
+                        if inputs.empty_or_trailing()
+                            && (args.peek(Token![...])
+                                || args.peek(Ident)
+                                    && args.peek2(Token![:])
+                                    && args.peek3(Token![...]))
+                        {
+                            variadic = Some(parse_bare_variadic(&args, attrs)?);
+                            break;
+                        }
+
+                        let allow_self = inputs.is_empty();
+                        let arg = parse_bare_fn_arg(&args, allow_self)?;
+                        inputs.push_value(BareFnArg { attrs, ..arg });
+                        if args.is_empty() {
+                            break;
+                        }
+
+                        let comma = args.parse()?;
+                        inputs.push_punct(comma);
+                    }
+
+                    inputs
+                },
+                variadic,
+                output: input.call(ReturnType::without_plus)?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeNever {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(TypeNever {
+                bang_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeInfer {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(TypeInfer {
+                underscore_token: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeTuple {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            let paren_token = parenthesized!(content in input);
+
+            if content.is_empty() {
+                return Ok(TypeTuple {
+                    paren_token,
+                    elems: Punctuated::new(),
+                });
+            }
+
+            let first: Type = content.parse()?;
+            Ok(TypeTuple {
+                paren_token,
+                elems: {
+                    let mut elems = Punctuated::new();
+                    elems.push_value(first);
+                    elems.push_punct(content.parse()?);
+                    while !content.is_empty() {
+                        elems.push_value(content.parse()?);
+                        if content.is_empty() {
+                            break;
+                        }
+                        elems.push_punct(content.parse()?);
+                    }
+                    elems
+                },
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(TypeMacro {
+                mac: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypePath {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let expr_style = false;
+            let (qself, path) = path::parsing::qpath(input, expr_style)?;
+            Ok(TypePath { qself, path })
+        }
+    }
+
+    impl ReturnType {
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn without_plus(input: ParseStream) -> Result<Self> {
+            let allow_plus = false;
+            Self::parse(input, allow_plus)
+        }
+
+        pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
+            if input.peek(Token![->]) {
+                let arrow = input.parse()?;
+                let allow_group_generic = true;
+                let ty = ambig_ty(input, allow_plus, allow_group_generic)?;
+                Ok(ReturnType::Type(arrow, Box::new(ty)))
+            } else {
+                Ok(ReturnType::Default)
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for ReturnType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_plus = true;
+            Self::parse(input, allow_plus)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeTraitObject {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_plus = true;
+            Self::parse(input, allow_plus)
+        }
+    }
+
+    impl TypeTraitObject {
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn without_plus(input: ParseStream) -> Result<Self> {
+            let allow_plus = false;
+            Self::parse(input, allow_plus)
+        }
+
+        // Only allow multiple trait references if allow_plus is true.
+        pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
+            let dyn_token: Option<Token![dyn]> = input.parse()?;
+            let dyn_span = match &dyn_token {
+                Some(token) => token.span,
+                None => input.span(),
+            };
+            let bounds = Self::parse_bounds(dyn_span, input, allow_plus)?;
+            Ok(TypeTraitObject { dyn_token, bounds })
+        }
+
+        fn parse_bounds(
+            dyn_span: Span,
+            input: ParseStream,
+            allow_plus: bool,
+        ) -> Result<Punctuated<TypeParamBound, Token![+]>> {
+            let bounds = TypeParamBound::parse_multiple(input, allow_plus)?;
+            let mut last_lifetime_span = None;
+            let mut at_least_one_trait = false;
+            for bound in &bounds {
+                match bound {
+                    TypeParamBound::Trait(_) | TypeParamBound::Verbatim(_) => {
+                        at_least_one_trait = true;
+                        break;
+                    }
+                    TypeParamBound::Lifetime(lifetime) => {
+                        last_lifetime_span = Some(lifetime.ident.span());
+                    }
+                }
+            }
+            // Just lifetimes like `'a + 'b` is not a TraitObject.
+            if !at_least_one_trait {
+                let msg = "at least one trait is required for an object type";
+                return Err(error::new2(dyn_span, last_lifetime_span.unwrap(), msg));
+            }
+            Ok(bounds)
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeImplTrait {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_plus = true;
+            Self::parse(input, allow_plus)
+        }
+    }
+
+    impl TypeImplTrait {
+        #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+        pub fn without_plus(input: ParseStream) -> Result<Self> {
+            let allow_plus = false;
+            Self::parse(input, allow_plus)
+        }
+
+        pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
+            let impl_token: Token![impl] = input.parse()?;
+            let bounds = TypeParamBound::parse_multiple(input, allow_plus)?;
+            let mut last_lifetime_span = None;
+            let mut at_least_one_trait = false;
+            for bound in &bounds {
+                match bound {
+                    TypeParamBound::Trait(_) | TypeParamBound::Verbatim(_) => {
+                        at_least_one_trait = true;
+                        break;
+                    }
+                    TypeParamBound::Lifetime(lifetime) => {
+                        last_lifetime_span = Some(lifetime.ident.span());
+                    }
+                }
+            }
+            if !at_least_one_trait {
+                let msg = "at least one trait must be specified";
+                return Err(error::new2(
+                    impl_token.span,
+                    last_lifetime_span.unwrap(),
+                    msg,
+                ));
+            }
+            Ok(TypeImplTrait { impl_token, bounds })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeGroup {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let group = crate::group::parse_group(input)?;
+            Ok(TypeGroup {
+                group_token: group.token,
+                elem: group.content.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for TypeParen {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_plus = false;
+            Self::parse(input, allow_plus)
+        }
+    }
+
+    impl TypeParen {
+        fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
+            let content;
+            Ok(TypeParen {
+                paren_token: parenthesized!(content in input),
+                elem: Box::new({
+                    let allow_group_generic = true;
+                    ambig_ty(&content, allow_plus, allow_group_generic)?
+                }),
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for BareFnArg {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_self = false;
+            parse_bare_fn_arg(input, allow_self)
+        }
+    }
+
+    fn parse_bare_fn_arg(input: ParseStream, allow_self: bool) -> Result<BareFnArg> {
+        let attrs = input.call(Attribute::parse_outer)?;
+
+        let begin = input.fork();
+
+        let has_mut_self = allow_self && input.peek(Token![mut]) && input.peek2(Token![self]);
+        if has_mut_self {
+            input.parse::<Token![mut]>()?;
+        }
+
+        let mut has_self = false;
+        let mut name = if (input.peek(Ident) || input.peek(Token![_]) || {
+            has_self = allow_self && input.peek(Token![self]);
+            has_self
+        }) && input.peek2(Token![:])
+            && !input.peek2(Token![::])
+        {
+            let name = input.call(Ident::parse_any)?;
+            let colon: Token![:] = input.parse()?;
+            Some((name, colon))
+        } else {
+            has_self = false;
+            None
+        };
+
+        let ty = if allow_self && !has_self && input.peek(Token![mut]) && input.peek2(Token![self])
+        {
+            input.parse::<Token![mut]>()?;
+            input.parse::<Token![self]>()?;
+            None
+        } else if has_mut_self && name.is_none() {
+            input.parse::<Token![self]>()?;
+            None
+        } else {
+            Some(input.parse()?)
+        };
+
+        let ty = match ty {
+            Some(ty) if !has_mut_self => ty,
+            _ => {
+                name = None;
+                Type::Verbatim(verbatim::between(&begin, input))
+            }
+        };
+
+        Ok(BareFnArg { attrs, name, ty })
+    }
+
+    fn parse_bare_variadic(input: ParseStream, attrs: Vec<Attribute>) -> Result<BareVariadic> {
+        Ok(BareVariadic {
+            attrs,
+            name: if input.peek(Ident) || input.peek(Token![_]) {
+                let name = input.call(Ident::parse_any)?;
+                let colon: Token![:] = input.parse()?;
+                Some((name, colon))
+            } else {
+                None
+            },
+            dots: input.parse()?,
+            comma: input.parse()?,
+        })
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Abi {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(Abi {
+                extern_token: input.parse()?,
+                name: input.parse()?,
+            })
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+    impl Parse for Option<Abi> {
+        fn parse(input: ParseStream) -> Result<Self> {
+            if input.peek(Token![extern]) {
+                input.parse().map(Some)
+            } else {
+                Ok(None)
+            }
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use super::*;
+    use crate::attr::FilterAttrs;
+    use crate::print::TokensOrDefault;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeSlice {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.bracket_token.surround(tokens, |tokens| {
+                self.elem.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeArray {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.bracket_token.surround(tokens, |tokens| {
+                self.elem.to_tokens(tokens);
+                self.semi_token.to_tokens(tokens);
+                self.len.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypePtr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.star_token.to_tokens(tokens);
+            match &self.mutability {
+                Some(tok) => tok.to_tokens(tokens),
+                None => {
+                    TokensOrDefault(&self.const_token).to_tokens(tokens);
+                }
+            }
+            self.elem.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeReference {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.and_token.to_tokens(tokens);
+            self.lifetime.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.elem.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeBareFn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.lifetimes.to_tokens(tokens);
+            self.unsafety.to_tokens(tokens);
+            self.abi.to_tokens(tokens);
+            self.fn_token.to_tokens(tokens);
+            self.paren_token.surround(tokens, |tokens| {
+                self.inputs.to_tokens(tokens);
+                if let Some(variadic) = &self.variadic {
+                    if !self.inputs.empty_or_trailing() {
+                        let span = variadic.dots.spans[0];
+                        Token![,](span).to_tokens(tokens);
+                    }
+                    variadic.to_tokens(tokens);
+                }
+            });
+            self.output.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeNever {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.bang_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeTuple {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+                // If we only have one argument, we need a trailing comma to
+                // distinguish TypeTuple from TypeParen.
+                if self.elems.len() == 1 && !self.elems.trailing_punct() {
+                    <Token![,]>::default().to_tokens(tokens);
+                }
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypePath {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            path::printing::print_path(tokens, &self.qself, &self.path);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeTraitObject {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.dyn_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeImplTrait {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.impl_token.to_tokens(tokens);
+            self.bounds.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeGroup {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.group_token.surround(tokens, |tokens| {
+                self.elem.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeParen {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.paren_token.surround(tokens, |tokens| {
+                self.elem.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeInfer {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.underscore_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for TypeMacro {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.mac.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for ReturnType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                ReturnType::Default => {}
+                ReturnType::Type(arrow, ty) => {
+                    arrow.to_tokens(tokens);
+                    ty.to_tokens(tokens);
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for BareFnArg {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some((name, colon)) = &self.name {
+                name.to_tokens(tokens);
+                colon.to_tokens(tokens);
+            }
+            self.ty.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for BareVariadic {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some((name, colon)) = &self.name {
+                name.to_tokens(tokens);
+                colon.to_tokens(tokens);
+            }
+            self.dots.to_tokens(tokens);
+            self.comma.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+    impl ToTokens for Abi {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            self.extern_token.to_tokens(tokens);
+            self.name.to_tokens(tokens);
+        }
+    }
+}
diff --git a/vendor/syn/src/verbatim.rs b/vendor/syn/src/verbatim.rs
new file mode 100644
index 0000000..54dc1cf
--- /dev/null
+++ b/vendor/syn/src/verbatim.rs
@@ -0,0 +1,33 @@
+use crate::parse::ParseStream;
+use proc_macro2::{Delimiter, TokenStream};
+use std::cmp::Ordering;
+use std::iter;
+
+pub(crate) fn between<'a>(begin: ParseStream<'a>, end: ParseStream<'a>) -> TokenStream {
+    let end = end.cursor();
+    let mut cursor = begin.cursor();
+    assert!(crate::buffer::same_buffer(end, cursor));
+
+    let mut tokens = TokenStream::new();
+    while cursor != end {
+        let (tt, next) = cursor.token_tree().unwrap();
+
+        if crate::buffer::cmp_assuming_same_buffer(end, next) == Ordering::Less {
+            // A syntax node can cross the boundary of a None-delimited group
+            // due to such groups being transparent to the parser in most cases.
+            // Any time this occurs the group is known to be semantically
+            // irrelevant. https://github.com/dtolnay/syn/issues/1235
+            if let Some((inside, _span, after)) = cursor.group(Delimiter::None) {
+                assert!(next == after);
+                cursor = inside;
+                continue;
+            } else {
+                panic!("verbatim end must not be inside a delimited group");
+            }
+        }
+
+        tokens.extend(iter::once(tt));
+        cursor = next;
+    }
+    tokens
+}
diff --git a/vendor/syn/src/whitespace.rs b/vendor/syn/src/whitespace.rs
new file mode 100644
index 0000000..f8de1b9
--- /dev/null
+++ b/vendor/syn/src/whitespace.rs
@@ -0,0 +1,65 @@
+pub(crate) fn skip(mut s: &str) -> &str {
+    'skip: while !s.is_empty() {
+        let byte = s.as_bytes()[0];
+        if byte == b'/' {
+            if s.starts_with("//")
+                && (!s.starts_with("///") || s.starts_with("////"))
+                && !s.starts_with("//!")
+            {
+                if let Some(i) = s.find('\n') {
+                    s = &s[i + 1..];
+                    continue;
+                } else {
+                    return "";
+                }
+            } else if s.starts_with("/**/") {
+                s = &s[4..];
+                continue;
+            } else if s.starts_with("/*")
+                && (!s.starts_with("/**") || s.starts_with("/***"))
+                && !s.starts_with("/*!")
+            {
+                let mut depth = 0;
+                let bytes = s.as_bytes();
+                let mut i = 0;
+                let upper = bytes.len() - 1;
+                while i < upper {
+                    if bytes[i] == b'/' && bytes[i + 1] == b'*' {
+                        depth += 1;
+                        i += 1; // eat '*'
+                    } else if bytes[i] == b'*' && bytes[i + 1] == b'/' {
+                        depth -= 1;
+                        if depth == 0 {
+                            s = &s[i + 2..];
+                            continue 'skip;
+                        }
+                        i += 1; // eat '/'
+                    }
+                    i += 1;
+                }
+                return s;
+            }
+        }
+        match byte {
+            b' ' | 0x09..=0x0d => {
+                s = &s[1..];
+                continue;
+            }
+            b if b <= 0x7f => {}
+            _ => {
+                let ch = s.chars().next().unwrap();
+                if is_whitespace(ch) {
+                    s = &s[ch.len_utf8()..];
+                    continue;
+                }
+            }
+        }
+        return s;
+    }
+    s
+}
+
+fn is_whitespace(ch: char) -> bool {
+    // Rust treats left-to-right mark and right-to-left mark as whitespace
+    ch.is_whitespace() || ch == '\u{200e}' || ch == '\u{200f}'
+}
diff --git a/vendor/syn/tests/common/eq.rs b/vendor/syn/tests/common/eq.rs
new file mode 100644
index 0000000..3c2b1c1
--- /dev/null
+++ b/vendor/syn/tests/common/eq.rs
@@ -0,0 +1,865 @@
+#![allow(unused_macro_rules)]
+
+extern crate rustc_ast;
+extern crate rustc_data_structures;
+extern crate rustc_driver;
+extern crate rustc_span;
+extern crate thin_vec;
+
+use rustc_ast::ast::AngleBracketedArg;
+use rustc_ast::ast::AngleBracketedArgs;
+use rustc_ast::ast::AnonConst;
+use rustc_ast::ast::Arm;
+use rustc_ast::ast::AssocConstraint;
+use rustc_ast::ast::AssocConstraintKind;
+use rustc_ast::ast::AssocItemKind;
+use rustc_ast::ast::Async;
+use rustc_ast::ast::AttrArgs;
+use rustc_ast::ast::AttrArgsEq;
+use rustc_ast::ast::AttrId;
+use rustc_ast::ast::AttrItem;
+use rustc_ast::ast::AttrKind;
+use rustc_ast::ast::AttrStyle;
+use rustc_ast::ast::Attribute;
+use rustc_ast::ast::BareFnTy;
+use rustc_ast::ast::BinOpKind;
+use rustc_ast::ast::BindingAnnotation;
+use rustc_ast::ast::Block;
+use rustc_ast::ast::BlockCheckMode;
+use rustc_ast::ast::BorrowKind;
+use rustc_ast::ast::BoundPolarity;
+use rustc_ast::ast::ByRef;
+use rustc_ast::ast::CaptureBy;
+use rustc_ast::ast::Closure;
+use rustc_ast::ast::ClosureBinder;
+use rustc_ast::ast::Const;
+use rustc_ast::ast::ConstItem;
+use rustc_ast::ast::Crate;
+use rustc_ast::ast::Defaultness;
+use rustc_ast::ast::DelimArgs;
+use rustc_ast::ast::EnumDef;
+use rustc_ast::ast::Expr;
+use rustc_ast::ast::ExprField;
+use rustc_ast::ast::ExprKind;
+use rustc_ast::ast::Extern;
+use rustc_ast::ast::FieldDef;
+use rustc_ast::ast::FloatTy;
+use rustc_ast::ast::Fn;
+use rustc_ast::ast::FnDecl;
+use rustc_ast::ast::FnHeader;
+use rustc_ast::ast::FnRetTy;
+use rustc_ast::ast::FnSig;
+use rustc_ast::ast::ForeignItemKind;
+use rustc_ast::ast::ForeignMod;
+use rustc_ast::ast::FormatAlignment;
+use rustc_ast::ast::FormatArgPosition;
+use rustc_ast::ast::FormatArgPositionKind;
+use rustc_ast::ast::FormatArgs;
+use rustc_ast::ast::FormatArgsPiece;
+use rustc_ast::ast::FormatArgument;
+use rustc_ast::ast::FormatArgumentKind;
+use rustc_ast::ast::FormatArguments;
+use rustc_ast::ast::FormatCount;
+use rustc_ast::ast::FormatDebugHex;
+use rustc_ast::ast::FormatOptions;
+use rustc_ast::ast::FormatPlaceholder;
+use rustc_ast::ast::FormatSign;
+use rustc_ast::ast::FormatTrait;
+use rustc_ast::ast::GenericArg;
+use rustc_ast::ast::GenericArgs;
+use rustc_ast::ast::GenericBound;
+use rustc_ast::ast::GenericParam;
+use rustc_ast::ast::GenericParamKind;
+use rustc_ast::ast::Generics;
+use rustc_ast::ast::Impl;
+use rustc_ast::ast::ImplPolarity;
+use rustc_ast::ast::Inline;
+use rustc_ast::ast::InlineAsm;
+use rustc_ast::ast::InlineAsmOperand;
+use rustc_ast::ast::InlineAsmOptions;
+use rustc_ast::ast::InlineAsmRegOrRegClass;
+use rustc_ast::ast::InlineAsmSym;
+use rustc_ast::ast::InlineAsmTemplatePiece;
+use rustc_ast::ast::IntTy;
+use rustc_ast::ast::IsAuto;
+use rustc_ast::ast::Item;
+use rustc_ast::ast::ItemKind;
+use rustc_ast::ast::Label;
+use rustc_ast::ast::Lifetime;
+use rustc_ast::ast::LitFloatType;
+use rustc_ast::ast::LitIntType;
+use rustc_ast::ast::LitKind;
+use rustc_ast::ast::Local;
+use rustc_ast::ast::LocalKind;
+use rustc_ast::ast::MacCall;
+use rustc_ast::ast::MacCallStmt;
+use rustc_ast::ast::MacStmtStyle;
+use rustc_ast::ast::MacroDef;
+use rustc_ast::ast::MetaItemLit;
+use rustc_ast::ast::MethodCall;
+use rustc_ast::ast::ModKind;
+use rustc_ast::ast::ModSpans;
+use rustc_ast::ast::Movability;
+use rustc_ast::ast::MutTy;
+use rustc_ast::ast::Mutability;
+use rustc_ast::ast::NodeId;
+use rustc_ast::ast::NormalAttr;
+use rustc_ast::ast::Param;
+use rustc_ast::ast::ParenthesizedArgs;
+use rustc_ast::ast::Pat;
+use rustc_ast::ast::PatField;
+use rustc_ast::ast::PatKind;
+use rustc_ast::ast::Path;
+use rustc_ast::ast::PathSegment;
+use rustc_ast::ast::PolyTraitRef;
+use rustc_ast::ast::QSelf;
+use rustc_ast::ast::RangeEnd;
+use rustc_ast::ast::RangeLimits;
+use rustc_ast::ast::RangeSyntax;
+use rustc_ast::ast::StaticItem;
+use rustc_ast::ast::Stmt;
+use rustc_ast::ast::StmtKind;
+use rustc_ast::ast::StrLit;
+use rustc_ast::ast::StrStyle;
+use rustc_ast::ast::StructExpr;
+use rustc_ast::ast::StructRest;
+use rustc_ast::ast::Term;
+use rustc_ast::ast::Trait;
+use rustc_ast::ast::TraitBoundModifier;
+use rustc_ast::ast::TraitObjectSyntax;
+use rustc_ast::ast::TraitRef;
+use rustc_ast::ast::Ty;
+use rustc_ast::ast::TyAlias;
+use rustc_ast::ast::TyAliasWhereClause;
+use rustc_ast::ast::TyKind;
+use rustc_ast::ast::UintTy;
+use rustc_ast::ast::UnOp;
+use rustc_ast::ast::Unsafe;
+use rustc_ast::ast::UnsafeSource;
+use rustc_ast::ast::UseTree;
+use rustc_ast::ast::UseTreeKind;
+use rustc_ast::ast::Variant;
+use rustc_ast::ast::VariantData;
+use rustc_ast::ast::Visibility;
+use rustc_ast::ast::VisibilityKind;
+use rustc_ast::ast::WhereBoundPredicate;
+use rustc_ast::ast::WhereClause;
+use rustc_ast::ast::WhereEqPredicate;
+use rustc_ast::ast::WherePredicate;
+use rustc_ast::ast::WhereRegionPredicate;
+use rustc_ast::ptr::P;
+use rustc_ast::token::{self, CommentKind, Delimiter, Lit, Nonterminal, Token, TokenKind};
+use rustc_ast::tokenstream::{
+    AttrTokenStream, AttrTokenTree, AttributesData, DelimSpan, LazyAttrTokenStream, Spacing,
+    TokenStream, TokenTree,
+};
+use rustc_data_structures::sync::Lrc;
+use rustc_span::source_map::Spanned;
+use rustc_span::symbol::{sym, Ident};
+use rustc_span::{ErrorGuaranteed, Span, Symbol, SyntaxContext, DUMMY_SP};
+use std::collections::HashMap;
+use std::hash::{BuildHasher, Hash};
+use thin_vec::ThinVec;
+
+pub trait SpanlessEq {
+    fn eq(&self, other: &Self) -> bool;
+}
+
+impl<T: ?Sized + SpanlessEq> SpanlessEq for Box<T> {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&**self, &**other)
+    }
+}
+
+impl<T: ?Sized + SpanlessEq> SpanlessEq for P<T> {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&**self, &**other)
+    }
+}
+
+impl<T: ?Sized + SpanlessEq> SpanlessEq for Lrc<T> {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&**self, &**other)
+    }
+}
+
+impl<T: SpanlessEq> SpanlessEq for Option<T> {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (None, None) => true,
+            (Some(this), Some(other)) => SpanlessEq::eq(this, other),
+            _ => false,
+        }
+    }
+}
+
+impl<T: SpanlessEq, E: SpanlessEq> SpanlessEq for Result<T, E> {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Ok(this), Ok(other)) => SpanlessEq::eq(this, other),
+            (Err(this), Err(other)) => SpanlessEq::eq(this, other),
+            _ => false,
+        }
+    }
+}
+
+impl<T: SpanlessEq> SpanlessEq for [T] {
+    fn eq(&self, other: &Self) -> bool {
+        self.len() == other.len() && self.iter().zip(other).all(|(a, b)| SpanlessEq::eq(a, b))
+    }
+}
+
+impl<T: SpanlessEq> SpanlessEq for Vec<T> {
+    fn eq(&self, other: &Self) -> bool {
+        <[T] as SpanlessEq>::eq(self, other)
+    }
+}
+
+impl<T: SpanlessEq> SpanlessEq for ThinVec<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.len() == other.len()
+            && self
+                .iter()
+                .zip(other.iter())
+                .all(|(a, b)| SpanlessEq::eq(a, b))
+    }
+}
+
+impl<K: Eq + Hash, V: SpanlessEq, S: BuildHasher> SpanlessEq for HashMap<K, V, S> {
+    fn eq(&self, other: &Self) -> bool {
+        self.len() == other.len()
+            && self.iter().all(|(key, this_v)| {
+                other
+                    .get(key)
+                    .map_or(false, |other_v| SpanlessEq::eq(this_v, other_v))
+            })
+    }
+}
+
+impl<T: SpanlessEq> SpanlessEq for Spanned<T> {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&self.node, &other.node)
+    }
+}
+
+impl<A: SpanlessEq, B: SpanlessEq> SpanlessEq for (A, B) {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&self.0, &other.0) && SpanlessEq::eq(&self.1, &other.1)
+    }
+}
+
+impl<A: SpanlessEq, B: SpanlessEq, C: SpanlessEq> SpanlessEq for (A, B, C) {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(&self.0, &other.0)
+            && SpanlessEq::eq(&self.1, &other.1)
+            && SpanlessEq::eq(&self.2, &other.2)
+    }
+}
+
+macro_rules! spanless_eq_true {
+    ($name:ty) => {
+        impl SpanlessEq for $name {
+            fn eq(&self, _other: &Self) -> bool {
+                true
+            }
+        }
+    };
+}
+
+spanless_eq_true!(Span);
+spanless_eq_true!(DelimSpan);
+spanless_eq_true!(AttrId);
+spanless_eq_true!(NodeId);
+spanless_eq_true!(SyntaxContext);
+spanless_eq_true!(Spacing);
+
+macro_rules! spanless_eq_partial_eq {
+    ($name:ty) => {
+        impl SpanlessEq for $name {
+            fn eq(&self, other: &Self) -> bool {
+                PartialEq::eq(self, other)
+            }
+        }
+    };
+}
+
+spanless_eq_partial_eq!(bool);
+spanless_eq_partial_eq!(u8);
+spanless_eq_partial_eq!(u16);
+spanless_eq_partial_eq!(u32);
+spanless_eq_partial_eq!(u128);
+spanless_eq_partial_eq!(usize);
+spanless_eq_partial_eq!(char);
+spanless_eq_partial_eq!(String);
+spanless_eq_partial_eq!(Symbol);
+spanless_eq_partial_eq!(CommentKind);
+spanless_eq_partial_eq!(Delimiter);
+spanless_eq_partial_eq!(InlineAsmOptions);
+spanless_eq_partial_eq!(token::LitKind);
+spanless_eq_partial_eq!(ErrorGuaranteed);
+
+macro_rules! spanless_eq_struct {
+    {
+        $($name:ident)::+ $(<$param:ident>)?
+        $([$field:tt $this:ident $other:ident])*
+        $(![$ignore:tt])*;
+    } => {
+        impl $(<$param: SpanlessEq>)* SpanlessEq for $($name)::+ $(<$param>)* {
+            fn eq(&self, other: &Self) -> bool {
+                let $($name)::+ { $($field: $this,)* $($ignore: _,)* } = self;
+                let $($name)::+ { $($field: $other,)* $($ignore: _,)* } = other;
+                true $(&& SpanlessEq::eq($this, $other))*
+            }
+        }
+    };
+
+    {
+        $($name:ident)::+ $(<$param:ident>)?
+        $([$field:tt $this:ident $other:ident])*
+        $(![$ignore:tt])*;
+        !$next:tt
+        $($rest:tt)*
+    } => {
+        spanless_eq_struct! {
+            $($name)::+ $(<$param>)*
+            $([$field $this $other])*
+            $(![$ignore])*
+            ![$next];
+            $($rest)*
+        }
+    };
+
+    {
+        $($name:ident)::+ $(<$param:ident>)?
+        $([$field:tt $this:ident $other:ident])*
+        $(![$ignore:tt])*;
+        $next:tt
+        $($rest:tt)*
+    } => {
+        spanless_eq_struct! {
+            $($name)::+ $(<$param>)*
+            $([$field $this $other])*
+            [$next this other]
+            $(![$ignore])*;
+            $($rest)*
+        }
+    };
+}
+
+macro_rules! spanless_eq_enum {
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $([$field:tt $this:ident $other:ident])* $(![$ignore:tt])*])*
+    } => {
+        impl SpanlessEq for $($name)::+ {
+            fn eq(&self, other: &Self) -> bool {
+                match self {
+                    $(
+                        $($variant)::+ { .. } => {}
+                    )*
+                }
+                #[allow(unreachable_patterns)]
+                match (self, other) {
+                    $(
+                        (
+                            $($variant)::+ { $($field: $this,)* $($ignore: _,)* },
+                            $($variant)::+ { $($field: $other,)* $($ignore: _,)* },
+                        ) => {
+                            true $(&& SpanlessEq::eq($this, $other))*
+                        }
+                    )*
+                    _ => false,
+                }
+            }
+        }
+    };
+
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $($fields:tt)*])*
+        $next:ident [$([$($named:tt)*])* $(![$ignore:tt])*] (!$i:tt $($field:tt)*)
+        $($rest:tt)*
+    } => {
+        spanless_eq_enum! {
+            $($name)::+;
+            $([$($variant)::+; $($fields)*])*
+            $next [$([$($named)*])* $(![$ignore])* ![$i]] ($($field)*)
+            $($rest)*
+        }
+    };
+
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $($fields:tt)*])*
+        $next:ident [$([$($named:tt)*])* $(![$ignore:tt])*] ($i:tt $($field:tt)*)
+        $($rest:tt)*
+    } => {
+        spanless_eq_enum! {
+            $($name)::+;
+            $([$($variant)::+; $($fields)*])*
+            $next [$([$($named)*])* [$i this other] $(![$ignore])*] ($($field)*)
+            $($rest)*
+        }
+    };
+
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $($fields:tt)*])*
+        $next:ident [$($named:tt)*] ()
+        $($rest:tt)*
+    } => {
+        spanless_eq_enum! {
+            $($name)::+;
+            $([$($variant)::+; $($fields)*])*
+            [$($name)::+::$next; $($named)*]
+            $($rest)*
+        }
+    };
+
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $($fields:tt)*])*
+        $next:ident ($($field:tt)*)
+        $($rest:tt)*
+    } => {
+        spanless_eq_enum! {
+            $($name)::+;
+            $([$($variant)::+; $($fields)*])*
+            $next [] ($($field)*)
+            $($rest)*
+        }
+    };
+
+    {
+        $($name:ident)::+;
+        $([$($variant:ident)::+; $($fields:tt)*])*
+        $next:ident
+        $($rest:tt)*
+    } => {
+        spanless_eq_enum! {
+            $($name)::+;
+            $([$($variant)::+; $($fields)*])*
+            [$($name)::+::$next;]
+            $($rest)*
+        }
+    };
+}
+
+spanless_eq_struct!(AngleBracketedArgs; span args);
+spanless_eq_struct!(AnonConst; id value);
+spanless_eq_struct!(Arm; attrs pat guard body span id is_placeholder);
+spanless_eq_struct!(AssocConstraint; id ident gen_args kind span);
+spanless_eq_struct!(AttrItem; path args tokens);
+spanless_eq_struct!(AttrTokenStream; 0);
+spanless_eq_struct!(Attribute; kind id style span);
+spanless_eq_struct!(AttributesData; attrs tokens);
+spanless_eq_struct!(BareFnTy; unsafety ext generic_params decl decl_span);
+spanless_eq_struct!(BindingAnnotation; 0 1);
+spanless_eq_struct!(Block; stmts id rules span tokens could_be_bare_literal);
+spanless_eq_struct!(Closure; binder capture_clause constness asyncness movability fn_decl body !fn_decl_span !fn_arg_span);
+spanless_eq_struct!(ConstItem; defaultness generics ty expr);
+spanless_eq_struct!(Crate; attrs items spans id is_placeholder);
+spanless_eq_struct!(DelimArgs; dspan delim tokens);
+spanless_eq_struct!(EnumDef; variants);
+spanless_eq_struct!(Expr; id kind span attrs !tokens);
+spanless_eq_struct!(ExprField; attrs id span ident expr is_shorthand is_placeholder);
+spanless_eq_struct!(FieldDef; attrs id span vis ident ty is_placeholder);
+spanless_eq_struct!(Fn; defaultness generics sig body);
+spanless_eq_struct!(FnDecl; inputs output);
+spanless_eq_struct!(FnHeader; constness asyncness unsafety ext);
+spanless_eq_struct!(FnSig; header decl span);
+spanless_eq_struct!(ForeignMod; unsafety abi items);
+spanless_eq_struct!(FormatArgPosition; index kind span);
+spanless_eq_struct!(FormatArgs; span template arguments);
+spanless_eq_struct!(FormatArgument; kind expr);
+spanless_eq_struct!(FormatOptions; width precision alignment fill sign alternate zero_pad debug_hex);
+spanless_eq_struct!(FormatPlaceholder; argument span format_trait format_options);
+spanless_eq_struct!(GenericParam; id ident attrs bounds is_placeholder kind !colon_span);
+spanless_eq_struct!(Generics; params where_clause span);
+spanless_eq_struct!(Impl; defaultness unsafety generics constness polarity of_trait self_ty items);
+spanless_eq_struct!(InlineAsm; template template_strs operands clobber_abis options line_spans);
+spanless_eq_struct!(InlineAsmSym; id qself path);
+spanless_eq_struct!(Item<K>; attrs id span vis ident kind !tokens);
+spanless_eq_struct!(Label; ident);
+spanless_eq_struct!(Lifetime; id ident);
+spanless_eq_struct!(Lit; kind symbol suffix);
+spanless_eq_struct!(Local; pat ty kind id span attrs !tokens);
+spanless_eq_struct!(MacCall; path args);
+spanless_eq_struct!(MacCallStmt; mac style attrs tokens);
+spanless_eq_struct!(MacroDef; body macro_rules);
+spanless_eq_struct!(MetaItemLit; symbol suffix kind span);
+spanless_eq_struct!(MethodCall; seg receiver args !span);
+spanless_eq_struct!(ModSpans; !inner_span !inject_use_span);
+spanless_eq_struct!(MutTy; ty mutbl);
+spanless_eq_struct!(NormalAttr; item tokens);
+spanless_eq_struct!(ParenthesizedArgs; span inputs inputs_span output);
+spanless_eq_struct!(Pat; id kind span tokens);
+spanless_eq_struct!(PatField; ident pat is_shorthand attrs id span is_placeholder);
+spanless_eq_struct!(Path; span segments tokens);
+spanless_eq_struct!(PathSegment; ident id args);
+spanless_eq_struct!(PolyTraitRef; bound_generic_params trait_ref span);
+spanless_eq_struct!(QSelf; ty path_span position);
+spanless_eq_struct!(StaticItem; ty mutability expr);
+spanless_eq_struct!(Stmt; id kind span);
+spanless_eq_struct!(StrLit; symbol suffix symbol_unescaped style span);
+spanless_eq_struct!(StructExpr; qself path fields rest);
+spanless_eq_struct!(Token; kind span);
+spanless_eq_struct!(Trait; unsafety is_auto generics bounds items);
+spanless_eq_struct!(TraitRef; path ref_id);
+spanless_eq_struct!(Ty; id kind span tokens);
+spanless_eq_struct!(TyAlias; defaultness generics where_clauses !where_predicates_split bounds ty);
+spanless_eq_struct!(TyAliasWhereClause; !0 1);
+spanless_eq_struct!(UseTree; prefix kind span);
+spanless_eq_struct!(Variant; attrs id span !vis ident data disr_expr is_placeholder);
+spanless_eq_struct!(Visibility; kind span tokens);
+spanless_eq_struct!(WhereBoundPredicate; span bound_generic_params bounded_ty bounds);
+spanless_eq_struct!(WhereClause; has_where_token predicates span);
+spanless_eq_struct!(WhereEqPredicate; span lhs_ty rhs_ty);
+spanless_eq_struct!(WhereRegionPredicate; span lifetime bounds);
+spanless_eq_enum!(AngleBracketedArg; Arg(0) Constraint(0));
+spanless_eq_enum!(AssocConstraintKind; Equality(term) Bound(bounds));
+spanless_eq_enum!(AssocItemKind; Const(0) Fn(0) Type(0) MacCall(0));
+spanless_eq_enum!(Async; Yes(span closure_id return_impl_trait_id) No);
+spanless_eq_enum!(AttrArgs; Empty Delimited(0) Eq(0 1));
+spanless_eq_enum!(AttrArgsEq; Ast(0) Hir(0));
+spanless_eq_enum!(AttrStyle; Outer Inner);
+spanless_eq_enum!(AttrTokenTree; Token(0 1) Delimited(0 1 2) Attributes(0));
+spanless_eq_enum!(BinOpKind; Add Sub Mul Div Rem And Or BitXor BitAnd BitOr Shl Shr Eq Lt Le Ne Ge Gt);
+spanless_eq_enum!(BlockCheckMode; Default Unsafe(0));
+spanless_eq_enum!(BorrowKind; Ref Raw);
+spanless_eq_enum!(BoundPolarity; Positive Negative(0) Maybe(0));
+spanless_eq_enum!(ByRef; Yes No);
+spanless_eq_enum!(CaptureBy; Value Ref);
+spanless_eq_enum!(ClosureBinder; NotPresent For(span generic_params));
+spanless_eq_enum!(Const; Yes(0) No);
+spanless_eq_enum!(Defaultness; Default(0) Final);
+spanless_eq_enum!(Extern; None Implicit(0) Explicit(0 1));
+spanless_eq_enum!(FloatTy; F32 F64);
+spanless_eq_enum!(FnRetTy; Default(0) Ty(0));
+spanless_eq_enum!(ForeignItemKind; Static(0 1 2) Fn(0) TyAlias(0) MacCall(0));
+spanless_eq_enum!(FormatAlignment; Left Right Center);
+spanless_eq_enum!(FormatArgPositionKind; Implicit Number Named);
+spanless_eq_enum!(FormatArgsPiece; Literal(0) Placeholder(0));
+spanless_eq_enum!(FormatArgumentKind; Normal Named(0) Captured(0));
+spanless_eq_enum!(FormatCount; Literal(0) Argument(0));
+spanless_eq_enum!(FormatDebugHex; Lower Upper);
+spanless_eq_enum!(FormatSign; Plus Minus);
+spanless_eq_enum!(FormatTrait; Display Debug LowerExp UpperExp Octal Pointer Binary LowerHex UpperHex);
+spanless_eq_enum!(GenericArg; Lifetime(0) Type(0) Const(0));
+spanless_eq_enum!(GenericArgs; AngleBracketed(0) Parenthesized(0));
+spanless_eq_enum!(GenericBound; Trait(0 1) Outlives(0));
+spanless_eq_enum!(GenericParamKind; Lifetime Type(default) Const(ty kw_span default));
+spanless_eq_enum!(ImplPolarity; Positive Negative(0));
+spanless_eq_enum!(Inline; Yes No);
+spanless_eq_enum!(InlineAsmRegOrRegClass; Reg(0) RegClass(0));
+spanless_eq_enum!(InlineAsmTemplatePiece; String(0) Placeholder(operand_idx modifier span));
+spanless_eq_enum!(IntTy; Isize I8 I16 I32 I64 I128);
+spanless_eq_enum!(IsAuto; Yes No);
+spanless_eq_enum!(LitFloatType; Suffixed(0) Unsuffixed);
+spanless_eq_enum!(LitIntType; Signed(0) Unsigned(0) Unsuffixed);
+spanless_eq_enum!(LocalKind; Decl Init(0) InitElse(0 1));
+spanless_eq_enum!(MacStmtStyle; Semicolon Braces NoBraces);
+spanless_eq_enum!(ModKind; Loaded(0 1 2) Unloaded);
+spanless_eq_enum!(Movability; Static Movable);
+spanless_eq_enum!(Mutability; Mut Not);
+spanless_eq_enum!(RangeEnd; Included(0) Excluded);
+spanless_eq_enum!(RangeLimits; HalfOpen Closed);
+spanless_eq_enum!(StmtKind; Local(0) Item(0) Expr(0) Semi(0) Empty MacCall(0));
+spanless_eq_enum!(StrStyle; Cooked Raw(0));
+spanless_eq_enum!(StructRest; Base(0) Rest(0) None);
+spanless_eq_enum!(Term; Ty(0) Const(0));
+spanless_eq_enum!(TokenTree; Token(0 1) Delimited(0 1 2));
+spanless_eq_enum!(TraitBoundModifier; None Negative Maybe MaybeConst MaybeConstNegative MaybeConstMaybe);
+spanless_eq_enum!(TraitObjectSyntax; Dyn DynStar None);
+spanless_eq_enum!(UintTy; Usize U8 U16 U32 U64 U128);
+spanless_eq_enum!(UnOp; Deref Not Neg);
+spanless_eq_enum!(Unsafe; Yes(0) No);
+spanless_eq_enum!(UnsafeSource; CompilerGenerated UserProvided);
+spanless_eq_enum!(UseTreeKind; Simple(0) Nested(0) Glob);
+spanless_eq_enum!(VariantData; Struct(0 1) Tuple(0 1) Unit(0));
+spanless_eq_enum!(VisibilityKind; Public Restricted(path id shorthand) Inherited);
+spanless_eq_enum!(WherePredicate; BoundPredicate(0) RegionPredicate(0) EqPredicate(0));
+spanless_eq_enum!(ExprKind; Array(0) ConstBlock(0) Call(0 1) MethodCall(0)
+    Tup(0) Binary(0 1 2) Unary(0 1) Lit(0) Cast(0 1) Type(0 1) Let(0 1 2 3)
+    If(0 1 2) While(0 1 2) ForLoop(0 1 2 3) Loop(0 1 2) Match(0 1) Closure(0)
+    Block(0 1) Async(0 1) Await(0 1) TryBlock(0) Assign(0 1 2) AssignOp(0 1 2)
+    Field(0 1) Index(0 1 2) Underscore Range(0 1 2) Path(0 1) AddrOf(0 1 2)
+    Break(0 1) Continue(0) Ret(0) InlineAsm(0) OffsetOf(0 1) MacCall(0)
+    Struct(0) Repeat(0 1) Paren(0) Try(0) Yield(0) Yeet(0) Become(0)
+    IncludedBytes(0) FormatArgs(0) Err);
+spanless_eq_enum!(InlineAsmOperand; In(reg expr) Out(reg late expr)
+    InOut(reg late expr) SplitInOut(reg late in_expr out_expr) Const(anon_const)
+    Sym(sym));
+spanless_eq_enum!(ItemKind; ExternCrate(0) Use(0) Static(0) Const(0) Fn(0)
+    Mod(0 1) ForeignMod(0) GlobalAsm(0) TyAlias(0) Enum(0 1) Struct(0 1)
+    Union(0 1) Trait(0) TraitAlias(0 1) Impl(0) MacCall(0) MacroDef(0));
+spanless_eq_enum!(LitKind; Str(0 1) ByteStr(0 1) CStr(0 1) Byte(0) Char(0)
+    Int(0 1) Float(0 1) Bool(0) Err);
+spanless_eq_enum!(PatKind; Wild Ident(0 1 2) Struct(0 1 2 3) TupleStruct(0 1 2)
+    Or(0) Path(0 1) Tuple(0) Box(0) Ref(0 1) Lit(0) Range(0 1 2) Slice(0) Rest
+    Paren(0) MacCall(0));
+spanless_eq_enum!(TyKind; Slice(0) Array(0 1) Ptr(0) Ref(0 1) BareFn(0) Never
+    Tup(0) AnonStruct(0) AnonUnion(0) Path(0 1) TraitObject(0 1) ImplTrait(0 1)
+    Paren(0) Typeof(0) Infer ImplicitSelf MacCall(0) Err CVarArgs);
+
+impl SpanlessEq for Ident {
+    fn eq(&self, other: &Self) -> bool {
+        self.as_str() == other.as_str()
+    }
+}
+
+impl SpanlessEq for RangeSyntax {
+    fn eq(&self, _other: &Self) -> bool {
+        match self {
+            RangeSyntax::DotDotDot | RangeSyntax::DotDotEq => true,
+        }
+    }
+}
+
+impl SpanlessEq for Param {
+    fn eq(&self, other: &Self) -> bool {
+        let Param {
+            attrs,
+            ty,
+            pat,
+            id,
+            span: _,
+            is_placeholder,
+        } = self;
+        let Param {
+            attrs: attrs2,
+            ty: ty2,
+            pat: pat2,
+            id: id2,
+            span: _,
+            is_placeholder: is_placeholder2,
+        } = other;
+        SpanlessEq::eq(id, id2)
+            && SpanlessEq::eq(is_placeholder, is_placeholder2)
+            && (matches!(ty.kind, TyKind::Err)
+                || matches!(ty2.kind, TyKind::Err)
+                || SpanlessEq::eq(attrs, attrs2)
+                    && SpanlessEq::eq(ty, ty2)
+                    && SpanlessEq::eq(pat, pat2))
+    }
+}
+
+impl SpanlessEq for TokenKind {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (TokenKind::Literal(this), TokenKind::Literal(other)) => SpanlessEq::eq(this, other),
+            (TokenKind::DotDotEq | TokenKind::DotDotDot, _) => match other {
+                TokenKind::DotDotEq | TokenKind::DotDotDot => true,
+                _ => false,
+            },
+            (TokenKind::Interpolated(this), TokenKind::Interpolated(other)) => {
+                match (this.as_ref(), other.as_ref()) {
+                    (Nonterminal::NtExpr(this), Nonterminal::NtExpr(other)) => {
+                        SpanlessEq::eq(this, other)
+                    }
+                    _ => this == other,
+                }
+            }
+            _ => self == other,
+        }
+    }
+}
+
+impl SpanlessEq for TokenStream {
+    fn eq(&self, other: &Self) -> bool {
+        let mut this_trees = self.trees();
+        let mut other_trees = other.trees();
+        loop {
+            let this = match this_trees.next() {
+                None => return other_trees.next().is_none(),
+                Some(tree) => tree,
+            };
+            let other = match other_trees.next() {
+                None => return false,
+                Some(tree) => tree,
+            };
+            if SpanlessEq::eq(this, other) {
+                continue;
+            }
+            if let (TokenTree::Token(this, _), TokenTree::Token(other, _)) = (this, other) {
+                if match (&this.kind, &other.kind) {
+                    (TokenKind::Literal(this), TokenKind::Literal(other)) => {
+                        SpanlessEq::eq(this, other)
+                    }
+                    (TokenKind::DocComment(_kind, style, symbol), TokenKind::Pound) => {
+                        doc_comment(*style, *symbol, &mut other_trees)
+                    }
+                    (TokenKind::Pound, TokenKind::DocComment(_kind, style, symbol)) => {
+                        doc_comment(*style, *symbol, &mut this_trees)
+                    }
+                    _ => false,
+                } {
+                    continue;
+                }
+            }
+            return false;
+        }
+    }
+}
+
+fn doc_comment<'a>(
+    style: AttrStyle,
+    unescaped: Symbol,
+    trees: &mut impl Iterator<Item = &'a TokenTree>,
+) -> bool {
+    if match style {
+        AttrStyle::Outer => false,
+        AttrStyle::Inner => true,
+    } {
+        match trees.next() {
+            Some(TokenTree::Token(
+                Token {
+                    kind: TokenKind::Not,
+                    span: _,
+                },
+                _spacing,
+            )) => {}
+            _ => return false,
+        }
+    }
+    let stream = match trees.next() {
+        Some(TokenTree::Delimited(_span, Delimiter::Bracket, stream)) => stream,
+        _ => return false,
+    };
+    let mut trees = stream.trees();
+    match trees.next() {
+        Some(TokenTree::Token(
+            Token {
+                kind: TokenKind::Ident(symbol, false),
+                span: _,
+            },
+            _spacing,
+        )) if *symbol == sym::doc => {}
+        _ => return false,
+    }
+    match trees.next() {
+        Some(TokenTree::Token(
+            Token {
+                kind: TokenKind::Eq,
+                span: _,
+            },
+            _spacing,
+        )) => {}
+        _ => return false,
+    }
+    match trees.next() {
+        Some(TokenTree::Token(token, _spacing)) => {
+            is_escaped_literal_token(token, unescaped) && trees.next().is_none()
+        }
+        _ => false,
+    }
+}
+
+fn is_escaped_literal_token(token: &Token, unescaped: Symbol) -> bool {
+    match token {
+        Token {
+            kind: TokenKind::Literal(lit),
+            span: _,
+        } => match MetaItemLit::from_token_lit(*lit, DUMMY_SP) {
+            Ok(lit) => is_escaped_literal_meta_item_lit(&lit, unescaped),
+            Err(_) => false,
+        },
+        Token {
+            kind: TokenKind::Interpolated(nonterminal),
+            span: _,
+        } => match nonterminal.as_ref() {
+            Nonterminal::NtExpr(expr) => match &expr.kind {
+                ExprKind::Lit(lit) => is_escaped_lit(lit, unescaped),
+                _ => false,
+            },
+            _ => false,
+        },
+        _ => false,
+    }
+}
+
+fn is_escaped_literal_attr_args(value: &AttrArgsEq, unescaped: Symbol) -> bool {
+    match value {
+        AttrArgsEq::Ast(expr) => match &expr.kind {
+            ExprKind::Lit(lit) => is_escaped_lit(lit, unescaped),
+            _ => false,
+        },
+        AttrArgsEq::Hir(lit) => is_escaped_literal_meta_item_lit(lit, unescaped),
+    }
+}
+
+fn is_escaped_literal_meta_item_lit(lit: &MetaItemLit, unescaped: Symbol) -> bool {
+    match lit {
+        MetaItemLit {
+            symbol: _,
+            suffix: None,
+            kind,
+            span: _,
+        } => is_escaped_lit_kind(kind, unescaped),
+        _ => false,
+    }
+}
+
+fn is_escaped_lit(lit: &Lit, unescaped: Symbol) -> bool {
+    match lit {
+        Lit {
+            kind: token::LitKind::Str,
+            symbol: _,
+            suffix: None,
+        } => match LitKind::from_token_lit(*lit) {
+            Ok(lit_kind) => is_escaped_lit_kind(&lit_kind, unescaped),
+            _ => false,
+        },
+        _ => false,
+    }
+}
+
+fn is_escaped_lit_kind(kind: &LitKind, unescaped: Symbol) -> bool {
+    match kind {
+        LitKind::Str(symbol, StrStyle::Cooked) => {
+            symbol.as_str().replace('\r', "") == unescaped.as_str().replace('\r', "")
+        }
+        _ => false,
+    }
+}
+
+impl SpanlessEq for LazyAttrTokenStream {
+    fn eq(&self, other: &Self) -> bool {
+        let this = self.to_attr_token_stream();
+        let other = other.to_attr_token_stream();
+        SpanlessEq::eq(&this, &other)
+    }
+}
+
+impl SpanlessEq for AttrKind {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (AttrKind::Normal(normal), AttrKind::Normal(normal2)) => {
+                SpanlessEq::eq(normal, normal2)
+            }
+            (AttrKind::DocComment(kind, symbol), AttrKind::DocComment(kind2, symbol2)) => {
+                SpanlessEq::eq(kind, kind2) && SpanlessEq::eq(symbol, symbol2)
+            }
+            (AttrKind::DocComment(kind, unescaped), AttrKind::Normal(normal2)) => {
+                match kind {
+                    CommentKind::Line | CommentKind::Block => {}
+                }
+                let path = Path::from_ident(Ident::with_dummy_span(sym::doc));
+                SpanlessEq::eq(&path, &normal2.item.path)
+                    && match &normal2.item.args {
+                        AttrArgs::Empty | AttrArgs::Delimited(_) => false,
+                        AttrArgs::Eq(_span, value) => {
+                            is_escaped_literal_attr_args(value, *unescaped)
+                        }
+                    }
+            }
+            (AttrKind::Normal(_), AttrKind::DocComment(..)) => SpanlessEq::eq(other, self),
+        }
+    }
+}
+
+impl SpanlessEq for FormatArguments {
+    fn eq(&self, other: &Self) -> bool {
+        SpanlessEq::eq(self.all_args(), other.all_args())
+    }
+}
diff --git a/vendor/syn/tests/common/mod.rs b/vendor/syn/tests/common/mod.rs
new file mode 100644
index 0000000..2156530
--- /dev/null
+++ b/vendor/syn/tests/common/mod.rs
@@ -0,0 +1,28 @@
+#![allow(dead_code)]
+#![allow(clippy::module_name_repetitions, clippy::shadow_unrelated)]
+
+use rayon::ThreadPoolBuilder;
+use std::env;
+
+pub mod eq;
+pub mod parse;
+
+/// Read the `ABORT_AFTER_FAILURE` environment variable, and parse it.
+pub fn abort_after() -> usize {
+    match env::var("ABORT_AFTER_FAILURE") {
+        Ok(s) => s.parse().expect("failed to parse ABORT_AFTER_FAILURE"),
+        Err(_) => usize::max_value(),
+    }
+}
+
+/// Configure Rayon threadpool.
+pub fn rayon_init() {
+    let stack_size = match env::var("RUST_MIN_STACK") {
+        Ok(s) => s.parse().expect("failed to parse RUST_MIN_STACK"),
+        Err(_) => 20 * 1024 * 1024,
+    };
+    ThreadPoolBuilder::new()
+        .stack_size(stack_size)
+        .build_global()
+        .unwrap();
+}
diff --git a/vendor/syn/tests/common/parse.rs b/vendor/syn/tests/common/parse.rs
new file mode 100644
index 0000000..73be101
--- /dev/null
+++ b/vendor/syn/tests/common/parse.rs
@@ -0,0 +1,51 @@
+extern crate rustc_ast;
+extern crate rustc_driver;
+extern crate rustc_expand;
+extern crate rustc_parse as parse;
+extern crate rustc_session;
+extern crate rustc_span;
+
+use rustc_ast::ast;
+use rustc_ast::ptr::P;
+use rustc_session::parse::ParseSess;
+use rustc_span::source_map::FilePathMapping;
+use rustc_span::FileName;
+use std::panic;
+
+pub fn librustc_expr(input: &str) -> Option<P<ast::Expr>> {
+    match panic::catch_unwind(|| {
+        let locale_resources = rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec();
+        let file_path_mapping = FilePathMapping::empty();
+        let sess = ParseSess::new(locale_resources, file_path_mapping);
+        let e = parse::new_parser_from_source_str(
+            &sess,
+            FileName::Custom("test_precedence".to_string()),
+            input.to_string(),
+        )
+        .parse_expr();
+        match e {
+            Ok(expr) => Some(expr),
+            Err(mut diagnostic) => {
+                diagnostic.emit();
+                None
+            }
+        }
+    }) {
+        Ok(Some(e)) => Some(e),
+        Ok(None) => None,
+        Err(_) => {
+            errorf!("librustc panicked\n");
+            None
+        }
+    }
+}
+
+pub fn syn_expr(input: &str) -> Option<syn::Expr> {
+    match syn::parse_str(input) {
+        Ok(e) => Some(e),
+        Err(msg) => {
+            errorf!("syn failed to parse\n{:?}\n", msg);
+            None
+        }
+    }
+}
diff --git a/vendor/syn/tests/debug/gen.rs b/vendor/syn/tests/debug/gen.rs
new file mode 100644
index 0000000..3f92598
--- /dev/null
+++ b/vendor/syn/tests/debug/gen.rs
@@ -0,0 +1,4664 @@
+// This file is @generated by syn-internal-codegen.
+// It is not intended for manual editing.
+
+#![allow(repr_transparent_external_private_fields)]
+#![allow(clippy::match_wildcard_for_single_variants)]
+use super::{Lite, Present};
+use ref_cast::RefCast;
+use std::fmt::{self, Debug, Display};
+impl Debug for Lite<syn::Abi> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Abi");
+        if let Some(val) = &self.value.name {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::LitStr);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("name", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::AngleBracketedGenericArguments> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("AngleBracketedGenericArguments");
+        if self.value.colon2_token.is_some() {
+            formatter.field("colon2_token", &Present);
+        }
+        if !self.value.args.is_empty() {
+            formatter.field("args", Lite(&self.value.args));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Arm> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Arm");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        if let Some(val) = &self.value.guard {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::If, Box<syn::Expr>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("guard", Print::ref_cast(val));
+        }
+        formatter.field("body", Lite(&self.value.body));
+        if self.value.comma.is_some() {
+            formatter.field("comma", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::AssocConst> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("AssocConst");
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.generics {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::AngleBracketedGenericArguments);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("generics", Print::ref_cast(val));
+        }
+        formatter.field("value", Lite(&self.value.value));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::AssocType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("AssocType");
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.generics {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::AngleBracketedGenericArguments);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("generics", Print::ref_cast(val));
+        }
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::AttrStyle> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::AttrStyle::Outer => formatter.write_str("AttrStyle::Outer"),
+            syn::AttrStyle::Inner(_val) => {
+                formatter.write_str("AttrStyle::Inner")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Attribute> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Attribute");
+        formatter.field("style", Lite(&self.value.style));
+        formatter.field("meta", Lite(&self.value.meta));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::BareFnArg> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BareFnArg");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.name {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((proc_macro2::Ident, syn::token::Colon));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("name", Print::ref_cast(val));
+        }
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::BareVariadic> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BareVariadic");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.name {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((proc_macro2::Ident, syn::token::Colon));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("name", Print::ref_cast(val));
+        }
+        if self.value.comma.is_some() {
+            formatter.field("comma", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::BinOp> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::BinOp::Add(_val) => {
+                formatter.write_str("BinOp::Add")?;
+                Ok(())
+            }
+            syn::BinOp::Sub(_val) => {
+                formatter.write_str("BinOp::Sub")?;
+                Ok(())
+            }
+            syn::BinOp::Mul(_val) => {
+                formatter.write_str("BinOp::Mul")?;
+                Ok(())
+            }
+            syn::BinOp::Div(_val) => {
+                formatter.write_str("BinOp::Div")?;
+                Ok(())
+            }
+            syn::BinOp::Rem(_val) => {
+                formatter.write_str("BinOp::Rem")?;
+                Ok(())
+            }
+            syn::BinOp::And(_val) => {
+                formatter.write_str("BinOp::And")?;
+                Ok(())
+            }
+            syn::BinOp::Or(_val) => {
+                formatter.write_str("BinOp::Or")?;
+                Ok(())
+            }
+            syn::BinOp::BitXor(_val) => {
+                formatter.write_str("BinOp::BitXor")?;
+                Ok(())
+            }
+            syn::BinOp::BitAnd(_val) => {
+                formatter.write_str("BinOp::BitAnd")?;
+                Ok(())
+            }
+            syn::BinOp::BitOr(_val) => {
+                formatter.write_str("BinOp::BitOr")?;
+                Ok(())
+            }
+            syn::BinOp::Shl(_val) => {
+                formatter.write_str("BinOp::Shl")?;
+                Ok(())
+            }
+            syn::BinOp::Shr(_val) => {
+                formatter.write_str("BinOp::Shr")?;
+                Ok(())
+            }
+            syn::BinOp::Eq(_val) => {
+                formatter.write_str("BinOp::Eq")?;
+                Ok(())
+            }
+            syn::BinOp::Lt(_val) => {
+                formatter.write_str("BinOp::Lt")?;
+                Ok(())
+            }
+            syn::BinOp::Le(_val) => {
+                formatter.write_str("BinOp::Le")?;
+                Ok(())
+            }
+            syn::BinOp::Ne(_val) => {
+                formatter.write_str("BinOp::Ne")?;
+                Ok(())
+            }
+            syn::BinOp::Ge(_val) => {
+                formatter.write_str("BinOp::Ge")?;
+                Ok(())
+            }
+            syn::BinOp::Gt(_val) => {
+                formatter.write_str("BinOp::Gt")?;
+                Ok(())
+            }
+            syn::BinOp::AddAssign(_val) => {
+                formatter.write_str("BinOp::AddAssign")?;
+                Ok(())
+            }
+            syn::BinOp::SubAssign(_val) => {
+                formatter.write_str("BinOp::SubAssign")?;
+                Ok(())
+            }
+            syn::BinOp::MulAssign(_val) => {
+                formatter.write_str("BinOp::MulAssign")?;
+                Ok(())
+            }
+            syn::BinOp::DivAssign(_val) => {
+                formatter.write_str("BinOp::DivAssign")?;
+                Ok(())
+            }
+            syn::BinOp::RemAssign(_val) => {
+                formatter.write_str("BinOp::RemAssign")?;
+                Ok(())
+            }
+            syn::BinOp::BitXorAssign(_val) => {
+                formatter.write_str("BinOp::BitXorAssign")?;
+                Ok(())
+            }
+            syn::BinOp::BitAndAssign(_val) => {
+                formatter.write_str("BinOp::BitAndAssign")?;
+                Ok(())
+            }
+            syn::BinOp::BitOrAssign(_val) => {
+                formatter.write_str("BinOp::BitOrAssign")?;
+                Ok(())
+            }
+            syn::BinOp::ShlAssign(_val) => {
+                formatter.write_str("BinOp::ShlAssign")?;
+                Ok(())
+            }
+            syn::BinOp::ShrAssign(_val) => {
+                formatter.write_str("BinOp::ShrAssign")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::Block> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Block");
+        if !self.value.stmts.is_empty() {
+            formatter.field("stmts", Lite(&self.value.stmts));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::BoundLifetimes> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("BoundLifetimes");
+        if !self.value.lifetimes.is_empty() {
+            formatter.field("lifetimes", Lite(&self.value.lifetimes));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ConstParam> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ConstParam");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("ty", Lite(&self.value.ty));
+        if self.value.eq_token.is_some() {
+            formatter.field("eq_token", &Present);
+        }
+        if let Some(val) = &self.value.default {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Expr);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("default", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Constraint> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Constraint");
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.generics {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::AngleBracketedGenericArguments);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("generics", Print::ref_cast(val));
+        }
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Data> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Data::Struct(_val) => {
+                let mut formatter = formatter.debug_struct("Data::Struct");
+                formatter.field("fields", Lite(&_val.fields));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::Data::Enum(_val) => {
+                let mut formatter = formatter.debug_struct("Data::Enum");
+                if !_val.variants.is_empty() {
+                    formatter.field("variants", Lite(&_val.variants));
+                }
+                formatter.finish()
+            }
+            syn::Data::Union(_val) => {
+                let mut formatter = formatter.debug_struct("Data::Union");
+                formatter.field("fields", Lite(&_val.fields));
+                formatter.finish()
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::DataEnum> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("DataEnum");
+        if !self.value.variants.is_empty() {
+            formatter.field("variants", Lite(&self.value.variants));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::DataStruct> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("DataStruct");
+        formatter.field("fields", Lite(&self.value.fields));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::DataUnion> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("DataUnion");
+        formatter.field("fields", Lite(&self.value.fields));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::DeriveInput> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("DeriveInput");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("data", Lite(&self.value.data));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Expr> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Expr::Array(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Array");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Assign(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Assign");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("left", Lite(&_val.left));
+                formatter.field("right", Lite(&_val.right));
+                formatter.finish()
+            }
+            syn::Expr::Async(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Async");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.capture.is_some() {
+                    formatter.field("capture", &Present);
+                }
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Expr::Await(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Await");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("base", Lite(&_val.base));
+                formatter.finish()
+            }
+            syn::Expr::Binary(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Binary");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("left", Lite(&_val.left));
+                formatter.field("op", Lite(&_val.op));
+                formatter.field("right", Lite(&_val.right));
+                formatter.finish()
+            }
+            syn::Expr::Block(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Block");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Label);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Expr::Break(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Break");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Lifetime);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                if let Some(val) = &_val.expr {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("expr", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Call(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Call");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("func", Lite(&_val.func));
+                if !_val.args.is_empty() {
+                    formatter.field("args", Lite(&_val.args));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Cast(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Cast");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.finish()
+            }
+            syn::Expr::Closure(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Closure");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.lifetimes {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::BoundLifetimes);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("lifetimes", Print::ref_cast(val));
+                }
+                if _val.constness.is_some() {
+                    formatter.field("constness", &Present);
+                }
+                if _val.movability.is_some() {
+                    formatter.field("movability", &Present);
+                }
+                if _val.asyncness.is_some() {
+                    formatter.field("asyncness", &Present);
+                }
+                if _val.capture.is_some() {
+                    formatter.field("capture", &Present);
+                }
+                if !_val.inputs.is_empty() {
+                    formatter.field("inputs", Lite(&_val.inputs));
+                }
+                formatter.field("output", Lite(&_val.output));
+                formatter.field("body", Lite(&_val.body));
+                formatter.finish()
+            }
+            syn::Expr::Const(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Const");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Expr::Continue(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Continue");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Lifetime);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Field(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Field");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("base", Lite(&_val.base));
+                formatter.field("member", Lite(&_val.member));
+                formatter.finish()
+            }
+            syn::Expr::ForLoop(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::ForLoop");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Label);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.field("body", Lite(&_val.body));
+                formatter.finish()
+            }
+            syn::Expr::Group(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Group");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::If(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::If");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("cond", Lite(&_val.cond));
+                formatter.field("then_branch", Lite(&_val.then_branch));
+                if let Some(val) = &_val.else_branch {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::Else, Box<syn::Expr>));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("else_branch", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Index(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Index");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.field("index", Lite(&_val.index));
+                formatter.finish()
+            }
+            syn::Expr::Infer(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Infer");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Let(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Let");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::Lit(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Lit");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("lit", Lite(&_val.lit));
+                formatter.finish()
+            }
+            syn::Expr::Loop(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Loop");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Label);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                formatter.field("body", Lite(&_val.body));
+                formatter.finish()
+            }
+            syn::Expr::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                formatter.finish()
+            }
+            syn::Expr::Match(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Match");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                if !_val.arms.is_empty() {
+                    formatter.field("arms", Lite(&_val.arms));
+                }
+                formatter.finish()
+            }
+            syn::Expr::MethodCall(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::MethodCall");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("receiver", Lite(&_val.receiver));
+                formatter.field("method", Lite(&_val.method));
+                if let Some(val) = &_val.turbofish {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::AngleBracketedGenericArguments);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("turbofish", Print::ref_cast(val));
+                }
+                if !_val.args.is_empty() {
+                    formatter.field("args", Lite(&_val.args));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Paren(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Paren");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::Path(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Path");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.qself {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::QSelf);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("qself", Print::ref_cast(val));
+                }
+                formatter.field("path", Lite(&_val.path));
+                formatter.finish()
+            }
+            syn::Expr::Range(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Range");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.start {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("start", Print::ref_cast(val));
+                }
+                formatter.field("limits", Lite(&_val.limits));
+                if let Some(val) = &_val.end {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("end", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Reference(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Reference");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.mutability.is_some() {
+                    formatter.field("mutability", &Present);
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::Repeat(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Repeat");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.field("len", Lite(&_val.len));
+                formatter.finish()
+            }
+            syn::Expr::Return(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Return");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.expr {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("expr", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Struct(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Struct");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.qself {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::QSelf);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("qself", Print::ref_cast(val));
+                }
+                formatter.field("path", Lite(&_val.path));
+                if !_val.fields.is_empty() {
+                    formatter.field("fields", Lite(&_val.fields));
+                }
+                if _val.dot2_token.is_some() {
+                    formatter.field("dot2_token", &Present);
+                }
+                if let Some(val) = &_val.rest {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("rest", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Try(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Try");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::TryBlock(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::TryBlock");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Expr::Tuple(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Tuple");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Expr::Unary(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Unary");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("op", Lite(&_val.op));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Expr::Unsafe(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Unsafe");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Expr::Verbatim(_val) => {
+                formatter.write_str("Expr::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            syn::Expr::While(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::While");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.label {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Label);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("label", Print::ref_cast(val));
+                }
+                formatter.field("cond", Lite(&_val.cond));
+                formatter.field("body", Lite(&_val.body));
+                formatter.finish()
+            }
+            syn::Expr::Yield(_val) => {
+                let mut formatter = formatter.debug_struct("Expr::Yield");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.expr {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(Box<syn::Expr>);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("expr", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::ExprArray> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprArray");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprAssign> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprAssign");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("left", Lite(&self.value.left));
+        formatter.field("right", Lite(&self.value.right));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprAsync> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprAsync");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.capture.is_some() {
+            formatter.field("capture", &Present);
+        }
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprAwait> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprAwait");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("base", Lite(&self.value.base));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprBinary> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprBinary");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("left", Lite(&self.value.left));
+        formatter.field("op", Lite(&self.value.op));
+        formatter.field("right", Lite(&self.value.right));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprBlock> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprBlock");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Label);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprBreak> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprBreak");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Lifetime);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        if let Some(val) = &self.value.expr {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("expr", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprCall> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprCall");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("func", Lite(&self.value.func));
+        if !self.value.args.is_empty() {
+            formatter.field("args", Lite(&self.value.args));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprCast> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprCast");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprClosure> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprClosure");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.lifetimes {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::BoundLifetimes);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("lifetimes", Print::ref_cast(val));
+        }
+        if self.value.constness.is_some() {
+            formatter.field("constness", &Present);
+        }
+        if self.value.movability.is_some() {
+            formatter.field("movability", &Present);
+        }
+        if self.value.asyncness.is_some() {
+            formatter.field("asyncness", &Present);
+        }
+        if self.value.capture.is_some() {
+            formatter.field("capture", &Present);
+        }
+        if !self.value.inputs.is_empty() {
+            formatter.field("inputs", Lite(&self.value.inputs));
+        }
+        formatter.field("output", Lite(&self.value.output));
+        formatter.field("body", Lite(&self.value.body));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprConst> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprConst");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprContinue> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprContinue");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Lifetime);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprField> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprField");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("base", Lite(&self.value.base));
+        formatter.field("member", Lite(&self.value.member));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprForLoop> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprForLoop");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Label);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.field("body", Lite(&self.value.body));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprGroup> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprGroup");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprIf> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprIf");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("cond", Lite(&self.value.cond));
+        formatter.field("then_branch", Lite(&self.value.then_branch));
+        if let Some(val) = &self.value.else_branch {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Else, Box<syn::Expr>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("else_branch", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprIndex> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprIndex");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.field("index", Lite(&self.value.index));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprInfer> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprInfer");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprLet> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprLet");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprLit> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprLit");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("lit", Lite(&self.value.lit));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprLoop> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprLoop");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Label);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        formatter.field("body", Lite(&self.value.body));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprMatch> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprMatch");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        if !self.value.arms.is_empty() {
+            formatter.field("arms", Lite(&self.value.arms));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprMethodCall> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprMethodCall");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("receiver", Lite(&self.value.receiver));
+        formatter.field("method", Lite(&self.value.method));
+        if let Some(val) = &self.value.turbofish {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::AngleBracketedGenericArguments);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("turbofish", Print::ref_cast(val));
+        }
+        if !self.value.args.is_empty() {
+            formatter.field("args", Lite(&self.value.args));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprParen> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprParen");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprPath> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprPath");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.qself {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::QSelf);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("qself", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprRange> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprRange");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.start {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("start", Print::ref_cast(val));
+        }
+        formatter.field("limits", Lite(&self.value.limits));
+        if let Some(val) = &self.value.end {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("end", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprReference> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprReference");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprRepeat> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprRepeat");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.field("len", Lite(&self.value.len));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprReturn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprReturn");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.expr {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("expr", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprStruct> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprStruct");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.qself {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::QSelf);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("qself", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        if !self.value.fields.is_empty() {
+            formatter.field("fields", Lite(&self.value.fields));
+        }
+        if self.value.dot2_token.is_some() {
+            formatter.field("dot2_token", &Present);
+        }
+        if let Some(val) = &self.value.rest {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("rest", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprTry> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprTry");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprTryBlock> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprTryBlock");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprTuple> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprTuple");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprUnary> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprUnary");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("op", Lite(&self.value.op));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprUnsafe> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprUnsafe");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprWhile> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprWhile");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.label {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Label);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("label", Print::ref_cast(val));
+        }
+        formatter.field("cond", Lite(&self.value.cond));
+        formatter.field("body", Lite(&self.value.body));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ExprYield> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ExprYield");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.expr {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(Box<syn::Expr>);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("expr", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Field> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Field");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        match self.value.mutability {
+            syn::FieldMutability::None => {}
+            _ => {
+                formatter.field("mutability", Lite(&self.value.mutability));
+            }
+        }
+        if let Some(val) = &self.value.ident {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(proc_macro2::Ident);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("ident", Print::ref_cast(val));
+        }
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::FieldMutability> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::FieldMutability::None => formatter.write_str("FieldMutability::None"),
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::FieldPat> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldPat");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("member", Lite(&self.value.member));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::FieldValue> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldValue");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("member", Lite(&self.value.member));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Fields> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Fields::Named(_val) => {
+                let mut formatter = formatter.debug_struct("Fields::Named");
+                if !_val.named.is_empty() {
+                    formatter.field("named", Lite(&_val.named));
+                }
+                formatter.finish()
+            }
+            syn::Fields::Unnamed(_val) => {
+                let mut formatter = formatter.debug_struct("Fields::Unnamed");
+                if !_val.unnamed.is_empty() {
+                    formatter.field("unnamed", Lite(&_val.unnamed));
+                }
+                formatter.finish()
+            }
+            syn::Fields::Unit => formatter.write_str("Fields::Unit"),
+        }
+    }
+}
+impl Debug for Lite<syn::FieldsNamed> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldsNamed");
+        if !self.value.named.is_empty() {
+            formatter.field("named", Lite(&self.value.named));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::FieldsUnnamed> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("FieldsUnnamed");
+        if !self.value.unnamed.is_empty() {
+            formatter.field("unnamed", Lite(&self.value.unnamed));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::File> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("File");
+        if let Some(val) = &self.value.shebang {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(String);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("shebang", Print::ref_cast(val));
+        }
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if !self.value.items.is_empty() {
+            formatter.field("items", Lite(&self.value.items));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::FnArg> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::FnArg::Receiver(_val) => {
+                formatter.write_str("FnArg::Receiver")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::FnArg::Typed(_val) => {
+                formatter.write_str("FnArg::Typed")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::ForeignItem> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::ForeignItem::Fn(_val) => {
+                let mut formatter = formatter.debug_struct("ForeignItem::Fn");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("sig", Lite(&_val.sig));
+                formatter.finish()
+            }
+            syn::ForeignItem::Static(_val) => {
+                let mut formatter = formatter.debug_struct("ForeignItem::Static");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                match _val.mutability {
+                    syn::StaticMutability::None => {}
+                    _ => {
+                        formatter.field("mutability", Lite(&_val.mutability));
+                    }
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.finish()
+            }
+            syn::ForeignItem::Type(_val) => {
+                let mut formatter = formatter.debug_struct("ForeignItem::Type");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.finish()
+            }
+            syn::ForeignItem::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("ForeignItem::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::ForeignItem::Verbatim(_val) => {
+                formatter.write_str("ForeignItem::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::ForeignItemFn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ForeignItemFn");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("sig", Lite(&self.value.sig));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ForeignItemMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ForeignItemMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ForeignItemStatic> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ForeignItemStatic");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        match self.value.mutability {
+            syn::StaticMutability::None => {}
+            _ => {
+                formatter.field("mutability", Lite(&self.value.mutability));
+            }
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ForeignItemType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ForeignItemType");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::GenericArgument> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::GenericArgument::Lifetime(_val) => {
+                formatter.write_str("GenericArgument::Lifetime")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericArgument::Type(_val) => {
+                formatter.write_str("GenericArgument::Type")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericArgument::Const(_val) => {
+                formatter.write_str("GenericArgument::Const")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericArgument::AssocType(_val) => {
+                formatter.write_str("GenericArgument::AssocType")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericArgument::AssocConst(_val) => {
+                formatter.write_str("GenericArgument::AssocConst")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericArgument::Constraint(_val) => {
+                formatter.write_str("GenericArgument::Constraint")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::GenericParam> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::GenericParam::Lifetime(_val) => {
+                formatter.write_str("GenericParam::Lifetime")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericParam::Type(_val) => {
+                formatter.write_str("GenericParam::Type")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::GenericParam::Const(_val) => {
+                formatter.write_str("GenericParam::Const")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Generics> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Generics");
+        if self.value.lt_token.is_some() {
+            formatter.field("lt_token", &Present);
+        }
+        if !self.value.params.is_empty() {
+            formatter.field("params", Lite(&self.value.params));
+        }
+        if self.value.gt_token.is_some() {
+            formatter.field("gt_token", &Present);
+        }
+        if let Some(val) = &self.value.where_clause {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::WhereClause);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("where_clause", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ImplItem> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::ImplItem::Const(_val) => {
+                let mut formatter = formatter.debug_struct("ImplItem::Const");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.defaultness.is_some() {
+                    formatter.field("defaultness", &Present);
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::ImplItem::Fn(_val) => {
+                let mut formatter = formatter.debug_struct("ImplItem::Fn");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.defaultness.is_some() {
+                    formatter.field("defaultness", &Present);
+                }
+                formatter.field("sig", Lite(&_val.sig));
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::ImplItem::Type(_val) => {
+                let mut formatter = formatter.debug_struct("ImplItem::Type");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.defaultness.is_some() {
+                    formatter.field("defaultness", &Present);
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.finish()
+            }
+            syn::ImplItem::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("ImplItem::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::ImplItem::Verbatim(_val) => {
+                formatter.write_str("ImplItem::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::ImplItemConst> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ImplItemConst");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.defaultness.is_some() {
+            formatter.field("defaultness", &Present);
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ImplItemFn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ImplItemFn");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.defaultness.is_some() {
+            formatter.field("defaultness", &Present);
+        }
+        formatter.field("sig", Lite(&self.value.sig));
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ImplItemMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ImplItemMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ImplItemType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ImplItemType");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.defaultness.is_some() {
+            formatter.field("defaultness", &Present);
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ImplRestriction> {
+    fn fmt(&self, _formatter: &mut fmt::Formatter) -> fmt::Result {
+        unreachable!()
+    }
+}
+impl Debug for Lite<syn::Index> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Index");
+        formatter.field("index", Lite(&self.value.index));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Item> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Item::Const(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Const");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Item::Enum(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Enum");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                if !_val.variants.is_empty() {
+                    formatter.field("variants", Lite(&_val.variants));
+                }
+                formatter.finish()
+            }
+            syn::Item::ExternCrate(_val) => {
+                let mut formatter = formatter.debug_struct("Item::ExternCrate");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                if let Some(val) = &_val.rename {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::As, proc_macro2::Ident));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("rename", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Item::Fn(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Fn");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("sig", Lite(&_val.sig));
+                formatter.field("block", Lite(&_val.block));
+                formatter.finish()
+            }
+            syn::Item::ForeignMod(_val) => {
+                let mut formatter = formatter.debug_struct("Item::ForeignMod");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.unsafety.is_some() {
+                    formatter.field("unsafety", &Present);
+                }
+                formatter.field("abi", Lite(&_val.abi));
+                if !_val.items.is_empty() {
+                    formatter.field("items", Lite(&_val.items));
+                }
+                formatter.finish()
+            }
+            syn::Item::Impl(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Impl");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.defaultness.is_some() {
+                    formatter.field("defaultness", &Present);
+                }
+                if _val.unsafety.is_some() {
+                    formatter.field("unsafety", &Present);
+                }
+                formatter.field("generics", Lite(&_val.generics));
+                if let Some(val) = &_val.trait_ {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((Option<syn::token::Not>, syn::Path, syn::token::For));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(
+                                &(
+                                    &super::Option {
+                                        present: self.0.0.is_some(),
+                                    },
+                                    Lite(&self.0.1),
+                                ),
+                                formatter,
+                            )?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("trait_", Print::ref_cast(val));
+                }
+                formatter.field("self_ty", Lite(&_val.self_ty));
+                if !_val.items.is_empty() {
+                    formatter.field("items", Lite(&_val.items));
+                }
+                formatter.finish()
+            }
+            syn::Item::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.ident {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(proc_macro2::Ident);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("ident", Print::ref_cast(val));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::Item::Mod(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Mod");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.unsafety.is_some() {
+                    formatter.field("unsafety", &Present);
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                if let Some(val) = &_val.content {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::Brace, Vec<syn::Item>));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("content", Print::ref_cast(val));
+                }
+                if _val.semi.is_some() {
+                    formatter.field("semi", &Present);
+                }
+                formatter.finish()
+            }
+            syn::Item::Static(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Static");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                match _val.mutability {
+                    syn::StaticMutability::None => {}
+                    _ => {
+                        formatter.field("mutability", Lite(&_val.mutability));
+                    }
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.field("expr", Lite(&_val.expr));
+                formatter.finish()
+            }
+            syn::Item::Struct(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Struct");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("fields", Lite(&_val.fields));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::Item::Trait(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Trait");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.unsafety.is_some() {
+                    formatter.field("unsafety", &Present);
+                }
+                if _val.auto_token.is_some() {
+                    formatter.field("auto_token", &Present);
+                }
+                if let Some(val) = &_val.restriction {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::ImplRestriction);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("restriction", Print::ref_cast(val));
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                if _val.colon_token.is_some() {
+                    formatter.field("colon_token", &Present);
+                }
+                if !_val.supertraits.is_empty() {
+                    formatter.field("supertraits", Lite(&_val.supertraits));
+                }
+                if !_val.items.is_empty() {
+                    formatter.field("items", Lite(&_val.items));
+                }
+                formatter.finish()
+            }
+            syn::Item::TraitAlias(_val) => {
+                let mut formatter = formatter.debug_struct("Item::TraitAlias");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                if !_val.bounds.is_empty() {
+                    formatter.field("bounds", Lite(&_val.bounds));
+                }
+                formatter.finish()
+            }
+            syn::Item::Type(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Type");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.finish()
+            }
+            syn::Item::Union(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Union");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("fields", Lite(&_val.fields));
+                formatter.finish()
+            }
+            syn::Item::Use(_val) => {
+                let mut formatter = formatter.debug_struct("Item::Use");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("vis", Lite(&_val.vis));
+                if _val.leading_colon.is_some() {
+                    formatter.field("leading_colon", &Present);
+                }
+                formatter.field("tree", Lite(&_val.tree));
+                formatter.finish()
+            }
+            syn::Item::Verbatim(_val) => {
+                formatter.write_str("Item::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::ItemConst> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemConst");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemEnum> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemEnum");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        if !self.value.variants.is_empty() {
+            formatter.field("variants", Lite(&self.value.variants));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemExternCrate> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemExternCrate");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.rename {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::As, proc_macro2::Ident));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("rename", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemFn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemFn");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("sig", Lite(&self.value.sig));
+        formatter.field("block", Lite(&self.value.block));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemForeignMod> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemForeignMod");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        formatter.field("abi", Lite(&self.value.abi));
+        if !self.value.items.is_empty() {
+            formatter.field("items", Lite(&self.value.items));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemImpl> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemImpl");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.defaultness.is_some() {
+            formatter.field("defaultness", &Present);
+        }
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        formatter.field("generics", Lite(&self.value.generics));
+        if let Some(val) = &self.value.trait_ {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((Option<syn::token::Not>, syn::Path, syn::token::For));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(
+                        &(
+                            &super::Option {
+                                present: self.0.0.is_some(),
+                            },
+                            Lite(&self.0.1),
+                        ),
+                        formatter,
+                    )?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("trait_", Print::ref_cast(val));
+        }
+        formatter.field("self_ty", Lite(&self.value.self_ty));
+        if !self.value.items.is_empty() {
+            formatter.field("items", Lite(&self.value.items));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.ident {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(proc_macro2::Ident);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("ident", Print::ref_cast(val));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemMod> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemMod");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.content {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Brace, Vec<syn::Item>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("content", Print::ref_cast(val));
+        }
+        if self.value.semi.is_some() {
+            formatter.field("semi", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemStatic> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemStatic");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        match self.value.mutability {
+            syn::StaticMutability::None => {}
+            _ => {
+                formatter.field("mutability", Lite(&self.value.mutability));
+            }
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.field("expr", Lite(&self.value.expr));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemStruct> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemStruct");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("fields", Lite(&self.value.fields));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemTrait> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemTrait");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        if self.value.auto_token.is_some() {
+            formatter.field("auto_token", &Present);
+        }
+        if let Some(val) = &self.value.restriction {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::ImplRestriction);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("restriction", Print::ref_cast(val));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        if !self.value.supertraits.is_empty() {
+            formatter.field("supertraits", Lite(&self.value.supertraits));
+        }
+        if !self.value.items.is_empty() {
+            formatter.field("items", Lite(&self.value.items));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemTraitAlias> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemTraitAlias");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemType");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemUnion> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemUnion");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("fields", Lite(&self.value.fields));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ItemUse> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ItemUse");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("vis", Lite(&self.value.vis));
+        if self.value.leading_colon.is_some() {
+            formatter.field("leading_colon", &Present);
+        }
+        formatter.field("tree", Lite(&self.value.tree));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Label> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Label");
+        formatter.field("name", Lite(&self.value.name));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Lifetime> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Lifetime");
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::LifetimeParam> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("LifetimeParam");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("lifetime", Lite(&self.value.lifetime));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Lit> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Lit::Str(_val) => write!(formatter, "{:?}", _val.value()),
+            syn::Lit::ByteStr(_val) => write!(formatter, "{:?}", _val.value()),
+            syn::Lit::Byte(_val) => write!(formatter, "{:?}", _val.value()),
+            syn::Lit::Char(_val) => write!(formatter, "{:?}", _val.value()),
+            syn::Lit::Int(_val) => write!(formatter, "{}", _val),
+            syn::Lit::Float(_val) => write!(formatter, "{}", _val),
+            syn::Lit::Bool(_val) => {
+                let mut formatter = formatter.debug_struct("Lit::Bool");
+                formatter.field("value", Lite(&_val.value));
+                formatter.finish()
+            }
+            syn::Lit::Verbatim(_val) => {
+                formatter.write_str("Lit::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::LitBool> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("LitBool");
+        formatter.field("value", Lite(&self.value.value));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::LitByte> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value.value())
+    }
+}
+impl Debug for Lite<syn::LitByteStr> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value.value())
+    }
+}
+impl Debug for Lite<syn::LitChar> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value.value())
+    }
+}
+impl Debug for Lite<syn::LitFloat> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", & self.value)
+    }
+}
+impl Debug for Lite<syn::LitInt> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", & self.value)
+    }
+}
+impl Debug for Lite<syn::LitStr> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value.value())
+    }
+}
+impl Debug for Lite<syn::Local> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Local");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        if let Some(val) = &self.value.init {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::LocalInit);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("init", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::LocalInit> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("LocalInit");
+        formatter.field("expr", Lite(&self.value.expr));
+        if let Some(val) = &self.value.diverge {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Else, Box<syn::Expr>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("diverge", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Macro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Macro");
+        formatter.field("path", Lite(&self.value.path));
+        formatter.field("delimiter", Lite(&self.value.delimiter));
+        formatter.field("tokens", Lite(&self.value.tokens));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::MacroDelimiter> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::MacroDelimiter::Paren(_val) => {
+                formatter.write_str("MacroDelimiter::Paren")?;
+                Ok(())
+            }
+            syn::MacroDelimiter::Brace(_val) => {
+                formatter.write_str("MacroDelimiter::Brace")?;
+                Ok(())
+            }
+            syn::MacroDelimiter::Bracket(_val) => {
+                formatter.write_str("MacroDelimiter::Bracket")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Member> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Member::Named(_val) => {
+                formatter.write_str("Member::Named")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Member::Unnamed(_val) => {
+                formatter.write_str("Member::Unnamed")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Meta> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Meta::Path(_val) => {
+                let mut formatter = formatter.debug_struct("Meta::Path");
+                if _val.leading_colon.is_some() {
+                    formatter.field("leading_colon", &Present);
+                }
+                if !_val.segments.is_empty() {
+                    formatter.field("segments", Lite(&_val.segments));
+                }
+                formatter.finish()
+            }
+            syn::Meta::List(_val) => {
+                let mut formatter = formatter.debug_struct("Meta::List");
+                formatter.field("path", Lite(&_val.path));
+                formatter.field("delimiter", Lite(&_val.delimiter));
+                formatter.field("tokens", Lite(&_val.tokens));
+                formatter.finish()
+            }
+            syn::Meta::NameValue(_val) => {
+                let mut formatter = formatter.debug_struct("Meta::NameValue");
+                formatter.field("path", Lite(&_val.path));
+                formatter.field("value", Lite(&_val.value));
+                formatter.finish()
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::MetaList> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("MetaList");
+        formatter.field("path", Lite(&self.value.path));
+        formatter.field("delimiter", Lite(&self.value.delimiter));
+        formatter.field("tokens", Lite(&self.value.tokens));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::MetaNameValue> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("MetaNameValue");
+        formatter.field("path", Lite(&self.value.path));
+        formatter.field("value", Lite(&self.value.value));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ParenthesizedGenericArguments> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("ParenthesizedGenericArguments");
+        if !self.value.inputs.is_empty() {
+            formatter.field("inputs", Lite(&self.value.inputs));
+        }
+        formatter.field("output", Lite(&self.value.output));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Pat> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Pat::Const(_val) => {
+                formatter.write_str("Pat::Const")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Pat::Ident(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Ident");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.by_ref.is_some() {
+                    formatter.field("by_ref", &Present);
+                }
+                if _val.mutability.is_some() {
+                    formatter.field("mutability", &Present);
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                if let Some(val) = &_val.subpat {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::At, Box<syn::Pat>));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("subpat", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Lit(_val) => {
+                formatter.write_str("Pat::Lit")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Pat::Macro(_val) => {
+                formatter.write_str("Pat::Macro")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Pat::Or(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Or");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.leading_vert.is_some() {
+                    formatter.field("leading_vert", &Present);
+                }
+                if !_val.cases.is_empty() {
+                    formatter.field("cases", Lite(&_val.cases));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Paren(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Paren");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                formatter.finish()
+            }
+            syn::Pat::Path(_val) => {
+                formatter.write_str("Pat::Path")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Pat::Range(_val) => {
+                formatter.write_str("Pat::Range")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Pat::Reference(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Reference");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if _val.mutability.is_some() {
+                    formatter.field("mutability", &Present);
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                formatter.finish()
+            }
+            syn::Pat::Rest(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Rest");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Slice(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Slice");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Struct(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Struct");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.qself {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::QSelf);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("qself", Print::ref_cast(val));
+                }
+                formatter.field("path", Lite(&_val.path));
+                if !_val.fields.is_empty() {
+                    formatter.field("fields", Lite(&_val.fields));
+                }
+                if let Some(val) = &_val.rest {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::PatRest);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("rest", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Tuple(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Tuple");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Pat::TupleStruct(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::TupleStruct");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                if let Some(val) = &_val.qself {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::QSelf);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("qself", Print::ref_cast(val));
+                }
+                formatter.field("path", Lite(&_val.path));
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Pat::Type(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Type");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                formatter.field("ty", Lite(&_val.ty));
+                formatter.finish()
+            }
+            syn::Pat::Verbatim(_val) => {
+                formatter.write_str("Pat::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            syn::Pat::Wild(_val) => {
+                let mut formatter = formatter.debug_struct("Pat::Wild");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.finish()
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::PatIdent> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatIdent");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.by_ref.is_some() {
+            formatter.field("by_ref", &Present);
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        if let Some(val) = &self.value.subpat {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::At, Box<syn::Pat>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("subpat", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatOr> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatOr");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.leading_vert.is_some() {
+            formatter.field("leading_vert", &Present);
+        }
+        if !self.value.cases.is_empty() {
+            formatter.field("cases", Lite(&self.value.cases));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatParen> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatParen");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatReference> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatReference");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatRest> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatRest");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatSlice> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatSlice");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatStruct> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatStruct");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.qself {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::QSelf);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("qself", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        if !self.value.fields.is_empty() {
+            formatter.field("fields", Lite(&self.value.fields));
+        }
+        if let Some(val) = &self.value.rest {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::PatRest);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("rest", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatTuple> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatTuple");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatTupleStruct> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatTupleStruct");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.qself {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::QSelf);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("qself", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatType");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("pat", Lite(&self.value.pat));
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PatWild> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PatWild");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Path> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Path");
+        if self.value.leading_colon.is_some() {
+            formatter.field("leading_colon", &Present);
+        }
+        if !self.value.segments.is_empty() {
+            formatter.field("segments", Lite(&self.value.segments));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PathArguments> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::PathArguments::None => formatter.write_str("PathArguments::None"),
+            syn::PathArguments::AngleBracketed(_val) => {
+                let mut formatter = formatter
+                    .debug_struct("PathArguments::AngleBracketed");
+                if _val.colon2_token.is_some() {
+                    formatter.field("colon2_token", &Present);
+                }
+                if !_val.args.is_empty() {
+                    formatter.field("args", Lite(&_val.args));
+                }
+                formatter.finish()
+            }
+            syn::PathArguments::Parenthesized(_val) => {
+                let mut formatter = formatter
+                    .debug_struct("PathArguments::Parenthesized");
+                if !_val.inputs.is_empty() {
+                    formatter.field("inputs", Lite(&_val.inputs));
+                }
+                formatter.field("output", Lite(&_val.output));
+                formatter.finish()
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::PathSegment> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PathSegment");
+        formatter.field("ident", Lite(&self.value.ident));
+        match self.value.arguments {
+            syn::PathArguments::None => {}
+            _ => {
+                formatter.field("arguments", Lite(&self.value.arguments));
+            }
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PredicateLifetime> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PredicateLifetime");
+        formatter.field("lifetime", Lite(&self.value.lifetime));
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::PredicateType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("PredicateType");
+        if let Some(val) = &self.value.lifetimes {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::BoundLifetimes);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("lifetimes", Print::ref_cast(val));
+        }
+        formatter.field("bounded_ty", Lite(&self.value.bounded_ty));
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::QSelf> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("QSelf");
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.field("position", Lite(&self.value.position));
+        if self.value.as_token.is_some() {
+            formatter.field("as_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::RangeLimits> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::RangeLimits::HalfOpen(_val) => {
+                formatter.write_str("RangeLimits::HalfOpen")?;
+                Ok(())
+            }
+            syn::RangeLimits::Closed(_val) => {
+                formatter.write_str("RangeLimits::Closed")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Receiver> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Receiver");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.reference {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::And, Option<syn::Lifetime>));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(
+                        {
+                            #[derive(RefCast)]
+                            #[repr(transparent)]
+                            struct Print(Option<syn::Lifetime>);
+                            impl Debug for Print {
+                                fn fmt(
+                                    &self,
+                                    formatter: &mut fmt::Formatter,
+                                ) -> fmt::Result {
+                                    match &self.0 {
+                                        Some(_val) => {
+                                            formatter.write_str("Some(")?;
+                                            Debug::fmt(Lite(_val), formatter)?;
+                                            formatter.write_str(")")?;
+                                            Ok(())
+                                        }
+                                        None => formatter.write_str("None"),
+                                    }
+                                }
+                            }
+                            Print::ref_cast(&self.0.1)
+                        },
+                        formatter,
+                    )?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("reference", Print::ref_cast(val));
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        formatter.field("ty", Lite(&self.value.ty));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::ReturnType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::ReturnType::Default => formatter.write_str("ReturnType::Default"),
+            syn::ReturnType::Type(_v0, _v1) => {
+                let mut formatter = formatter.debug_tuple("ReturnType::Type");
+                formatter.field(Lite(_v1));
+                formatter.finish()
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Signature> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Signature");
+        if self.value.constness.is_some() {
+            formatter.field("constness", &Present);
+        }
+        if self.value.asyncness.is_some() {
+            formatter.field("asyncness", &Present);
+        }
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        if let Some(val) = &self.value.abi {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Abi);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("abi", Print::ref_cast(val));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        if !self.value.inputs.is_empty() {
+            formatter.field("inputs", Lite(&self.value.inputs));
+        }
+        if let Some(val) = &self.value.variadic {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Variadic);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("variadic", Print::ref_cast(val));
+        }
+        formatter.field("output", Lite(&self.value.output));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::StaticMutability> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::StaticMutability::Mut(_val) => {
+                formatter.write_str("StaticMutability::Mut")?;
+                Ok(())
+            }
+            syn::StaticMutability::None => formatter.write_str("StaticMutability::None"),
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::Stmt> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Stmt::Local(_val) => {
+                let mut formatter = formatter.debug_struct("Stmt::Local");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("pat", Lite(&_val.pat));
+                if let Some(val) = &_val.init {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::LocalInit);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("init", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::Stmt::Item(_val) => {
+                formatter.write_str("Stmt::Item")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::Stmt::Expr(_v0, _v1) => {
+                let mut formatter = formatter.debug_tuple("Stmt::Expr");
+                formatter.field(Lite(_v0));
+                formatter
+                    .field(
+                        &super::Option {
+                            present: _v1.is_some(),
+                        },
+                    );
+                formatter.finish()
+            }
+            syn::Stmt::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("Stmt::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::StmtMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("StmtMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TraitBound> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitBound");
+        if self.value.paren_token.is_some() {
+            formatter.field("paren_token", &Present);
+        }
+        match self.value.modifier {
+            syn::TraitBoundModifier::None => {}
+            _ => {
+                formatter.field("modifier", Lite(&self.value.modifier));
+            }
+        }
+        if let Some(val) = &self.value.lifetimes {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::BoundLifetimes);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("lifetimes", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TraitBoundModifier> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::TraitBoundModifier::None => {
+                formatter.write_str("TraitBoundModifier::None")
+            }
+            syn::TraitBoundModifier::Maybe(_val) => {
+                formatter.write_str("TraitBoundModifier::Maybe")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::TraitItem> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::TraitItem::Const(_val) => {
+                let mut formatter = formatter.debug_struct("TraitItem::Const");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                formatter.field("ty", Lite(&_val.ty));
+                if let Some(val) = &_val.default {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::Eq, syn::Expr));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("default", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::TraitItem::Fn(_val) => {
+                let mut formatter = formatter.debug_struct("TraitItem::Fn");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("sig", Lite(&_val.sig));
+                if let Some(val) = &_val.default {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Block);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("default", Print::ref_cast(val));
+                }
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::TraitItem::Type(_val) => {
+                let mut formatter = formatter.debug_struct("TraitItem::Type");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.field("generics", Lite(&_val.generics));
+                if _val.colon_token.is_some() {
+                    formatter.field("colon_token", &Present);
+                }
+                if !_val.bounds.is_empty() {
+                    formatter.field("bounds", Lite(&_val.bounds));
+                }
+                if let Some(val) = &_val.default {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print((syn::token::Eq, syn::Type));
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0.1), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("default", Print::ref_cast(val));
+                }
+                formatter.finish()
+            }
+            syn::TraitItem::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("TraitItem::Macro");
+                if !_val.attrs.is_empty() {
+                    formatter.field("attrs", Lite(&_val.attrs));
+                }
+                formatter.field("mac", Lite(&_val.mac));
+                if _val.semi_token.is_some() {
+                    formatter.field("semi_token", &Present);
+                }
+                formatter.finish()
+            }
+            syn::TraitItem::Verbatim(_val) => {
+                formatter.write_str("TraitItem::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::TraitItemConst> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitItemConst");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        formatter.field("ty", Lite(&self.value.ty));
+        if let Some(val) = &self.value.default {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Eq, syn::Expr));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("default", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TraitItemFn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitItemFn");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("sig", Lite(&self.value.sig));
+        if let Some(val) = &self.value.default {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Block);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("default", Print::ref_cast(val));
+        }
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TraitItemMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitItemMacro");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("mac", Lite(&self.value.mac));
+        if self.value.semi_token.is_some() {
+            formatter.field("semi_token", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TraitItemType> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TraitItemType");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("generics", Lite(&self.value.generics));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        if let Some(val) = &self.value.default {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Eq, syn::Type));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("default", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Type> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Type::Array(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Array");
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.field("len", Lite(&_val.len));
+                formatter.finish()
+            }
+            syn::Type::BareFn(_val) => {
+                let mut formatter = formatter.debug_struct("Type::BareFn");
+                if let Some(val) = &_val.lifetimes {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::BoundLifetimes);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("lifetimes", Print::ref_cast(val));
+                }
+                if _val.unsafety.is_some() {
+                    formatter.field("unsafety", &Present);
+                }
+                if let Some(val) = &_val.abi {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Abi);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("abi", Print::ref_cast(val));
+                }
+                if !_val.inputs.is_empty() {
+                    formatter.field("inputs", Lite(&_val.inputs));
+                }
+                if let Some(val) = &_val.variadic {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::BareVariadic);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("variadic", Print::ref_cast(val));
+                }
+                formatter.field("output", Lite(&_val.output));
+                formatter.finish()
+            }
+            syn::Type::Group(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Group");
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.finish()
+            }
+            syn::Type::ImplTrait(_val) => {
+                let mut formatter = formatter.debug_struct("Type::ImplTrait");
+                if !_val.bounds.is_empty() {
+                    formatter.field("bounds", Lite(&_val.bounds));
+                }
+                formatter.finish()
+            }
+            syn::Type::Infer(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Infer");
+                formatter.finish()
+            }
+            syn::Type::Macro(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Macro");
+                formatter.field("mac", Lite(&_val.mac));
+                formatter.finish()
+            }
+            syn::Type::Never(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Never");
+                formatter.finish()
+            }
+            syn::Type::Paren(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Paren");
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.finish()
+            }
+            syn::Type::Path(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Path");
+                if let Some(val) = &_val.qself {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::QSelf);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("qself", Print::ref_cast(val));
+                }
+                formatter.field("path", Lite(&_val.path));
+                formatter.finish()
+            }
+            syn::Type::Ptr(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Ptr");
+                if _val.const_token.is_some() {
+                    formatter.field("const_token", &Present);
+                }
+                if _val.mutability.is_some() {
+                    formatter.field("mutability", &Present);
+                }
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.finish()
+            }
+            syn::Type::Reference(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Reference");
+                if let Some(val) = &_val.lifetime {
+                    #[derive(RefCast)]
+                    #[repr(transparent)]
+                    struct Print(syn::Lifetime);
+                    impl Debug for Print {
+                        fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str("Some(")?;
+                            Debug::fmt(Lite(&self.0), formatter)?;
+                            formatter.write_str(")")?;
+                            Ok(())
+                        }
+                    }
+                    formatter.field("lifetime", Print::ref_cast(val));
+                }
+                if _val.mutability.is_some() {
+                    formatter.field("mutability", &Present);
+                }
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.finish()
+            }
+            syn::Type::Slice(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Slice");
+                formatter.field("elem", Lite(&_val.elem));
+                formatter.finish()
+            }
+            syn::Type::TraitObject(_val) => {
+                let mut formatter = formatter.debug_struct("Type::TraitObject");
+                if _val.dyn_token.is_some() {
+                    formatter.field("dyn_token", &Present);
+                }
+                if !_val.bounds.is_empty() {
+                    formatter.field("bounds", Lite(&_val.bounds));
+                }
+                formatter.finish()
+            }
+            syn::Type::Tuple(_val) => {
+                let mut formatter = formatter.debug_struct("Type::Tuple");
+                if !_val.elems.is_empty() {
+                    formatter.field("elems", Lite(&_val.elems));
+                }
+                formatter.finish()
+            }
+            syn::Type::Verbatim(_val) => {
+                formatter.write_str("Type::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::TypeArray> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeArray");
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.field("len", Lite(&self.value.len));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeBareFn> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeBareFn");
+        if let Some(val) = &self.value.lifetimes {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::BoundLifetimes);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("lifetimes", Print::ref_cast(val));
+        }
+        if self.value.unsafety.is_some() {
+            formatter.field("unsafety", &Present);
+        }
+        if let Some(val) = &self.value.abi {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Abi);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("abi", Print::ref_cast(val));
+        }
+        if !self.value.inputs.is_empty() {
+            formatter.field("inputs", Lite(&self.value.inputs));
+        }
+        if let Some(val) = &self.value.variadic {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::BareVariadic);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("variadic", Print::ref_cast(val));
+        }
+        formatter.field("output", Lite(&self.value.output));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeGroup> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeGroup");
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeImplTrait> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeImplTrait");
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeInfer> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeInfer");
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeMacro> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeMacro");
+        formatter.field("mac", Lite(&self.value.mac));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeNever> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeNever");
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeParam> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeParam");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        if self.value.colon_token.is_some() {
+            formatter.field("colon_token", &Present);
+        }
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        if self.value.eq_token.is_some() {
+            formatter.field("eq_token", &Present);
+        }
+        if let Some(val) = &self.value.default {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Type);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("default", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeParamBound> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::TypeParamBound::Trait(_val) => {
+                formatter.write_str("TypeParamBound::Trait")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::TypeParamBound::Lifetime(_val) => {
+                let mut formatter = formatter.debug_struct("TypeParamBound::Lifetime");
+                formatter.field("ident", Lite(&_val.ident));
+                formatter.finish()
+            }
+            syn::TypeParamBound::Verbatim(_val) => {
+                formatter.write_str("TypeParamBound::Verbatim")?;
+                formatter.write_str("(`")?;
+                Display::fmt(_val, formatter)?;
+                formatter.write_str("`)")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::TypeParen> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeParen");
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypePath> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypePath");
+        if let Some(val) = &self.value.qself {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::QSelf);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("qself", Print::ref_cast(val));
+        }
+        formatter.field("path", Lite(&self.value.path));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypePtr> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypePtr");
+        if self.value.const_token.is_some() {
+            formatter.field("const_token", &Present);
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeReference> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeReference");
+        if let Some(val) = &self.value.lifetime {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print(syn::Lifetime);
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("lifetime", Print::ref_cast(val));
+        }
+        if self.value.mutability.is_some() {
+            formatter.field("mutability", &Present);
+        }
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeSlice> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeSlice");
+        formatter.field("elem", Lite(&self.value.elem));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeTraitObject> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeTraitObject");
+        if self.value.dyn_token.is_some() {
+            formatter.field("dyn_token", &Present);
+        }
+        if !self.value.bounds.is_empty() {
+            formatter.field("bounds", Lite(&self.value.bounds));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::TypeTuple> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("TypeTuple");
+        if !self.value.elems.is_empty() {
+            formatter.field("elems", Lite(&self.value.elems));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UnOp> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::UnOp::Deref(_val) => {
+                formatter.write_str("UnOp::Deref")?;
+                Ok(())
+            }
+            syn::UnOp::Not(_val) => {
+                formatter.write_str("UnOp::Not")?;
+                Ok(())
+            }
+            syn::UnOp::Neg(_val) => {
+                formatter.write_str("UnOp::Neg")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+impl Debug for Lite<syn::UseGlob> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseGlob");
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UseGroup> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseGroup");
+        if !self.value.items.is_empty() {
+            formatter.field("items", Lite(&self.value.items));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UseName> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseName");
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UsePath> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UsePath");
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("tree", Lite(&self.value.tree));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UseRename> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("UseRename");
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("rename", Lite(&self.value.rename));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::UseTree> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::UseTree::Path(_val) => {
+                formatter.write_str("UseTree::Path")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::UseTree::Name(_val) => {
+                formatter.write_str("UseTree::Name")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::UseTree::Rename(_val) => {
+                formatter.write_str("UseTree::Rename")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::UseTree::Glob(_val) => {
+                formatter.write_str("UseTree::Glob")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::UseTree::Group(_val) => {
+                formatter.write_str("UseTree::Group")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+        }
+    }
+}
+impl Debug for Lite<syn::Variadic> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Variadic");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        if let Some(val) = &self.value.pat {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((Box<syn::Pat>, syn::token::Colon));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.0), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("pat", Print::ref_cast(val));
+        }
+        if self.value.comma.is_some() {
+            formatter.field("comma", &Present);
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Variant> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("Variant");
+        if !self.value.attrs.is_empty() {
+            formatter.field("attrs", Lite(&self.value.attrs));
+        }
+        formatter.field("ident", Lite(&self.value.ident));
+        formatter.field("fields", Lite(&self.value.fields));
+        if let Some(val) = &self.value.discriminant {
+            #[derive(RefCast)]
+            #[repr(transparent)]
+            struct Print((syn::token::Eq, syn::Expr));
+            impl Debug for Print {
+                fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str("Some(")?;
+                    Debug::fmt(Lite(&self.0.1), formatter)?;
+                    formatter.write_str(")")?;
+                    Ok(())
+                }
+            }
+            formatter.field("discriminant", Print::ref_cast(val));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::VisRestricted> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("VisRestricted");
+        if self.value.in_token.is_some() {
+            formatter.field("in_token", &Present);
+        }
+        formatter.field("path", Lite(&self.value.path));
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::Visibility> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::Visibility::Public(_val) => {
+                formatter.write_str("Visibility::Public")?;
+                Ok(())
+            }
+            syn::Visibility::Restricted(_val) => {
+                let mut formatter = formatter.debug_struct("Visibility::Restricted");
+                if _val.in_token.is_some() {
+                    formatter.field("in_token", &Present);
+                }
+                formatter.field("path", Lite(&_val.path));
+                formatter.finish()
+            }
+            syn::Visibility::Inherited => formatter.write_str("Visibility::Inherited"),
+        }
+    }
+}
+impl Debug for Lite<syn::WhereClause> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut formatter = formatter.debug_struct("WhereClause");
+        if !self.value.predicates.is_empty() {
+            formatter.field("predicates", Lite(&self.value.predicates));
+        }
+        formatter.finish()
+    }
+}
+impl Debug for Lite<syn::WherePredicate> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match &self.value {
+            syn::WherePredicate::Lifetime(_val) => {
+                formatter.write_str("WherePredicate::Lifetime")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            syn::WherePredicate::Type(_val) => {
+                formatter.write_str("WherePredicate::Type")?;
+                formatter.write_str("(")?;
+                Debug::fmt(Lite(_val), formatter)?;
+                formatter.write_str(")")?;
+                Ok(())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
diff --git a/vendor/syn/tests/debug/mod.rs b/vendor/syn/tests/debug/mod.rs
new file mode 100644
index 0000000..caf9eed
--- /dev/null
+++ b/vendor/syn/tests/debug/mod.rs
@@ -0,0 +1,143 @@
+#![allow(
+    clippy::no_effect_underscore_binding,
+    clippy::too_many_lines,
+    clippy::used_underscore_binding
+)]
+
+#[rustfmt::skip]
+mod gen;
+
+use proc_macro2::{Ident, Literal, TokenStream};
+use ref_cast::RefCast;
+use std::fmt::{self, Debug};
+use std::ops::Deref;
+use syn::punctuated::Punctuated;
+
+#[derive(RefCast)]
+#[repr(transparent)]
+pub struct Lite<T: ?Sized> {
+    value: T,
+}
+
+#[allow(non_snake_case)]
+pub fn Lite<T: ?Sized>(value: &T) -> &Lite<T> {
+    Lite::ref_cast(value)
+}
+
+impl<T: ?Sized> Deref for Lite<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.value
+    }
+}
+
+impl Debug for Lite<bool> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", self.value)
+    }
+}
+
+impl Debug for Lite<u32> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", self.value)
+    }
+}
+
+impl Debug for Lite<usize> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", self.value)
+    }
+}
+
+impl Debug for Lite<String> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value)
+    }
+}
+
+impl Debug for Lite<Ident> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self.value.to_string())
+    }
+}
+
+impl Debug for Lite<Literal> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{}", self.value)
+    }
+}
+
+impl Debug for Lite<TokenStream> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let string = self.value.to_string();
+        if string.len() <= 80 {
+            write!(formatter, "TokenStream(`{}`)", self.value)
+        } else {
+            formatter
+                .debug_tuple("TokenStream")
+                .field(&format_args!("`{}`", string))
+                .finish()
+        }
+    }
+}
+
+impl<'a, T> Debug for Lite<&'a T>
+where
+    Lite<T>: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(Lite(self.value), formatter)
+    }
+}
+
+impl<T> Debug for Lite<Box<T>>
+where
+    Lite<T>: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(Lite(&*self.value), formatter)
+    }
+}
+
+impl<T> Debug for Lite<Vec<T>>
+where
+    Lite<T>: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_list()
+            .entries(self.value.iter().map(Lite))
+            .finish()
+    }
+}
+
+impl<T, P> Debug for Lite<Punctuated<T, P>>
+where
+    Lite<T>: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_list()
+            .entries(self.value.iter().map(Lite))
+            .finish()
+    }
+}
+
+struct Present;
+
+impl Debug for Present {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Some")
+    }
+}
+
+struct Option {
+    present: bool,
+}
+
+impl Debug for Option {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(if self.present { "Some" } else { "None" })
+    }
+}
diff --git a/vendor/syn/tests/macros/mod.rs b/vendor/syn/tests/macros/mod.rs
new file mode 100644
index 0000000..3bfbe03
--- /dev/null
+++ b/vendor/syn/tests/macros/mod.rs
@@ -0,0 +1,88 @@
+#![allow(unused_macros, unused_macro_rules)]
+
+#[path = "../debug/mod.rs"]
+pub mod debug;
+
+use syn::parse::{Parse, Result};
+
+macro_rules! errorf {
+    ($($tt:tt)*) => {{
+        use ::std::io::Write;
+        let stderr = ::std::io::stderr();
+        write!(stderr.lock(), $($tt)*).unwrap();
+    }};
+}
+
+macro_rules! punctuated {
+    ($($e:expr,)+) => {{
+        let mut seq = ::syn::punctuated::Punctuated::new();
+        $(
+            seq.push($e);
+        )+
+        seq
+    }};
+
+    ($($e:expr),+) => {
+        punctuated!($($e,)+)
+    };
+}
+
+macro_rules! snapshot {
+    ($($args:tt)*) => {
+        snapshot_impl!(() $($args)*)
+    };
+}
+
+macro_rules! snapshot_impl {
+    (($expr:ident) as $t:ty, @$snapshot:literal) => {
+        let $expr = crate::macros::Tokens::parse::<$t>($expr).unwrap();
+        let debug = crate::macros::debug::Lite(&$expr);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)] // https://github.com/mitsuhiko/insta/issues/389
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+    };
+    (($($expr:tt)*) as $t:ty, @$snapshot:literal) => {{
+        let syntax_tree = crate::macros::Tokens::parse::<$t>($($expr)*).unwrap();
+        let debug = crate::macros::debug::Lite(&syntax_tree);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)]
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+        syntax_tree
+    }};
+    (($($expr:tt)*) , @$snapshot:literal) => {{
+        let syntax_tree = $($expr)*;
+        let debug = crate::macros::debug::Lite(&syntax_tree);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)]
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+        syntax_tree
+    }};
+    (($($expr:tt)*) $next:tt $($rest:tt)*) => {
+        snapshot_impl!(($($expr)* $next) $($rest)*)
+    };
+}
+
+pub trait Tokens {
+    fn parse<T: Parse>(self) -> Result<T>;
+}
+
+impl<'a> Tokens for &'a str {
+    fn parse<T: Parse>(self) -> Result<T> {
+        syn::parse_str(self)
+    }
+}
+
+impl Tokens for proc_macro2::TokenStream {
+    fn parse<T: Parse>(self) -> Result<T> {
+        syn::parse2(self)
+    }
+}
diff --git a/vendor/syn/tests/regression.rs b/vendor/syn/tests/regression.rs
new file mode 100644
index 0000000..5c7fcdd
--- /dev/null
+++ b/vendor/syn/tests/regression.rs
@@ -0,0 +1,5 @@
+#![allow(clippy::let_underscore_untyped, clippy::uninlined_format_args)]
+
+mod regression {
+    automod::dir!("tests/regression");
+}
diff --git a/vendor/syn/tests/regression/issue1108.rs b/vendor/syn/tests/regression/issue1108.rs
new file mode 100644
index 0000000..11a82ad
--- /dev/null
+++ b/vendor/syn/tests/regression/issue1108.rs
@@ -0,0 +1,5 @@
+#[test]
+fn issue1108() {
+    let data = "impl<x<>>::x for";
+    let _ = syn::parse_file(data);
+}
diff --git a/vendor/syn/tests/regression/issue1235.rs b/vendor/syn/tests/regression/issue1235.rs
new file mode 100644
index 0000000..8836030
--- /dev/null
+++ b/vendor/syn/tests/regression/issue1235.rs
@@ -0,0 +1,32 @@
+use proc_macro2::{Delimiter, Group};
+use quote::quote;
+
+#[test]
+fn main() {
+    // Okay. Rustc allows top-level `static` with no value syntactically, but
+    // not semantically. Syn parses as Item::Verbatim.
+    let tokens = quote! {
+        pub static FOO: usize;
+        pub static BAR: usize;
+    };
+    let file = syn::parse2::<syn::File>(tokens).unwrap();
+    println!("{:#?}", file);
+
+    // Okay.
+    let inner = Group::new(
+        Delimiter::None,
+        quote!(static FOO: usize = 0; pub static BAR: usize = 0),
+    );
+    let tokens = quote!(pub #inner;);
+    let file = syn::parse2::<syn::File>(tokens).unwrap();
+    println!("{:#?}", file);
+
+    // Formerly parser crash.
+    let inner = Group::new(
+        Delimiter::None,
+        quote!(static FOO: usize; pub static BAR: usize),
+    );
+    let tokens = quote!(pub #inner;);
+    let file = syn::parse2::<syn::File>(tokens).unwrap();
+    println!("{:#?}", file);
+}
diff --git a/vendor/syn/tests/repo/mod.rs b/vendor/syn/tests/repo/mod.rs
new file mode 100644
index 0000000..f38dad8
--- /dev/null
+++ b/vendor/syn/tests/repo/mod.rs
@@ -0,0 +1,357 @@
+#![allow(clippy::manual_assert)]
+
+mod progress;
+
+use self::progress::Progress;
+use anyhow::Result;
+use flate2::read::GzDecoder;
+use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
+use std::collections::BTreeSet;
+use std::ffi::OsStr;
+use std::fs;
+use std::path::{Path, PathBuf};
+use tar::Archive;
+use walkdir::{DirEntry, WalkDir};
+
+const REVISION: &str = "9f5fc1bd443f59583e7af0d94d289f95fe1e20c4";
+
+#[rustfmt::skip]
+static EXCLUDE_FILES: &[&str] = &[
+    // TODO: CStr literals: c"…", cr"…"
+    // https://github.com/dtolnay/syn/issues/1502
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0085_expr_literals.rs",
+
+    // TODO: explicit tail calls: `become _g()`
+    // https://github.com/dtolnay/syn/issues/1501
+    "tests/ui/explicit-tail-calls/return-lifetime-sub.rs",
+
+    // TODO: non-lifetime binders: `where for<'a, T> &'a Struct<T>: Trait`
+    // https://github.com/dtolnay/syn/issues/1435
+    "tests/rustdoc-json/non_lifetime_binders.rs",
+    "tests/rustdoc/non_lifetime_binders.rs",
+
+    // TODO: return type notation: `where T: Trait<method(): Send>`
+    // https://github.com/dtolnay/syn/issues/1434
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0208_associated_return_type_bounds.rs",
+    "tests/ui/associated-type-bounds/return-type-notation/basic.rs",
+    "tests/ui/feature-gates/feature-gate-return_type_notation.rs",
+
+    // Compile-fail expr parameter in const generic position: f::<1 + 2>()
+    "tests/ui/const-generics/early/closing-args-token.rs",
+    "tests/ui/const-generics/early/const-expression-parameter.rs",
+
+    // Compile-fail variadics in not the last position of a function parameter list
+    "tests/ui/parser/variadic-ffi-syntactic-pass.rs",
+
+    // Need at least one trait in impl Trait, no such type as impl 'static
+    "tests/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.rs",
+
+    // Negative polarity trait bound: `where T: !Copy`
+    "src/tools/rustfmt/tests/target/negative-bounds.rs",
+
+    // Lifetime bound inside for<>: `T: ~const ?for<'a: 'b> Trait<'a>`
+    "tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-syntax.rs",
+
+    // Const impl that is not a trait impl: `impl ~const T {}`
+    "tests/ui/rfcs/rfc-2632-const-trait-impl/syntax.rs",
+
+    // Deprecated anonymous parameter syntax in traits
+    "src/tools/rustfmt/tests/source/trait.rs",
+    "src/tools/rustfmt/tests/target/trait.rs",
+    "tests/ui/issues/issue-13105.rs",
+    "tests/ui/issues/issue-13775.rs",
+    "tests/ui/issues/issue-34074.rs",
+    "tests/ui/proc-macro/trait-fn-args-2015.rs",
+
+    // Deprecated where-clause location
+    "src/tools/rustfmt/tests/source/issue_4257.rs",
+    "src/tools/rustfmt/tests/source/issue_4911.rs",
+    "src/tools/rustfmt/tests/target/issue_4257.rs",
+    "src/tools/rustfmt/tests/target/issue_4911.rs",
+    "tests/pretty/gat-bounds.rs",
+    "tests/rustdoc/generic-associated-types/gats.rs",
+
+    // Deprecated trait object syntax with parenthesized generic arguments and no dyn keyword
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0004_value_parameters_no_patterns.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0104_path_fn_trait_args.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0202_typepathfn_with_coloncolon.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0209_bare_dyn_types_with_paren_as_generic_args.rs",
+    "src/tools/rustfmt/tests/source/attrib.rs",
+    "src/tools/rustfmt/tests/source/closure.rs",
+    "src/tools/rustfmt/tests/source/existential_type.rs",
+    "src/tools/rustfmt/tests/source/fn-simple.rs",
+    "src/tools/rustfmt/tests/source/fn_args_layout-vertical.rs",
+    "src/tools/rustfmt/tests/source/issue-4689/one.rs",
+    "src/tools/rustfmt/tests/source/issue-4689/two.rs",
+    "src/tools/rustfmt/tests/source/paths.rs",
+    "src/tools/rustfmt/tests/source/structs.rs",
+    "src/tools/rustfmt/tests/target/attrib.rs",
+    "src/tools/rustfmt/tests/target/closure.rs",
+    "src/tools/rustfmt/tests/target/existential_type.rs",
+    "src/tools/rustfmt/tests/target/fn-simple.rs",
+    "src/tools/rustfmt/tests/target/fn.rs",
+    "src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs",
+    "src/tools/rustfmt/tests/target/issue-4689/one.rs",
+    "src/tools/rustfmt/tests/target/issue-4689/two.rs",
+    "src/tools/rustfmt/tests/target/paths.rs",
+    "src/tools/rustfmt/tests/target/structs.rs",
+    "tests/codegen-units/item-collection/non-generic-closures.rs",
+    "tests/debuginfo/recursive-enum.rs",
+    "tests/pretty/closure-reform-pretty.rs",
+    "tests/run-make/reproducible-build-2/reproducible-build.rs",
+    "tests/run-make/reproducible-build/reproducible-build.rs",
+    "tests/ui/auxiliary/typeid-intrinsic-aux1.rs",
+    "tests/ui/auxiliary/typeid-intrinsic-aux2.rs",
+    "tests/ui/impl-trait/generic-with-implicit-hrtb-without-dyn.rs",
+    "tests/ui/lifetimes/auxiliary/lifetime_bound_will_change_warning_lib.rs",
+    "tests/ui/lifetimes/bare-trait-object-borrowck.rs",
+    "tests/ui/lifetimes/bare-trait-object.rs",
+    "tests/ui/parser/bounds-obj-parens.rs",
+
+    // Obsolete box syntax
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0132_box_expr.rs",
+
+    // Invalid unparenthesized range pattern inside slice pattern: `[1..]`
+    "tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.rs",
+
+    // Various extensions to Rust syntax made up by rust-analyzer
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0012_type_item_where_clause.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0058_range_pat.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0123_param_list_vararg.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0131_existential_type.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0156_fn_def_param.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0179_use_tree_abs_star.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0188_const_param_default_path.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0015_use_tree.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0029_range_forms.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0051_parameter_attrs.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0055_dot_dot_dot.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0068_item_modifiers.rs",
+    "src/tools/rust-analyzer/crates/syntax/test_data/parser/validation/0031_block_inner_attrs.rs",
+    "src/tools/rust-analyzer/crates/syntax/test_data/parser/validation/0038_endless_inclusive_range.rs",
+    "src/tools/rust-analyzer/crates/syntax/test_data/parser/validation/0045_ambiguous_trait_object.rs",
+    "src/tools/rust-analyzer/crates/syntax/test_data/parser/validation/0046_mutable_const_item.rs",
+
+    // Placeholder syntax for "throw expressions"
+    "compiler/rustc_errors/src/translation.rs",
+    "src/tools/clippy/tests/ui/needless_return.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0204_yeet_expr.rs",
+    "tests/pretty/yeet-expr.rs",
+    "tests/ui/try-trait/yeet-for-option.rs",
+    "tests/ui/try-trait/yeet-for-result.rs",
+
+    // Edition 2015 code using identifiers that are now keywords
+    // TODO: some of these we should probably parse
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0159_try_macro_fallback.rs",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/0160_try_macro_rules.rs",
+    "src/tools/rustfmt/tests/source/configs/indent_style/block_call.rs",
+    "src/tools/rustfmt/tests/source/configs/use_try_shorthand/false.rs",
+    "src/tools/rustfmt/tests/source/configs/use_try_shorthand/true.rs",
+    "src/tools/rustfmt/tests/source/issue_1306.rs",
+    "src/tools/rustfmt/tests/source/try-conversion.rs",
+    "src/tools/rustfmt/tests/target/configs/indent_style/block_call.rs",
+    "src/tools/rustfmt/tests/target/configs/use_try_shorthand/false.rs",
+    "src/tools/rustfmt/tests/target/issue-1681.rs",
+    "src/tools/rustfmt/tests/target/issue_1306.rs",
+    "tests/ui/dyn-keyword/dyn-2015-no-warnings-without-lints.rs",
+    "tests/ui/editions/edition-keywords-2015-2015.rs",
+    "tests/ui/editions/edition-keywords-2015-2018.rs",
+    "tests/ui/lint/lint_pre_expansion_extern_module_aux.rs",
+    "tests/ui/macros/macro-comma-support-rpass.rs",
+    "tests/ui/macros/try-macro.rs",
+    "tests/ui/parser/extern-crate-async.rs",
+    "tests/ui/try-block/try-is-identifier-edition2015.rs",
+
+    // Excessive nesting
+    "tests/ui/issues/issue-74564-if-expr-stack-overflow.rs",
+
+    // Testing tools on invalid syntax
+    "src/tools/rustfmt/tests/coverage/target/comments.rs",
+    "src/tools/rustfmt/tests/parser/issue-4126/invalid.rs",
+    "src/tools/rustfmt/tests/parser/issue_4418.rs",
+    "src/tools/rustfmt/tests/parser/unclosed-delims/issue_4466.rs",
+    "src/tools/rustfmt/tests/source/configs/disable_all_formatting/true.rs",
+    "src/tools/rustfmt/tests/source/configs/spaces_around_ranges/false.rs",
+    "src/tools/rustfmt/tests/source/configs/spaces_around_ranges/true.rs",
+    "src/tools/rustfmt/tests/source/type.rs",
+    "src/tools/rustfmt/tests/target/configs/spaces_around_ranges/false.rs",
+    "src/tools/rustfmt/tests/target/configs/spaces_around_ranges/true.rs",
+    "src/tools/rustfmt/tests/target/type.rs",
+    "tests/run-make/translation/test.rs",
+    "tests/ui/generics/issue-94432-garbage-ice.rs",
+
+    // Generated file containing a top-level expression, used with `include!`
+    "compiler/rustc_codegen_gcc/src/intrinsic/archs.rs",
+
+    // Clippy lint lists represented as expressions
+    "src/tools/clippy/clippy_lints/src/lib.deprecated.rs",
+
+    // Not actually test cases
+    "tests/ui/lint/expansion-time-include.rs",
+    "tests/ui/macros/auxiliary/macro-comma-support.rs",
+    "tests/ui/macros/auxiliary/macro-include-items-expr.rs",
+    "tests/ui/macros/include-single-expr-helper.rs",
+    "tests/ui/macros/include-single-expr-helper-1.rs",
+    "tests/ui/parser/issues/auxiliary/issue-21146-inc.rs",
+];
+
+#[rustfmt::skip]
+static EXCLUDE_DIRS: &[&str] = &[
+    // Inputs that intentionally do not parse
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/err",
+    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/err",
+
+    // Inputs that lex but do not necessarily parse
+    "src/tools/rust-analyzer/crates/parser/test_data/lexer",
+
+    // Inputs that used to crash rust-analyzer, but aren't necessarily supposed to parse
+    "src/tools/rust-analyzer/crates/syntax/test_data/parser/fuzz-failures",
+    "src/tools/rust-analyzer/crates/syntax/test_data/reparse/fuzz-failures",
+];
+
+// Directories in which a .stderr implies the corresponding .rs is not expected
+// to work.
+static UI_TEST_DIRS: &[&str] = &["tests/ui", "tests/rustdoc-ui"];
+
+pub fn for_each_rust_file(for_each: impl Fn(&Path) + Sync + Send) {
+    let mut rs_files = BTreeSet::new();
+
+    let repo_dir = Path::new("tests/rust");
+    for entry in WalkDir::new(repo_dir)
+        .into_iter()
+        .filter_entry(base_dir_filter)
+    {
+        let entry = entry.unwrap();
+        if !entry.file_type().is_dir() {
+            rs_files.insert(entry.into_path());
+        }
+    }
+
+    for ui_test_dir in UI_TEST_DIRS {
+        for entry in WalkDir::new(repo_dir.join(ui_test_dir)) {
+            let mut path = entry.unwrap().into_path();
+            if path.extension() == Some(OsStr::new("stderr")) {
+                loop {
+                    rs_files.remove(&path.with_extension("rs"));
+                    path = path.with_extension("");
+                    if path.extension().is_none() {
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    rs_files.par_iter().map(PathBuf::as_path).for_each(for_each);
+}
+
+pub fn base_dir_filter(entry: &DirEntry) -> bool {
+    let path = entry.path();
+
+    let mut path_string = path.to_string_lossy();
+    if cfg!(windows) {
+        path_string = path_string.replace('\\', "/").into();
+    }
+    let path_string = if path_string == "tests/rust" {
+        return true;
+    } else if let Some(path) = path_string.strip_prefix("tests/rust/") {
+        path
+    } else {
+        panic!("unexpected path in Rust dist: {}", path_string);
+    };
+
+    if path.is_dir() {
+        return !EXCLUDE_DIRS.contains(&path_string);
+    }
+
+    if path.extension() != Some(OsStr::new("rs")) {
+        return false;
+    }
+
+    !EXCLUDE_FILES.contains(&path_string)
+}
+
+#[allow(dead_code)]
+pub fn edition(path: &Path) -> &'static str {
+    if path.ends_with("dyn-2015-no-warnings-without-lints.rs") {
+        "2015"
+    } else {
+        "2018"
+    }
+}
+
+/*pub fn clone_rust() {
+    let needs_clone = match fs::read_to_string("tests/rust/COMMIT") {
+        Err(_) => true,
+        Ok(contents) => contents.trim() != REVISION,
+    };
+    if needs_clone {
+        download_and_unpack().unwrap();
+    }
+
+    let mut missing = String::new();
+    let test_src = Path::new("tests/rust");
+
+    let mut exclude_files_set = BTreeSet::new();
+    for exclude in EXCLUDE_FILES {
+        if !exclude_files_set.insert(exclude) {
+            panic!("duplicate path in EXCLUDE_FILES: {}", exclude);
+        }
+        for dir in EXCLUDE_DIRS {
+            if Path::new(exclude).starts_with(dir) {
+                panic!("excluded file {} is inside an excluded dir", exclude);
+            }
+        }
+        if !test_src.join(exclude).is_file() {
+            missing += "\ntests/rust/";
+            missing += exclude;
+        }
+    }
+
+    let mut exclude_dirs_set = BTreeSet::new();
+    for exclude in EXCLUDE_DIRS {
+        if !exclude_dirs_set.insert(exclude) {
+            panic!("duplicate path in EXCLUDE_DIRS: {}", exclude);
+        }
+        if !test_src.join(exclude).is_dir() {
+            missing += "\ntests/rust/";
+            missing += exclude;
+            missing += "/";
+        }
+    }
+
+    if !missing.is_empty() {
+        panic!("excluded test file does not exist:{}\n", missing);
+    }
+}*/
+
+/*fn download_and_unpack() -> Result<()> {
+    let url = format!(
+        "https://github.com/rust-lang/rust/archive/{}.tar.gz",
+        REVISION
+    );
+    let response = reqwest::blocking::get(url)?.error_for_status()?;
+    let progress = Progress::new(response);
+    let decoder = GzDecoder::new(progress);
+    let mut archive = Archive::new(decoder);
+    let prefix = format!("rust-{}", REVISION);
+
+    let tests_rust = Path::new("tests/rust");
+    if tests_rust.exists() {
+        fs::remove_dir_all(tests_rust)?;
+    }
+
+    for entry in archive.entries()? {
+        let mut entry = entry?;
+        let path = entry.path()?;
+        if path == Path::new("pax_global_header") {
+            continue;
+        }
+        let relative = path.strip_prefix(&prefix)?;
+        let out = tests_rust.join(relative);
+        entry.unpack(&out)?;
+    }
+
+    fs::write("tests/rust/COMMIT", REVISION)?;
+    Ok(())
+}*/
diff --git a/vendor/syn/tests/repo/progress.rs b/vendor/syn/tests/repo/progress.rs
new file mode 100644
index 0000000..28c8a44
--- /dev/null
+++ b/vendor/syn/tests/repo/progress.rs
@@ -0,0 +1,37 @@
+use std::io::{Read, Result};
+use std::time::{Duration, Instant};
+
+pub struct Progress<R> {
+    bytes: usize,
+    tick: Instant,
+    stream: R,
+}
+
+impl<R> Progress<R> {
+    pub fn new(stream: R) -> Self {
+        Progress {
+            bytes: 0,
+            tick: Instant::now() + Duration::from_millis(2000),
+            stream,
+        }
+    }
+}
+
+impl<R: Read> Read for Progress<R> {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
+        let num = self.stream.read(buf)?;
+        self.bytes += num;
+        let now = Instant::now();
+        if now > self.tick {
+            self.tick = now + Duration::from_millis(500);
+            errorf!("downloading... {} bytes\n", self.bytes);
+        }
+        Ok(num)
+    }
+}
+
+impl<R> Drop for Progress<R> {
+    fn drop(&mut self) {
+        errorf!("done ({} bytes)\n", self.bytes);
+    }
+}
diff --git a/vendor/syn/tests/test_asyncness.rs b/vendor/syn/tests/test_asyncness.rs
new file mode 100644
index 0000000..6bc5a16
--- /dev/null
+++ b/vendor/syn/tests/test_asyncness.rs
@@ -0,0 +1,39 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use syn::{Expr, Item};
+
+#[test]
+fn test_async_fn() {
+    let input = "async fn process() {}";
+
+    snapshot!(input as Item, @r###"
+    Item::Fn {
+        vis: Visibility::Inherited,
+        sig: Signature {
+            asyncness: Some,
+            ident: "process",
+            generics: Generics,
+            output: ReturnType::Default,
+        },
+        block: Block,
+    }
+    "###);
+}
+
+#[test]
+fn test_async_closure() {
+    let input = "async || {}";
+
+    snapshot!(input as Expr, @r###"
+    Expr::Closure {
+        asyncness: Some,
+        output: ReturnType::Default,
+        body: Expr::Block {
+            block: Block,
+        },
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_attribute.rs b/vendor/syn/tests/test_attribute.rs
new file mode 100644
index 0000000..597ae3a
--- /dev/null
+++ b/vendor/syn/tests/test_attribute.rs
@@ -0,0 +1,225 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use syn::parse::Parser;
+use syn::{Attribute, Meta};
+
+#[test]
+fn test_meta_item_word() {
+    let meta = test("#[foo]");
+
+    snapshot!(meta, @r###"
+    Meta::Path {
+        segments: [
+            PathSegment {
+                ident: "foo",
+            },
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_name_value() {
+    let meta = test("#[foo = 5]");
+
+    snapshot!(meta, @r###"
+    Meta::NameValue {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        value: Expr::Lit {
+            lit: 5,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_bool_value() {
+    let meta = test("#[foo = true]");
+
+    snapshot!(meta, @r###"
+    Meta::NameValue {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        value: Expr::Lit {
+            lit: Lit::Bool {
+                value: true,
+            },
+        },
+    }
+    "###);
+
+    let meta = test("#[foo = false]");
+
+    snapshot!(meta, @r###"
+    Meta::NameValue {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        value: Expr::Lit {
+            lit: Lit::Bool {
+                value: false,
+            },
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_list_lit() {
+    let meta = test("#[foo(5)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`5`),
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_list_word() {
+    let meta = test("#[foo(bar)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`bar`),
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_list_name_value() {
+    let meta = test("#[foo(bar = 5)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`bar = 5`),
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_list_bool_value() {
+    let meta = test("#[foo(bar = true)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`bar = true`),
+    }
+    "###);
+}
+
+#[test]
+fn test_meta_item_multiple() {
+    let meta = test("#[foo(word, name = 5, list(name2 = 6), word2)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`word , name = 5 , list (name2 = 6) , word2`),
+    }
+    "###);
+}
+
+#[test]
+fn test_bool_lit() {
+    let meta = test("#[foo(true)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`true`),
+    }
+    "###);
+}
+
+#[test]
+fn test_negative_lit() {
+    let meta = test("#[form(min = -1, max = 200)]");
+
+    snapshot!(meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "form",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`min = - 1 , max = 200`),
+    }
+    "###);
+}
+
+fn test(input: &str) -> Meta {
+    let attrs = Attribute::parse_outer.parse_str(input).unwrap();
+
+    assert_eq!(attrs.len(), 1);
+    let attr = attrs.into_iter().next().unwrap();
+
+    attr.meta
+}
diff --git a/vendor/syn/tests/test_derive_input.rs b/vendor/syn/tests/test_derive_input.rs
new file mode 100644
index 0000000..3ec6aec
--- /dev/null
+++ b/vendor/syn/tests/test_derive_input.rs
@@ -0,0 +1,767 @@
+#![allow(
+    clippy::assertions_on_result_states,
+    clippy::manual_let_else,
+    clippy::too_many_lines,
+    clippy::uninlined_format_args
+)]
+
+#[macro_use]
+mod macros;
+
+use quote::quote;
+use syn::{Data, DeriveInput};
+
+#[test]
+fn test_unit() {
+    let input = quote! {
+        struct Unit;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "Unit",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_struct() {
+    let input = quote! {
+        #[derive(Debug, Clone)]
+        pub struct Item {
+            pub ident: Ident,
+            pub attrs: Vec<Attribute>
+        }
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::List {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "derive",
+                            },
+                        ],
+                    },
+                    delimiter: MacroDelimiter::Paren,
+                    tokens: TokenStream(`Debug , Clone`),
+                },
+            },
+        ],
+        vis: Visibility::Public,
+        ident: "Item",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Named {
+                named: [
+                    Field {
+                        vis: Visibility::Public,
+                        ident: Some("ident"),
+                        colon_token: Some,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "Ident",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                    Field {
+                        vis: Visibility::Public,
+                        ident: Some("attrs"),
+                        colon_token: Some,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "Vec",
+                                        arguments: PathArguments::AngleBracketed {
+                                            args: [
+                                                GenericArgument::Type(Type::Path {
+                                                    path: Path {
+                                                        segments: [
+                                                            PathSegment {
+                                                                ident: "Attribute",
+                                                            },
+                                                        ],
+                                                    },
+                                                }),
+                                            ],
+                                        },
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+
+    snapshot!(&input.attrs[0].meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "derive",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`Debug , Clone`),
+    }
+    "###);
+}
+
+#[test]
+fn test_union() {
+    let input = quote! {
+        union MaybeUninit<T> {
+            uninit: (),
+            value: T
+        }
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "MaybeUninit",
+        generics: Generics {
+            lt_token: Some,
+            params: [
+                GenericParam::Type(TypeParam {
+                    ident: "T",
+                }),
+            ],
+            gt_token: Some,
+        },
+        data: Data::Union {
+            fields: FieldsNamed {
+                named: [
+                    Field {
+                        vis: Visibility::Inherited,
+                        ident: Some("uninit"),
+                        colon_token: Some,
+                        ty: Type::Tuple,
+                    },
+                    Field {
+                        vis: Visibility::Inherited,
+                        ident: Some("value"),
+                        colon_token: Some,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "T",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+}
+
+#[test]
+#[cfg(feature = "full")]
+fn test_enum() {
+    let input = quote! {
+        /// See the std::result module documentation for details.
+        #[must_use]
+        pub enum Result<T, E> {
+            Ok(T),
+            Err(E),
+            Surprise = 0isize,
+
+            // Smuggling data into a proc_macro_derive,
+            // in the style of https://github.com/dtolnay/proc-macro-hack
+            ProcMacroHack = (0, "data").0
+        }
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::NameValue {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "doc",
+                            },
+                        ],
+                    },
+                    value: Expr::Lit {
+                        lit: " See the std::result module documentation for details.",
+                    },
+                },
+            },
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::Path {
+                    segments: [
+                        PathSegment {
+                            ident: "must_use",
+                        },
+                    ],
+                },
+            },
+        ],
+        vis: Visibility::Public,
+        ident: "Result",
+        generics: Generics {
+            lt_token: Some,
+            params: [
+                GenericParam::Type(TypeParam {
+                    ident: "T",
+                }),
+                GenericParam::Type(TypeParam {
+                    ident: "E",
+                }),
+            ],
+            gt_token: Some,
+        },
+        data: Data::Enum {
+            variants: [
+                Variant {
+                    ident: "Ok",
+                    fields: Fields::Unnamed {
+                        unnamed: [
+                            Field {
+                                vis: Visibility::Inherited,
+                                ty: Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "T",
+                                            },
+                                        ],
+                                    },
+                                },
+                            },
+                        ],
+                    },
+                },
+                Variant {
+                    ident: "Err",
+                    fields: Fields::Unnamed {
+                        unnamed: [
+                            Field {
+                                vis: Visibility::Inherited,
+                                ty: Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "E",
+                                            },
+                                        ],
+                                    },
+                                },
+                            },
+                        ],
+                    },
+                },
+                Variant {
+                    ident: "Surprise",
+                    fields: Fields::Unit,
+                    discriminant: Some(Expr::Lit {
+                        lit: 0isize,
+                    }),
+                },
+                Variant {
+                    ident: "ProcMacroHack",
+                    fields: Fields::Unit,
+                    discriminant: Some(Expr::Field {
+                        base: Expr::Tuple {
+                            elems: [
+                                Expr::Lit {
+                                    lit: 0,
+                                },
+                                Expr::Lit {
+                                    lit: "data",
+                                },
+                            ],
+                        },
+                        member: Member::Unnamed(Index {
+                            index: 0,
+                        }),
+                    }),
+                },
+            ],
+        },
+    }
+    "###);
+
+    let meta_items: Vec<_> = input.attrs.into_iter().map(|attr| attr.meta).collect();
+
+    snapshot!(meta_items, @r###"
+    [
+        Meta::NameValue {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "doc",
+                    },
+                ],
+            },
+            value: Expr::Lit {
+                lit: " See the std::result module documentation for details.",
+            },
+        },
+        Meta::Path {
+            segments: [
+                PathSegment {
+                    ident: "must_use",
+                },
+            ],
+        },
+    ]
+    "###);
+}
+
+#[test]
+fn test_attr_with_non_mod_style_path() {
+    let input = quote! {
+        #[inert <T>]
+        struct S;
+    };
+
+    syn::parse2::<DeriveInput>(input).unwrap_err();
+}
+
+#[test]
+fn test_attr_with_mod_style_path_with_self() {
+    let input = quote! {
+        #[foo::self]
+        struct S;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::Path {
+                    segments: [
+                        PathSegment {
+                            ident: "foo",
+                        },
+                        PathSegment {
+                            ident: "self",
+                        },
+                    ],
+                },
+            },
+        ],
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+
+    snapshot!(&input.attrs[0].meta, @r###"
+    Meta::Path {
+        segments: [
+            PathSegment {
+                ident: "foo",
+            },
+            PathSegment {
+                ident: "self",
+            },
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_pub_restricted() {
+    // Taken from tests/rust/src/test/ui/resolve/auxiliary/privacy-struct-ctor.rs
+    let input = quote! {
+        pub(in m) struct Z(pub(in m::n) u8);
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Restricted {
+            in_token: Some,
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "m",
+                    },
+                ],
+            },
+        },
+        ident: "Z",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unnamed {
+                unnamed: [
+                    Field {
+                        vis: Visibility::Restricted {
+                            in_token: Some,
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "m",
+                                    },
+                                    PathSegment {
+                                        ident: "n",
+                                    },
+                                ],
+                            },
+                        },
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "u8",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+            semi_token: Some,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_pub_restricted_crate() {
+    let input = quote! {
+        pub(crate) struct S;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Restricted {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "crate",
+                    },
+                ],
+            },
+        },
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_pub_restricted_super() {
+    let input = quote! {
+        pub(super) struct S;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Restricted {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "super",
+                    },
+                ],
+            },
+        },
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_pub_restricted_in_super() {
+    let input = quote! {
+        pub(in super) struct S;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Restricted {
+            in_token: Some,
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "super",
+                    },
+                ],
+            },
+        },
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_fields_on_unit_struct() {
+    let input = quote! {
+        struct S;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+
+    let data = match input.data {
+        Data::Struct(data) => data,
+        _ => panic!("expected a struct"),
+    };
+
+    assert_eq!(0, data.fields.iter().count());
+}
+
+#[test]
+fn test_fields_on_named_struct() {
+    let input = quote! {
+        struct S {
+            foo: i32,
+            pub bar: String,
+        }
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Named {
+                named: [
+                    Field {
+                        vis: Visibility::Inherited,
+                        ident: Some("foo"),
+                        colon_token: Some,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "i32",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                    Field {
+                        vis: Visibility::Public,
+                        ident: Some("bar"),
+                        colon_token: Some,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "String",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+
+    let data = match input.data {
+        Data::Struct(data) => data,
+        _ => panic!("expected a struct"),
+    };
+
+    snapshot!(data.fields.into_iter().collect::<Vec<_>>(), @r###"
+    [
+        Field {
+            vis: Visibility::Inherited,
+            ident: Some("foo"),
+            colon_token: Some,
+            ty: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "i32",
+                        },
+                    ],
+                },
+            },
+        },
+        Field {
+            vis: Visibility::Public,
+            ident: Some("bar"),
+            colon_token: Some,
+            ty: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "String",
+                        },
+                    ],
+                },
+            },
+        },
+    ]
+    "###);
+}
+
+#[test]
+fn test_fields_on_tuple_struct() {
+    let input = quote! {
+        struct S(i32, pub String);
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unnamed {
+                unnamed: [
+                    Field {
+                        vis: Visibility::Inherited,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "i32",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                    Field {
+                        vis: Visibility::Public,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "String",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+            semi_token: Some,
+        },
+    }
+    "###);
+
+    let data = match input.data {
+        Data::Struct(data) => data,
+        _ => panic!("expected a struct"),
+    };
+
+    snapshot!(data.fields.iter().collect::<Vec<_>>(), @r###"
+    [
+        Field {
+            vis: Visibility::Inherited,
+            ty: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "i32",
+                        },
+                    ],
+                },
+            },
+        },
+        Field {
+            vis: Visibility::Public,
+            ty: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "String",
+                        },
+                    ],
+                },
+            },
+        },
+    ]
+    "###);
+}
+
+#[test]
+fn test_ambiguous_crate() {
+    let input = quote! {
+        // The field type is `(crate::X)` not `crate (::X)`.
+        struct S(crate::X);
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Unnamed {
+                unnamed: [
+                    Field {
+                        vis: Visibility::Inherited,
+                        ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "crate",
+                                    },
+                                    PathSegment {
+                                        ident: "X",
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                ],
+            },
+            semi_token: Some,
+        },
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_expr.rs b/vendor/syn/tests/test_expr.rs
new file mode 100644
index 0000000..5d529bf
--- /dev/null
+++ b/vendor/syn/tests/test_expr.rs
@@ -0,0 +1,312 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::{Expr, ExprRange};
+
+#[test]
+fn test_expr_parse() {
+    let tokens = quote!(..100u32);
+    snapshot!(tokens as Expr, @r###"
+    Expr::Range {
+        limits: RangeLimits::HalfOpen,
+        end: Some(Expr::Lit {
+            lit: 100u32,
+        }),
+    }
+    "###);
+
+    let tokens = quote!(..100u32);
+    snapshot!(tokens as ExprRange, @r###"
+    ExprRange {
+        limits: RangeLimits::HalfOpen,
+        end: Some(Expr::Lit {
+            lit: 100u32,
+        }),
+    }
+    "###);
+}
+
+#[test]
+fn test_await() {
+    // Must not parse as Expr::Field.
+    let tokens = quote!(fut.await);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Await {
+        base: Expr::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "fut",
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+}
+
+#[rustfmt::skip]
+#[test]
+fn test_tuple_multi_index() {
+    let expected = snapshot!("tuple.0.0" as Expr, @r###"
+    Expr::Field {
+        base: Expr::Field {
+            base: Expr::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "tuple",
+                        },
+                    ],
+                },
+            },
+            member: Member::Unnamed(Index {
+                index: 0,
+            }),
+        },
+        member: Member::Unnamed(Index {
+            index: 0,
+        }),
+    }
+    "###);
+
+    for &input in &[
+        "tuple .0.0",
+        "tuple. 0.0",
+        "tuple.0 .0",
+        "tuple.0. 0",
+        "tuple . 0 . 0",
+    ] {
+        assert_eq!(expected, syn::parse_str(input).unwrap());
+    }
+
+    for tokens in [
+        quote!(tuple.0.0),
+        quote!(tuple .0.0),
+        quote!(tuple. 0.0),
+        quote!(tuple.0 .0),
+        quote!(tuple.0. 0),
+        quote!(tuple . 0 . 0),
+    ] {
+        assert_eq!(expected, syn::parse2(tokens).unwrap());
+    }
+}
+
+#[test]
+fn test_macro_variable_func() {
+    // mimics the token stream corresponding to `$fn()`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { f })),
+        TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Call {
+        func: Expr::Group {
+            expr: Expr::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "f",
+                        },
+                    ],
+                },
+            },
+        },
+    }
+    "###);
+
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Punct(Punct::new('#', Spacing::Alone)),
+        TokenTree::Group(Group::new(Delimiter::Bracket, quote! { outside })),
+        TokenTree::Group(Group::new(Delimiter::None, quote! { #[inside] f })),
+        TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Call {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::Path {
+                    segments: [
+                        PathSegment {
+                            ident: "outside",
+                        },
+                    ],
+                },
+            },
+        ],
+        func: Expr::Group {
+            expr: Expr::Path {
+                attrs: [
+                    Attribute {
+                        style: AttrStyle::Outer,
+                        meta: Meta::Path {
+                            segments: [
+                                PathSegment {
+                                    ident: "inside",
+                                },
+                            ],
+                        },
+                    },
+                ],
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "f",
+                        },
+                    ],
+                },
+            },
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_macro_variable_macro() {
+    // mimics the token stream corresponding to `$macro!()`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { m })),
+        TokenTree::Punct(Punct::new('!', Spacing::Alone)),
+        TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Macro {
+        mac: Macro {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "m",
+                    },
+                ],
+            },
+            delimiter: MacroDelimiter::Paren,
+            tokens: TokenStream(``),
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_macro_variable_struct() {
+    // mimics the token stream corresponding to `$struct {}`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { S })),
+        TokenTree::Group(Group::new(Delimiter::Brace, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Struct {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "S",
+                },
+            ],
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_macro_variable_match_arm() {
+    // mimics the token stream corresponding to `match v { _ => $expr }`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Ident(Ident::new("match", Span::call_site())),
+        TokenTree::Ident(Ident::new("v", Span::call_site())),
+        TokenTree::Group(Group::new(
+            Delimiter::Brace,
+            TokenStream::from_iter(vec![
+                TokenTree::Punct(Punct::new('_', Spacing::Alone)),
+                TokenTree::Punct(Punct::new('=', Spacing::Joint)),
+                TokenTree::Punct(Punct::new('>', Spacing::Alone)),
+                TokenTree::Group(Group::new(Delimiter::None, quote! { #[a] () })),
+            ]),
+        )),
+    ]);
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Match {
+        expr: Expr::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "v",
+                    },
+                ],
+            },
+        },
+        arms: [
+            Arm {
+                pat: Pat::Wild,
+                body: Expr::Group {
+                    expr: Expr::Tuple {
+                        attrs: [
+                            Attribute {
+                                style: AttrStyle::Outer,
+                                meta: Meta::Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "a",
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                    },
+                },
+            },
+        ],
+    }
+    "###);
+}
+
+// https://github.com/dtolnay/syn/issues/1019
+#[test]
+fn test_closure_vs_rangefull() {
+    #[rustfmt::skip] // rustfmt bug: https://github.com/rust-lang/rustfmt/issues/4808
+    let tokens = quote!(|| .. .method());
+    snapshot!(tokens as Expr, @r###"
+    Expr::MethodCall {
+        receiver: Expr::Closure {
+            output: ReturnType::Default,
+            body: Expr::Range {
+                limits: RangeLimits::HalfOpen,
+            },
+        },
+        method: "method",
+    }
+    "###);
+}
+
+#[test]
+fn test_postfix_operator_after_cast() {
+    syn::parse_str::<Expr>("|| &x as T[0]").unwrap_err();
+    syn::parse_str::<Expr>("|| () as ()()").unwrap_err();
+}
+
+#[test]
+fn test_ranges() {
+    syn::parse_str::<Expr>("..").unwrap();
+    syn::parse_str::<Expr>("..hi").unwrap();
+    syn::parse_str::<Expr>("lo..").unwrap();
+    syn::parse_str::<Expr>("lo..hi").unwrap();
+
+    syn::parse_str::<Expr>("..=").unwrap_err();
+    syn::parse_str::<Expr>("..=hi").unwrap();
+    syn::parse_str::<Expr>("lo..=").unwrap_err();
+    syn::parse_str::<Expr>("lo..=hi").unwrap();
+
+    syn::parse_str::<Expr>("...").unwrap_err();
+    syn::parse_str::<Expr>("...hi").unwrap_err();
+    syn::parse_str::<Expr>("lo...").unwrap_err();
+    syn::parse_str::<Expr>("lo...hi").unwrap_err();
+}
diff --git a/vendor/syn/tests/test_generics.rs b/vendor/syn/tests/test_generics.rs
new file mode 100644
index 0000000..51119ad
--- /dev/null
+++ b/vendor/syn/tests/test_generics.rs
@@ -0,0 +1,276 @@
+#![allow(
+    clippy::manual_let_else,
+    clippy::too_many_lines,
+    clippy::uninlined_format_args
+)]
+
+#[macro_use]
+mod macros;
+
+use quote::quote;
+use syn::{DeriveInput, ItemFn, TypeParamBound, WhereClause, WherePredicate};
+
+#[test]
+fn test_split_for_impl() {
+    let input = quote! {
+        struct S<'a, 'b: 'a, #[may_dangle] T: 'a = ()> where T: Debug;
+    };
+
+    snapshot!(input as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics {
+            lt_token: Some,
+            params: [
+                GenericParam::Lifetime(LifetimeParam {
+                    lifetime: Lifetime {
+                        ident: "a",
+                    },
+                }),
+                GenericParam::Lifetime(LifetimeParam {
+                    lifetime: Lifetime {
+                        ident: "b",
+                    },
+                    colon_token: Some,
+                    bounds: [
+                        Lifetime {
+                            ident: "a",
+                        },
+                    ],
+                }),
+                GenericParam::Type(TypeParam {
+                    attrs: [
+                        Attribute {
+                            style: AttrStyle::Outer,
+                            meta: Meta::Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "may_dangle",
+                                    },
+                                ],
+                            },
+                        },
+                    ],
+                    ident: "T",
+                    colon_token: Some,
+                    bounds: [
+                        TypeParamBound::Lifetime {
+                            ident: "a",
+                        },
+                    ],
+                    eq_token: Some,
+                    default: Some(Type::Tuple),
+                }),
+            ],
+            gt_token: Some,
+            where_clause: Some(WhereClause {
+                predicates: [
+                    WherePredicate::Type(PredicateType {
+                        bounded_ty: Type::Path {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "T",
+                                    },
+                                ],
+                            },
+                        },
+                        bounds: [
+                            TypeParamBound::Trait(TraitBound {
+                                path: Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "Debug",
+                                        },
+                                    ],
+                                },
+                            }),
+                        ],
+                    }),
+                ],
+            }),
+        },
+        data: Data::Struct {
+            fields: Fields::Unit,
+            semi_token: Some,
+        },
+    }
+    "###);
+
+    let generics = input.generics;
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
+    let generated = quote! {
+        impl #impl_generics MyTrait for Test #ty_generics #where_clause {}
+    };
+    let expected = quote! {
+        impl<'a, 'b: 'a, #[may_dangle] T: 'a> MyTrait
+        for Test<'a, 'b, T>
+        where
+            T: Debug
+        {}
+    };
+    assert_eq!(generated.to_string(), expected.to_string());
+
+    let turbofish = ty_generics.as_turbofish();
+    let generated = quote! {
+        Test #turbofish
+    };
+    let expected = quote! {
+        Test::<'a, 'b, T>
+    };
+    assert_eq!(generated.to_string(), expected.to_string());
+}
+
+#[test]
+fn test_ty_param_bound() {
+    let tokens = quote!('a);
+    snapshot!(tokens as TypeParamBound, @r###"
+    TypeParamBound::Lifetime {
+        ident: "a",
+    }
+    "###);
+
+    let tokens = quote!('_);
+    snapshot!(tokens as TypeParamBound, @r###"
+    TypeParamBound::Lifetime {
+        ident: "_",
+    }
+    "###);
+
+    let tokens = quote!(Debug);
+    snapshot!(tokens as TypeParamBound, @r###"
+    TypeParamBound::Trait(TraitBound {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "Debug",
+                },
+            ],
+        },
+    })
+    "###);
+
+    let tokens = quote!(?Sized);
+    snapshot!(tokens as TypeParamBound, @r###"
+    TypeParamBound::Trait(TraitBound {
+        modifier: TraitBoundModifier::Maybe,
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "Sized",
+                },
+            ],
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_fn_precedence_in_where_clause() {
+    // This should parse as two separate bounds, `FnOnce() -> i32` and `Send` - not
+    // `FnOnce() -> (i32 + Send)`.
+    let input = quote! {
+        fn f<G>()
+        where
+            G: FnOnce() -> i32 + Send,
+        {
+        }
+    };
+
+    snapshot!(input as ItemFn, @r###"
+    ItemFn {
+        vis: Visibility::Inherited,
+        sig: Signature {
+            ident: "f",
+            generics: Generics {
+                lt_token: Some,
+                params: [
+                    GenericParam::Type(TypeParam {
+                        ident: "G",
+                    }),
+                ],
+                gt_token: Some,
+                where_clause: Some(WhereClause {
+                    predicates: [
+                        WherePredicate::Type(PredicateType {
+                            bounded_ty: Type::Path {
+                                path: Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "G",
+                                        },
+                                    ],
+                                },
+                            },
+                            bounds: [
+                                TypeParamBound::Trait(TraitBound {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "FnOnce",
+                                                arguments: PathArguments::Parenthesized {
+                                                    output: ReturnType::Type(
+                                                        Type::Path {
+                                                            path: Path {
+                                                                segments: [
+                                                                    PathSegment {
+                                                                        ident: "i32",
+                                                                    },
+                                                                ],
+                                                            },
+                                                        },
+                                                    ),
+                                                },
+                                            },
+                                        ],
+                                    },
+                                }),
+                                TypeParamBound::Trait(TraitBound {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "Send",
+                                            },
+                                        ],
+                                    },
+                                }),
+                            ],
+                        }),
+                    ],
+                }),
+            },
+            output: ReturnType::Default,
+        },
+        block: Block,
+    }
+    "###);
+
+    let where_clause = input.sig.generics.where_clause.as_ref().unwrap();
+    assert_eq!(where_clause.predicates.len(), 1);
+
+    let predicate = match &where_clause.predicates[0] {
+        WherePredicate::Type(pred) => pred,
+        _ => panic!("wrong predicate kind"),
+    };
+
+    assert_eq!(predicate.bounds.len(), 2, "{:#?}", predicate.bounds);
+
+    let first_bound = &predicate.bounds[0];
+    assert_eq!(quote!(#first_bound).to_string(), "FnOnce () -> i32");
+
+    let second_bound = &predicate.bounds[1];
+    assert_eq!(quote!(#second_bound).to_string(), "Send");
+}
+
+#[test]
+fn test_where_clause_at_end_of_input() {
+    let input = quote! {
+        where
+    };
+
+    snapshot!(input as WhereClause, @"WhereClause");
+
+    assert_eq!(input.predicates.len(), 0);
+}
diff --git a/vendor/syn/tests/test_grouping.rs b/vendor/syn/tests/test_grouping.rs
new file mode 100644
index 0000000..6a73a92
--- /dev/null
+++ b/vendor/syn/tests/test_grouping.rs
@@ -0,0 +1,53 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Literal, Punct, Spacing, TokenStream, TokenTree};
+use syn::Expr;
+
+#[test]
+fn test_grouping() {
+    let tokens: TokenStream = TokenStream::from_iter(vec![
+        TokenTree::Literal(Literal::i32_suffixed(1)),
+        TokenTree::Punct(Punct::new('+', Spacing::Alone)),
+        TokenTree::Group(Group::new(
+            Delimiter::None,
+            TokenStream::from_iter(vec![
+                TokenTree::Literal(Literal::i32_suffixed(2)),
+                TokenTree::Punct(Punct::new('+', Spacing::Alone)),
+                TokenTree::Literal(Literal::i32_suffixed(3)),
+            ]),
+        )),
+        TokenTree::Punct(Punct::new('*', Spacing::Alone)),
+        TokenTree::Literal(Literal::i32_suffixed(4)),
+    ]);
+
+    assert_eq!(tokens.to_string(), "1i32 + 2i32 + 3i32 * 4i32");
+
+    snapshot!(tokens as Expr, @r###"
+    Expr::Binary {
+        left: Expr::Lit {
+            lit: 1i32,
+        },
+        op: BinOp::Add,
+        right: Expr::Binary {
+            left: Expr::Group {
+                expr: Expr::Binary {
+                    left: Expr::Lit {
+                        lit: 2i32,
+                    },
+                    op: BinOp::Add,
+                    right: Expr::Lit {
+                        lit: 3i32,
+                    },
+                },
+            },
+            op: BinOp::Mul,
+            right: Expr::Lit {
+                lit: 4i32,
+            },
+        },
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_ident.rs b/vendor/syn/tests/test_ident.rs
new file mode 100644
index 0000000..ee01bfc
--- /dev/null
+++ b/vendor/syn/tests/test_ident.rs
@@ -0,0 +1,85 @@
+use proc_macro2::{Ident, Span, TokenStream};
+use std::str::FromStr;
+use syn::Result;
+
+fn parse(s: &str) -> Result<Ident> {
+    syn::parse2(TokenStream::from_str(s).unwrap())
+}
+
+fn new(s: &str) -> Ident {
+    Ident::new(s, Span::call_site())
+}
+
+#[test]
+fn ident_parse() {
+    parse("String").unwrap();
+}
+
+#[test]
+fn ident_parse_keyword() {
+    parse("abstract").unwrap_err();
+}
+
+#[test]
+fn ident_parse_empty() {
+    parse("").unwrap_err();
+}
+
+#[test]
+fn ident_parse_lifetime() {
+    parse("'static").unwrap_err();
+}
+
+#[test]
+fn ident_parse_underscore() {
+    parse("_").unwrap_err();
+}
+
+#[test]
+fn ident_parse_number() {
+    parse("255").unwrap_err();
+}
+
+#[test]
+fn ident_parse_invalid() {
+    parse("a#").unwrap_err();
+}
+
+#[test]
+fn ident_new() {
+    new("String");
+}
+
+#[test]
+fn ident_new_keyword() {
+    new("abstract");
+}
+
+#[test]
+#[should_panic(expected = "use Option<Ident>")]
+fn ident_new_empty() {
+    new("");
+}
+
+#[test]
+#[should_panic(expected = "not a valid Ident")]
+fn ident_new_lifetime() {
+    new("'static");
+}
+
+#[test]
+fn ident_new_underscore() {
+    new("_");
+}
+
+#[test]
+#[should_panic(expected = "use Literal instead")]
+fn ident_new_number() {
+    new("255");
+}
+
+#[test]
+#[should_panic(expected = "\"a#\" is not a valid Ident")]
+fn ident_new_invalid() {
+    new("a#");
+}
diff --git a/vendor/syn/tests/test_item.rs b/vendor/syn/tests/test_item.rs
new file mode 100644
index 0000000..9b0e1c9
--- /dev/null
+++ b/vendor/syn/tests/test_item.rs
@@ -0,0 +1,326 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::{Item, ItemTrait};
+
+#[test]
+fn test_macro_variable_attr() {
+    // mimics the token stream corresponding to `$attr fn f() {}`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { #[test] })),
+        TokenTree::Ident(Ident::new("fn", Span::call_site())),
+        TokenTree::Ident(Ident::new("f", Span::call_site())),
+        TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+        TokenTree::Group(Group::new(Delimiter::Brace, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Item, @r###"
+    Item::Fn {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Outer,
+                meta: Meta::Path {
+                    segments: [
+                        PathSegment {
+                            ident: "test",
+                        },
+                    ],
+                },
+            },
+        ],
+        vis: Visibility::Inherited,
+        sig: Signature {
+            ident: "f",
+            generics: Generics,
+            output: ReturnType::Default,
+        },
+        block: Block,
+    }
+    "###);
+}
+
+#[test]
+fn test_negative_impl() {
+    // Rustc parses all of the following.
+
+    #[cfg(any())]
+    impl ! {}
+    let tokens = quote! {
+        impl ! {}
+    };
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics,
+        self_ty: Type::Never,
+    }
+    "###);
+
+    #[cfg(any())]
+    #[rustfmt::skip]
+    impl !Trait {}
+    let tokens = quote! {
+        impl !Trait {}
+    };
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics,
+        self_ty: Type::Verbatim(`! Trait`),
+    }
+    "###);
+
+    #[cfg(any())]
+    impl !Trait for T {}
+    let tokens = quote! {
+        impl !Trait for T {}
+    };
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics,
+        trait_: Some((
+            Some,
+            Path {
+                segments: [
+                    PathSegment {
+                        ident: "Trait",
+                    },
+                ],
+            },
+        )),
+        self_ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "T",
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+
+    #[cfg(any())]
+    #[rustfmt::skip]
+    impl !! {}
+    let tokens = quote! {
+        impl !! {}
+    };
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics,
+        self_ty: Type::Verbatim(`! !`),
+    }
+    "###);
+}
+
+#[test]
+fn test_macro_variable_impl() {
+    // mimics the token stream corresponding to `impl $trait for $ty {}`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Ident(Ident::new("impl", Span::call_site())),
+        TokenTree::Group(Group::new(Delimiter::None, quote!(Trait))),
+        TokenTree::Ident(Ident::new("for", Span::call_site())),
+        TokenTree::Group(Group::new(Delimiter::None, quote!(Type))),
+        TokenTree::Group(Group::new(Delimiter::Brace, TokenStream::new())),
+    ]);
+
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics,
+        trait_: Some((
+            None,
+            Path {
+                segments: [
+                    PathSegment {
+                        ident: "Trait",
+                    },
+                ],
+            },
+        )),
+        self_ty: Type::Group {
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Type",
+                        },
+                    ],
+                },
+            },
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_supertraits() {
+    // Rustc parses all of the following.
+
+    #[rustfmt::skip]
+    let tokens = quote!(trait Trait where {});
+    snapshot!(tokens as ItemTrait, @r###"
+    ItemTrait {
+        vis: Visibility::Inherited,
+        ident: "Trait",
+        generics: Generics {
+            where_clause: Some(WhereClause),
+        },
+    }
+    "###);
+
+    #[rustfmt::skip]
+    let tokens = quote!(trait Trait: where {});
+    snapshot!(tokens as ItemTrait, @r###"
+    ItemTrait {
+        vis: Visibility::Inherited,
+        ident: "Trait",
+        generics: Generics {
+            where_clause: Some(WhereClause),
+        },
+        colon_token: Some,
+    }
+    "###);
+
+    #[rustfmt::skip]
+    let tokens = quote!(trait Trait: Sized where {});
+    snapshot!(tokens as ItemTrait, @r###"
+    ItemTrait {
+        vis: Visibility::Inherited,
+        ident: "Trait",
+        generics: Generics {
+            where_clause: Some(WhereClause),
+        },
+        colon_token: Some,
+        supertraits: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Sized",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+
+    #[rustfmt::skip]
+    let tokens = quote!(trait Trait: Sized + where {});
+    snapshot!(tokens as ItemTrait, @r###"
+    ItemTrait {
+        vis: Visibility::Inherited,
+        ident: "Trait",
+        generics: Generics {
+            where_clause: Some(WhereClause),
+        },
+        colon_token: Some,
+        supertraits: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Sized",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_type_empty_bounds() {
+    #[rustfmt::skip]
+    let tokens = quote! {
+        trait Foo {
+            type Bar: ;
+        }
+    };
+
+    snapshot!(tokens as ItemTrait, @r###"
+    ItemTrait {
+        vis: Visibility::Inherited,
+        ident: "Foo",
+        generics: Generics,
+        items: [
+            TraitItem::Type {
+                ident: "Bar",
+                generics: Generics,
+                colon_token: Some,
+            },
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_impl_visibility() {
+    let tokens = quote! {
+        pub default unsafe impl union {}
+    };
+
+    snapshot!(tokens as Item, @"Item::Verbatim(`pub default unsafe impl union { }`)");
+}
+
+#[test]
+fn test_impl_type_parameter_defaults() {
+    #[cfg(any())]
+    impl<T = ()> () {}
+    let tokens = quote! {
+        impl<T = ()> () {}
+    };
+    snapshot!(tokens as Item, @r###"
+    Item::Impl {
+        generics: Generics {
+            lt_token: Some,
+            params: [
+                GenericParam::Type(TypeParam {
+                    ident: "T",
+                    eq_token: Some,
+                    default: Some(Type::Tuple),
+                }),
+            ],
+            gt_token: Some,
+        },
+        self_ty: Type::Tuple,
+    }
+    "###);
+}
+
+#[test]
+fn test_impl_trait_trailing_plus() {
+    let tokens = quote! {
+        fn f() -> impl Sized + {}
+    };
+
+    snapshot!(tokens as Item, @r###"
+    Item::Fn {
+        vis: Visibility::Inherited,
+        sig: Signature {
+            ident: "f",
+            generics: Generics,
+            output: ReturnType::Type(
+                Type::ImplTrait {
+                    bounds: [
+                        TypeParamBound::Trait(TraitBound {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "Sized",
+                                    },
+                                ],
+                            },
+                        }),
+                    ],
+                },
+            ),
+        },
+        block: Block,
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_iterators.rs b/vendor/syn/tests/test_iterators.rs
new file mode 100644
index 0000000..5f0eff5
--- /dev/null
+++ b/vendor/syn/tests/test_iterators.rs
@@ -0,0 +1,70 @@
+#![allow(clippy::uninlined_format_args)]
+
+use syn::punctuated::{Pair, Punctuated};
+use syn::Token;
+
+#[macro_use]
+mod macros;
+
+macro_rules! check_exact_size_iterator {
+    ($iter:expr) => {{
+        let iter = $iter;
+        let size_hint = iter.size_hint();
+        let len = iter.len();
+        let count = iter.count();
+        assert_eq!(len, count);
+        assert_eq!(size_hint, (count, Some(count)));
+    }};
+}
+
+#[test]
+fn pairs() {
+    let mut p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+
+    check_exact_size_iterator!(p.pairs());
+    check_exact_size_iterator!(p.pairs_mut());
+    check_exact_size_iterator!(p.into_pairs());
+
+    let mut p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+
+    assert_eq!(p.pairs().next_back().map(Pair::into_value), Some(&4));
+    assert_eq!(
+        p.pairs_mut().next_back().map(Pair::into_value),
+        Some(&mut 4)
+    );
+    assert_eq!(p.into_pairs().next_back().map(Pair::into_value), Some(4));
+}
+
+#[test]
+fn iter() {
+    let mut p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+
+    check_exact_size_iterator!(p.iter());
+    check_exact_size_iterator!(p.iter_mut());
+    check_exact_size_iterator!(p.into_iter());
+
+    let mut p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+
+    assert_eq!(p.iter().next_back(), Some(&4));
+    assert_eq!(p.iter_mut().next_back(), Some(&mut 4));
+    assert_eq!(p.into_iter().next_back(), Some(4));
+}
+
+#[test]
+fn may_dangle() {
+    let p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+    for element in &p {
+        if *element == 2 {
+            drop(p);
+            break;
+        }
+    }
+
+    let mut p: Punctuated<_, Token![,]> = punctuated!(2, 3, 4);
+    for element in &mut p {
+        if *element == 2 {
+            drop(p);
+            break;
+        }
+    }
+}
diff --git a/vendor/syn/tests/test_lit.rs b/vendor/syn/tests/test_lit.rs
new file mode 100644
index 0000000..bc50136
--- /dev/null
+++ b/vendor/syn/tests/test_lit.rs
@@ -0,0 +1,273 @@
+#![allow(
+    clippy::float_cmp,
+    clippy::non_ascii_literal,
+    clippy::single_match_else,
+    clippy::uninlined_format_args
+)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Literal, Span, TokenStream, TokenTree};
+use quote::ToTokens;
+use std::str::FromStr;
+use syn::{Lit, LitFloat, LitInt, LitStr};
+
+fn lit(s: &str) -> Lit {
+    let mut tokens = TokenStream::from_str(s).unwrap().into_iter();
+    match tokens.next().unwrap() {
+        TokenTree::Literal(lit) => {
+            assert!(tokens.next().is_none());
+            Lit::new(lit)
+        }
+        wrong => panic!("{:?}", wrong),
+    }
+}
+
+#[test]
+fn strings() {
+    fn test_string(s: &str, value: &str) {
+        match lit(s) {
+            Lit::Str(lit) => {
+                assert_eq!(lit.value(), value);
+                let again = lit.into_token_stream().to_string();
+                if again != s {
+                    test_string(&again, value);
+                }
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_string("\"a\"", "a");
+    test_string("\"\\n\"", "\n");
+    test_string("\"\\r\"", "\r");
+    test_string("\"\\t\"", "\t");
+    test_string("\"🐕\"", "🐕"); // NOTE: This is an emoji
+    test_string("\"\\\"\"", "\"");
+    test_string("\"'\"", "'");
+    test_string("\"\"", "");
+    test_string("\"\\u{1F415}\"", "\u{1F415}");
+    test_string("\"\\u{1_2__3_}\"", "\u{123}");
+    test_string(
+        "\"contains\nnewlines\\\nescaped newlines\"",
+        "contains\nnewlinesescaped newlines",
+    );
+    test_string(
+        "\"escaped newline\\\n \x0C unsupported whitespace\"",
+        "escaped newline\x0C unsupported whitespace",
+    );
+    test_string("r\"raw\nstring\\\nhere\"", "raw\nstring\\\nhere");
+    test_string("\"...\"q", "...");
+    test_string("r\"...\"q", "...");
+    test_string("r##\"...\"##q", "...");
+}
+
+#[test]
+fn byte_strings() {
+    fn test_byte_string(s: &str, value: &[u8]) {
+        match lit(s) {
+            Lit::ByteStr(lit) => {
+                assert_eq!(lit.value(), value);
+                let again = lit.into_token_stream().to_string();
+                if again != s {
+                    test_byte_string(&again, value);
+                }
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_byte_string("b\"a\"", b"a");
+    test_byte_string("b\"\\n\"", b"\n");
+    test_byte_string("b\"\\r\"", b"\r");
+    test_byte_string("b\"\\t\"", b"\t");
+    test_byte_string("b\"\\\"\"", b"\"");
+    test_byte_string("b\"'\"", b"'");
+    test_byte_string("b\"\"", b"");
+    test_byte_string(
+        "b\"contains\nnewlines\\\nescaped newlines\"",
+        b"contains\nnewlinesescaped newlines",
+    );
+    test_byte_string("br\"raw\nstring\\\nhere\"", b"raw\nstring\\\nhere");
+    test_byte_string("b\"...\"q", b"...");
+    test_byte_string("br\"...\"q", b"...");
+    test_byte_string("br##\"...\"##q", b"...");
+}
+
+#[test]
+fn bytes() {
+    fn test_byte(s: &str, value: u8) {
+        match lit(s) {
+            Lit::Byte(lit) => {
+                assert_eq!(lit.value(), value);
+                let again = lit.into_token_stream().to_string();
+                assert_eq!(again, s);
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_byte("b'a'", b'a');
+    test_byte("b'\\n'", b'\n');
+    test_byte("b'\\r'", b'\r');
+    test_byte("b'\\t'", b'\t');
+    test_byte("b'\\''", b'\'');
+    test_byte("b'\"'", b'"');
+    test_byte("b'a'q", b'a');
+}
+
+#[test]
+fn chars() {
+    fn test_char(s: &str, value: char) {
+        match lit(s) {
+            Lit::Char(lit) => {
+                assert_eq!(lit.value(), value);
+                let again = lit.into_token_stream().to_string();
+                if again != s {
+                    test_char(&again, value);
+                }
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_char("'a'", 'a');
+    test_char("'\\n'", '\n');
+    test_char("'\\r'", '\r');
+    test_char("'\\t'", '\t');
+    test_char("'🐕'", '🐕'); // NOTE: This is an emoji
+    test_char("'\\''", '\'');
+    test_char("'\"'", '"');
+    test_char("'\\u{1F415}'", '\u{1F415}');
+    test_char("'a'q", 'a');
+}
+
+#[test]
+fn ints() {
+    fn test_int(s: &str, value: u64, suffix: &str) {
+        match lit(s) {
+            Lit::Int(lit) => {
+                assert_eq!(lit.base10_digits().parse::<u64>().unwrap(), value);
+                assert_eq!(lit.suffix(), suffix);
+                let again = lit.into_token_stream().to_string();
+                if again != s {
+                    test_int(&again, value, suffix);
+                }
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_int("5", 5, "");
+    test_int("5u32", 5, "u32");
+    test_int("0E", 0, "E");
+    test_int("0ECMA", 0, "ECMA");
+    test_int("0o0A", 0, "A");
+    test_int("5_0", 50, "");
+    test_int("5_____0_____", 50, "");
+    test_int("0x7f", 127, "");
+    test_int("0x7F", 127, "");
+    test_int("0b1001", 9, "");
+    test_int("0o73", 59, "");
+    test_int("0x7Fu8", 127, "u8");
+    test_int("0b1001i8", 9, "i8");
+    test_int("0o73u32", 59, "u32");
+    test_int("0x__7___f_", 127, "");
+    test_int("0x__7___F_", 127, "");
+    test_int("0b_1_0__01", 9, "");
+    test_int("0o_7__3", 59, "");
+    test_int("0x_7F__u8", 127, "u8");
+    test_int("0b__10__0_1i8", 9, "i8");
+    test_int("0o__7__________________3u32", 59, "u32");
+    test_int("0e1\u{5c5}", 0, "e1\u{5c5}");
+}
+
+#[test]
+fn floats() {
+    fn test_float(s: &str, value: f64, suffix: &str) {
+        match lit(s) {
+            Lit::Float(lit) => {
+                assert_eq!(lit.base10_digits().parse::<f64>().unwrap(), value);
+                assert_eq!(lit.suffix(), suffix);
+                let again = lit.into_token_stream().to_string();
+                if again != s {
+                    test_float(&again, value, suffix);
+                }
+            }
+            wrong => panic!("{:?}", wrong),
+        }
+    }
+
+    test_float("5.5", 5.5, "");
+    test_float("5.5E12", 5.5e12, "");
+    test_float("5.5e12", 5.5e12, "");
+    test_float("1.0__3e-12", 1.03e-12, "");
+    test_float("1.03e+12", 1.03e12, "");
+    test_float("9e99e99", 9e99, "e99");
+    test_float("1e_0", 1.0, "");
+    test_float("0.0ECMA", 0.0, "ECMA");
+}
+
+#[test]
+fn negative() {
+    let span = Span::call_site();
+    assert_eq!("-1", LitInt::new("-1", span).to_string());
+    assert_eq!("-1i8", LitInt::new("-1i8", span).to_string());
+    assert_eq!("-1i16", LitInt::new("-1i16", span).to_string());
+    assert_eq!("-1i32", LitInt::new("-1i32", span).to_string());
+    assert_eq!("-1i64", LitInt::new("-1i64", span).to_string());
+    assert_eq!("-1.5", LitFloat::new("-1.5", span).to_string());
+    assert_eq!("-1.5f32", LitFloat::new("-1.5f32", span).to_string());
+    assert_eq!("-1.5f64", LitFloat::new("-1.5f64", span).to_string());
+}
+
+#[test]
+fn suffix() {
+    fn get_suffix(token: &str) -> String {
+        let lit = syn::parse_str::<Lit>(token).unwrap();
+        match lit {
+            Lit::Str(lit) => lit.suffix().to_owned(),
+            Lit::ByteStr(lit) => lit.suffix().to_owned(),
+            Lit::Byte(lit) => lit.suffix().to_owned(),
+            Lit::Char(lit) => lit.suffix().to_owned(),
+            Lit::Int(lit) => lit.suffix().to_owned(),
+            Lit::Float(lit) => lit.suffix().to_owned(),
+            _ => unimplemented!(),
+        }
+    }
+
+    assert_eq!(get_suffix("\"\"s"), "s");
+    assert_eq!(get_suffix("r\"\"r"), "r");
+    assert_eq!(get_suffix("b\"\"b"), "b");
+    assert_eq!(get_suffix("br\"\"br"), "br");
+    assert_eq!(get_suffix("r#\"\"#r"), "r");
+    assert_eq!(get_suffix("'c'c"), "c");
+    assert_eq!(get_suffix("b'b'b"), "b");
+    assert_eq!(get_suffix("1i32"), "i32");
+    assert_eq!(get_suffix("1_i32"), "i32");
+    assert_eq!(get_suffix("1.0f32"), "f32");
+    assert_eq!(get_suffix("1.0_f32"), "f32");
+}
+
+#[test]
+fn test_deep_group_empty() {
+    let tokens = TokenStream::from_iter(vec![TokenTree::Group(Group::new(
+        Delimiter::None,
+        TokenStream::from_iter(vec![TokenTree::Group(Group::new(
+            Delimiter::None,
+            TokenStream::from_iter(vec![TokenTree::Literal(Literal::string("hi"))]),
+        ))]),
+    ))]);
+
+    snapshot!(tokens as Lit, @r#""hi""# );
+}
+
+#[test]
+fn test_error() {
+    let err = syn::parse_str::<LitStr>("...").unwrap_err();
+    assert_eq!("expected string literal", err.to_string());
+
+    let err = syn::parse_str::<LitStr>("5").unwrap_err();
+    assert_eq!("expected string literal", err.to_string());
+}
diff --git a/vendor/syn/tests/test_meta.rs b/vendor/syn/tests/test_meta.rs
new file mode 100644
index 0000000..91a9807
--- /dev/null
+++ b/vendor/syn/tests/test_meta.rs
@@ -0,0 +1,153 @@
+#![allow(
+    clippy::shadow_unrelated,
+    clippy::too_many_lines,
+    clippy::uninlined_format_args
+)]
+
+#[macro_use]
+mod macros;
+
+use syn::{Meta, MetaList, MetaNameValue};
+
+#[test]
+fn test_parse_meta_item_word() {
+    let input = "hello";
+
+    snapshot!(input as Meta, @r###"
+    Meta::Path {
+        segments: [
+            PathSegment {
+                ident: "hello",
+            },
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_parse_meta_name_value() {
+    let input = "foo = 5";
+    let (inner, meta) = (input, input);
+
+    snapshot!(inner as MetaNameValue, @r###"
+    MetaNameValue {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        value: Expr::Lit {
+            lit: 5,
+        },
+    }
+    "###);
+
+    snapshot!(meta as Meta, @r###"
+    Meta::NameValue {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        value: Expr::Lit {
+            lit: 5,
+        },
+    }
+    "###);
+
+    assert_eq!(meta, inner.into());
+}
+
+#[test]
+fn test_parse_meta_item_list_lit() {
+    let input = "foo(5)";
+    let (inner, meta) = (input, input);
+
+    snapshot!(inner as MetaList, @r###"
+    MetaList {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`5`),
+    }
+    "###);
+
+    snapshot!(meta as Meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`5`),
+    }
+    "###);
+
+    assert_eq!(meta, inner.into());
+}
+
+#[test]
+fn test_parse_meta_item_multiple() {
+    let input = "foo(word, name = 5, list(name2 = 6), word2)";
+    let (inner, meta) = (input, input);
+
+    snapshot!(inner as MetaList, @r###"
+    MetaList {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`word , name = 5 , list (name2 = 6) , word2`),
+    }
+    "###);
+
+    snapshot!(meta as Meta, @r###"
+    Meta::List {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "foo",
+                },
+            ],
+        },
+        delimiter: MacroDelimiter::Paren,
+        tokens: TokenStream(`word , name = 5 , list (name2 = 6) , word2`),
+    }
+    "###);
+
+    assert_eq!(meta, inner.into());
+}
+
+#[test]
+fn test_parse_path() {
+    let input = "::serde::Serialize";
+    snapshot!(input as Meta, @r###"
+    Meta::Path {
+        leading_colon: Some,
+        segments: [
+            PathSegment {
+                ident: "serde",
+            },
+            PathSegment {
+                ident: "Serialize",
+            },
+        ],
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_parse_buffer.rs b/vendor/syn/tests/test_parse_buffer.rs
new file mode 100644
index 0000000..f2ca59c
--- /dev/null
+++ b/vendor/syn/tests/test_parse_buffer.rs
@@ -0,0 +1,91 @@
+#![allow(clippy::non_ascii_literal)]
+
+use proc_macro2::{Delimiter, Group, Punct, Spacing, TokenStream, TokenTree};
+use syn::parse::{discouraged::Speculative, Parse, ParseStream, Parser, Result};
+use syn::{parenthesized, Token};
+
+#[test]
+#[should_panic(expected = "Fork was not derived from the advancing parse stream")]
+fn smuggled_speculative_cursor_between_sources() {
+    struct BreakRules;
+    impl Parse for BreakRules {
+        fn parse(input1: ParseStream) -> Result<Self> {
+            let nested = |input2: ParseStream| {
+                input1.advance_to(input2);
+                Ok(Self)
+            };
+            nested.parse_str("")
+        }
+    }
+
+    syn::parse_str::<BreakRules>("").unwrap();
+}
+
+#[test]
+#[should_panic(expected = "Fork was not derived from the advancing parse stream")]
+fn smuggled_speculative_cursor_between_brackets() {
+    struct BreakRules;
+    impl Parse for BreakRules {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let a;
+            let b;
+            parenthesized!(a in input);
+            parenthesized!(b in input);
+            a.advance_to(&b);
+            Ok(Self)
+        }
+    }
+
+    syn::parse_str::<BreakRules>("()()").unwrap();
+}
+
+#[test]
+#[should_panic(expected = "Fork was not derived from the advancing parse stream")]
+fn smuggled_speculative_cursor_into_brackets() {
+    struct BreakRules;
+    impl Parse for BreakRules {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let a;
+            parenthesized!(a in input);
+            input.advance_to(&a);
+            Ok(Self)
+        }
+    }
+
+    syn::parse_str::<BreakRules>("()").unwrap();
+}
+
+#[test]
+fn trailing_empty_none_group() {
+    fn parse(input: ParseStream) -> Result<()> {
+        input.parse::<Token![+]>()?;
+
+        let content;
+        parenthesized!(content in input);
+        content.parse::<Token![+]>()?;
+
+        Ok(())
+    }
+
+    // `+ ( + <Ø Ø> ) <Ø <Ø Ø> Ø>`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Punct(Punct::new('+', Spacing::Alone)),
+        TokenTree::Group(Group::new(
+            Delimiter::Parenthesis,
+            TokenStream::from_iter(vec![
+                TokenTree::Punct(Punct::new('+', Spacing::Alone)),
+                TokenTree::Group(Group::new(Delimiter::None, TokenStream::new())),
+            ]),
+        )),
+        TokenTree::Group(Group::new(Delimiter::None, TokenStream::new())),
+        TokenTree::Group(Group::new(
+            Delimiter::None,
+            TokenStream::from_iter(vec![TokenTree::Group(Group::new(
+                Delimiter::None,
+                TokenStream::new(),
+            ))]),
+        )),
+    ]);
+
+    parse.parse2(tokens).unwrap();
+}
diff --git a/vendor/syn/tests/test_parse_stream.rs b/vendor/syn/tests/test_parse_stream.rs
new file mode 100644
index 0000000..2265dfe
--- /dev/null
+++ b/vendor/syn/tests/test_parse_stream.rs
@@ -0,0 +1,14 @@
+#![allow(clippy::let_underscore_untyped)]
+
+use syn::ext::IdentExt;
+use syn::parse::ParseStream;
+use syn::{Ident, Token};
+
+#[test]
+fn test_peek() {
+    let _ = |input: ParseStream| {
+        let _ = input.peek(Ident);
+        let _ = input.peek(Ident::peek_any);
+        let _ = input.peek(Token![::]);
+    };
+}
diff --git a/vendor/syn/tests/test_pat.rs b/vendor/syn/tests/test_pat.rs
new file mode 100644
index 0000000..cab7aa7
--- /dev/null
+++ b/vendor/syn/tests/test_pat.rs
@@ -0,0 +1,97 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
+use quote::quote;
+use syn::parse::Parser;
+use syn::{Item, Pat, Stmt};
+
+#[test]
+fn test_pat_ident() {
+    match Pat::parse_single.parse2(quote!(self)).unwrap() {
+        Pat::Ident(_) => (),
+        value => panic!("expected PatIdent, got {:?}", value),
+    }
+}
+
+#[test]
+fn test_pat_path() {
+    match Pat::parse_single.parse2(quote!(self::CONST)).unwrap() {
+        Pat::Path(_) => (),
+        value => panic!("expected PatPath, got {:?}", value),
+    }
+}
+
+#[test]
+fn test_leading_vert() {
+    // https://github.com/rust-lang/rust/blob/1.43.0/src/test/ui/or-patterns/remove-leading-vert.rs
+
+    syn::parse_str::<Item>("fn f() {}").unwrap();
+    syn::parse_str::<Item>("fn fun1(| A: E) {}").unwrap_err();
+    syn::parse_str::<Item>("fn fun2(|| A: E) {}").unwrap_err();
+
+    syn::parse_str::<Stmt>("let | () = ();").unwrap_err();
+    syn::parse_str::<Stmt>("let (| A): E;").unwrap();
+    syn::parse_str::<Stmt>("let (|| A): (E);").unwrap_err();
+    syn::parse_str::<Stmt>("let (| A,): (E,);").unwrap();
+    syn::parse_str::<Stmt>("let [| A]: [E; 1];").unwrap();
+    syn::parse_str::<Stmt>("let [|| A]: [E; 1];").unwrap_err();
+    syn::parse_str::<Stmt>("let TS(| A): TS;").unwrap();
+    syn::parse_str::<Stmt>("let TS(|| A): TS;").unwrap_err();
+    syn::parse_str::<Stmt>("let NS { f: | A }: NS;").unwrap();
+    syn::parse_str::<Stmt>("let NS { f: || A }: NS;").unwrap_err();
+}
+
+#[test]
+fn test_group() {
+    let group = Group::new(Delimiter::None, quote!(Some(_)));
+    let tokens = TokenStream::from_iter(vec![TokenTree::Group(group)]);
+    let pat = Pat::parse_single.parse2(tokens).unwrap();
+
+    snapshot!(pat, @r###"
+    Pat::TupleStruct {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "Some",
+                },
+            ],
+        },
+        elems: [
+            Pat::Wild,
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_ranges() {
+    Pat::parse_single.parse_str("..").unwrap();
+    Pat::parse_single.parse_str("..hi").unwrap();
+    Pat::parse_single.parse_str("lo..").unwrap();
+    Pat::parse_single.parse_str("lo..hi").unwrap();
+
+    Pat::parse_single.parse_str("..=").unwrap_err();
+    Pat::parse_single.parse_str("..=hi").unwrap();
+    Pat::parse_single.parse_str("lo..=").unwrap_err();
+    Pat::parse_single.parse_str("lo..=hi").unwrap();
+
+    Pat::parse_single.parse_str("...").unwrap_err();
+    Pat::parse_single.parse_str("...hi").unwrap_err();
+    Pat::parse_single.parse_str("lo...").unwrap_err();
+    Pat::parse_single.parse_str("lo...hi").unwrap();
+
+    Pat::parse_single.parse_str("[lo..]").unwrap_err();
+    Pat::parse_single.parse_str("[..=hi]").unwrap_err();
+    Pat::parse_single.parse_str("[(lo..)]").unwrap();
+    Pat::parse_single.parse_str("[(..=hi)]").unwrap();
+    Pat::parse_single.parse_str("[lo..=hi]").unwrap();
+
+    Pat::parse_single.parse_str("[_, lo.., _]").unwrap_err();
+    Pat::parse_single.parse_str("[_, ..=hi, _]").unwrap_err();
+    Pat::parse_single.parse_str("[_, (lo..), _]").unwrap();
+    Pat::parse_single.parse_str("[_, (..=hi), _]").unwrap();
+    Pat::parse_single.parse_str("[_, lo..=hi, _]").unwrap();
+}
diff --git a/vendor/syn/tests/test_path.rs b/vendor/syn/tests/test_path.rs
new file mode 100644
index 0000000..6aded74
--- /dev/null
+++ b/vendor/syn/tests/test_path.rs
@@ -0,0 +1,128 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
+use quote::{quote, ToTokens};
+use syn::{parse_quote, Expr, Type, TypePath};
+
+#[test]
+fn parse_interpolated_leading_component() {
+    // mimics the token stream corresponding to `$mod::rest`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { first })),
+        TokenTree::Punct(Punct::new(':', Spacing::Joint)),
+        TokenTree::Punct(Punct::new(':', Spacing::Alone)),
+        TokenTree::Ident(Ident::new("rest", Span::call_site())),
+    ]);
+
+    snapshot!(tokens.clone() as Expr, @r###"
+    Expr::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "first",
+                },
+                PathSegment {
+                    ident: "rest",
+                },
+            ],
+        },
+    }
+    "###);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "first",
+                },
+                PathSegment {
+                    ident: "rest",
+                },
+            ],
+        },
+    }
+    "###);
+}
+
+#[test]
+fn print_incomplete_qpath() {
+    // qpath with `as` token
+    let mut ty: TypePath = parse_quote!(<Self as A>::Q);
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self as A > :: Q`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self as A > ::`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self >`)
+    "###);
+    assert!(ty.path.segments.pop().is_none());
+
+    // qpath without `as` token
+    let mut ty: TypePath = parse_quote!(<Self>::A::B);
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self > :: A :: B`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self > :: A ::`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`< Self > ::`)
+    "###);
+    assert!(ty.path.segments.pop().is_none());
+
+    // normal path
+    let mut ty: TypePath = parse_quote!(Self::A::B);
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`Self :: A :: B`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`Self :: A ::`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(`Self ::`)
+    "###);
+    assert!(ty.path.segments.pop().is_some());
+    snapshot!(ty.to_token_stream(), @r###"
+    TokenStream(``)
+    "###);
+    assert!(ty.path.segments.pop().is_none());
+}
+
+#[test]
+fn parse_parenthesized_path_arguments_with_disambiguator() {
+    #[rustfmt::skip]
+    let tokens = quote!(dyn FnOnce::() -> !);
+    snapshot!(tokens as Type, @r###"
+    Type::TraitObject {
+        dyn_token: Some,
+        bounds: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "FnOnce",
+                            arguments: PathArguments::Parenthesized {
+                                output: ReturnType::Type(
+                                    Type::Never,
+                                ),
+                            },
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_precedence.rs b/vendor/syn/tests/test_precedence.rs
new file mode 100644
index 0000000..bf0510b
--- /dev/null
+++ b/vendor/syn/tests/test_precedence.rs
@@ -0,0 +1,497 @@
+#![cfg(not(syn_disable_nightly_tests))]
+#![cfg(not(miri))]
+#![recursion_limit = "1024"]
+#![feature(rustc_private)]
+#![allow(
+    clippy::explicit_deref_methods,
+    clippy::let_underscore_untyped,
+    clippy::manual_assert,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::match_wildcard_for_single_variants,
+    clippy::too_many_lines,
+    clippy::uninlined_format_args
+)]
+
+//! The tests in this module do the following:
+//!
+//! 1. Parse a given expression in both `syn` and `librustc`.
+//! 2. Fold over the expression adding brackets around each subexpression (with
+//!    some complications - see the `syn_brackets` and `librustc_brackets`
+//!    methods).
+//! 3. Serialize the `syn` expression back into a string, and re-parse it with
+//!    `librustc`.
+//! 4. Respan all of the expressions, replacing the spans with the default
+//!    spans.
+//! 5. Compare the expressions with one another, if they are not equal fail.
+
+extern crate rustc_ast;
+extern crate rustc_ast_pretty;
+extern crate rustc_data_structures;
+extern crate rustc_driver;
+extern crate rustc_span;
+extern crate smallvec;
+extern crate thin_vec;
+
+use crate::common::eq::SpanlessEq;
+use crate::common::parse;
+use quote::quote;
+use regex::Regex;
+use rustc_ast::ast;
+use rustc_ast::ptr::P;
+use rustc_ast_pretty::pprust;
+use rustc_span::edition::Edition;
+use std::fs;
+use std::path::Path;
+use std::process;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+#[macro_use]
+mod macros;
+
+#[allow(dead_code)]
+mod common;
+
+mod repo;
+
+#[test]
+fn test_rustc_precedence() {
+    common::rayon_init();
+    repo::clone_rust();
+    let abort_after = common::abort_after();
+    if abort_after == 0 {
+        panic!("Skipping all precedence tests");
+    }
+
+    let passed = AtomicUsize::new(0);
+    let failed = AtomicUsize::new(0);
+
+    // 2018 edition is hard
+    let edition_regex = Regex::new(r"\b(async|try)[!(]").unwrap();
+
+    repo::for_each_rust_file(|path| {
+        let content = fs::read_to_string(path).unwrap();
+        let content = edition_regex.replace_all(&content, "_$0");
+
+        let (l_passed, l_failed) = match syn::parse_file(&content) {
+            Ok(file) => {
+                let edition = repo::edition(path).parse().unwrap();
+                let exprs = collect_exprs(file);
+                let (l_passed, l_failed) = test_expressions(path, edition, exprs);
+                errorf!(
+                    "=== {}: {} passed | {} failed\n",
+                    path.display(),
+                    l_passed,
+                    l_failed,
+                );
+                (l_passed, l_failed)
+            }
+            Err(msg) => {
+                errorf!("\nFAIL {} - syn failed to parse: {}\n", path.display(), msg);
+                (0, 1)
+            }
+        };
+
+        passed.fetch_add(l_passed, Ordering::Relaxed);
+        let prev_failed = failed.fetch_add(l_failed, Ordering::Relaxed);
+
+        if prev_failed + l_failed >= abort_after {
+            process::exit(1);
+        }
+    });
+
+    let passed = passed.load(Ordering::Relaxed);
+    let failed = failed.load(Ordering::Relaxed);
+
+    errorf!("\n===== Precedence Test Results =====\n");
+    errorf!("{} passed | {} failed\n", passed, failed);
+
+    if failed > 0 {
+        panic!("{} failures", failed);
+    }
+}
+
+fn test_expressions(path: &Path, edition: Edition, exprs: Vec<syn::Expr>) -> (usize, usize) {
+    let mut passed = 0;
+    let mut failed = 0;
+
+    rustc_span::create_session_if_not_set_then(edition, |_| {
+        for expr in exprs {
+            let raw = quote!(#expr).to_string();
+
+            let librustc_ast = if let Some(e) = librustc_parse_and_rewrite(&raw) {
+                e
+            } else {
+                failed += 1;
+                errorf!("\nFAIL {} - librustc failed to parse raw\n", path.display());
+                continue;
+            };
+
+            let syn_expr = syn_brackets(expr);
+            let syn_ast = if let Some(e) = parse::librustc_expr(&quote!(#syn_expr).to_string()) {
+                e
+            } else {
+                failed += 1;
+                errorf!(
+                    "\nFAIL {} - librustc failed to parse bracketed\n",
+                    path.display(),
+                );
+                continue;
+            };
+
+            if SpanlessEq::eq(&syn_ast, &librustc_ast) {
+                passed += 1;
+            } else {
+                failed += 1;
+                let syn_program = pprust::expr_to_string(&syn_ast);
+                let librustc_program = pprust::expr_to_string(&librustc_ast);
+                errorf!(
+                    "\nFAIL {}\n{}\nsyn != rustc\n{}\n",
+                    path.display(),
+                    syn_program,
+                    librustc_program,
+                );
+            }
+        }
+    });
+
+    (passed, failed)
+}
+
+fn librustc_parse_and_rewrite(input: &str) -> Option<P<ast::Expr>> {
+    parse::librustc_expr(input).and_then(librustc_brackets)
+}
+
+/// Wrap every expression which is not already wrapped in parens with parens, to
+/// reveal the precedence of the parsed expressions, and produce a stringified
+/// form of the resulting expression.
+///
+/// This method operates on librustc objects.
+fn librustc_brackets(mut librustc_expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
+    use rustc_ast::ast::{
+        AssocItem, AssocItemKind, Attribute, BinOpKind, Block, BorrowKind, Expr, ExprField,
+        ExprKind, GenericArg, GenericBound, ItemKind, Local, LocalKind, Pat, Stmt, StmtKind,
+        StructExpr, StructRest, TraitBoundModifier, Ty,
+    };
+    use rustc_ast::mut_visit::{
+        noop_flat_map_assoc_item, noop_visit_generic_arg, noop_visit_item_kind, noop_visit_local,
+        noop_visit_param_bound, MutVisitor,
+    };
+    use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
+    use rustc_span::DUMMY_SP;
+    use smallvec::SmallVec;
+    use std::mem;
+    use std::ops::DerefMut;
+    use thin_vec::ThinVec;
+
+    struct BracketsVisitor {
+        failed: bool,
+    }
+
+    fn contains_let_chain(expr: &Expr) -> bool {
+        match &expr.kind {
+            ExprKind::Let(..) => true,
+            ExprKind::Binary(binop, left, right) => {
+                binop.node == BinOpKind::And
+                    && (contains_let_chain(left) || contains_let_chain(right))
+            }
+            _ => false,
+        }
+    }
+
+    fn flat_map_field<T: MutVisitor>(mut f: ExprField, vis: &mut T) -> Vec<ExprField> {
+        if f.is_shorthand {
+            noop_visit_expr(&mut f.expr, vis);
+        } else {
+            vis.visit_expr(&mut f.expr);
+        }
+        vec![f]
+    }
+
+    fn flat_map_stmt<T: MutVisitor>(stmt: Stmt, vis: &mut T) -> Vec<Stmt> {
+        let kind = match stmt.kind {
+            // Don't wrap toplevel expressions in statements.
+            StmtKind::Expr(mut e) => {
+                noop_visit_expr(&mut e, vis);
+                StmtKind::Expr(e)
+            }
+            StmtKind::Semi(mut e) => {
+                noop_visit_expr(&mut e, vis);
+                StmtKind::Semi(e)
+            }
+            s => s,
+        };
+
+        vec![Stmt { kind, ..stmt }]
+    }
+
+    fn noop_visit_expr<T: MutVisitor>(e: &mut Expr, vis: &mut T) {
+        use rustc_ast::mut_visit::{noop_visit_expr, visit_attrs};
+        match &mut e.kind {
+            ExprKind::AddrOf(BorrowKind::Raw, ..) => {}
+            ExprKind::Struct(expr) => {
+                let StructExpr {
+                    qself,
+                    path,
+                    fields,
+                    rest,
+                } = expr.deref_mut();
+                vis.visit_qself(qself);
+                vis.visit_path(path);
+                fields.flat_map_in_place(|field| flat_map_field(field, vis));
+                if let StructRest::Base(rest) = rest {
+                    vis.visit_expr(rest);
+                }
+                vis.visit_id(&mut e.id);
+                vis.visit_span(&mut e.span);
+                visit_attrs(&mut e.attrs, vis);
+            }
+            _ => noop_visit_expr(e, vis),
+        }
+    }
+
+    impl MutVisitor for BracketsVisitor {
+        fn visit_expr(&mut self, e: &mut P<Expr>) {
+            noop_visit_expr(e, self);
+            match e.kind {
+                ExprKind::Block(..) | ExprKind::If(..) | ExprKind::Let(..) => {}
+                ExprKind::Binary(..) if contains_let_chain(e) => {}
+                _ => {
+                    let inner = mem::replace(
+                        e,
+                        P(Expr {
+                            id: ast::DUMMY_NODE_ID,
+                            kind: ExprKind::Err,
+                            span: DUMMY_SP,
+                            attrs: ThinVec::new(),
+                            tokens: None,
+                        }),
+                    );
+                    e.kind = ExprKind::Paren(inner);
+                }
+            }
+        }
+
+        fn visit_generic_arg(&mut self, arg: &mut GenericArg) {
+            match arg {
+                // Don't wrap unbraced const generic arg as that's invalid syntax.
+                GenericArg::Const(anon_const) => {
+                    if let ExprKind::Block(..) = &mut anon_const.value.kind {
+                        noop_visit_expr(&mut anon_const.value, self);
+                    }
+                }
+                _ => noop_visit_generic_arg(arg, self),
+            }
+        }
+
+        fn visit_param_bound(&mut self, bound: &mut GenericBound) {
+            match bound {
+                GenericBound::Trait(
+                    _,
+                    TraitBoundModifier::MaybeConst | TraitBoundModifier::MaybeConstMaybe,
+                ) => {}
+                _ => noop_visit_param_bound(bound, self),
+            }
+        }
+
+        fn visit_block(&mut self, block: &mut P<Block>) {
+            self.visit_id(&mut block.id);
+            block
+                .stmts
+                .flat_map_in_place(|stmt| flat_map_stmt(stmt, self));
+            self.visit_span(&mut block.span);
+        }
+
+        fn visit_local(&mut self, local: &mut P<Local>) {
+            match local.kind {
+                LocalKind::InitElse(..) => {}
+                _ => noop_visit_local(local, self),
+            }
+        }
+
+        fn visit_item_kind(&mut self, item: &mut ItemKind) {
+            match item {
+                ItemKind::Const(const_item)
+                    if !const_item.generics.params.is_empty()
+                        || !const_item.generics.where_clause.predicates.is_empty() => {}
+                _ => noop_visit_item_kind(item, self),
+            }
+        }
+
+        fn flat_map_trait_item(&mut self, item: P<AssocItem>) -> SmallVec<[P<AssocItem>; 1]> {
+            match &item.kind {
+                AssocItemKind::Const(const_item)
+                    if !const_item.generics.params.is_empty()
+                        || !const_item.generics.where_clause.predicates.is_empty() =>
+                {
+                    SmallVec::from([item])
+                }
+                _ => noop_flat_map_assoc_item(item, self),
+            }
+        }
+
+        fn flat_map_impl_item(&mut self, item: P<AssocItem>) -> SmallVec<[P<AssocItem>; 1]> {
+            match &item.kind {
+                AssocItemKind::Const(const_item)
+                    if !const_item.generics.params.is_empty()
+                        || !const_item.generics.where_clause.predicates.is_empty() =>
+                {
+                    SmallVec::from([item])
+                }
+                _ => noop_flat_map_assoc_item(item, self),
+            }
+        }
+
+        // We don't want to look at expressions that might appear in patterns or
+        // types yet. We'll look into comparing those in the future. For now
+        // focus on expressions appearing in other places.
+        fn visit_pat(&mut self, pat: &mut P<Pat>) {
+            let _ = pat;
+        }
+
+        fn visit_ty(&mut self, ty: &mut P<Ty>) {
+            let _ = ty;
+        }
+
+        fn visit_attribute(&mut self, attr: &mut Attribute) {
+            let _ = attr;
+        }
+    }
+
+    let mut folder = BracketsVisitor { failed: false };
+    folder.visit_expr(&mut librustc_expr);
+    if folder.failed {
+        None
+    } else {
+        Some(librustc_expr)
+    }
+}
+
+/// Wrap every expression which is not already wrapped in parens with parens, to
+/// reveal the precedence of the parsed expressions, and produce a stringified
+/// form of the resulting expression.
+fn syn_brackets(syn_expr: syn::Expr) -> syn::Expr {
+    use syn::fold::{fold_expr, fold_generic_argument, Fold};
+    use syn::{token, BinOp, Expr, ExprParen, GenericArgument, MetaNameValue, Pat, Stmt, Type};
+
+    struct ParenthesizeEveryExpr;
+
+    fn parenthesize(expr: Expr) -> Expr {
+        Expr::Paren(ExprParen {
+            attrs: Vec::new(),
+            expr: Box::new(expr),
+            paren_token: token::Paren::default(),
+        })
+    }
+
+    fn needs_paren(expr: &Expr) -> bool {
+        match expr {
+            Expr::Group(_) => unreachable!(),
+            Expr::If(_) | Expr::Unsafe(_) | Expr::Block(_) | Expr::Let(_) => false,
+            Expr::Binary(_) => !contains_let_chain(expr),
+            _ => true,
+        }
+    }
+
+    fn contains_let_chain(expr: &Expr) -> bool {
+        match expr {
+            Expr::Let(_) => true,
+            Expr::Binary(expr) => {
+                matches!(expr.op, BinOp::And(_))
+                    && (contains_let_chain(&expr.left) || contains_let_chain(&expr.right))
+            }
+            _ => false,
+        }
+    }
+
+    impl Fold for ParenthesizeEveryExpr {
+        fn fold_expr(&mut self, expr: Expr) -> Expr {
+            let needs_paren = needs_paren(&expr);
+            let folded = fold_expr(self, expr);
+            if needs_paren {
+                parenthesize(folded)
+            } else {
+                folded
+            }
+        }
+
+        fn fold_generic_argument(&mut self, arg: GenericArgument) -> GenericArgument {
+            match arg {
+                GenericArgument::Const(arg) => GenericArgument::Const(match arg {
+                    Expr::Block(_) => fold_expr(self, arg),
+                    // Don't wrap unbraced const generic arg as that's invalid syntax.
+                    _ => arg,
+                }),
+                _ => fold_generic_argument(self, arg),
+            }
+        }
+
+        fn fold_stmt(&mut self, stmt: Stmt) -> Stmt {
+            match stmt {
+                // Don't wrap toplevel expressions in statements.
+                Stmt::Expr(Expr::Verbatim(_), Some(_)) => stmt,
+                Stmt::Expr(e, semi) => Stmt::Expr(fold_expr(self, e), semi),
+                s => s,
+            }
+        }
+
+        fn fold_meta_name_value(&mut self, meta: MetaNameValue) -> MetaNameValue {
+            // Don't turn #[p = "..."] into #[p = ("...")].
+            meta
+        }
+
+        // We don't want to look at expressions that might appear in patterns or
+        // types yet. We'll look into comparing those in the future. For now
+        // focus on expressions appearing in other places.
+        fn fold_pat(&mut self, pat: Pat) -> Pat {
+            pat
+        }
+
+        fn fold_type(&mut self, ty: Type) -> Type {
+            ty
+        }
+    }
+
+    let mut folder = ParenthesizeEveryExpr;
+    folder.fold_expr(syn_expr)
+}
+
+/// Walk through a crate collecting all expressions we can find in it.
+fn collect_exprs(file: syn::File) -> Vec<syn::Expr> {
+    use syn::fold::Fold;
+    use syn::punctuated::Punctuated;
+    use syn::{token, ConstParam, Expr, ExprTuple, Pat, Path};
+
+    struct CollectExprs(Vec<Expr>);
+    impl Fold for CollectExprs {
+        fn fold_expr(&mut self, expr: Expr) -> Expr {
+            match expr {
+                Expr::Verbatim(_) => {}
+                _ => self.0.push(expr),
+            }
+
+            Expr::Tuple(ExprTuple {
+                attrs: vec![],
+                elems: Punctuated::new(),
+                paren_token: token::Paren::default(),
+            })
+        }
+
+        fn fold_pat(&mut self, pat: Pat) -> Pat {
+            pat
+        }
+
+        fn fold_path(&mut self, path: Path) -> Path {
+            // Skip traversing into const generic path arguments
+            path
+        }
+
+        fn fold_const_param(&mut self, const_param: ConstParam) -> ConstParam {
+            const_param
+        }
+    }
+
+    let mut folder = CollectExprs(vec![]);
+    folder.fold_file(file);
+    folder.0
+}
diff --git a/vendor/syn/tests/test_receiver.rs b/vendor/syn/tests/test_receiver.rs
new file mode 100644
index 0000000..8decb55
--- /dev/null
+++ b/vendor/syn/tests/test_receiver.rs
@@ -0,0 +1,321 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use syn::{parse_quote, TraitItemFn};
+
+#[test]
+fn test_by_value() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn by_value(self: Self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        colon_token: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Self",
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_by_mut_value() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn by_mut(mut self: Self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        mutability: Some,
+        colon_token: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Self",
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_by_ref() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn by_ref(self: &Self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        colon_token: Some,
+        ty: Type::Reference {
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Self",
+                        },
+                    ],
+                },
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_by_box() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn by_box(self: Box<Self>);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        colon_token: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Box",
+                        arguments: PathArguments::AngleBracketed {
+                            args: [
+                                GenericArgument::Type(Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "Self",
+                                            },
+                                        ],
+                                    },
+                                }),
+                            ],
+                        },
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_by_pin() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn by_pin(self: Pin<Self>);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        colon_token: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Pin",
+                        arguments: PathArguments::AngleBracketed {
+                            args: [
+                                GenericArgument::Type(Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "Self",
+                                            },
+                                        ],
+                                    },
+                                }),
+                            ],
+                        },
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_explicit_type() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn explicit_type(self: Pin<MyType>);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        colon_token: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Pin",
+                        arguments: PathArguments::AngleBracketed {
+                            args: [
+                                GenericArgument::Type(Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "MyType",
+                                            },
+                                        ],
+                                    },
+                                }),
+                            ],
+                        },
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_value_shorthand() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn value_shorthand(self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Self",
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_mut_value_shorthand() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn mut_value_shorthand(mut self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        mutability: Some,
+        ty: Type::Path {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Self",
+                    },
+                ],
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_ref_shorthand() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn ref_shorthand(&self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        reference: Some(None),
+        ty: Type::Reference {
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Self",
+                        },
+                    ],
+                },
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_ref_shorthand_with_lifetime() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn ref_shorthand(&'a self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        reference: Some(Some(Lifetime {
+            ident: "a",
+        })),
+        ty: Type::Reference {
+            lifetime: Some(Lifetime {
+                ident: "a",
+            }),
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Self",
+                        },
+                    ],
+                },
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_ref_mut_shorthand() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn ref_mut_shorthand(&mut self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        reference: Some(None),
+        mutability: Some,
+        ty: Type::Reference {
+            mutability: Some,
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Self",
+                        },
+                    ],
+                },
+            },
+        },
+    })
+    "###);
+}
+
+#[test]
+fn test_ref_mut_shorthand_with_lifetime() {
+    let TraitItemFn { sig, .. } = parse_quote! {
+        fn ref_mut_shorthand(&'a mut self);
+    };
+    snapshot!(&sig.inputs[0], @r###"
+    FnArg::Receiver(Receiver {
+        reference: Some(Some(Lifetime {
+            ident: "a",
+        })),
+        mutability: Some,
+        ty: Type::Reference {
+            lifetime: Some(Lifetime {
+                ident: "a",
+            }),
+            mutability: Some,
+            elem: Type::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Self",
+                        },
+                    ],
+                },
+            },
+        },
+    })
+    "###);
+}
diff --git a/vendor/syn/tests/test_round_trip.rs b/vendor/syn/tests/test_round_trip.rs
new file mode 100644
index 0000000..c0af30d
--- /dev/null
+++ b/vendor/syn/tests/test_round_trip.rs
@@ -0,0 +1,238 @@
+#![cfg(not(syn_disable_nightly_tests))]
+#![cfg(not(miri))]
+#![recursion_limit = "1024"]
+#![feature(rustc_private)]
+#![allow(
+    clippy::manual_assert,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::uninlined_format_args
+)]
+
+extern crate rustc_ast;
+extern crate rustc_ast_pretty;
+extern crate rustc_data_structures;
+extern crate rustc_driver;
+extern crate rustc_error_messages;
+extern crate rustc_errors;
+extern crate rustc_expand;
+extern crate rustc_parse as parse;
+extern crate rustc_session;
+extern crate rustc_span;
+
+use crate::common::eq::SpanlessEq;
+use quote::quote;
+use rustc_ast::ast::{
+    AngleBracketedArg, AngleBracketedArgs, Crate, GenericArg, GenericParamKind, Generics,
+    WhereClause,
+};
+use rustc_ast::mut_visit::{self, MutVisitor};
+use rustc_ast_pretty::pprust;
+use rustc_error_messages::{DiagnosticMessage, LazyFallbackBundle};
+use rustc_errors::{translation, Diagnostic, PResult};
+use rustc_session::parse::ParseSess;
+use rustc_span::source_map::FilePathMapping;
+use rustc_span::FileName;
+use std::borrow::Cow;
+use std::fs;
+use std::panic;
+use std::path::Path;
+use std::process;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::time::Instant;
+
+#[macro_use]
+mod macros;
+
+#[allow(dead_code)]
+mod common;
+
+mod repo;
+
+#[test]
+fn test_round_trip() {
+    common::rayon_init();
+    repo::clone_rust();
+    let abort_after = common::abort_after();
+    if abort_after == 0 {
+        panic!("Skipping all round_trip tests");
+    }
+
+    let failed = AtomicUsize::new(0);
+
+    repo::for_each_rust_file(|path| test(path, &failed, abort_after));
+
+    let failed = failed.load(Ordering::Relaxed);
+    if failed > 0 {
+        panic!("{} failures", failed);
+    }
+}
+
+fn test(path: &Path, failed: &AtomicUsize, abort_after: usize) {
+    let content = fs::read_to_string(path).unwrap();
+
+    let start = Instant::now();
+    let (krate, elapsed) = match syn::parse_file(&content) {
+        Ok(krate) => (krate, start.elapsed()),
+        Err(msg) => {
+            errorf!("=== {}: syn failed to parse\n{:?}\n", path.display(), msg);
+            let prev_failed = failed.fetch_add(1, Ordering::Relaxed);
+            if prev_failed + 1 >= abort_after {
+                process::exit(1);
+            }
+            return;
+        }
+    };
+    let back = quote!(#krate).to_string();
+    let edition = repo::edition(path).parse().unwrap();
+
+    rustc_span::create_session_if_not_set_then(edition, |_| {
+        let equal = match panic::catch_unwind(|| {
+            let locale_resources = rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec();
+            let file_path_mapping = FilePathMapping::empty();
+            let sess = ParseSess::new(locale_resources, file_path_mapping);
+            let before = match librustc_parse(content, &sess) {
+                Ok(before) => before,
+                Err(diagnostic) => {
+                    errorf!(
+                        "=== {}: ignore - librustc failed to parse original content: {}\n",
+                        path.display(),
+                        translate_message(&diagnostic),
+                    );
+                    diagnostic.cancel();
+                    return Err(true);
+                }
+            };
+            let after = match librustc_parse(back, &sess) {
+                Ok(after) => after,
+                Err(mut diagnostic) => {
+                    errorf!("=== {}: librustc failed to parse", path.display());
+                    diagnostic.emit();
+                    return Err(false);
+                }
+            };
+            Ok((before, after))
+        }) {
+            Err(_) => {
+                errorf!("=== {}: ignoring librustc panic\n", path.display());
+                true
+            }
+            Ok(Err(equal)) => equal,
+            Ok(Ok((mut before, mut after))) => {
+                normalize(&mut before);
+                normalize(&mut after);
+                if SpanlessEq::eq(&before, &after) {
+                    errorf!(
+                        "=== {}: pass in {}ms\n",
+                        path.display(),
+                        elapsed.as_secs() * 1000 + u64::from(elapsed.subsec_nanos()) / 1_000_000
+                    );
+                    true
+                } else {
+                    errorf!(
+                        "=== {}: FAIL\n{}\n!=\n{}\n",
+                        path.display(),
+                        pprust::crate_to_string_for_macros(&before),
+                        pprust::crate_to_string_for_macros(&after),
+                    );
+                    false
+                }
+            }
+        };
+        if !equal {
+            let prev_failed = failed.fetch_add(1, Ordering::Relaxed);
+            if prev_failed + 1 >= abort_after {
+                process::exit(1);
+            }
+        }
+    });
+}
+
+fn librustc_parse(content: String, sess: &ParseSess) -> PResult<Crate> {
+    static COUNTER: AtomicUsize = AtomicUsize::new(0);
+    let counter = COUNTER.fetch_add(1, Ordering::Relaxed);
+    let name = FileName::Custom(format!("test_round_trip{}", counter));
+    parse::parse_crate_from_source_str(name, content, sess)
+}
+
+fn translate_message(diagnostic: &Diagnostic) -> Cow<'static, str> {
+    thread_local! {
+        static FLUENT_BUNDLE: LazyFallbackBundle = {
+            let locale_resources = rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec();
+            let with_directionality_markers = false;
+            rustc_error_messages::fallback_fluent_bundle(locale_resources, with_directionality_markers)
+        };
+    }
+
+    let message = &diagnostic.message[0].0;
+    let args = translation::to_fluent_args(diagnostic.args());
+
+    let (identifier, attr) = match message {
+        DiagnosticMessage::Str(msg) | DiagnosticMessage::Eager(msg) => return msg.clone(),
+        DiagnosticMessage::FluentIdentifier(identifier, attr) => (identifier, attr),
+    };
+
+    FLUENT_BUNDLE.with(|fluent_bundle| {
+        let message = fluent_bundle
+            .get_message(identifier)
+            .expect("missing diagnostic in fluent bundle");
+        let value = match attr {
+            Some(attr) => message
+                .get_attribute(attr)
+                .expect("missing attribute in fluent message")
+                .value(),
+            None => message.value().expect("missing value in fluent message"),
+        };
+
+        let mut err = Vec::new();
+        let translated = fluent_bundle.format_pattern(value, Some(&args), &mut err);
+        assert!(err.is_empty());
+        Cow::Owned(translated.into_owned())
+    })
+}
+
+fn normalize(krate: &mut Crate) {
+    struct NormalizeVisitor;
+
+    impl MutVisitor for NormalizeVisitor {
+        fn visit_angle_bracketed_parameter_data(&mut self, e: &mut AngleBracketedArgs) {
+            #[derive(Ord, PartialOrd, Eq, PartialEq)]
+            enum Group {
+                Lifetimes,
+                TypesAndConsts,
+                Constraints,
+            }
+            e.args.sort_by_key(|arg| match arg {
+                AngleBracketedArg::Arg(arg) => match arg {
+                    GenericArg::Lifetime(_) => Group::Lifetimes,
+                    GenericArg::Type(_) | GenericArg::Const(_) => Group::TypesAndConsts,
+                },
+                AngleBracketedArg::Constraint(_) => Group::Constraints,
+            });
+            mut_visit::noop_visit_angle_bracketed_parameter_data(e, self);
+        }
+
+        fn visit_generics(&mut self, e: &mut Generics) {
+            #[derive(Ord, PartialOrd, Eq, PartialEq)]
+            enum Group {
+                Lifetimes,
+                TypesAndConsts,
+            }
+            e.params.sort_by_key(|param| match param.kind {
+                GenericParamKind::Lifetime => Group::Lifetimes,
+                GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
+                    Group::TypesAndConsts
+                }
+            });
+            mut_visit::noop_visit_generics(e, self);
+        }
+
+        fn visit_where_clause(&mut self, e: &mut WhereClause) {
+            if e.predicates.is_empty() {
+                e.has_where_token = false;
+            }
+        }
+    }
+
+    NormalizeVisitor.visit_crate(krate);
+}
diff --git a/vendor/syn/tests/test_shebang.rs b/vendor/syn/tests/test_shebang.rs
new file mode 100644
index 0000000..4c2a204
--- /dev/null
+++ b/vendor/syn/tests/test_shebang.rs
@@ -0,0 +1,63 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+#[test]
+fn test_basic() {
+    let content = "#!/usr/bin/env rustx\nfn main() {}";
+    let file = syn::parse_file(content).unwrap();
+    snapshot!(file, @r###"
+    File {
+        shebang: Some("#!/usr/bin/env rustx"),
+        items: [
+            Item::Fn {
+                vis: Visibility::Inherited,
+                sig: Signature {
+                    ident: "main",
+                    generics: Generics,
+                    output: ReturnType::Default,
+                },
+                block: Block,
+            },
+        ],
+    }
+    "###);
+}
+
+#[test]
+fn test_comment() {
+    let content = "#!//am/i/a/comment\n[allow(dead_code)] fn main() {}";
+    let file = syn::parse_file(content).unwrap();
+    snapshot!(file, @r###"
+    File {
+        attrs: [
+            Attribute {
+                style: AttrStyle::Inner,
+                meta: Meta::List {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "allow",
+                            },
+                        ],
+                    },
+                    delimiter: MacroDelimiter::Paren,
+                    tokens: TokenStream(`dead_code`),
+                },
+            },
+        ],
+        items: [
+            Item::Fn {
+                vis: Visibility::Inherited,
+                sig: Signature {
+                    ident: "main",
+                    generics: Generics,
+                    output: ReturnType::Default,
+                },
+                block: Block,
+            },
+        ],
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_should_parse.rs b/vendor/syn/tests/test_should_parse.rs
new file mode 100644
index 0000000..180d859
--- /dev/null
+++ b/vendor/syn/tests/test_should_parse.rs
@@ -0,0 +1,45 @@
+macro_rules! should_parse {
+    ($name:ident, { $($in:tt)* }) => {
+        #[test]
+        fn $name() {
+            // Make sure we can parse the file!
+            syn::parse_file(stringify!($($in)*)).unwrap();
+        }
+    }
+}
+
+should_parse!(generic_associated_type, {
+    impl Foo {
+        type Item = &'a i32;
+        fn foo<'a>(&'a self) -> Self::Item<'a> {}
+    }
+});
+
+#[rustfmt::skip]
+should_parse!(const_generics_use, {
+    type X = Foo<5>;
+    type Y = Foo<"foo">;
+    type Z = Foo<X>;
+    type W = Foo<{ X + 10 }>;
+});
+
+should_parse!(trailing_plus_type, {
+    type A = Box<Foo>;
+    type A = Box<Foo + 'a>;
+    type A = Box<'a + Foo>;
+});
+
+should_parse!(generic_associated_type_where, {
+    trait Foo {
+        type Item;
+        fn foo<T>(&self, t: T) -> Self::Item<T>;
+    }
+});
+
+should_parse!(match_with_block_expr, {
+    fn main() {
+        match false {
+            _ => {}.a(),
+        }
+    }
+});
diff --git a/vendor/syn/tests/test_size.rs b/vendor/syn/tests/test_size.rs
new file mode 100644
index 0000000..943fcd3
--- /dev/null
+++ b/vendor/syn/tests/test_size.rs
@@ -0,0 +1,36 @@
+// Assumes proc-macro2's "span-locations" feature is off.
+
+#![cfg(target_pointer_width = "64")]
+
+use std::mem;
+use syn::{Expr, Item, Lit, Pat, Type};
+
+#[rustversion::attr(before(2022-11-24), ignore)]
+#[test]
+fn test_expr_size() {
+    assert_eq!(mem::size_of::<Expr>(), 176);
+}
+
+#[rustversion::attr(before(2022-09-09), ignore)]
+#[test]
+fn test_item_size() {
+    assert_eq!(mem::size_of::<Item>(), 360);
+}
+
+#[rustversion::attr(before(2023-04-29), ignore)]
+#[test]
+fn test_type_size() {
+    assert_eq!(mem::size_of::<Type>(), 232);
+}
+
+#[rustversion::attr(before(2023-04-29), ignore)]
+#[test]
+fn test_pat_size() {
+    assert_eq!(mem::size_of::<Pat>(), 184);
+}
+
+#[rustversion::attr(before(2022-09-09), ignore)]
+#[test]
+fn test_lit_size() {
+    assert_eq!(mem::size_of::<Lit>(), 32);
+}
diff --git a/vendor/syn/tests/test_stmt.rs b/vendor/syn/tests/test_stmt.rs
new file mode 100644
index 0000000..bc57685
--- /dev/null
+++ b/vendor/syn/tests/test_stmt.rs
@@ -0,0 +1,236 @@
+#![allow(
+    clippy::assertions_on_result_states,
+    clippy::non_ascii_literal,
+    clippy::uninlined_format_args
+)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::Stmt;
+
+#[test]
+fn test_raw_operator() {
+    let stmt = syn::parse_str::<Stmt>("let _ = &raw const x;").unwrap();
+
+    snapshot!(stmt, @r###"
+    Stmt::Local {
+        pat: Pat::Wild,
+        init: Some(LocalInit {
+            expr: Expr::Verbatim(`& raw const x`),
+        }),
+    }
+    "###);
+}
+
+#[test]
+fn test_raw_variable() {
+    let stmt = syn::parse_str::<Stmt>("let _ = &raw;").unwrap();
+
+    snapshot!(stmt, @r###"
+    Stmt::Local {
+        pat: Pat::Wild,
+        init: Some(LocalInit {
+            expr: Expr::Reference {
+                expr: Expr::Path {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "raw",
+                            },
+                        ],
+                    },
+                },
+            },
+        }),
+    }
+    "###);
+}
+
+#[test]
+fn test_raw_invalid() {
+    assert!(syn::parse_str::<Stmt>("let _ = &raw x;").is_err());
+}
+
+#[test]
+fn test_none_group() {
+    // <Ø async fn f() {} Ø>
+    let tokens = TokenStream::from_iter(vec![TokenTree::Group(Group::new(
+        Delimiter::None,
+        TokenStream::from_iter(vec![
+            TokenTree::Ident(Ident::new("async", Span::call_site())),
+            TokenTree::Ident(Ident::new("fn", Span::call_site())),
+            TokenTree::Ident(Ident::new("f", Span::call_site())),
+            TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+            TokenTree::Group(Group::new(Delimiter::Brace, TokenStream::new())),
+        ]),
+    ))]);
+
+    snapshot!(tokens as Stmt, @r###"
+    Stmt::Item(Item::Fn {
+        vis: Visibility::Inherited,
+        sig: Signature {
+            asyncness: Some,
+            ident: "f",
+            generics: Generics,
+            output: ReturnType::Default,
+        },
+        block: Block,
+    })
+    "###);
+}
+
+#[test]
+fn test_let_dot_dot() {
+    let tokens = quote! {
+        let .. = 10;
+    };
+
+    snapshot!(tokens as Stmt, @r###"
+    Stmt::Local {
+        pat: Pat::Rest,
+        init: Some(LocalInit {
+            expr: Expr::Lit {
+                lit: 10,
+            },
+        }),
+    }
+    "###);
+}
+
+#[test]
+fn test_let_else() {
+    let tokens = quote! {
+        let Some(x) = None else { return 0; };
+    };
+
+    snapshot!(tokens as Stmt, @r###"
+    Stmt::Local {
+        pat: Pat::TupleStruct {
+            path: Path {
+                segments: [
+                    PathSegment {
+                        ident: "Some",
+                    },
+                ],
+            },
+            elems: [
+                Pat::Ident {
+                    ident: "x",
+                },
+            ],
+        },
+        init: Some(LocalInit {
+            expr: Expr::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "None",
+                        },
+                    ],
+                },
+            },
+            diverge: Some(Expr::Block {
+                block: Block {
+                    stmts: [
+                        Stmt::Expr(
+                            Expr::Return {
+                                expr: Some(Expr::Lit {
+                                    lit: 0,
+                                }),
+                            },
+                            Some,
+                        ),
+                    ],
+                },
+            }),
+        }),
+    }
+    "###);
+}
+
+#[test]
+fn test_macros() {
+    let tokens = quote! {
+        fn main() {
+            macro_rules! mac {}
+            thread_local! { static FOO }
+            println!("");
+            vec![]
+        }
+    };
+
+    snapshot!(tokens as Stmt, @r###"
+    Stmt::Item(Item::Fn {
+        vis: Visibility::Inherited,
+        sig: Signature {
+            ident: "main",
+            generics: Generics,
+            output: ReturnType::Default,
+        },
+        block: Block {
+            stmts: [
+                Stmt::Item(Item::Macro {
+                    ident: Some("mac"),
+                    mac: Macro {
+                        path: Path {
+                            segments: [
+                                PathSegment {
+                                    ident: "macro_rules",
+                                },
+                            ],
+                        },
+                        delimiter: MacroDelimiter::Brace,
+                        tokens: TokenStream(``),
+                    },
+                }),
+                Stmt::Macro {
+                    mac: Macro {
+                        path: Path {
+                            segments: [
+                                PathSegment {
+                                    ident: "thread_local",
+                                },
+                            ],
+                        },
+                        delimiter: MacroDelimiter::Brace,
+                        tokens: TokenStream(`static FOO`),
+                    },
+                },
+                Stmt::Macro {
+                    mac: Macro {
+                        path: Path {
+                            segments: [
+                                PathSegment {
+                                    ident: "println",
+                                },
+                            ],
+                        },
+                        delimiter: MacroDelimiter::Paren,
+                        tokens: TokenStream(`""`),
+                    },
+                    semi_token: Some,
+                },
+                Stmt::Expr(
+                    Expr::Macro {
+                        mac: Macro {
+                            path: Path {
+                                segments: [
+                                    PathSegment {
+                                        ident: "vec",
+                                    },
+                                ],
+                            },
+                            delimiter: MacroDelimiter::Bracket,
+                            tokens: TokenStream(``),
+                        },
+                    },
+                    None,
+                ),
+            ],
+        },
+    })
+    "###);
+}
diff --git a/vendor/syn/tests/test_token_trees.rs b/vendor/syn/tests/test_token_trees.rs
new file mode 100644
index 0000000..f5a067f
--- /dev/null
+++ b/vendor/syn/tests/test_token_trees.rs
@@ -0,0 +1,32 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::Lit;
+
+#[test]
+fn test_struct() {
+    let input = "
+        #[derive(Debug, Clone)]
+        pub struct Item {
+            pub ident: Ident,
+            pub attrs: Vec<Attribute>,
+        }
+    ";
+
+    snapshot!(input as TokenStream, @r###"
+    TokenStream(
+        `# [derive (Debug , Clone)] pub struct Item { pub ident : Ident , pub attrs : Vec < Attribute >, }`,
+    )
+    "###);
+}
+
+#[test]
+fn test_literal_mangling() {
+    let code = "0_4";
+    let parsed: Lit = syn::parse_str(code).unwrap();
+    assert_eq!(code, quote!(#parsed).to_string());
+}
diff --git a/vendor/syn/tests/test_ty.rs b/vendor/syn/tests/test_ty.rs
new file mode 100644
index 0000000..a400a76
--- /dev/null
+++ b/vendor/syn/tests/test_ty.rs
@@ -0,0 +1,337 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::Type;
+
+#[test]
+fn test_mut_self() {
+    syn::parse_str::<Type>("fn(mut self)").unwrap();
+    syn::parse_str::<Type>("fn(mut self,)").unwrap();
+    syn::parse_str::<Type>("fn(mut self: ())").unwrap();
+    syn::parse_str::<Type>("fn(mut self: ...)").unwrap_err();
+    syn::parse_str::<Type>("fn(mut self: mut self)").unwrap_err();
+    syn::parse_str::<Type>("fn(mut self::T)").unwrap_err();
+}
+
+#[test]
+fn test_macro_variable_type() {
+    // mimics the token stream corresponding to `$ty<T>`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { ty })),
+        TokenTree::Punct(Punct::new('<', Spacing::Alone)),
+        TokenTree::Ident(Ident::new("T", Span::call_site())),
+        TokenTree::Punct(Punct::new('>', Spacing::Alone)),
+    ]);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "ty",
+                    arguments: PathArguments::AngleBracketed {
+                        args: [
+                            GenericArgument::Type(Type::Path {
+                                path: Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "T",
+                                        },
+                                    ],
+                                },
+                            }),
+                        ],
+                    },
+                },
+            ],
+        },
+    }
+    "###);
+
+    // mimics the token stream corresponding to `$ty::<T>`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { ty })),
+        TokenTree::Punct(Punct::new(':', Spacing::Joint)),
+        TokenTree::Punct(Punct::new(':', Spacing::Alone)),
+        TokenTree::Punct(Punct::new('<', Spacing::Alone)),
+        TokenTree::Ident(Ident::new("T", Span::call_site())),
+        TokenTree::Punct(Punct::new('>', Spacing::Alone)),
+    ]);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "ty",
+                    arguments: PathArguments::AngleBracketed {
+                        colon2_token: Some,
+                        args: [
+                            GenericArgument::Type(Type::Path {
+                                path: Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "T",
+                                        },
+                                    ],
+                                },
+                            }),
+                        ],
+                    },
+                },
+            ],
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_group_angle_brackets() {
+    // mimics the token stream corresponding to `Option<$ty>`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Ident(Ident::new("Option", Span::call_site())),
+        TokenTree::Punct(Punct::new('<', Spacing::Alone)),
+        TokenTree::Group(Group::new(Delimiter::None, quote! { Vec<u8> })),
+        TokenTree::Punct(Punct::new('>', Spacing::Alone)),
+    ]);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "Option",
+                    arguments: PathArguments::AngleBracketed {
+                        args: [
+                            GenericArgument::Type(Type::Group {
+                                elem: Type::Path {
+                                    path: Path {
+                                        segments: [
+                                            PathSegment {
+                                                ident: "Vec",
+                                                arguments: PathArguments::AngleBracketed {
+                                                    args: [
+                                                        GenericArgument::Type(Type::Path {
+                                                            path: Path {
+                                                                segments: [
+                                                                    PathSegment {
+                                                                        ident: "u8",
+                                                                    },
+                                                                ],
+                                                            },
+                                                        }),
+                                                    ],
+                                                },
+                                            },
+                                        ],
+                                    },
+                                },
+                            }),
+                        ],
+                    },
+                },
+            ],
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_group_colons() {
+    // mimics the token stream corresponding to `$ty::Item`
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { Vec<u8> })),
+        TokenTree::Punct(Punct::new(':', Spacing::Joint)),
+        TokenTree::Punct(Punct::new(':', Spacing::Alone)),
+        TokenTree::Ident(Ident::new("Item", Span::call_site())),
+    ]);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        path: Path {
+            segments: [
+                PathSegment {
+                    ident: "Vec",
+                    arguments: PathArguments::AngleBracketed {
+                        args: [
+                            GenericArgument::Type(Type::Path {
+                                path: Path {
+                                    segments: [
+                                        PathSegment {
+                                            ident: "u8",
+                                        },
+                                    ],
+                                },
+                            }),
+                        ],
+                    },
+                },
+                PathSegment {
+                    ident: "Item",
+                },
+            ],
+        },
+    }
+    "###);
+
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Group(Group::new(Delimiter::None, quote! { [T] })),
+        TokenTree::Punct(Punct::new(':', Spacing::Joint)),
+        TokenTree::Punct(Punct::new(':', Spacing::Alone)),
+        TokenTree::Ident(Ident::new("Element", Span::call_site())),
+    ]);
+
+    snapshot!(tokens as Type, @r###"
+    Type::Path {
+        qself: Some(QSelf {
+            ty: Type::Slice {
+                elem: Type::Path {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "T",
+                            },
+                        ],
+                    },
+                },
+            },
+            position: 0,
+        }),
+        path: Path {
+            leading_colon: Some,
+            segments: [
+                PathSegment {
+                    ident: "Element",
+                },
+            ],
+        },
+    }
+    "###);
+}
+
+#[test]
+fn test_trait_object() {
+    let tokens = quote!(dyn for<'a> Trait<'a> + 'static);
+    snapshot!(tokens as Type, @r###"
+    Type::TraitObject {
+        dyn_token: Some,
+        bounds: [
+            TypeParamBound::Trait(TraitBound {
+                lifetimes: Some(BoundLifetimes {
+                    lifetimes: [
+                        GenericParam::Lifetime(LifetimeParam {
+                            lifetime: Lifetime {
+                                ident: "a",
+                            },
+                        }),
+                    ],
+                }),
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Trait",
+                            arguments: PathArguments::AngleBracketed {
+                                args: [
+                                    GenericArgument::Lifetime(Lifetime {
+                                        ident: "a",
+                                    }),
+                                ],
+                            },
+                        },
+                    ],
+                },
+            }),
+            TypeParamBound::Lifetime {
+                ident: "static",
+            },
+        ],
+    }
+    "###);
+
+    let tokens = quote!(dyn 'a + Trait);
+    snapshot!(tokens as Type, @r###"
+    Type::TraitObject {
+        dyn_token: Some,
+        bounds: [
+            TypeParamBound::Lifetime {
+                ident: "a",
+            },
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Trait",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+
+    // None of the following are valid Rust types.
+    syn::parse_str::<Type>("for<'a> dyn Trait<'a>").unwrap_err();
+    syn::parse_str::<Type>("dyn for<'a> 'a + Trait").unwrap_err();
+}
+
+#[test]
+fn test_trailing_plus() {
+    #[rustfmt::skip]
+    let tokens = quote!(impl Trait +);
+    snapshot!(tokens as Type, @r###"
+    Type::ImplTrait {
+        bounds: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Trait",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+
+    #[rustfmt::skip]
+    let tokens = quote!(dyn Trait +);
+    snapshot!(tokens as Type, @r###"
+    Type::TraitObject {
+        dyn_token: Some,
+        bounds: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Trait",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+
+    #[rustfmt::skip]
+    let tokens = quote!(Trait +);
+    snapshot!(tokens as Type, @r###"
+    Type::TraitObject {
+        bounds: [
+            TypeParamBound::Trait(TraitBound {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "Trait",
+                        },
+                    ],
+                },
+            }),
+        ],
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/test_visibility.rs b/vendor/syn/tests/test_visibility.rs
new file mode 100644
index 0000000..496e007
--- /dev/null
+++ b/vendor/syn/tests/test_visibility.rs
@@ -0,0 +1,144 @@
+#![allow(clippy::uninlined_format_args)]
+
+#[macro_use]
+mod macros;
+
+use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
+use syn::parse::{Parse, ParseStream};
+use syn::{DeriveInput, Result, Visibility};
+
+#[derive(Debug)]
+struct VisRest {
+    vis: Visibility,
+    rest: TokenStream,
+}
+
+impl Parse for VisRest {
+    fn parse(input: ParseStream) -> Result<Self> {
+        Ok(VisRest {
+            vis: input.parse()?,
+            rest: input.parse()?,
+        })
+    }
+}
+
+macro_rules! assert_vis_parse {
+    ($input:expr, Ok($p:pat)) => {
+        assert_vis_parse!($input, Ok($p) + "");
+    };
+
+    ($input:expr, Ok($p:pat) + $rest:expr) => {
+        let expected = $rest.parse::<TokenStream>().unwrap();
+        let parse: VisRest = syn::parse_str($input).unwrap();
+
+        match parse.vis {
+            $p => {}
+            _ => panic!("Expected {}, got {:?}", stringify!($p), parse.vis),
+        }
+
+        // NOTE: Round-trips through `to_string` to avoid potential whitespace
+        // diffs.
+        assert_eq!(parse.rest.to_string(), expected.to_string());
+    };
+
+    ($input:expr, Err) => {
+        syn::parse2::<VisRest>($input.parse().unwrap()).unwrap_err();
+    };
+}
+
+#[test]
+fn test_pub() {
+    assert_vis_parse!("pub", Ok(Visibility::Public(_)));
+}
+
+#[test]
+fn test_inherited() {
+    assert_vis_parse!("", Ok(Visibility::Inherited));
+}
+
+#[test]
+fn test_in() {
+    assert_vis_parse!("pub(in foo::bar)", Ok(Visibility::Restricted(_)));
+}
+
+#[test]
+fn test_pub_crate() {
+    assert_vis_parse!("pub(crate)", Ok(Visibility::Restricted(_)));
+}
+
+#[test]
+fn test_pub_self() {
+    assert_vis_parse!("pub(self)", Ok(Visibility::Restricted(_)));
+}
+
+#[test]
+fn test_pub_super() {
+    assert_vis_parse!("pub(super)", Ok(Visibility::Restricted(_)));
+}
+
+#[test]
+fn test_missing_in() {
+    assert_vis_parse!("pub(foo::bar)", Ok(Visibility::Public(_)) + "(foo::bar)");
+}
+
+#[test]
+fn test_missing_in_path() {
+    assert_vis_parse!("pub(in)", Err);
+}
+
+#[test]
+fn test_crate_path() {
+    assert_vis_parse!(
+        "pub(crate::A, crate::B)",
+        Ok(Visibility::Public(_)) + "(crate::A, crate::B)"
+    );
+}
+
+#[test]
+fn test_junk_after_in() {
+    assert_vis_parse!("pub(in some::path @@garbage)", Err);
+}
+
+#[test]
+fn test_empty_group_vis() {
+    // mimics `struct S { $vis $field: () }` where $vis is empty
+    let tokens = TokenStream::from_iter(vec![
+        TokenTree::Ident(Ident::new("struct", Span::call_site())),
+        TokenTree::Ident(Ident::new("S", Span::call_site())),
+        TokenTree::Group(Group::new(
+            Delimiter::Brace,
+            TokenStream::from_iter(vec![
+                TokenTree::Group(Group::new(Delimiter::None, TokenStream::new())),
+                TokenTree::Group(Group::new(
+                    Delimiter::None,
+                    TokenStream::from_iter(vec![TokenTree::Ident(Ident::new(
+                        "f",
+                        Span::call_site(),
+                    ))]),
+                )),
+                TokenTree::Punct(Punct::new(':', Spacing::Alone)),
+                TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
+            ]),
+        )),
+    ]);
+
+    snapshot!(tokens as DeriveInput, @r###"
+    DeriveInput {
+        vis: Visibility::Inherited,
+        ident: "S",
+        generics: Generics,
+        data: Data::Struct {
+            fields: Fields::Named {
+                named: [
+                    Field {
+                        vis: Visibility::Inherited,
+                        ident: Some("f"),
+                        colon_token: Some,
+                        ty: Type::Tuple,
+                    },
+                ],
+            },
+        },
+    }
+    "###);
+}
diff --git a/vendor/syn/tests/zzz_stable.rs b/vendor/syn/tests/zzz_stable.rs
new file mode 100644
index 0000000..a1a670d
--- /dev/null
+++ b/vendor/syn/tests/zzz_stable.rs
@@ -0,0 +1,33 @@
+#![cfg(syn_disable_nightly_tests)]
+
+use std::io::{self, Write};
+use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
+
+const MSG: &str = "\
+‖
+‖   WARNING:
+‖   This is not a nightly compiler so not all tests were able to
+‖   run. Syn includes tests that compare Syn's parser against the
+‖   compiler's parser, which requires access to unstable librustc
+‖   data structures and a nightly compiler.
+‖
+";
+
+#[test]
+fn notice() -> io::Result<()> {
+    let header = "WARNING";
+    let index_of_header = MSG.find(header).unwrap();
+    let before = &MSG[..index_of_header];
+    let after = &MSG[index_of_header + header.len()..];
+
+    let mut stderr = StandardStream::stderr(ColorChoice::Auto);
+    stderr.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
+    write!(&mut stderr, "{}", before)?;
+    stderr.set_color(ColorSpec::new().set_bold(true).set_fg(Some(Color::Yellow)))?;
+    write!(&mut stderr, "{}", header)?;
+    stderr.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
+    write!(&mut stderr, "{}", after)?;
+    stderr.reset()?;
+
+    Ok(())
+}