Enum ImplTraitContext

Source

pub(crate) enum ImplTraitContext {
    Universal,
    OpaqueTy {
        origin: OpaqueTyOrigin<LocalDefId>,
    },
    InBinding,
    FeatureGated(ImplTraitPosition, Symbol),
    Disallowed(ImplTraitPosition),
}

Expand description

Context of impl Trait in code, which determines whether it is allowed in an HIR subtree, and if so, what meaning it has.

Variants§

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Universal

Treat impl Trait as shorthand for a new universal generic parameter. Example: fn foo(x: impl Debug), where impl Debug is conceptually equivalent to a fresh universal parameter like fn foo<T: Debug>(x: T).

Newly generated parameters should be inserted into the given Vec.

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OpaqueTy

Treat impl Trait as shorthand for a new opaque type. Example: fn foo() -> impl Debug, where impl Debug is conceptually equivalent to a new opaque type like type T = impl Debug; fn foo() -> T.

Fields

§origin: OpaqueTyOrigin<LocalDefId>

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InBinding

Treat impl Trait as a “trait ascription”, which is like a type variable but that also enforces that a set of trait goals hold.

This is useful to guide inference for unnameable types.

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FeatureGated(ImplTraitPosition, Symbol)

impl Trait is unstably accepted in this position.

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Disallowed(ImplTraitPosition)

impl Trait is not accepted in this position.

Enum ImplTraitContextCopy item path

Variants§

Universal

OpaqueTy

Fields

InBinding

FeatureGated(ImplTraitPosition, Symbol)

Disallowed(ImplTraitPosition)

Trait Implementations§

impl Clone for ImplTraitContext

fn clone(&self) -> ImplTraitContext

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

impl Debug for ImplTraitContext

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

impl PartialEq for ImplTraitContext

fn eq(&self, other: &ImplTraitContext) -> bool

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

impl Copy for ImplTraitContext

impl Eq for ImplTraitContext

impl StructuralPartialEq for ImplTraitContext

Auto Trait Implementations§

impl DynSend for ImplTraitContext

impl DynSync for ImplTraitContext

impl Freeze for ImplTraitContext

impl RefUnwindSafe for ImplTraitContext

impl Send for ImplTraitContext

impl Sync for ImplTraitContext

impl Unpin for ImplTraitContext

impl UnwindSafe for ImplTraitContext

Blanket Implementations§

impl<T> Aligned for T

const ALIGN: Alignment

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

fn type_id(&self) -> TypeId

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

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

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

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 u8)

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

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

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

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

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

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

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<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 ImplTraitContext

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

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

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

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

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

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<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, 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,