Enum rustc_middle::infer::canonical::Certainty

source ·

pub enum Certainty {
    Proven,
    Ambiguous,
}

Expand description

Indicates whether or not we were able to prove the query to be true.

Variants§

§

Proven

The query is known to be true, presuming that you apply the given var_values and the region-constraints are satisfied.

§

Ambiguous

The query is not known to be true, but also not known to be false. The var_values represent either values that must hold in order for the query to be true, or helpful tips that might make it true. Currently rustc’s trait solver cannot distinguish the two (e.g., due to our preference for where clauses over impls).

After some unification and things have been done, it makes sense to try and prove again – of course, at that point, the canonical form will be different, making this a distinct query.

Enum rustc_middle::infer::canonical::Certainty

Variants§

Proven

Ambiguous

Implementations§

impl Certainty

pub fn is_proven(&self) -> bool

Trait Implementations§

impl Clone for Certainty

fn clone(&self) -> Certainty

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

impl Debug for Certainty

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

impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for Certainty

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

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Certainty

fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F ) -> Result<Self, F::Error>

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

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Certainty

fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>( &self, _: &mut F ) -> ControlFlow<F::BreakTy>

impl Copy for Certainty

Auto Trait Implementations§

impl RefUnwindSafe for Certainty

impl Send for Certainty

impl Sync for Certainty

impl Unpin for Certainty

impl UnwindSafe for Certainty

Blanket Implementations§

impl<T> Aligned for T

const ALIGN: Alignment = _

impl<T> Any for Twhere T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere T: Copy,

fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T

fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T> ) -> &'a mut [T]

impl<T> Borrow<T> for Twhere T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T, R> CollectAndApply<T, R> for T

fn collect_and_apply<I, F>(iter: I, f: F) -> Rwhere I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

type Output = R

impl<Tcx, T> DepNodeParams<Tcx> for Twhere Tcx: DepContext, T: for<'a> HashStable<StableHashingContext<'a>> + Debug,

default fn fingerprint_style() -> FingerprintStyle

default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint

default fn to_debug_str(&self, _: Tcx) -> String

default fn recover(_: Tcx, _: &DepNode) -> Option<T>

impl<T> From<T> for T

fn from(t: T) -> T

impl<T, U> Into<U> for Twhere U: From<T>,

fn into(self) -> U

impl<P> IntoQueryParam<P> for P

fn into_query_param(self) -> P

impl<'tcx, T> IsSuggestable<'tcx> for Twhere T: TypeVisitable<TyCtxt<'tcx>> + TypeFoldable<TyCtxt<'tcx>>,

fn is_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> bool

fn make_suggestable( self, tcx: TyCtxt<'tcx>, infer_suggestable: bool ) -> Option<T>

impl<T> MaybeResult<T> for T

type Error = !

fn from(_: Result<T, <T as MaybeResult<T>>::Error>) -> T

fn to_result(self) -> Result<T, <T as MaybeResult<T>>::Error>

impl<T> ToOwned for Twhere T: Clone,

type Owned = T

fn to_owned(&self) -> T

fn clone_into(&self, target: &mut T)

impl<'tcx, T> ToPredicate<'tcx, T> for T

fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> T

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

impl<'tcx, T> TypeVisitableExt<'tcx> for Twhere T: TypeVisitable<TyCtxt<'tcx>>,

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

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

fn has_escaping_bound_vars(&self) -> bool

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

fn has_projections(&self) -> bool

fn has_inherent_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

impl<'ctx> HashStable<StableHashingContext<'ctx>> for Certainty

fn hash_stable( &self, hcx: &mut StableHashingContext<'ctx>, __hasher: &mut StableHasher )

impl<T> Any for T
where T: 'static + ?Sized,

impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

impl<T> Borrow<T> for T
where T: ?Sized,

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn collect_and_apply<I, F>(iter: I, f: F) -> R
where I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

impl<Tcx, T> DepNodeParams<Tcx> for T
where Tcx: DepContext, T: for<'a> HashStable<StableHashingContext<'a>> + Debug,

impl<T, U> Into<U> for T
where U: From<T>,

impl<'tcx, T> IsSuggestable<'tcx> for T
where T: TypeVisitable<TyCtxt<'tcx>> + TypeFoldable<TyCtxt<'tcx>>,

impl<T> ToOwned for T
where T: Clone,

impl<T, U> TryFrom<U> for T
where U: Into<T>,

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

impl<'tcx, T> TypeVisitableExt<'tcx> for T
where T: TypeVisitable<TyCtxt<'tcx>>,

impl<Tcx, T> Value<Tcx> for T
where Tcx: DepContext,