Enum PredicateKind

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

Variants

Clause(ClauseKind<I>)

Prove a clause

DynCompatible(I::DefId)

Trait must be dyn-compatible.

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::Const, I::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 always be an unconstrained inference variable. It is used to normalize alias as much as possible. In case the alias is rigid - i.e. it cannot be normalized in the current environment - this constrains term to be equal to the alias itself.

It is likely more useful to think of this as a function normalizes_to(alias), whose return value is written into term.

AliasRelate(I::Term, I::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) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Interner> Debug for PredicateKind<I>

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

Formats the value using the given formatter.

impl<I: Interner, __D: TyDecoder<I = I>> Decodable<__D> for PredicateKind<I>

where ClauseKind<I>: Decodable<__D>, I::DefId: Decodable<__D>, SubtypePredicate<I>: Decodable<__D>, CoercePredicate<I>: Decodable<__D>, I::Const: Decodable<__D>, NormalizesTo<I>: Decodable<__D>, I::Term: Decodable<__D>,

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

impl<I: Interner, __E: TyEncoder<I = I>> Encodable<__E> for PredicateKind<I>

where ClauseKind<I>: Encodable<__E>, I::DefId: Encodable<__E>, SubtypePredicate<I>: Encodable<__E>, CoercePredicate<I>: Encodable<__E>, I::Const: Encodable<__E>, NormalizesTo<I>: Encodable<__E>, I::Term: Encodable<__E>,

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

impl<I> Hash for PredicateKind<I>

where I: Interner,

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

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

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

impl<I> PartialEq for PredicateKind<I>

where I: Interner,

fn eq(&self, __other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

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

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

fn try_fold_with<__F: FallibleTypeFolder<I>>( 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<I>>(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<I> TypeVisitable<I> for PredicateKind<I>

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

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

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

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.