rust: syn: import crate

This is a subset of the Rust `syn` crate, version 2.0.106 (released
2025-08-16), licensed under "Apache-2.0 OR MIT", from:

    https://github.com/dtolnay/syn/raw/2.0.106/src

The files are copied as-is, with no modifications whatsoever (not even
adding the SPDX identifiers).

For copyright details, please see:

    https://github.com/dtolnay/syn/blob/2.0.106/README.md#license
    https://github.com/dtolnay/syn/blob/2.0.106/LICENSE-APACHE
    https://github.com/dtolnay/syn/blob/2.0.106/LICENSE-MIT

The next two patches modify these files as needed for use within the
kernel. This patch split allows reviewers to double-check the import
and to clearly see the differences introduced.

The following script may be used to verify the contents:

    for path in $(cd rust/syn/ && find . -type f -name '*.rs'); do
        curl --silent --show-error --location \
            https://github.com/dtolnay/syn/raw/2.0.106/src/$path \
            | diff --unified rust/syn/$path - && echo $path: OK
    done

Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-16-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 4173 insertions, 0 deletions

diff --git a/rust/syn/expr.rs b/rust/syn/expr.rs
new file mode 100644
index 000000000000..1e49d9a6633e
--- /dev/null
+++ b/rust/syn/expr.rs
@@ -0,0 +1,4173 @@
+use crate::attr::Attribute;
+#[cfg(all(feature = "parsing", feature = "full"))]
+use crate::error::Result;
+#[cfg(feature = "parsing")]
+use crate::ext::IdentExt as _;
+#[cfg(feature = "full")]
+use crate::generics::BoundLifetimes;
+use crate::ident::Ident;
+#[cfg(any(feature = "parsing", feature = "full"))]
+use crate::lifetime::Lifetime;
+use crate::lit::Lit;
+use crate::mac::Macro;
+use crate::op::{BinOp, UnOp};
+#[cfg(feature = "parsing")]
+use crate::parse::ParseStream;
+#[cfg(feature = "full")]
+use crate::pat::Pat;
+use crate::path::{AngleBracketedGenericArguments, Path, QSelf};
+use crate::punctuated::Punctuated;
+#[cfg(feature = "full")]
+use crate::stmt::Block;
+use crate::token;
+#[cfg(feature = "full")]
+use crate::ty::ReturnType;
+use crate::ty::Type;
+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(all(feature = "parsing", feature = "full"))]
+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(docsrs, 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),
+
+        /// Address-of operation: `&raw const place` or `&raw mut place`.
+        RawAddr(ExprRawAddr),
+
+        /// 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 {
+        //         #![cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //
+        //         Expr::Array(expr) => {...}
+        //         Expr::Assign(expr) => {...}
+        //         ...
+        //         Expr::Yield(expr) => {...}
+        //
+        //         _ => { /* 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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 { ... }`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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 `_`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct ExprInfer #full {
+        pub attrs: Vec<Attribute>,
+        pub underscore_token: Token![_],
+    }
+}
+
+ast_struct! {
+    /// A `let` guard: `let Some(x) = opt`.
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprLit {
+        pub attrs: Vec<Attribute>,
+        pub lit: Lit,
+    }
+}
+
+ast_struct! {
+    /// Conditionless loop: `loop { ... }`.
+    #[cfg_attr(docsrs, 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)`.
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprMacro {
+        pub attrs: Vec<Attribute>,
+        pub mac: Macro,
+    }
+}
+
+ast_struct! {
+    /// A `match` expression: `match n { Some(n) => {}, None => {} }`.
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprMethodCall {
+        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(docsrs, 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(docsrs, 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(docsrs, 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! {
+    /// Address-of operation: `&raw const place` or `&raw mut place`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct ExprRawAddr #full {
+        pub attrs: Vec<Attribute>,
+        pub and_token: Token![&],
+        pub raw: Token![raw],
+        pub mutability: PointerMutability,
+        pub expr: Box<Expr>,
+    }
+}
+
+ast_struct! {
+    /// A referencing operation: `&a` or `&mut a`.
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprReference {
+        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(docsrs, 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(docsrs, 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(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    pub struct ExprStruct {
+        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(docsrs, 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(docsrs, 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(docsrs, doc(cfg(feature = "full")))]
+    pub struct ExprTuple {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Expr, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A unary operation: `!x`, `*x`.
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, doc(cfg(feature = "full")))]
+    pub struct ExprYield #full {
+        pub attrs: Vec<Attribute>,
+        pub yield_token: Token![yield],
+        pub expr: Option<Box<Expr>>,
+    }
+}
+
+impl Expr {
+    /// An unspecified invalid expression.
+    ///
+    /// ```
+    /// use quote::ToTokens;
+    /// use std::mem;
+    /// use syn::{parse_quote, Expr};
+    ///
+    /// fn unparenthesize(e: &mut Expr) {
+    ///     while let Expr::Paren(paren) = e {
+    ///         *e = mem::replace(&mut *paren.expr, Expr::PLACEHOLDER);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let mut e: Expr = parse_quote! { ((1 + 1)) };
+    ///     unparenthesize(&mut e);
+    ///     assert_eq!("1 + 1", e.to_token_stream().to_string());
+    /// }
+    /// ```
+    pub const PLACEHOLDER: Self = Expr::Path(ExprPath {
+        attrs: Vec::new(),
+        qself: None,
+        path: Path {
+            leading_colon: None,
+            segments: Punctuated::new(),
+        },
+    });
+
+    /// 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.
+    ///
+    /// [`Parse`]: crate::parse::Parse
+    ///
+    /// 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(all(feature = "full", feature = "parsing"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "full", feature = "parsing"))))]
+    pub fn parse_without_eager_brace(input: ParseStream) -> Result<Expr> {
+        parsing::ambiguous_expr(input, parsing::AllowStruct(false))
+    }
+
+    /// An alternative to the primary `Expr::parse` parser (from the [`Parse`]
+    /// trait) for syntactic positions in which expression boundaries are placed
+    /// more eagerly than done by the typical expression grammar. This includes
+    /// expressions at the head of a statement or in the right-hand side of a
+    /// `match` arm.
+    ///
+    /// [`Parse`]: crate::parse::Parse
+    ///
+    /// Compare the following cases:
+    ///
+    /// 1.
+    ///   ```
+    ///   # let result = ();
+    ///   # let guard = false;
+    ///   # let cond = true;
+    ///   # let f = true;
+    ///   # let g = f;
+    ///   #
+    ///   let _ = match result {
+    ///       () if guard => if cond { f } else { g }
+    ///       () => false,
+    ///   };
+    ///   ```
+    ///
+    /// 2.
+    ///   ```
+    ///   # let cond = true;
+    ///   # let f = ();
+    ///   # let g = f;
+    ///   #
+    ///   let _ = || {
+    ///       if cond { f } else { g }
+    ///       ()
+    ///   };
+    ///   ```
+    ///
+    /// 3.
+    ///   ```
+    ///   # let cond = true;
+    ///   # let f = || ();
+    ///   # let g = f;
+    ///   #
+    ///   let _ = [if cond { f } else { g } ()];
+    ///   ```
+    ///
+    /// The same sequence of tokens `if cond { f } else { g } ()` appears in
+    /// expression position 3 times. The first two syntactic positions use eager
+    /// placement of expression boundaries, and parse as `Expr::If`, with the
+    /// adjacent `()` becoming `Pat::Tuple` or `Expr::Tuple`. In contrast, the
+    /// third case uses standard expression boundaries and parses as
+    /// `Expr::Call`.
+    ///
+    /// As with [`parse_without_eager_brace`], this ambiguity in the Rust
+    /// grammar is independent of precedence.
+    ///
+    /// [`parse_without_eager_brace`]: Self::parse_without_eager_brace
+    #[cfg(all(feature = "full", feature = "parsing"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "full", feature = "parsing"))))]
+    pub fn parse_with_earlier_boundary_rule(input: ParseStream) -> Result<Expr> {
+        parsing::parse_with_earlier_boundary_rule(input)
+    }
+
+    /// Returns whether the next token in the parse stream is one that might
+    /// possibly form the beginning of an expr.
+    ///
+    /// This classification is a load-bearing part of the grammar of some Rust
+    /// expressions, notably `return` and `break`. For example `return < …` will
+    /// never parse `<` as a binary operator regardless of what comes after,
+    /// because `<` is a legal starting token for an expression and so it's
+    /// required to be continued as a return value, such as `return <Struct as
+    /// Trait>::CONST`. Meanwhile `return > …` treats the `>` as a binary
+    /// operator because it cannot be a starting token for any Rust expression.
+    #[cfg(feature = "parsing")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    pub fn peek(input: ParseStream) -> bool {
+        input.peek(Ident::peek_any) && !input.peek(Token![as]) // value name or keyword
+            || input.peek(token::Paren) // tuple
+            || input.peek(token::Bracket) // array
+            || input.peek(token::Brace) // block
+            || input.peek(Lit) // literal
+            || input.peek(Token![!]) && !input.peek(Token![!=]) // operator not
+            || input.peek(Token![-]) && !input.peek(Token![-=]) && !input.peek(Token![->]) // unary minus
+            || input.peek(Token![*]) && !input.peek(Token![*=]) // dereference
+            || input.peek(Token![|]) && !input.peek(Token![|=]) // closure
+            || input.peek(Token![&]) && !input.peek(Token![&=]) // reference
+            || input.peek(Token![..]) // range
+            || input.peek(Token![<]) && !input.peek(Token![<=]) && !input.peek(Token![<<=]) // associated path
+            || input.peek(Token![::]) // absolute path
+            || input.peek(Lifetime) // labeled loop
+            || input.peek(Token![#]) // expression attributes
+    }
+
+    #[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::RawAddr(ExprRawAddr { 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(docsrs, 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),
+        }
+    }
+}
+
+#[cfg(any(feature = "parsing", feature = "printing"))]
+impl Member {
+    pub(crate) fn is_named(&self) -> bool {
+        match self {
+            Member::Named(_) => true,
+            Member::Unnamed(_) => false,
+        }
+    }
+}
+
+ast_struct! {
+    /// The index of an unnamed tuple struct field.
+    #[cfg_attr(docsrs, 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 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)
+    }
+}
+
+ast_struct! {
+    /// A field-value pair in a struct literal.
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
+    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(docsrs, 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(docsrs, 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(docsrs, 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(feature = "full")]
+ast_enum! {
+    /// Mutability of a raw pointer (`*const T`, `*mut T`), in which non-mutable
+    /// isn't the implicit default.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub enum PointerMutability {
+        Const(Token![const]),
+        Mut(Token![mut]),
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    #[cfg(feature = "full")]
+    use crate::attr;
+    use crate::attr::Attribute;
+    #[cfg(feature = "full")]
+    use crate::classify;
+    use crate::error::{Error, Result};
+    #[cfg(feature = "full")]
+    use crate::expr::{
+        Arm, ExprArray, ExprAssign, ExprAsync, ExprAwait, ExprBlock, ExprBreak, ExprClosure,
+        ExprConst, ExprContinue, ExprForLoop, ExprIf, ExprInfer, ExprLet, ExprLoop, ExprMatch,
+        ExprRange, ExprRawAddr, ExprRepeat, ExprReturn, ExprTry, ExprTryBlock, ExprUnsafe,
+        ExprWhile, ExprYield, Label, PointerMutability, RangeLimits,
+    };
+    use crate::expr::{
+        Expr, ExprBinary, ExprCall, ExprCast, ExprField, ExprGroup, ExprIndex, ExprLit, ExprMacro,
+        ExprMethodCall, ExprParen, ExprPath, ExprReference, ExprStruct, ExprTuple, ExprUnary,
+        FieldValue, Index, Member,
+    };
+    #[cfg(feature = "full")]
+    use crate::generics::{self, BoundLifetimes};
+    use crate::ident::Ident;
+    #[cfg(feature = "full")]
+    use crate::lifetime::Lifetime;
+    use crate::lit::{Lit, LitFloat, LitInt};
+    use crate::mac::{self, Macro};
+    use crate::op::BinOp;
+    use crate::parse::discouraged::Speculative as _;
+    #[cfg(feature = "full")]
+    use crate::parse::ParseBuffer;
+    use crate::parse::{Parse, ParseStream};
+    #[cfg(feature = "full")]
+    use crate::pat::{Pat, PatType};
+    use crate::path::{self, AngleBracketedGenericArguments, Path, QSelf};
+    use crate::precedence::Precedence;
+    use crate::punctuated::Punctuated;
+    #[cfg(feature = "full")]
+    use crate::stmt::Block;
+    use crate::token;
+    use crate::ty;
+    #[cfg(feature = "full")]
+    use crate::ty::{ReturnType, Type};
+    use crate::verbatim;
+    #[cfg(feature = "full")]
+    use proc_macro2::{Span, TokenStream};
+    use std::mem;
+
+    // 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(super) struct AllowStruct(pub bool);
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for Expr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            ambiguous_expr(
+                input,
+                #[cfg(feature = "full")]
+                AllowStruct(true),
+            )
+        }
+    }
+
+    #[cfg(feature = "full")]
+    pub(super) fn parse_with_earlier_boundary_rule(input: ParseStream) -> Result<Expr> {
+        let mut attrs = input.call(expr_attrs)?;
+        let mut expr = if input.peek(token::Group) {
+            let allow_struct = AllowStruct(true);
+            let atom = expr_group(input, allow_struct)?;
+            if continue_parsing_early(&atom) {
+                trailer_helper(input, atom)?
+            } else {
+                atom
+            }
+        } else 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])
+            && !generics::parsing::choose_generics_over_qpath_after_keyword(input)
+        {
+            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 if input.peek(Lifetime) {
+            atom_labeled(input)?
+        } else {
+            let allow_struct = AllowStruct(true);
+            unary_expr(input, allow_struct)?
+        };
+
+        if continue_parsing_early(&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::MIN);
+        }
+
+        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::MIN);
+        }
+
+        attrs.extend(expr.replace_attrs(Vec::new()));
+        expr.replace_attrs(attrs);
+        Ok(expr)
+    }
+
+    #[cfg(feature = "full")]
+    impl Copy for AllowStruct {}
+
+    #[cfg(feature = "full")]
+    impl Clone for AllowStruct {
+        fn clone(&self) -> Self {
+            *self
+        }
+    }
+
+    #[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 Expr::Range(_) = lhs {
+                // A range cannot be the left-hand side of another binary operator.
+                break;
+            } else if let Ok(op) = ahead.parse::<BinOp>() {
+                let precedence = Precedence::of_binop(&op);
+                if precedence < base {
+                    break;
+                }
+                if precedence == Precedence::Assign {
+                    if let Expr::Range(_) = lhs {
+                        break;
+                    }
+                }
+                if precedence == Precedence::Compare {
+                    if let Expr::Binary(lhs) = &lhs {
+                        if Precedence::of_binop(&lhs.op) == Precedence::Compare {
+                            return Err(input.error("comparison operators cannot be chained"));
+                        }
+                    }
+                }
+                input.advance_to(&ahead);
+                let right = parse_binop_rhs(input, allow_struct, precedence)?;
+                lhs = Expr::Binary(ExprBinary {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    op,
+                    right,
+                });
+            } else if Precedence::Assign >= base
+                && input.peek(Token![=])
+                && !input.peek(Token![=>])
+                && match lhs {
+                    Expr::Range(_) => false,
+                    _ => true,
+                }
+            {
+                let eq_token: Token![=] = input.parse()?;
+                let right = parse_binop_rhs(input, allow_struct, Precedence::Assign)?;
+                lhs = Expr::Assign(ExprAssign {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    eq_token,
+                    right,
+                });
+            } else if Precedence::Range >= base && input.peek(Token![..]) {
+                let limits: RangeLimits = input.parse()?;
+                let end = parse_range_end(input, &limits, allow_struct)?;
+                lhs = Expr::Range(ExprRange {
+                    attrs: Vec::new(),
+                    start: Some(Box::new(lhs)),
+                    limits,
+                    end,
+                });
+            } 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 Ok(op) = ahead.parse::<BinOp>() {
+                let precedence = Precedence::of_binop(&op);
+                if precedence < base {
+                    break;
+                }
+                if precedence == Precedence::Compare {
+                    if let Expr::Binary(lhs) = &lhs {
+                        if Precedence::of_binop(&lhs.op) == Precedence::Compare {
+                            return Err(input.error("comparison operators cannot be chained"));
+                        }
+                    }
+                }
+                input.advance_to(&ahead);
+                let right = parse_binop_rhs(input, precedence)?;
+                lhs = Expr::Binary(ExprBinary {
+                    attrs: Vec::new(),
+                    left: Box::new(lhs),
+                    op,
+                    right,
+                });
+            } 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 parse_binop_rhs(
+        input: ParseStream,
+        #[cfg(feature = "full")] allow_struct: AllowStruct,
+        precedence: Precedence,
+    ) -> Result<Box<Expr>> {
+        let mut rhs = unary_expr(
+            input,
+            #[cfg(feature = "full")]
+            allow_struct,
+        )?;
+        loop {
+            let next = peek_precedence(input);
+            if next > precedence || next == precedence && precedence == Precedence::Assign {
+                let cursor = input.cursor();
+                rhs = parse_expr(
+                    input,
+                    rhs,
+                    #[cfg(feature = "full")]
+                    allow_struct,
+                    next,
+                )?;
+                if cursor == input.cursor() {
+                    // Bespoke grammar restrictions separate from precedence can
+                    // cause parsing to not advance, such as `..a` being
+                    // disallowed in the left-hand side of binary operators,
+                    // even ones that have lower precedence than `..`.
+                    break;
+                }
+            } else {
+                break;
+            }
+        }
+        Ok(Box::new(rhs))
+    }
+
+    fn peek_precedence(input: ParseStream) -> Precedence {
+        if let Ok(op) = input.fork().parse() {
+            Precedence::of_binop(&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::MIN
+        }
+    }
+
+    // Parse an arbitrary expression.
+    pub(super) 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::MIN,
+        )
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_attrs(input: ParseStream) -> Result<Vec<Attribute>> {
+        let mut attrs = Vec::new();
+        while !input.peek(token::Group) && input.peek(Token![#]) {
+            attrs.push(input.call(attr::parsing::single_parse_outer)?);
+        }
+        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::Group) {
+            return trailer_expr(begin, attrs, input, allow_struct);
+        }
+
+        if input.peek(Token![&]) {
+            let and_token: Token![&] = input.parse()?;
+            let raw: Option<Token![raw]> = if input.peek(Token![raw])
+                && (input.peek2(Token![mut]) || input.peek2(Token![const]))
+            {
+                Some(input.parse()?)
+            } else {
+                None
+            };
+            let mutability: Option<Token![mut]> = input.parse()?;
+            let const_token: Option<Token![const]> = if raw.is_some() && mutability.is_none() {
+                Some(input.parse()?)
+            } else {
+                None
+            };
+            let expr = Box::new(unary_expr(input, allow_struct)?);
+            if let Some(raw) = raw {
+                Ok(Expr::RawAddr(ExprRawAddr {
+                    attrs,
+                    and_token,
+                    raw,
+                    mutability: match mutability {
+                        Some(mut_token) => PointerMutability::Mut(mut_token),
+                        None => PointerMutability::Const(const_token.unwrap()),
+                    },
+                    expr,
+                }))
+            } 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![&]) {
+            Ok(Expr::Reference(ExprReference {
+                attrs: Vec::new(),
+                and_token: input.parse()?,
+                mutability: input.parse()?,
+                expr: Box::new(unary_expr(input)?),
+            }))
+        } else 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 if !attrs.is_empty() {
+            if let Expr::Range(range) = e {
+                let spans: &[Span] = match &range.limits {
+                    RangeLimits::HalfOpen(limits) => &limits.spans,
+                    RangeLimits::Closed(limits) => &limits.spans,
+                };
+                return Err(crate::error::new2(
+                    spans[0],
+                    *spans.last().unwrap(),
+                    "attributes are not allowed on range expressions starting with `..`",
+                ));
+            }
+            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![?])
+                && match e {
+                    Expr::Range(_) => false,
+                    _ => true,
+                }
+            {
+                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;
+                    }
+                }
+
+                let member: Member = input.parse()?;
+                let turbofish = if member.is_named() && input.peek(Token![::]) {
+                    let colon2_token: Token![::] = input.parse()?;
+                    let turbofish =
+                        AngleBracketedGenericArguments::do_parse(Some(colon2_token), input)?;
+                    Some(turbofish)
+                } 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 {
+                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) {
+            expr_group(input, allow_struct)
+        } 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])
+                && generics::parsing::choose_generics_over_qpath_after_keyword(input)
+            || 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 token::parsing::peek_keyword(input.cursor(), "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]) {
+            input.parse().map(Expr::Return)
+        } else if input.peek(Token![become]) {
+            expr_become(input)
+        } else if input.peek(token::Bracket) {
+            array_or_repeat(input)
+        } else if input.peek(Token![let]) {
+            expr_let(input, allow_struct).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) {
+            atom_labeled(input)
+        } else {
+            Err(input.error("expected an expression"))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn atom_labeled(input: ParseStream) -> Result<Expr> {
+        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)
+    }
+
+    #[cfg(not(feature = "full"))]
+    fn atom_expr(input: ParseStream) -> Result<Expr> {
+        if input.peek(token::Group) {
+            expr_group(input)
+        } else if input.peek(Lit) {
+            input.parse().map(Expr::Lit)
+        } else if input.peek(token::Paren) {
+            paren_or_tuple(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])
+        {
+            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();
+
+        token::parsing::keyword(input, "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 expr_style = true;
+        let (qself, path) = path::parsing::qpath(input, expr_style)?;
+        rest_of_path_or_macro_or_struct(
+            qself,
+            path,
+            input,
+            #[cfg(feature = "full")]
+            allow_struct,
+        )
+    }
+
+    fn rest_of_path_or_macro_or_struct(
+        qself: Option<QSelf>,
+        path: Path,
+        input: ParseStream,
+        #[cfg(feature = "full")] allow_struct: AllowStruct,
+    ) -> Result<Expr> {
+        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(not(feature = "full"))]
+        let allow_struct = (true,);
+        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(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprMacro {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprMacro {
+                attrs: Vec::new(),
+                mac: input.parse()?,
+            })
+        }
+    }
+
+    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(docsrs, 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(docsrs, 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")]
+    fn continue_parsing_early(mut expr: &Expr) -> bool {
+        while let Expr::Group(group) = expr {
+            expr = &group.expr;
+        }
+        match expr {
+            Expr::If(_)
+            | Expr::While(_)
+            | Expr::ForLoop(_)
+            | Expr::Loop(_)
+            | Expr::Match(_)
+            | Expr::TryBlock(_)
+            | Expr::Unsafe(_)
+            | Expr::Const(_)
+            | Expr::Block(_) => false,
+            _ => true,
+        }
+    }
+
+    #[cfg_attr(docsrs, 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,
+        #[cfg(feature = "full")] allow_struct: AllowStruct,
+    ) -> Result<Expr> {
+        let group = crate::group::parse_group(input)?;
+        let mut inner: Expr = group.content.parse()?;
+
+        match inner {
+            Expr::Path(mut expr) if expr.attrs.is_empty() => {
+                let grouped_len = expr.path.segments.len();
+                Path::parse_rest(input, &mut expr.path, true)?;
+                match rest_of_path_or_macro_or_struct(
+                    expr.qself,
+                    expr.path,
+                    input,
+                    #[cfg(feature = "full")]
+                    allow_struct,
+                )? {
+                    Expr::Path(expr) if expr.path.segments.len() == grouped_len => {
+                        inner = Expr::Path(expr);
+                    }
+                    extended => return Ok(extended),
+                }
+            }
+            _ => {}
+        }
+
+        Ok(Expr::Group(ExprGroup {
+            attrs: Vec::new(),
+            group_token: group.token,
+            expr: Box::new(inner),
+        }))
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprParen {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let content;
+            Ok(ExprParen {
+                attrs: Vec::new(),
+                paren_token: parenthesized!(content in input),
+                expr: content.parse()?,
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprLet {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            expr_let(input, allow_struct)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_let(input: ParseStream, allow_struct: AllowStruct) -> Result<ExprLet> {
+        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 lhs = unary_expr(input, allow_struct)?;
+                parse_expr(input, lhs, allow_struct, Precedence::Compare)?
+            }),
+        })
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprIf {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let attrs = input.call(Attribute::parse_outer)?;
+
+            let mut clauses = Vec::new();
+            let mut expr;
+            loop {
+                let if_token: Token![if] = input.parse()?;
+                let cond = input.call(Expr::parse_without_eager_brace)?;
+                let then_branch: Block = input.parse()?;
+
+                expr = ExprIf {
+                    attrs: Vec::new(),
+                    if_token,
+                    cond: Box::new(cond),
+                    then_branch,
+                    else_branch: None,
+                };
+
+                if !input.peek(Token![else]) {
+                    break;
+                }
+
+                let else_token: Token![else] = input.parse()?;
+                let lookahead = input.lookahead1();
+                if lookahead.peek(Token![if]) {
+                    expr.else_branch = Some((else_token, Box::new(Expr::PLACEHOLDER)));
+                    clauses.push(expr);
+                } else if lookahead.peek(token::Brace) {
+                    expr.else_branch = Some((
+                        else_token,
+                        Box::new(Expr::Block(ExprBlock {
+                            attrs: Vec::new(),
+                            label: None,
+                            block: input.parse()?,
+                        })),
+                    ));
+                    break;
+                } else {
+                    return Err(lookahead.error());
+                }
+            }
+
+            while let Some(mut prev) = clauses.pop() {
+                *prev.else_branch.as_mut().unwrap().1 = Expr::If(expr);
+                expr = prev;
+            }
+            expr.attrs = attrs;
+            Ok(expr)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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 arms = Arm::parse_multiple(&content)?;
+
+            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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprRawAddr {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let allow_struct = AllowStruct(true);
+            Ok(ExprRawAddr {
+                attrs: Vec::new(),
+                and_token: input.parse()?,
+                raw: input.parse()?,
+                mutability: input.parse()?,
+                expr: Box::new(unary_expr(input, allow_struct)?),
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprReturn {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(ExprReturn {
+                attrs: Vec::new(),
+                return_token: input.parse()?,
+                expr: {
+                    if Expr::peek(input) {
+                        Some(input.parse()?)
+                    } else {
+                        None
+                    }
+                },
+            })
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn expr_become(input: ParseStream) -> Result<Expr> {
+        let begin = input.fork();
+        input.parse::<Token![become]>()?;
+        input.parse::<Expr>()?;
+        Ok(Expr::Verbatim(verbatim::between(&begin, input)))
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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 Expr::peek(input) {
+                        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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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> {
+        let break_token: Token![break] = input.parse()?;
+
+        let ahead = input.fork();
+        let label: Option<Lifetime> = ahead.parse()?;
+        if label.is_some() && ahead.peek(Token![:]) {
+            // Not allowed: `break 'label: loop {...}`
+            // Parentheses are required. `break ('label: loop {...})`
+            let _: Expr = input.parse()?;
+            let start_span = label.unwrap().apostrophe;
+            let end_span = input.cursor().prev_span();
+            return Err(crate::error::new2(
+                start_span,
+                end_span,
+                "parentheses required",
+            ));
+        }
+
+        input.advance_to(&ahead);
+        let expr = if Expr::peek(input) && (allow_struct.0 || !input.peek(token::Brace)) {
+            Some(input.parse()?)
+        } else {
+            None
+        };
+
+        Ok(ExprBreak {
+            attrs: Vec::new(),
+            break_token,
+            label,
+            expr,
+        })
+    }
+
+    #[cfg_attr(docsrs, 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_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for ExprStruct {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let expr_style = true;
+            let (qself, path) = path::parsing::qpath(input, expr_style)?;
+            expr_struct_helper(input, qself, path)
+        }
+    }
+
+    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(docsrs, 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(docsrs, 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 = parse_range_end(input, &limits, allow_struct)?;
+        Ok(ExprRange {
+            attrs: Vec::new(),
+            start: None,
+            limits,
+            end,
+        })
+    }
+
+    #[cfg(feature = "full")]
+    fn parse_range_end(
+        input: ParseStream,
+        limits: &RangeLimits,
+        allow_struct: AllowStruct,
+    ) -> Result<Option<Box<Expr>>> {
+        if matches!(limits, RangeLimits::HalfOpen(_))
+            && (input.is_empty()
+                || input.peek(Token![,])
+                || input.peek(Token![;])
+                || input.peek(Token![.]) && !input.peek(Token![..])
+                || input.peek(Token![?])
+                || input.peek(Token![=>])
+                || !allow_struct.0 && input.peek(token::Brace)
+                || input.peek(Token![=])
+                || input.peek(Token![+])
+                || input.peek(Token![/])
+                || input.peek(Token![%])
+                || input.peek(Token![^])
+                || input.peek(Token![>])
+                || input.peek(Token![<=])
+                || input.peek(Token![!=])
+                || input.peek(Token![-=])
+                || input.peek(Token![*=])
+                || input.peek(Token![&=])
+                || input.peek(Token![|=])
+                || input.peek(Token![<<=])
+                || input.peek(Token![as]))
+        {
+            Ok(None)
+        } else {
+            let end = parse_binop_rhs(input, allow_struct, Precedence::Range)?;
+            Ok(Some(end))
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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 expr_style = true;
+            let (qself, path) = path::parsing::qpath(input, expr_style)?;
+
+            Ok(ExprPath { attrs, qself, path })
+        }
+    }
+
+    #[cfg_attr(docsrs, 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")]
+    impl Arm {
+        pub(crate) fn parse_multiple(input: ParseStream) -> Result<Vec<Self>> {
+            let mut arms = Vec::new();
+            while !input.is_empty() {
+                arms.push(input.call(Arm::parse)?);
+            }
+            Ok(arms)
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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 = Expr::parse_with_earlier_boundary_rule(input)?;
+                    requires_comma = classify::requires_comma_to_be_match_arm(&body);
+                    Box::new(body)
+                },
+                comma: {
+                    if requires_comma && !input.is_empty() {
+                        Some(input.parse()?)
+                    } else {
+                        input.parse()?
+                    }
+                },
+            })
+        }
+    }
+
+    #[cfg_attr(docsrs, 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::PLACEHOLDER);
+            *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")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for PointerMutability {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Token![const]) {
+                Ok(PointerMutability::Const(input.parse()?))
+            } else if lookahead.peek(Token![mut]) {
+                Ok(PointerMutability::Mut(input.parse()?))
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
+    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 crate::attr::Attribute;
+    #[cfg(feature = "full")]
+    use crate::attr::FilterAttrs;
+    #[cfg(feature = "full")]
+    use crate::classify;
+    #[cfg(feature = "full")]
+    use crate::expr::{
+        Arm, ExprArray, ExprAssign, ExprAsync, ExprAwait, ExprBlock, ExprBreak, ExprClosure,
+        ExprConst, ExprContinue, ExprForLoop, ExprIf, ExprInfer, ExprLet, ExprLoop, ExprMatch,
+        ExprRange, ExprRawAddr, ExprRepeat, ExprReturn, ExprTry, ExprTryBlock, ExprUnsafe,
+        ExprWhile, ExprYield, Label, PointerMutability, RangeLimits,
+    };
+    use crate::expr::{
+        Expr, ExprBinary, ExprCall, ExprCast, ExprField, ExprGroup, ExprIndex, ExprLit, ExprMacro,
+        ExprMethodCall, ExprParen, ExprPath, ExprReference, ExprStruct, ExprTuple, ExprUnary,
+        FieldValue, Index, Member,
+    };
+    use crate::fixup::FixupContext;
+    use crate::op::BinOp;
+    use crate::path;
+    use crate::path::printing::PathStyle;
+    use crate::precedence::Precedence;
+    use crate::token;
+    #[cfg(feature = "full")]
+    use crate::ty::ReturnType;
+    use proc_macro2::{Literal, Span, TokenStream};
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[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) {}
+
+    pub(crate) fn print_subexpression(
+        expr: &Expr,
+        needs_group: bool,
+        tokens: &mut TokenStream,
+        mut fixup: FixupContext,
+    ) {
+        if needs_group {
+            // If we are surrounding the whole cond in parentheses, such as:
+            //
+            //     if (return Struct {}) {}
+            //
+            // then there is no need for parenthesizing the individual struct
+            // expressions within. On the other hand if the whole cond is not
+            // parenthesized, then print_expr must parenthesize exterior struct
+            // literals.
+            //
+            //     if x == (Struct {}) {}
+            //
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| print_expr(expr, tokens, fixup);
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    pub(crate) fn print_expr(expr: &Expr, tokens: &mut TokenStream, mut fixup: FixupContext) {
+        #[cfg(feature = "full")]
+        let needs_group = fixup.parenthesize(expr);
+        #[cfg(not(feature = "full"))]
+        let needs_group = false;
+
+        if needs_group {
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| match expr {
+            #[cfg(feature = "full")]
+            Expr::Array(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Assign(e) => print_expr_assign(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Async(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Await(e) => print_expr_await(e, tokens, fixup),
+            Expr::Binary(e) => print_expr_binary(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Block(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Break(e) => print_expr_break(e, tokens, fixup),
+            Expr::Call(e) => print_expr_call(e, tokens, fixup),
+            Expr::Cast(e) => print_expr_cast(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Closure(e) => print_expr_closure(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Const(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Continue(e) => e.to_tokens(tokens),
+            Expr::Field(e) => print_expr_field(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::ForLoop(e) => e.to_tokens(tokens),
+            Expr::Group(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::If(e) => e.to_tokens(tokens),
+            Expr::Index(e) => print_expr_index(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Infer(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Let(e) => print_expr_let(e, tokens, fixup),
+            Expr::Lit(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Loop(e) => e.to_tokens(tokens),
+            Expr::Macro(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Match(e) => e.to_tokens(tokens),
+            Expr::MethodCall(e) => print_expr_method_call(e, tokens, fixup),
+            Expr::Paren(e) => e.to_tokens(tokens),
+            Expr::Path(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Range(e) => print_expr_range(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::RawAddr(e) => print_expr_raw_addr(e, tokens, fixup),
+            Expr::Reference(e) => print_expr_reference(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Repeat(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Return(e) => print_expr_return(e, tokens, fixup),
+            Expr::Struct(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Try(e) => print_expr_try(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::TryBlock(e) => e.to_tokens(tokens),
+            Expr::Tuple(e) => e.to_tokens(tokens),
+            Expr::Unary(e) => print_expr_unary(e, tokens, fixup),
+            #[cfg(feature = "full")]
+            Expr::Unsafe(e) => e.to_tokens(tokens),
+            Expr::Verbatim(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::While(e) => e.to_tokens(tokens),
+            #[cfg(feature = "full")]
+            Expr::Yield(e) => print_expr_yield(e, tokens, fixup),
+
+            #[cfg(not(feature = "full"))]
+            _ => unreachable!(),
+        };
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprAssign {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_assign(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_assign(e: &ExprAssign, tokens: &mut TokenStream, mut fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+
+        let needs_group = !e.attrs.is_empty();
+        if needs_group {
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| {
+            let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+                &e.left,
+                false,
+                false,
+                Precedence::Assign,
+            );
+            print_subexpression(&e.left, left_prec <= Precedence::Range, tokens, left_fixup);
+            e.eq_token.to_tokens(tokens);
+            print_expr(
+                &e.right,
+                tokens,
+                fixup.rightmost_subexpression_fixup(false, false, Precedence::Assign),
+            );
+        };
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprAwait {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_await(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_await(e: &ExprAwait, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_dot(&e.base);
+        print_subexpression(
+            &e.base,
+            left_prec < Precedence::Unambiguous,
+            tokens,
+            left_fixup,
+        );
+        e.dot_token.to_tokens(tokens);
+        e.await_token.to_tokens(tokens);
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprBinary {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_binary(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_binary(e: &ExprBinary, tokens: &mut TokenStream, mut fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+
+        let needs_group = !e.attrs.is_empty();
+        if needs_group {
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| {
+            let binop_prec = Precedence::of_binop(&e.op);
+            let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+                &e.left,
+                #[cfg(feature = "full")]
+                match &e.op {
+                    BinOp::Sub(_)
+                    | BinOp::Mul(_)
+                    | BinOp::And(_)
+                    | BinOp::Or(_)
+                    | BinOp::BitAnd(_)
+                    | BinOp::BitOr(_)
+                    | BinOp::Shl(_)
+                    | BinOp::Lt(_) => true,
+                    _ => false,
+                },
+                match &e.op {
+                    BinOp::Shl(_) | BinOp::Lt(_) => true,
+                    _ => false,
+                },
+                #[cfg(feature = "full")]
+                binop_prec,
+            );
+            let left_needs_group = match binop_prec {
+                Precedence::Assign => left_prec <= Precedence::Range,
+                Precedence::Compare => left_prec <= binop_prec,
+                _ => left_prec < binop_prec,
+            };
+
+            let right_fixup = fixup.rightmost_subexpression_fixup(
+                #[cfg(feature = "full")]
+                false,
+                #[cfg(feature = "full")]
+                false,
+                #[cfg(feature = "full")]
+                binop_prec,
+            );
+            let right_needs_group = binop_prec != Precedence::Assign
+                && right_fixup.rightmost_subexpression_precedence(&e.right) <= binop_prec;
+
+            print_subexpression(&e.left, left_needs_group, tokens, left_fixup);
+            e.op.to_tokens(tokens);
+            print_subexpression(&e.right, right_needs_group, tokens, right_fixup);
+        };
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprBreak {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_break(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_break(e: &ExprBreak, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.break_token.to_tokens(tokens);
+        e.label.to_tokens(tokens);
+        if let Some(value) = &e.expr {
+            print_subexpression(
+                value,
+                // Parenthesize `break 'inner: loop { break 'inner 1 } + 1`
+                //                     ^---------------------------------^
+                e.label.is_none() && classify::expr_leading_label(value),
+                tokens,
+                fixup.rightmost_subexpression_fixup(true, true, Precedence::Jump),
+            );
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprCall {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_call(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_call(e: &ExprCall, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+            &e.func,
+            #[cfg(feature = "full")]
+            true,
+            false,
+            #[cfg(feature = "full")]
+            Precedence::Unambiguous,
+        );
+        let needs_group = if let Expr::Field(func) = &*e.func {
+            func.member.is_named()
+        } else {
+            left_prec < Precedence::Unambiguous
+        };
+        print_subexpression(&e.func, needs_group, tokens, left_fixup);
+
+        e.paren_token.surround(tokens, |tokens| {
+            e.args.to_tokens(tokens);
+        });
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprCast {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_cast(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_cast(e: &ExprCast, tokens: &mut TokenStream, mut fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+
+        let needs_group = !e.attrs.is_empty();
+        if needs_group {
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| {
+            let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+                &e.expr,
+                #[cfg(feature = "full")]
+                false,
+                false,
+                #[cfg(feature = "full")]
+                Precedence::Cast,
+            );
+            print_subexpression(&e.expr, left_prec < Precedence::Cast, tokens, left_fixup);
+            e.as_token.to_tokens(tokens);
+            e.ty.to_tokens(tokens);
+        };
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprClosure {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_closure(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_closure(e: &ExprClosure, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.lifetimes.to_tokens(tokens);
+        e.constness.to_tokens(tokens);
+        e.movability.to_tokens(tokens);
+        e.asyncness.to_tokens(tokens);
+        e.capture.to_tokens(tokens);
+        e.or1_token.to_tokens(tokens);
+        e.inputs.to_tokens(tokens);
+        e.or2_token.to_tokens(tokens);
+        e.output.to_tokens(tokens);
+        if matches!(e.output, ReturnType::Default)
+            || matches!(&*e.body, Expr::Block(body) if body.attrs.is_empty() && body.label.is_none())
+        {
+            print_expr(
+                &e.body,
+                tokens,
+                fixup.rightmost_subexpression_fixup(false, false, Precedence::Jump),
+            );
+        } else {
+            token::Brace::default().surround(tokens, |tokens| {
+                print_expr(&e.body, tokens, FixupContext::new_stmt());
+            });
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprField {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_field(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_field(e: &ExprField, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_dot(&e.base);
+        print_subexpression(
+            &e.base,
+            left_prec < Precedence::Unambiguous,
+            tokens,
+            left_fixup,
+        );
+        e.dot_token.to_tokens(tokens);
+        e.member.to_tokens(tokens);
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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);
+            print_expr(&self.expr, tokens, FixupContext::new_condition());
+            self.body.brace_token.surround(tokens, |tokens| {
+                inner_attrs_to_tokens(&self.attrs, tokens);
+                tokens.append_all(&self.body.stmts);
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprIf {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            outer_attrs_to_tokens(&self.attrs, tokens);
+
+            let mut expr = self;
+            loop {
+                expr.if_token.to_tokens(tokens);
+                print_expr(&expr.cond, tokens, FixupContext::new_condition());
+                expr.then_branch.to_tokens(tokens);
+
+                let (else_token, else_) = match &expr.else_branch {
+                    Some(else_branch) => else_branch,
+                    None => break,
+                };
+
+                else_token.to_tokens(tokens);
+                match &**else_ {
+                    Expr::If(next) => {
+                        expr = next;
+                    }
+                    Expr::Block(last) => {
+                        last.to_tokens(tokens);
+                        break;
+                    }
+                    // If this is not one of the valid expressions to exist in
+                    // an else clause, wrap it in a block.
+                    other => {
+                        token::Brace::default().surround(tokens, |tokens| {
+                            print_expr(other, tokens, FixupContext::new_stmt());
+                        });
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprIndex {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_index(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_index(e: &ExprIndex, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+            &e.expr,
+            #[cfg(feature = "full")]
+            true,
+            false,
+            #[cfg(feature = "full")]
+            Precedence::Unambiguous,
+        );
+        print_subexpression(
+            &e.expr,
+            left_prec < Precedence::Unambiguous,
+            tokens,
+            left_fixup,
+        );
+        e.bracket_token.surround(tokens, |tokens| {
+            e.index.to_tokens(tokens);
+        });
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprLet {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_let(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_let(e: &ExprLet, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.let_token.to_tokens(tokens);
+        e.pat.to_tokens(tokens);
+        e.eq_token.to_tokens(tokens);
+        let (right_prec, right_fixup) = fixup.rightmost_subexpression(&e.expr, Precedence::Let);
+        print_subexpression(&e.expr, right_prec < Precedence::Let, tokens, right_fixup);
+    }
+
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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);
+            print_expr(&self.expr, tokens, FixupContext::new_condition());
+            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
+                        && classify::requires_comma_to_be_match_arm(&arm.body)
+                        && arm.comma.is_none()
+                    {
+                        <Token![,]>::default().to_tokens(tokens);
+                    }
+                }
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprMethodCall {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_method_call(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_method_call(e: &ExprMethodCall, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_dot(&e.receiver);
+        print_subexpression(
+            &e.receiver,
+            left_prec < Precedence::Unambiguous,
+            tokens,
+            left_fixup,
+        );
+        e.dot_token.to_tokens(tokens);
+        e.method.to_tokens(tokens);
+        if let Some(turbofish) = &e.turbofish {
+            path::printing::print_angle_bracketed_generic_arguments(
+                tokens,
+                turbofish,
+                PathStyle::Expr,
+            );
+        }
+        e.paren_token.surround(tokens, |tokens| {
+            e.args.to_tokens(tokens);
+        });
+    }
+
+    #[cfg_attr(docsrs, 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(docsrs, 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_qpath(tokens, &self.qself, &self.path, PathStyle::Expr);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprRange {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_range(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_range(e: &ExprRange, tokens: &mut TokenStream, mut fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+
+        let needs_group = !e.attrs.is_empty();
+        if needs_group {
+            fixup = FixupContext::NONE;
+        }
+
+        let do_print_expr = |tokens: &mut TokenStream| {
+            if let Some(start) = &e.start {
+                let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_operator(
+                    start,
+                    true,
+                    false,
+                    Precedence::Range,
+                );
+                print_subexpression(start, left_prec <= Precedence::Range, tokens, left_fixup);
+            }
+            e.limits.to_tokens(tokens);
+            if let Some(end) = &e.end {
+                let right_fixup =
+                    fixup.rightmost_subexpression_fixup(false, true, Precedence::Range);
+                let right_prec = right_fixup.rightmost_subexpression_precedence(end);
+                print_subexpression(end, right_prec <= Precedence::Range, tokens, right_fixup);
+            }
+        };
+
+        if needs_group {
+            token::Paren::default().surround(tokens, do_print_expr);
+        } else {
+            do_print_expr(tokens);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprRawAddr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_raw_addr(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_raw_addr(e: &ExprRawAddr, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.and_token.to_tokens(tokens);
+        e.raw.to_tokens(tokens);
+        e.mutability.to_tokens(tokens);
+        let (right_prec, right_fixup) = fixup.rightmost_subexpression(&e.expr, Precedence::Prefix);
+        print_subexpression(
+            &e.expr,
+            right_prec < Precedence::Prefix,
+            tokens,
+            right_fixup,
+        );
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprReference {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_reference(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_reference(e: &ExprReference, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.and_token.to_tokens(tokens);
+        e.mutability.to_tokens(tokens);
+        let (right_prec, right_fixup) = fixup.rightmost_subexpression(
+            &e.expr,
+            #[cfg(feature = "full")]
+            Precedence::Prefix,
+        );
+        print_subexpression(
+            &e.expr,
+            right_prec < Precedence::Prefix,
+            tokens,
+            right_fixup,
+        );
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprReturn {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_return(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_return(e: &ExprReturn, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.return_token.to_tokens(tokens);
+        if let Some(expr) = &e.expr {
+            print_expr(
+                expr,
+                tokens,
+                fixup.rightmost_subexpression_fixup(true, false, Precedence::Jump),
+            );
+        }
+    }
+
+    #[cfg_attr(docsrs, 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_qpath(tokens, &self.qself, &self.path, PathStyle::Expr);
+            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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprTry {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_try(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_try(e: &ExprTry, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        let (left_prec, left_fixup) = fixup.leftmost_subexpression_with_dot(&e.expr);
+        print_subexpression(
+            &e.expr,
+            left_prec < Precedence::Unambiguous,
+            tokens,
+            left_fixup,
+        );
+        e.question_token.to_tokens(tokens);
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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_attr(docsrs, 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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprUnary {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_unary(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    fn print_expr_unary(e: &ExprUnary, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.op.to_tokens(tokens);
+        let (right_prec, right_fixup) = fixup.rightmost_subexpression(
+            &e.expr,
+            #[cfg(feature = "full")]
+            Precedence::Prefix,
+        );
+        print_subexpression(
+            &e.expr,
+            right_prec < Precedence::Prefix,
+            tokens,
+            right_fixup,
+        );
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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(docsrs, 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);
+            print_expr(&self.cond, tokens, FixupContext::new_condition());
+            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(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for ExprYield {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            print_expr_yield(self, tokens, FixupContext::NONE);
+        }
+    }
+
+    #[cfg(feature = "full")]
+    fn print_expr_yield(e: &ExprYield, tokens: &mut TokenStream, fixup: FixupContext) {
+        outer_attrs_to_tokens(&e.attrs, tokens);
+        e.yield_token.to_tokens(tokens);
+        if let Some(expr) = &e.expr {
+            print_expr(
+                expr,
+                tokens,
+                fixup.rightmost_subexpression_fixup(true, false, Precedence::Jump),
+            );
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, 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);
+            print_expr(&self.body, tokens, FixupContext::new_match_arm());
+            self.comma.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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(docsrs, 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),
+            }
+        }
+    }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PointerMutability {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                PointerMutability::Const(const_token) => const_token.to_tokens(tokens),
+                PointerMutability::Mut(mut_token) => mut_token.to_tokens(tokens),
+            }
+        }
+    }
+}