Enum Certainty

source

pub enum Certainty {
    Proven,
    Ambiguous,
}

Expand description

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

Variants§

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Proven

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

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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 CertaintyCopy item path

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<(), Error>

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

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher<SipHasher128>, )

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

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

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

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

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

impl Copy for Certainty

Auto Trait Implementations§

impl DynSend for Certainty

impl DynSync for Certainty

impl Freeze for Certainty

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

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

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

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

fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx 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> CloneToUninit for Twhere T: Clone,

unsafe fn clone_to_uninit(&self, dst: *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> Filterable for T

fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>

impl<T> From<T> for T

fn from(t: T) -> T

impl<T> Instrument for T

fn instrument(self, span: Span) -> Instrumented<Self>

fn in_current_span(self) -> Instrumented<Self>

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

fn into(self) -> U

impl<T> IntoEither for T

fn into_either(self, into_left: bool) -> Either<Self, Self>

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>where F: FnOnce(&Self) -> bool,

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, placeholder: Option<Ty<'tcx>>, ) -> 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> Pointable for T

const ALIGN: usize = _

type Init = T

unsafe fn init(init: <T as Pointable>::Init) -> usize

Enum Certainty

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

fn hash_stable( &self, hcx: &mut StableHashingContext<'ctx>, __hasher: &mut StableHasher<SipHasher128>, )

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

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

fn visit_with<F>(&self, _: &mut F) -> <F as TypeVisitor<TyCtxt<'tcx>>>::Result
where F: TypeVisitor<TyCtxt<'tcx>>,

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

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

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,

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

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>,

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

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<I, T> TypeVisitableExt<I> for T
where I: Interner, T: TypeVisitable<I>,

impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

impl<'a, T> Captures<'a> for T
where T: ?Sized,

impl<T> ErasedDestructor for T
where T: 'static,

impl<T> MaybeSendSync for T
where T: Send + Sync,