pub struct Placeholder<T> {
pub universe: UniverseIndex,
pub bound: T,
}
Expand description
The “placeholder index” fully defines a placeholder region, type, or const. Placeholders are identified by both a universe, as well as a name residing within that universe. Distinct bound regions/types/consts within the same universe simply have an unknown relationship to one another.
Fields§
§universe: UniverseIndex
§bound: T
Implementations§
source§impl Placeholder<BoundVar>
impl Placeholder<BoundVar>
pub fn find_const_ty_from_env<'tcx>(self, env: ParamEnv<'tcx>) -> Ty<'tcx>
Trait Implementations§
source§impl<T: Clone> Clone for Placeholder<T>
impl<T: Clone> Clone for Placeholder<T>
source§fn clone(&self) -> Placeholder<T>
fn clone(&self) -> Placeholder<T>
Returns a copy of the value. Read more
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source
. Read moresource§impl<T: Debug> Debug for Placeholder<T>
impl<T: Debug> Debug for Placeholder<T>
source§impl<T: Hash> Hash for Placeholder<T>
impl<T: Hash> Hash for Placeholder<T>
source§impl<'__ctx, T> HashStable<StableHashingContext<'__ctx>> for Placeholder<T>where
T: HashStable<StableHashingContext<'__ctx>>,
impl<'__ctx, T> HashStable<StableHashingContext<'__ctx>> for Placeholder<T>where
T: HashStable<StableHashingContext<'__ctx>>,
fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )
source§impl<T: Ord> Ord for Placeholder<T>
impl<T: Ord> Ord for Placeholder<T>
source§fn cmp(&self, other: &Placeholder<T>) -> Ordering
fn cmp(&self, other: &Placeholder<T>) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
Compares and returns the maximum of two values. Read more
source§impl<T: PartialEq> PartialEq for Placeholder<T>
impl<T: PartialEq> PartialEq for Placeholder<T>
source§impl<T: PartialOrd> PartialOrd for Placeholder<T>
impl<T: PartialOrd> PartialOrd for Placeholder<T>
source§impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundRegion>
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundRegion>
source§fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
_: &mut F,
) -> Result<Self, F::Error>
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F, ) -> Result<Self, F::Error>
source§impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundTy>
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundTy>
source§fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
_: &mut F,
) -> Result<Self, F::Error>
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F, ) -> Result<Self, F::Error>
source§impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundVar>
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundVar>
source§fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
_: &mut F,
) -> Result<Self, F::Error>
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F, ) -> Result<Self, F::Error>
source§impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundRegion>
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundRegion>
source§fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
source§impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundTy>
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundTy>
source§fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
source§impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundVar>
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundVar>
source§fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
impl<T: Copy> Copy for Placeholder<T>
impl<T: Eq> Eq for Placeholder<T>
impl<T> StructuralPartialEq for Placeholder<T>
Auto Trait Implementations§
impl<T> Freeze for Placeholder<T>where
T: Freeze,
impl<T> RefUnwindSafe for Placeholder<T>where
T: RefUnwindSafe,
impl<T> Send for Placeholder<T>where
T: Send,
impl<T> Sync for Placeholder<T>where
T: Sync,
impl<T> Unpin for Placeholder<T>where
T: Unpin,
impl<T> UnwindSafe for Placeholder<T>where
T: UnwindSafe,
Blanket Implementations§
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
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]
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
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]
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
Mutably borrows from an owned value. Read more
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)
🔬This is a nightly-only experimental API. (
clone_to_uninit
)source§impl<T, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Tcx, T> DepNodeParams<Tcx> for T
impl<Tcx, T> DepNodeParams<Tcx> for T
default fn fingerprint_style() -> FingerprintStyle
source§default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
This method turns the parameters of a DepNodeConstructor into an opaque
Fingerprint to be used in DepNode.
Not all DepNodeParams support being turned into a Fingerprint (they
don’t need to if the corresponding DepNode is anonymous).
default fn to_debug_str(&self, _: Tcx) -> String
source§default fn recover(_: Tcx, _: &DepNode) -> Option<T>
default fn recover(_: Tcx, _: &DepNode) -> Option<T>
This method tries to recover the query key from the given
DepNode
,
something which is needed when forcing DepNode
s during red-green
evaluation. The query system will only call this method if
fingerprint_style()
is not FingerprintStyle::Opaque
.
It is always valid to return None
here, in which case incremental
compilation will treat the query as having changed instead of forcing it.source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to
key
and return true
if they are equal.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>
Creates a filterable data provider with the given name for debugging. Read more
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>
Converts
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>
Converts
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<'tcx, T> IsSuggestable<'tcx> for T
impl<'tcx, T> IsSuggestable<'tcx> for T
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<I, T> TypeVisitableExt<I> for Twhere
I: Interner,
T: TypeVisitable<I>,
impl<I, T> TypeVisitableExt<I> for Twhere
I: Interner,
T: TypeVisitable<I>,
fn has_type_flags(&self, flags: TypeFlags) -> bool
source§fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool
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 error_reported(&self) -> Result<(), <I as Interner>::ErrorGuaranteed>
source§fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool
fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool
Returns
true
if this type has any regions that escape binder
(and
hence are not bound by it).source§fn has_escaping_bound_vars(&self) -> bool
fn has_escaping_bound_vars(&self) -> bool
Return
true
if this type has regions that are not a part of the type.
For example, for<'a> fn(&'a i32)
return false
, while fn(&'a i32)
would return true
. The latter can occur when traversing through the
former. Read morefn has_aliases(&self) -> bool
fn has_opaque_types(&self) -> bool
fn has_coroutines(&self) -> bool
fn references_error(&self) -> bool
fn has_non_region_param(&self) -> bool
fn has_infer_regions(&self) -> bool
fn has_infer_types(&self) -> bool
fn has_non_region_infer(&self) -> bool
fn has_infer(&self) -> bool
fn has_placeholders(&self) -> bool
fn has_non_region_placeholders(&self) -> bool
fn has_param(&self) -> bool
source§fn has_free_regions(&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
source§fn has_erasable_regions(&self) -> bool
fn has_erasable_regions(&self) -> bool
True if there are any un-erased free regions.
source§fn is_global(&self) -> bool
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.
source§fn has_bound_regions(&self) -> bool
fn has_bound_regions(&self) -> bool
True if there are any late-bound regions
source§fn has_non_region_bound_vars(&self) -> bool
fn has_non_region_bound_vars(&self) -> bool
True if there are any late-bound non-region variables
source§fn has_bound_vars(&self) -> bool
fn has_bound_vars(&self) -> bool
True if there are any bound variables
source§fn still_further_specializable(&self) -> bool
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.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: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.