pub enum CanonicalVarKind<'tcx> {
Ty(CanonicalTyVarKind),
PlaceholderTy(Placeholder<BoundTy>),
Region(UniverseIndex),
PlaceholderRegion(Placeholder<BoundRegion>),
Const(UniverseIndex, Ty<'tcx>),
Effect,
PlaceholderConst(Placeholder<BoundVar>, Ty<'tcx>),
}
Expand description
Describes the “kind” of the canonical variable. This is a “kind” in the type-theory sense of the term – i.e., a “meta” type system that analyzes type-like values.
Variants§
Ty(CanonicalTyVarKind)
Some kind of type inference variable.
PlaceholderTy(Placeholder<BoundTy>)
A “placeholder” that represents “any type”.
Region(UniverseIndex)
Region variable '?R
.
PlaceholderRegion(Placeholder<BoundRegion>)
A “placeholder” that represents “any region”. Created when you
are solving a goal like for<'a> T: Foo<'a>
to represent the
bound region 'a
.
Const(UniverseIndex, Ty<'tcx>)
Some kind of const inference variable.
Effect
Effect variable '?E
.
PlaceholderConst(Placeholder<BoundVar>, Ty<'tcx>)
A “placeholder” that represents “any const”.
Auto Trait Implementations§
impl<'tcx> !RefUnwindSafe for CanonicalVarKind<'tcx>
impl<'tcx> Send for CanonicalVarKind<'tcx>
impl<'tcx> Sync for CanonicalVarKind<'tcx>
impl<'tcx> Unpin for CanonicalVarKind<'tcx>
impl<'tcx> !UnwindSafe for CanonicalVarKind<'tcx>
Blanket Implementations§
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: 24 bytes
Size for each variant:
Ty
: 4 bytesPlaceholderTy
: 20 bytesRegion
: 4 bytesPlaceholderRegion
: 20 bytesConst
: 12 bytesEffect
: 0 bytesPlaceholderConst
: 20 bytes