Enum rustc_hir::PatKind

pub enum PatKind<'hir> {
    Wild,
    Binding(BindingAnnotation, HirId, Ident, Option<&'hir Pat<'hir>>),
    Struct(QPath<'hir>, &'hir [PatField<'hir>], bool),
    TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], Option<usize>),
    Or(&'hir [Pat<'hir>]),
    Path(QPath<'hir>),
    Tuple(&'hir [Pat<'hir>], Option<usize>),
    Box(&'hir Pat<'hir>),
    Ref(&'hir Pat<'hir>, Mutability),
    Lit(&'hir Expr<'hir>),
    Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd),
    Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
}

Variants

Wild

Represents a wildcard pattern (i.e., _).

Binding(BindingAnnotation, HirId, Ident, Option<&'hir Pat<'hir>>)

A fresh binding ref mut binding @ OPT_SUBPATTERN. The HirId is the canonical ID for the variable being bound, (e.g., in Ok(x) | Err(x), both x use the same canonical ID), which is the pattern ID of the first x.

Tuple Fields of Binding

0: BindingAnnotation1: HirId2: Ident3: Option<&'hir Pat<'hir>>

Struct(QPath<'hir>, &'hir [PatField<'hir>], bool)

A struct or struct variant pattern (e.g., Variant {x, y, ..}). The bool is true in the presence of a ...

Tuple Fields of Struct

0: QPath<'hir>1: &'hir [PatField<'hir>]2: bool

TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], Option<usize>)

A tuple struct/variant pattern Variant(x, y, .., z). If the .. pattern fragment is present, then Option<usize> denotes its position. 0 <= position <= subpats.len()

Tuple Fields of TupleStruct

0: QPath<'hir>1: &'hir [Pat<'hir>]2: Option<usize>

Or(&'hir [Pat<'hir>])

An or-pattern A | B | C. Invariant: pats.len() >= 2.

Tuple Fields of Or

0: &'hir [Pat<'hir>]

Path(QPath<'hir>)

A path pattern for a unit struct/variant or a (maybe-associated) constant.

Tuple Fields of Path

0: QPath<'hir>

Tuple(&'hir [Pat<'hir>], Option<usize>)

A tuple pattern (e.g., (a, b)). If the .. pattern fragment is present, then Option<usize> denotes its position. 0 <= position <= subpats.len()

Tuple Fields of Tuple

0: &'hir [Pat<'hir>]1: Option<usize>

Box(&'hir Pat<'hir>)

A box pattern.

Tuple Fields of Box

0: &'hir Pat<'hir>

Ref(&'hir Pat<'hir>, Mutability)

A reference pattern (e.g., &mut (a, b)).

Tuple Fields of Ref

0: &'hir Pat<'hir>1: Mutability

Lit(&'hir Expr<'hir>)

A literal.

Tuple Fields of Lit

0: &'hir Expr<'hir>

Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd)

A range pattern (e.g., 1..=2 or 1..2).

Tuple Fields of Range

0: Option<&'hir Expr<'hir>>1: Option<&'hir Expr<'hir>>2: RangeEnd

Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>])

A slice pattern, [before_0, ..., before_n, (slice, after_0, ..., after_n)?].

Here, slice is lowered from the syntax ($binding_mode $ident @)? ... If slice exists, then after can be non-empty.

The representation for e.g., [a, b, .., c, d] is:

PatKind::Slice([Binding(a), Binding(b)], Some(Wild), [Binding(c), Binding(d)])

Tuple Fields of Slice

0: &'hir [Pat<'hir>]1: Option<&'hir Pat<'hir>>2: &'hir [Pat<'hir>]

Trait Implementations

impl<'hir> Debug for PatKind<'hir>

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

Formats the value using the given formatter.

impl<'hir, __CTX> HashStable<__CTX> for PatKind<'hir> where
    __CTX: HashStableContext, 

fn hash_stable(&self, __hcx: &mut __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: 64 bytes

Size for each variant:

• Wild: 0 bytes
• Binding: 31 bytes
• Struct: 47 bytes
• TupleStruct: 63 bytes
• Or: 23 bytes
• Path: 31 bytes
• Tuple: 39 bytes
• Box: 15 bytes
• Ref: 15 bytes
• Lit: 15 bytes
• Range: 23 bytes
• Slice: 47 bytes