Enum rustc_infer::traits::ProjectionCacheEntry
source · pub enum ProjectionCacheEntry<'tcx> {
InProgress,
Ambiguous,
Recur,
Error,
NormalizedTerm {
ty: NormalizedTerm<'tcx>,
complete: Option<EvaluationResult>,
},
}
Variants§
InProgress
Ambiguous
Recur
Error
NormalizedTerm
Fields
ty: NormalizedTerm<'tcx>
complete: Option<EvaluationResult>
If we were able to successfully evaluate the
corresponding cache entry key during predicate
evaluation, then this field stores the final
result obtained from evaluating all of the projection
sub-obligations. During evaluation, we will skip
evaluating the cached sub-obligations in ty
if this field is set. Evaluation only
cares about the final result, so we don’t
care about any region constraint side-effects
produced by evaluating the sub-obligations.
Additionally, we will clear out the sub-obligations
entirely if we ever evaluate the cache entry (along
with all its sub obligations) to EvaluatedToOk
.
This affects all users of the cache, not just evaluation.
Since a result of EvaluatedToOk
means that there were
no region obligations that need to be tracked, it’s
fine to forget about the sub-obligations - they
don’t provide any additional information. However,
we do not discard any obligations when we see
EvaluatedToOkModuloRegions
- we don’t know
which sub-obligations may introduce region constraints,
so we keep them all to be safe.
When we are not performing evaluation
(e.g. in FulfillmentContext
), we ignore this field,
and always re-process the cached sub-obligations
(which may have been cleared out - see the above
paragraph).
This ensures that we do not lose any regions
constraints that arise from processing the
sub-obligations.
Trait Implementations§
source§impl<'tcx> Clone for ProjectionCacheEntry<'tcx>
impl<'tcx> Clone for ProjectionCacheEntry<'tcx>
source§fn clone(&self) -> ProjectionCacheEntry<'tcx>
fn clone(&self) -> ProjectionCacheEntry<'tcx>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreAuto Trait Implementations§
impl<'tcx> Freeze for ProjectionCacheEntry<'tcx>
impl<'tcx> !RefUnwindSafe for ProjectionCacheEntry<'tcx>
impl<'tcx> !Send for ProjectionCacheEntry<'tcx>
impl<'tcx> !Sync for ProjectionCacheEntry<'tcx>
impl<'tcx> Unpin for ProjectionCacheEntry<'tcx>
impl<'tcx> !UnwindSafe for ProjectionCacheEntry<'tcx>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<T, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
source§impl<T> Filterable for T
impl<T> Filterable for T
source§fn filterable(
self,
filter_name: &'static str,
) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§impl<P> IntoQueryParam<P> for P
impl<P> IntoQueryParam<P> for P
fn into_query_param(self) -> P
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
source§impl<I, T> UpcastFrom<I, T> for T
impl<I, T> UpcastFrom<I, T> for T
fn upcast_from(from: T, _tcx: I) -> T
source§impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T
source§impl<T> WithSubscriber for T
impl<T> WithSubscriber for T
source§fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
source§fn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
impl<'a, T> Captures<'a> for Twhere
T: ?Sized,
impl<T> ErasedDestructor for Twhere
T: 'static,
impl<T> MaybeSendSync for T
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: 40 bytes
Size for each variant:
InProgress
: 0 bytesAmbiguous
: 0 bytesRecur
: 0 bytesError
: 0 bytesNormalizedTerm
: 40 bytes