Enum rustc_trait_selection::traits::wf::Elaborate

source ·

enum Elaborate {
    All,
    None,
}

Expand description

Controls whether we “elaborate” supertraits and so forth on the WF predicates. This is a kind of hack to address #43784. The underlying problem in that issue was a trait structure like:

trait Foo: Copy { }
trait Bar: Foo { }
impl<T: Bar> Foo for T { }
impl<T> Bar for T { }

Here, in the Foo impl, we will check that T: Copy holds – but we decide that this is true because T: Bar is in the where-clauses (and we can elaborate that to include T: Copy). This wouldn’t be a problem, except that when we check the Bar impl, we decide that T: Foo must hold because of the Foo impl. And so nowhere did we check that T: Copy holds!

To resolve this, we elaborate the WF requirements that must be proven when checking impls. This means that (e.g.) the impl Bar for T will be forced to prove not only that T: Foo but also T: Copy (which it won’t be able to do, because there is no Copy impl for T).

Variants§

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Enum rustc_trait_selection::traits::wf::ElaborateCopy item path

Variants§

All

None

Trait Implementations§

impl Clone for Elaborate

fn clone(&self) -> Elaborate

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

impl Debug for Elaborate

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

impl PartialEq for Elaborate

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

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

impl Copy for Elaborate

impl Eq for Elaborate

impl StructuralPartialEq for Elaborate

Auto Trait Implementations§

impl Freeze for Elaborate

impl RefUnwindSafe for Elaborate

impl Send for Elaborate

impl Sync for Elaborate

impl Unpin for Elaborate

impl UnwindSafe for Elaborate

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

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

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

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

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

type Output = T

impl<T> ToOwned for Twhere T: Clone,

type Owned = T

fn to_owned(&self) -> T

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

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

type Error = Infallible

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

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

Enum rustc_trait_selection::traits::wf::Elaborate

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,