Enum rustc_middle::infer::canonical::CanonicalVarKind

pub enum CanonicalVarKind<'tcx> {
    Ty(CanonicalTyVarKind),
    PlaceholderTy(PlaceholderType),
    Region(UniverseIndex),
    PlaceholderRegion(PlaceholderRegion),
    Const(UniverseIndex, Ty<'tcx>),
    PlaceholderConst(PlaceholderConst<'tcx>, Ty<'tcx>),
}

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(PlaceholderType)

A “placeholder” that represents “any type”.

Region(UniverseIndex)

Region variable '?R.

PlaceholderRegion(PlaceholderRegion)

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.

PlaceholderConst(PlaceholderConst<'tcx>, Ty<'tcx>)

A “placeholder” that represents “any const”.

Implementations

impl<'tcx> CanonicalVarKind<'tcx>

pub fn universe(self) -> UniverseIndex

Trait Implementations

impl<'tcx> Clone for CanonicalVarKind<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for CanonicalVarKind<'tcx>

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

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<__D> for CanonicalVarKind<'tcx>

fn decode(__decoder: &mut __D) -> Self

impl<'tcx, __E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<__E> for CanonicalVarKind<'tcx>

fn encode(&self, __encoder: &mut __E)

impl<'tcx> Hash for CanonicalVarKind<'tcx>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

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

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

impl<'tcx> PartialEq<CanonicalVarKind<'tcx>> for CanonicalVarKind<'tcx>

fn eq(&self, other: &CanonicalVarKind<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'tcx> TypeFoldable<'tcx> for CanonicalVarKind<'tcx>

fn try_fold_with<__F: FallibleTypeFolder<'tcx>>(
    self,
    __folder: &mut __F
) -> Result<Self, __F::Error>

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

fn fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<'tcx> TypeVisitable<'tcx> for CanonicalVarKind<'tcx>

fn visit_with<__V: TypeVisitor<'tcx>>(
    &self,
    __visitor: &mut __V
) -> ControlFlow<__V::BreakTy>

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this type has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

Return true if this type has regions that are not a part of the type. For example, for<'a> fn(&'a i32) return false, while fn(&'a i32) would return true. The latter can occur when traversing through the former.

fn has_type_flags(&self, flags: TypeFlags) -> bool

fn has_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

fn references_error(&self) -> bool

fn error_reported(&self) -> Result<(), ErrorGuaranteed>

fn has_non_region_param(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_non_region_infer(&self) -> bool

fn needs_infer(&self) -> bool

fn has_placeholders(&self) -> bool

fn needs_subst(&self) -> bool

fn has_free_regions(&self) -> bool

“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound.

fn has_erased_regions(&self) -> bool

fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

fn is_global(&self) -> bool

Indicates whether this value references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching.

fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

impl<'tcx> Copy for CanonicalVarKind<'tcx>

impl<'tcx> Eq for CanonicalVarKind<'tcx>

impl<'tcx> StructuralEq for CanonicalVarKind<'tcx>

impl<'tcx> StructuralPartialEq for CanonicalVarKind<'tcx>

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 bytes
• PlaceholderTy: 16 bytes
• Region: 4 bytes
• PlaceholderRegion: 24 bytes
• Const: 24 bytes
• PlaceholderConst: 24 bytes