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>>)

Tuple Fields

0: BindingAnnotation

1: HirId

2: Ident

3: 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.

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

Tuple Fields

0: QPath<'hir>

1: &'hir [PatField<'hir>]

2: bool

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

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

Tuple Fields

0: QPath<'hir>

1: &'hir [Pat<'hir>]

2: 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()

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

Tuple Fields

0: &'hir [Pat<'hir>]

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

Path(QPath<'hir>)

Tuple Fields

0: QPath<'hir>

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

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

Tuple Fields

0: &'hir [Pat<'hir>]

1: 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()

Box(&'hir Pat<'hir>)

Tuple Fields

0: &'hir Pat<'hir>

A box pattern.

Ref(&'hir Pat<'hir>, Mutability)

Tuple Fields

0: &'hir Pat<'hir>

1: Mutability

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

Lit(&'hir Expr<'hir>)

Tuple Fields

0: &'hir Expr<'hir>

A literal.

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

Tuple Fields

0: Option<&'hir Expr<'hir>>

1: Option<&'hir Expr<'hir>>

2: RangeEnd

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

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

Tuple Fields

0: &'hir [Pat<'hir>]

1: Option<&'hir Pat<'hir>>

2: &'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)])

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