Enum rustc_trait_selection::infer::canonical::ir::PredicateKind

pub enum PredicateKind<I>
where
    I: Interner,
{
    Clause(ClauseKind<I>),
    ObjectSafe(<I as Interner>::DefId),
    Subtype(SubtypePredicate<I>),
    Coerce(CoercePredicate<I>),
    ConstEquate(<I as Interner>::Const, <I as Interner>::Const),
    Ambiguous,
    NormalizesTo(NormalizesTo<I>),
    AliasRelate(<I as Interner>::Term, <I as Interner>::Term, AliasRelationDirection),
}

Variants

Clause(ClauseKind<I>)

Prove a clause

ObjectSafe(<I as Interner>::DefId)

Trait must be object-safe.

Subtype(SubtypePredicate<I>)

T1 <: T2

This obligation is created most often when we have two unresolved type variables and hence don’t have enough information to process the subtyping obligation yet.

Coerce(CoercePredicate<I>)

T1 coerced to T2

Like a subtyping obligation, this is created most often when we have two unresolved type variables and hence don’t have enough information to process the coercion obligation yet. At the moment, we actually process coercions very much like subtyping and don’t handle the full coercion logic.

ConstEquate(<I as Interner>::Const, <I as Interner>::Const)

Constants must be equal. The first component is the const that is expected.

Ambiguous

A marker predicate that is always ambiguous. Used for coherence to mark opaque types as possibly equal to each other but ambiguous.

NormalizesTo(NormalizesTo<I>)

This should only be used inside of the new solver for AliasRelate and expects the term to be an unconstrained inference variable.

The alias normalizes to term. Unlike Projection, this always fails if the alias cannot be normalized in the current context. For the rigid alias T as Trait>::Assoc, Projection(<T as Trait>::Assoc, ?x) constrains ?x to <T as Trait>::Assoc while NormalizesTo(<T as Trait>::Assoc, ?x) results in NoSolution.

AliasRelate(<I as Interner>::Term, <I as Interner>::Term, AliasRelationDirection)

Separate from ClauseKind::Projection which is used for normalization in new solver. This predicate requires two terms to be equal to eachother.

Only used for new solver.

Trait Implementations

impl<I> Clone for PredicateKind<I>

where I: Interner,

fn clone(&self) -> PredicateKind<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I> Debug for PredicateKind<I>

where I: Interner,

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

Formats the value using the given formatter.

impl<I, __D> Decodable<__D> for PredicateKind<I>

where I: Interner, __D: TyDecoder<I = I>, ClauseKind<I>: Decodable<__D>, <I as Interner>::DefId: Decodable<__D>, SubtypePredicate<I>: Decodable<__D>, CoercePredicate<I>: Decodable<__D>, <I as Interner>::Const: Decodable<__D>, NormalizesTo<I>: Decodable<__D>, <I as Interner>::Term: Decodable<__D>,

fn decode(__decoder: &mut __D) -> PredicateKind<I>

impl<I, __E> Encodable<__E> for PredicateKind<I>

where I: Interner, __E: TyEncoder<I = I>, ClauseKind<I>: Encodable<__E>, <I as Interner>::DefId: Encodable<__E>, SubtypePredicate<I>: Encodable<__E>, CoercePredicate<I>: Encodable<__E>, <I as Interner>::Const: Encodable<__E>, NormalizesTo<I>: Encodable<__E>, <I as Interner>::Term: Encodable<__E>,

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

impl<'tcx, E> EncodableWithShorthand<E> for PredicateKind<TyCtxt<'tcx>>

where E: TyEncoder<I = TyCtxt<'tcx>>,

type Variant = PredicateKind<TyCtxt<'tcx>>

fn variant(&self) -> &PredicateKind<TyCtxt<'tcx>>

impl<I> Hash for PredicateKind<I>

where I: Interner,

fn hash<__HI>(&self, __state: &mut __HI)

where __HI: Hasher,

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<I, __CTX> HashStable<__CTX> for PredicateKind<I>

where I: Interner, ClauseKind<I>: HashStable<__CTX>, <I as Interner>::DefId: HashStable<__CTX>, SubtypePredicate<I>: HashStable<__CTX>, CoercePredicate<I>: HashStable<__CTX>, <I as Interner>::Const: HashStable<__CTX>, NormalizesTo<I>: HashStable<__CTX>, <I as Interner>::Term: HashStable<__CTX>,

fn hash_stable( &self, __hcx: &mut __CTX, __hasher: &mut StableHasher<SipHasher128>, )

impl<I> PartialEq for PredicateKind<I>

where I: Interner,

fn eq(&self, other: &PredicateKind<I>) -> 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, P> Print<'tcx, P> for PredicateKind<TyCtxt<'tcx>>

where P: PrettyPrinter<'tcx>,

fn print(&self, cx: &mut P) -> Result<(), Error>

impl<I> TypeFoldable<I> for PredicateKind<I>

where I: Interner, ClauseKind<I>: TypeFoldable<I>, <I as Interner>::DefId: TypeFoldable<I>, SubtypePredicate<I>: TypeFoldable<I>, CoercePredicate<I>: TypeFoldable<I>, <I as Interner>::Const: TypeFoldable<I>, NormalizesTo<I>: TypeFoldable<I>, <I as Interner>::Term: TypeFoldable<I>,

fn try_fold_with<__F>( self, __folder: &mut __F, ) -> Result<PredicateKind<I>, <__F as FallibleTypeFolder<I>>::Error>

where __F: FallibleTypeFolder<I>,

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

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

where F: TypeFolder<I>,

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<I> TypeVisitable<I> for PredicateKind<I>

where I: Interner, ClauseKind<I>: TypeVisitable<I>, <I as Interner>::DefId: TypeVisitable<I>, SubtypePredicate<I>: TypeVisitable<I>, CoercePredicate<I>: TypeVisitable<I>, <I as Interner>::Const: TypeVisitable<I>, NormalizesTo<I>: TypeVisitable<I>, <I as Interner>::Term: TypeVisitable<I>,

fn visit_with<__V>( &self, __visitor: &mut __V, ) -> <__V as TypeVisitor<I>>::Result

where __V: TypeVisitor<I>,

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

impl<'tcx> UpcastFrom<TyCtxt<'tcx>, PredicateKind<TyCtxt<'tcx>>> for Predicate<'tcx>

fn upcast_from( from: PredicateKind<TyCtxt<'tcx>>, tcx: TyCtxt<'tcx>, ) -> Predicate<'tcx>

impl<I> Copy for PredicateKind<I>

where I: Interner,

impl<I> Eq for PredicateKind<I>

where I: Interner,

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.