rustc_middle::ty

Struct Placeholder

Source
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>

Source

pub fn find_const_ty_from_env<'tcx>(self, env: ParamEnv<'tcx>) -> Ty<'tcx>

Trait Implementations§

Source§

impl<T: Clone> Clone for Placeholder<T>

Source§

fn clone(&self) -> Placeholder<T>

Returns a copy of the value. Read more
Source§

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

Performs copy-assignment from source. Read more
Source§

impl<T: Debug> Debug for Placeholder<T>

Source§

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

Formats the value using the given formatter. Read more
Source§

impl<T, __D: TyDecoder> Decodable<__D> for Placeholder<T>
where T: Decodable<__D>,

Source§

fn decode(__decoder: &mut __D) -> Self

Source§

impl<T, __E: TyEncoder> Encodable<__E> for Placeholder<T>
where T: Encodable<__E>,

Source§

fn encode(&self, __encoder: &mut __E)

Source§

impl<T: Hash> Hash for Placeholder<T>

Source§

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher. Read more
Source§

fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
Source§

impl<'__ctx, T> HashStable<StableHashingContext<'__ctx>> for Placeholder<T>
where T: HashStable<StableHashingContext<'__ctx>>,

Source§

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

Source§

impl<T: Ord> Ord for Placeholder<T>

Source§

fn cmp(&self, other: &Placeholder<T>) -> Ordering

This method returns an Ordering between self and other. Read more
Source§

fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
Source§

fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
Source§

fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized,

Restrict a value to a certain interval. Read more
Source§

impl<T: PartialEq> PartialEq for Placeholder<T>

Source§

fn eq(&self, other: &Placeholder<T>) -> bool

Tests for self and other values to be equal, and is used by ==.
Source§

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
Source§

impl<T: PartialOrd> PartialOrd for Placeholder<T>

Source§

fn partial_cmp(&self, other: &Placeholder<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
Source§

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator. Read more
Source§

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
Source§

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator. Read more
Source§

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Source§

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundRegion>

Source§

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

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f). Read more
Source§

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

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.
Source§

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundTy>

Source§

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

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f). Read more
Source§

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

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.
Source§

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Placeholder<BoundVar>

Source§

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

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f). Read more
Source§

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

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.
Source§

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundRegion>

Source§

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

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v). Read more
Source§

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundTy>

Source§

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

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v). Read more
Source§

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Placeholder<BoundVar>

Source§

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

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v). Read more
Source§

impl<T: Copy> Copy for Placeholder<T>

Source§

impl<T: Eq> Eq for Placeholder<T>

Source§

impl<T> StructuralPartialEq for Placeholder<T>

Auto Trait Implementations§

§

impl<T> DynSend for Placeholder<T>
where T: DynSend,

§

impl<T> DynSync for Placeholder<T>
where T: DynSync,

§

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<T> Aligned for T

Source§

const ALIGN: Alignment = _

Alignment of Self.
Source§

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

Source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
Source§

impl<T> AnyEq for T
where T: Any + PartialEq,

Source§

fn equals(&self, other: &(dyn Any + 'static)) -> bool

Source§

fn as_any(&self) -> &(dyn Any + 'static)

Source§

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

Source§

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

Source§

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

§

impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where 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> Borrow<T> for T
where T: ?Sized,

Source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
Source§

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

Source§

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

Mutably borrows from an owned value. Read more
Source§

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

Source§

unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
§

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

§

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

Equivalent to f(&iter.collect::<Vec<_>>()).

§

type Output = R

Source§

impl<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

Source§

fn compare(&self, key: &K) -> Ordering

Compare self to key and return their ordering.
§

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

§

default fn fingerprint_style() -> FingerprintStyle

§

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

§

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 DepNodes 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
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

Source§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
Source§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

Source§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
Source§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

Source§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
Source§

impl<T> Filterable for T

Source§

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> From<T> for T

Source§

fn from(t: T) -> T

Returns the argument unchanged.

Source§

impl<T> Instrument for T

Source§

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

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Source§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
Source§

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

Source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Source§

impl<T> IntoEither for T

Source§

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 more
Source§

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

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 more
Source§

impl<P> IntoQueryParam<P> for P

Source§

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

Source§

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

Whether this makes sense to suggest in a diagnostic. Read more
Source§

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

Source§

impl<T> MaybeResult<T> for T

Source§

type Error = !

Source§

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

Source§

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

Source§

impl<T> Pointable for T

Source§

const ALIGN: usize = _

The alignment of pointer.
Source§

type Init = T

The type for initializers.
Source§

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

Initializes a with the given initializer. Read more
Source§

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
Source§

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
Source§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
Source§

impl<T> Same for T

Source§

type Output = T

Should always be Self
Source§

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

Source§

type Owned = T

The resulting type after obtaining ownership.
Source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
Source§

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

Uses borrowed data to replace owned data, usually by cloning. Read more
Source§

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

Source§

type Error = Infallible

The type returned in the event of a conversion error.
Source§

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

Performs the conversion.
Source§

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

Source§

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

The type returned in the event of a conversion error.
Source§

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

Performs the conversion.
§

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

§

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

§

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).
§

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 more
§

fn 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

§

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_bound_regions(&self) -> bool

True if there are any late-bound regions
§

fn has_non_region_bound_vars(&self) -> bool

True if there are any late-bound non-region variables
§

fn has_bound_vars(&self) -> bool

True if there are any bound variables
§

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

§

fn upcast(self, interner: I) -> U

§

impl<I, T> UpcastFrom<I, T> for T

§

fn upcast_from(from: T, _tcx: I) -> T

Source§

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

Source§

fn vzip(self) -> V

§

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

§

default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T

Source§

impl<T> WithSubscriber for T

Source§

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

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Source§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
Source§

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

Source§

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

Source§

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

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.