Enum rustc_middle::ty::PredicateKind[][src]

pub enum PredicateKind<'tcx> {
    Trait(TraitPredicate<'tcx>),
    RegionOutlives(RegionOutlivesPredicate<'tcx>),
    TypeOutlives(TypeOutlivesPredicate<'tcx>),
    Projection(ProjectionPredicate<'tcx>),
    WellFormed(GenericArg<'tcx>),
    ObjectSafe(DefId),
    ClosureKind(DefIdSubstsRef<'tcx>, ClosureKind),
    Subtype(SubtypePredicate<'tcx>),
    Coerce(CoercePredicate<'tcx>),
    ConstEvaluatable(Unevaluated<'tcx, ()>),
    ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>),
    TypeWellFormedFromEnv(Ty<'tcx>),
}

Variants

Trait(TraitPredicate<'tcx>)

Corresponds to where Foo: Bar<A, B, C>. Foo here would be the Self type of the trait reference and A, B, and C would be the type parameters.

Tuple Fields of Trait

0: TraitPredicate<'tcx>
RegionOutlives(RegionOutlivesPredicate<'tcx>)

where 'a: 'b

Tuple Fields of RegionOutlives

0: RegionOutlivesPredicate<'tcx>
TypeOutlives(TypeOutlivesPredicate<'tcx>)

where T: 'a

Tuple Fields of TypeOutlives

0: TypeOutlivesPredicate<'tcx>
Projection(ProjectionPredicate<'tcx>)

where <T as TraitRef>::Name == X, approximately. See the ProjectionPredicate struct for details.

Tuple Fields of Projection

0: ProjectionPredicate<'tcx>
WellFormed(GenericArg<'tcx>)

No syntax: T well-formed.

Tuple Fields of WellFormed

0: GenericArg<'tcx>
ObjectSafe(DefId)

Trait must be object-safe.

Tuple Fields of ObjectSafe

0: DefId
ClosureKind(DefIdSubstsRef<'tcx>, ClosureKind)

No direct syntax. May be thought of as where T: FnFoo<...> for some substitutions ... and T being a closure type. Satisfied (or refuted) once we know the closure’s kind.

Tuple Fields of ClosureKind

0: DefId1: SubstsRef<'tcx>2: ClosureKind
Subtype(SubtypePredicate<'tcx>)

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.

Tuple Fields of Subtype

0: SubtypePredicate<'tcx>
Coerce(CoercePredicate<'tcx>)

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.

Tuple Fields of Coerce

0: CoercePredicate<'tcx>
ConstEvaluatable(Unevaluated<'tcx, ()>)

Constant initializer must evaluate successfully.

Tuple Fields of ConstEvaluatable

0: Unevaluated<'tcx, ()>
ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>)

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

Tuple Fields of ConstEquate

0: &'tcx Const<'tcx>1: &'tcx Const<'tcx>
TypeWellFormedFromEnv(Ty<'tcx>)

Represents a type found in the environment that we can use for implied bounds.

Only used for Chalk.

Tuple Fields of TypeWellFormedFromEnv

0: Ty<'tcx>

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

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

This method tests for !=.

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. Read more

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

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

True if there are any un-erased free regions.

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

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. Read more

True if there are any late-bound regions

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. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

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: 32 bytes

Size for each variant: