Enum ExprKind

pub enum ExprKind<'tcx> {
    Scope {
        region_scope: Scope,
        lint_level: LintLevel,
        value: ExprId,
    },
    Box {
        value: ExprId,
    },
    If {
        if_then_scope: Scope,
        cond: ExprId,
        then: ExprId,
        else_opt: Option<ExprId>,
    },
    Call {
        ty: Ty<'tcx>,
        fun: ExprId,
        args: Box<[ExprId]>,
        from_hir_call: bool,
        fn_span: Span,
    },
    Deref {
        arg: ExprId,
    },
    Binary {
        op: BinOp,
        lhs: ExprId,
        rhs: ExprId,
    },
    LogicalOp {
        op: LogicalOp,
        lhs: ExprId,
        rhs: ExprId,
    },
    Unary {
        op: UnOp,
        arg: ExprId,
    },
    Cast {
        source: ExprId,
    },
    Use {
        source: ExprId,
    },
    NeverToAny {
        source: ExprId,
    },
    PointerCoercion {
        cast: PointerCoercion,
        source: ExprId,
        is_from_as_cast: bool,
    },
    Loop {
        body: ExprId,
    },
    Let {
        expr: ExprId,
        pat: Box<Pat<'tcx>>,
    },
    Match {
        scrutinee: ExprId,
        scrutinee_hir_id: HirId,
        arms: Box<[ArmId]>,
        match_source: MatchSource,
    },
    Block {
        block: BlockId,
    },
    Assign {
        lhs: ExprId,
        rhs: ExprId,
    },
    AssignOp {
        op: BinOp,
        lhs: ExprId,
        rhs: ExprId,
    },
    Field {
        lhs: ExprId,
        variant_index: VariantIdx,
        name: FieldIdx,
    },
    Index {
        lhs: ExprId,
        index: ExprId,
    },
    VarRef {
        id: LocalVarId,
    },
    UpvarRef {
        closure_def_id: DefId,
        var_hir_id: LocalVarId,
    },
    Borrow {
        borrow_kind: BorrowKind,
        arg: ExprId,
    },
    RawBorrow {
        mutability: Mutability,
        arg: ExprId,
    },
    Break {
        label: Scope,
        value: Option<ExprId>,
    },
    Continue {
        label: Scope,
    },
    Return {
        value: Option<ExprId>,
    },
    Become {
        value: ExprId,
    },
    ConstBlock {
        did: DefId,
        args: GenericArgsRef<'tcx>,
    },
    Repeat {
        value: ExprId,
        count: Const<'tcx>,
    },
    Array {
        fields: Box<[ExprId]>,
    },
    Tuple {
        fields: Box<[ExprId]>,
    },
    Adt(Box<AdtExpr<'tcx>>),
    PlaceTypeAscription {
        source: ExprId,
        user_ty: Option<Box<CanonicalUserType<'tcx>>>,
        user_ty_span: Span,
    },
    ValueTypeAscription {
        source: ExprId,
        user_ty: Option<Box<CanonicalUserType<'tcx>>>,
        user_ty_span: Span,
    },
    Closure(Box<ClosureExpr<'tcx>>),
    Literal {
        lit: &'tcx Lit,
        neg: bool,
    },
    NonHirLiteral {
        lit: ScalarInt,
        user_ty: Option<Box<CanonicalUserType<'tcx>>>,
    },
    ZstLiteral {
        user_ty: Option<Box<CanonicalUserType<'tcx>>>,
    },
    NamedConst {
        def_id: DefId,
        args: GenericArgsRef<'tcx>,
        user_ty: Option<Box<CanonicalUserType<'tcx>>>,
    },
    ConstParam {
        param: ParamConst,
        def_id: DefId,
    },
    StaticRef {
        alloc_id: AllocId,
        ty: Ty<'tcx>,
        def_id: DefId,
    },
    InlineAsm(Box<InlineAsmExpr<'tcx>>),
    OffsetOf {
        container: Ty<'tcx>,
        fields: &'tcx List<(VariantIdx, FieldIdx)>,
    },
    ThreadLocalRef(DefId),
    Yield {
        value: ExprId,
    },
}

Variants

Scope

Scopes are used to explicitly mark destruction scopes, and to track the HirId of the expressions within the scope.

Fields

region_scope: Scope

lint_level: LintLevel

value: ExprId

Box

A box <value> expression.

Fields

value: ExprId

If

An if expression.

Fields

if_then_scope: Scope

cond: ExprId

then: ExprId

else_opt: Option<ExprId>

Call

A function call. Method calls and overloaded operators are converted to plain function calls.

Fields

ty: Ty<'tcx>

The type of the function. This is often a FnDef or a FnPtr.

fun: ExprId

The function itself.

args: Box<[ExprId]>

The arguments passed to the function.

Note: in some cases (like calling a closure), the function call f(...args) gets rewritten as a call to a function trait method (e.g. FnOnce::call_once(f, (...args))).

from_hir_call: bool

Whether this is from an overloaded operator rather than a function call from HIR. true for overloaded function call.

fn_span: Span

The span of the function, without the dot and receiver (e.g. foo(a, b) in x.foo(a, b)).

Deref

A non-overloaded dereference.

Fields

arg: ExprId

Binary

A non-overloaded binary operation.

Fields

op: BinOp

lhs: ExprId

rhs: ExprId

LogicalOp

A logical operation. This is distinct from BinaryOp because the operands need to be lazily evaluated.

Fields

op: LogicalOp

lhs: ExprId

rhs: ExprId

Unary

A non-overloaded unary operation. Note that here the deref (*) operator is represented by ExprKind::Deref.

Fields

op: UnOp

arg: ExprId

Cast

A cast: <source> as <type>. The type we cast to is the type of the parent expression.

Fields

source: ExprId

Use

Forces its contents to be treated as a value expression, not a place expression. This is inserted in some places where an operation would otherwise be erased completely (e.g. some no-op casts), but we still need to ensure that its operand is treated as a value and not a place.

Fields

source: ExprId

NeverToAny

A coercion from ! to any type.

Fields

source: ExprId

PointerCoercion

A pointer coercion. More information can be found in PointerCoercion. Pointer casts that cannot be done by coercions are represented by ExprKind::Cast.

Fields

cast: PointerCoercion

source: ExprId

is_from_as_cast: bool

Whether this coercion is written with an as cast in the source code.

Loop

A loop expression.

Fields

body: ExprId

Let

Special expression representing the let part of an if let or similar construct (including if let guards in match arms, and let-chains formed by &&).

This isn’t considered a real expression in surface Rust syntax, so it can only appear in specific situations, such as within the condition of an if.

(Not to be confused with StmtKind::Let, which is a normal let statement.)

Fields

expr: ExprId

pat: Box<Pat<'tcx>>

Match

A match expression.

Fields

scrutinee: ExprId

scrutinee_hir_id: HirId

arms: Box<[ArmId]>

match_source: MatchSource

Block

A block.

Fields

block: BlockId

Assign

An assignment: lhs = rhs.

Fields

lhs: ExprId

rhs: ExprId

AssignOp

A non-overloaded operation assignment, e.g. lhs += rhs.

Fields

op: BinOp

lhs: ExprId

rhs: ExprId

Field

Access to a field of a struct, a tuple, an union, or an enum.

Fields

lhs: ExprId

variant_index: VariantIdx

Variant containing the field.

name: FieldIdx

This can be a named (.foo) or unnamed (.0) field.

Index

A non-overloaded indexing operation.

Fields

lhs: ExprId

index: ExprId

VarRef

A local variable.

Fields

id: LocalVarId

UpvarRef

Used to represent upvars mentioned in a closure/coroutine

Fields

closure_def_id: DefId

DefId of the closure/coroutine

var_hir_id: LocalVarId

HirId of the root variable

Borrow

A borrow, e.g. &arg.

Fields

borrow_kind: BorrowKind

arg: ExprId

RawBorrow

A &raw [const|mut] $place_expr raw borrow resulting in type *[const|mut] T.

Fields

mutability: Mutability

arg: ExprId

Break

A break expression.

Fields

label: Scope

value: Option<ExprId>

Continue

A continue expression.

Fields

label: Scope

Return

A return expression.

Fields

value: Option<ExprId>

Become

A become expression.

Fields

value: ExprId

ConstBlock

An inline const block, e.g. const {}.

Fields

did: DefId

args: GenericArgsRef<'tcx>

Repeat

An array literal constructed from one repeated element, e.g. [1; 5].

Fields

value: ExprId

count: Const<'tcx>

Array

An array, e.g. [a, b, c, d].

Fields

fields: Box<[ExprId]>

Tuple

A tuple, e.g. (a, b, c, d).

Fields

fields: Box<[ExprId]>

Adt(Box<AdtExpr<'tcx>>)

An ADT constructor, e.g. Foo {x: 1, y: 2}.

PlaceTypeAscription

A type ascription on a place.

Fields

source: ExprId

user_ty: Option<Box<CanonicalUserType<'tcx>>>

Type that the user gave to this expression

user_ty_span: Span

ValueTypeAscription

A type ascription on a value, e.g. type_ascribe!(42, i32) or 42 as i32.

Fields

source: ExprId

user_ty: Option<Box<CanonicalUserType<'tcx>>>

Type that the user gave to this expression

user_ty_span: Span

Closure(Box<ClosureExpr<'tcx>>)

A closure definition.

Literal

A literal.

Fields

lit: &'tcx Lit

neg: bool

NonHirLiteral

For literals that don’t correspond to anything in the HIR

Fields

lit: ScalarInt

user_ty: Option<Box<CanonicalUserType<'tcx>>>

ZstLiteral

A literal of a ZST type.

Fields

user_ty: Option<Box<CanonicalUserType<'tcx>>>

NamedConst

Associated constants and named constants

Fields

def_id: DefId

args: GenericArgsRef<'tcx>

user_ty: Option<Box<CanonicalUserType<'tcx>>>

ConstParam

Fields

param: ParamConst

def_id: DefId

StaticRef

A literal containing the address of a static.

This is only distinguished from Literal so that we can register some info for diagnostics.

Fields

alloc_id: AllocId

ty: Ty<'tcx>

def_id: DefId

InlineAsm(Box<InlineAsmExpr<'tcx>>)

Inline assembly, i.e. asm!().

OffsetOf

Field offset (offset_of!)

Fields

container: Ty<'tcx>

fields: &'tcx List<(VariantIdx, FieldIdx)>

ThreadLocalRef(DefId)

An expression taking a reference to a thread local.

Yield

A yield expression.

Fields

value: ExprId

Trait Implementations

impl<'tcx> Clone for ExprKind<'tcx>

fn clone(&self) -> ExprKind<'tcx>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for ExprKind<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for ExprKind<'tcx>

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes

Size for each variant:

• Scope: 23 bytes
• Box: 7 bytes
• If: 23 bytes
• Call: 39 bytes
• Deref: 7 bytes
• Binary: 11 bytes
• LogicalOp: 11 bytes
• Unary: 7 bytes
• Cast: 7 bytes
• Use: 7 bytes
• NeverToAny: 7 bytes
• PointerCoercion: 7 bytes
• Loop: 7 bytes
• Let: 15 bytes
• Match: 39 bytes
• Block: 7 bytes
• Assign: 11 bytes
• AssignOp: 11 bytes
• Field: 15 bytes
• Index: 11 bytes
• VarRef: 11 bytes
• UpvarRef: 19 bytes
• Borrow: 7 bytes
• RawBorrow: 7 bytes
• Break: 15 bytes
• Continue: 11 bytes
• Return: 7 bytes
• Become: 7 bytes
• ConstBlock: 23 bytes
• Repeat: 15 bytes
• Array: 23 bytes
• Tuple: 23 bytes
• Adt: 15 bytes
• PlaceTypeAscription: 23 bytes
• ValueTypeAscription: 23 bytes
• Closure: 15 bytes
• Literal: 15 bytes
• NonHirLiteral: 31 bytes
• ZstLiteral: 15 bytes
• NamedConst: 31 bytes
• ConstParam: 19 bytes
• StaticRef: 31 bytes
• InlineAsm: 15 bytes
• OffsetOf: 23 bytes
• ThreadLocalRef: 11 bytes
• Yield: 7 bytes