Enum rustc_middle::ty::PredicateKind

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

Variants

Trait(TraitPredicate<'tcx>, Constness)

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.

A trait predicate will have Constness::Const if it originates from a bound on a const fn without the ?const opt-out (e.g., const fn foobar<Foo: Bar>() {}).

RegionOutlives(RegionOutlivesPredicate<'tcx>)

where 'a: 'b

TypeOutlives(TypeOutlivesPredicate<'tcx>)

where T: 'a

Projection(ProjectionPredicate<'tcx>)

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

WellFormed(GenericArg<'tcx>)

No syntax: T well-formed.

ObjectSafe(DefId)

Trait must be object-safe.

ClosureKind(DefId, SubstsRef<'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.

Subtype(SubtypePredicate<'tcx>)

T1 <: T2

ConstEvaluatable(WithOptConstParam<DefId>, SubstsRef<'tcx>)

Constant initializer must evaluate successfully.

ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>)

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

TypeWellFormedFromEnv(Ty<'tcx>)

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

Only used for Chalk.

Trait Implementations

impl<'tcx> Clone for PredicateKind<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for PredicateKind<'tcx>

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

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for PredicateKind<'tcx>

fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

impl<'tcx> Display for PredicateKind<'tcx>

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

Formats the value using the given formatter.

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for PredicateKind<'tcx>

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl<'tcx, E: TyEncoder<'tcx>> EncodableWithShorthand<'tcx, E> for PredicateKind<'tcx>

type Variant = PredicateKind<'tcx>

fn variant(&self) -> &Self::Variant

impl<'tcx> Hash for PredicateKind<'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, 

Feeds a slice of this type into the given Hasher.

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

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

impl<'a, 'tcx> Lift<'tcx> for PredicateKind<'a>

type Lifted = PredicateKind<'tcx>

fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted>

impl<'tcx> PartialEq<PredicateKind<'tcx>> for PredicateKind<'tcx>

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

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

fn ne(&self, other: &PredicateKind<'tcx>) -> bool

This method tests for !=.

impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for PredicateKind<'tcx>

type Output = P

type Error = Error

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

impl<'tcx> ToPredicate<'tcx> for PredicateKind<'tcx>

fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx>

impl<'tcx> TypeFoldable<'tcx> for PredicateKind<'tcx>

fn super_fold_with<__F: TypeFolder<'tcx>>(self, __folder: &mut __F) -> Self

fn super_visit_with<__F: TypeVisitor<'tcx>>(
    &self,
    __folder: &mut __F
) -> ControlFlow<__F::BreakTy>

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

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

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 self has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

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 has_param_types_or_consts(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_infer_types_or_consts(&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 PredicateKind<'tcx>

impl<'tcx> Eq for PredicateKind<'tcx>

impl<'tcx> StructuralEq for PredicateKind<'tcx>

impl<'tcx> StructuralPartialEq for PredicateKind<'tcx>