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>], DotDotPos),
Or(&'hir [Pat<'hir>]),
Path(QPath<'hir>),
Tuple(&'hir [Pat<'hir>], DotDotPos),
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
.
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 ..
.
TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], DotDotPos)
A tuple struct/variant pattern Variant(x, y, .., z)
.
If the ..
pattern fragment is present, then DotDotPos
denotes its position.
0 <= position <= subpats.len()
Or(&'hir [Pat<'hir>])
An or-pattern A | B | C
.
Invariant: pats.len() >= 2
.
Path(QPath<'hir>)
A path pattern for a unit struct/variant or a (maybe-associated) constant.
Tuple(&'hir [Pat<'hir>], DotDotPos)
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>)
A box
pattern.
Ref(&'hir Pat<'hir>, Mutability)
A reference pattern (e.g., &mut (a, b)
).
Lit(&'hir Expr<'hir>)
A literal.
Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd)
A range pattern (e.g., 1..=2
or 1..2
).
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)])
Trait Implementations§
source§impl<'hir, __CTX> HashStable<__CTX> for PatKind<'hir>where
__CTX: HashStableContext,
impl<'hir, __CTX> HashStable<__CTX> for PatKind<'hir>where __CTX: HashStableContext,
fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)
impl<'hir> Copy for PatKind<'hir>
Auto Trait Implementations§
impl<'hir> RefUnwindSafe for PatKind<'hir>
impl<'hir> !Send for PatKind<'hir>
impl<'hir> !Sync for PatKind<'hir>
impl<'hir> Unpin for PatKind<'hir>
impl<'hir> UnwindSafe for PatKind<'hir>
Blanket Implementations§
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere T: Copy,
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T
fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T> ) -> &'a mut [T]
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
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: 48 bytes
Size for each variant:
Wild
: 0 bytesBinding
: 31 bytesStruct
: 47 bytesTupleStruct
: 47 bytesOr
: 23 bytesPath
: 31 bytesTuple
: 23 bytesBox
: 15 bytesRef
: 15 bytesLit
: 15 bytesRange
: 23 bytesSlice
: 47 bytes