Enum rustc_trait_selection::traits::ImplSource

source ·
pub enum ImplSource<'tcx, N> {
    UserDefined(ImplSourceUserDefinedData<'tcx, N>),
    Param(Vec<N>),
    Builtin(BuiltinImplSource, Vec<N>),
}
Expand description

Given the successful resolution of an obligation, the ImplSource indicates where the impl comes from.

For example, the obligation may be satisfied by a specific impl (case A), or it may be relative to some bound that is in scope (case B).

impl<T:Clone> Clone<T> for Option<T> { ... } // Impl_1
impl<T:Clone> Clone<T> for Box<T> { ... }    // Impl_2
impl Clone for i32 { ... }                   // Impl_3

fn foo<T: Clone>(concrete: Option<Box<i32>>, param: T, mixed: Option<T>) {
    // Case A: ImplSource points at a specific impl. Only possible when
    // type is concretely known. If the impl itself has bounded
    // type parameters, ImplSource will carry resolutions for those as well:
    concrete.clone(); // ImplSource(Impl_1, [ImplSource(Impl_2, [ImplSource(Impl_3)])])

    // Case B: ImplSource must be provided by caller. This applies when
    // type is a type parameter.
    param.clone();    // ImplSource::Param

    // Case C: A mix of cases A and B.
    mixed.clone();    // ImplSource(Impl_1, [ImplSource::Param])
}

§The type parameter N

See explanation on ImplSourceUserDefinedData.

Variants§

§

UserDefined(ImplSourceUserDefinedData<'tcx, N>)

ImplSource identifying a particular impl.

§

Param(Vec<N>)

Successful resolution to an obligation provided by the caller for some type parameter. The Vec<N> represents the obligations incurred from normalizing the where-clause (if any).

§

Builtin(BuiltinImplSource, Vec<N>)

Successful resolution for a builtin impl.

Implementations§

source§

impl<'tcx, N> ImplSource<'tcx, N>

source

pub fn nested_obligations(self) -> Vec<N>

source

pub fn borrow_nested_obligations(&self) -> &[N]

source

pub fn borrow_nested_obligations_mut(&mut self) -> &mut [N]

source

pub fn map<M, F>(self, f: F) -> ImplSource<'tcx, M>
where F: FnMut(N) -> M,

Trait Implementations§

source§

impl<'tcx> ArenaAllocatable<'tcx> for ImplSource<'tcx, ()>

source§

fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut ImplSource<'tcx, ()>

source§

fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = ImplSource<'tcx, ()>>, ) -> &'a mut [ImplSource<'tcx, ()>]

source§

impl<'tcx, N> Clone for ImplSource<'tcx, N>
where N: Clone,

source§

fn clone(&self) -> ImplSource<'tcx, N>

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
source§

impl<'tcx, N> Debug for ImplSource<'tcx, N>
where N: Debug,

source§

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

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

impl<'tcx, D> Decodable<D> for &'tcx ImplSource<'tcx, ()>
where D: TyDecoder<I = TyCtxt<'tcx>>,

source§

fn decode(decoder: &mut D) -> &'tcx ImplSource<'tcx, ()>

source§

impl<'tcx, N, __D> Decodable<__D> for ImplSource<'tcx, N>
where __D: TyDecoder<I = TyCtxt<'tcx>>, ImplSourceUserDefinedData<'tcx, N>: Decodable<__D>, Vec<N>: Decodable<__D>,

source§

fn decode(__decoder: &mut __D) -> ImplSource<'tcx, N>

source§

impl<'tcx, N, __E> Encodable<__E> for ImplSource<'tcx, N>
where __E: TyEncoder<I = TyCtxt<'tcx>>, ImplSourceUserDefinedData<'tcx, N>: Encodable<__E>, Vec<N>: Encodable<__E>,

source§

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

source§

impl<'tcx, '__ctx, N> HashStable<StableHashingContext<'__ctx>> for ImplSource<'tcx, N>
where N: HashStable<StableHashingContext<'__ctx>>,

source§

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher<SipHasher128>, )

source§

impl<'tcx, N> PartialEq for ImplSource<'tcx, N>
where N: PartialEq,

source§

fn eq(&self, other: &ImplSource<'tcx, N>) -> bool

Tests for self and other values to be equal, and is used by ==.
1.0.0 · 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<'tcx, D> RefDecodable<'tcx, D> for ImplSource<'tcx, ()>
where D: TyDecoder<I = TyCtxt<'tcx>>,

source§

fn decode(decoder: &mut D) -> &'tcx ImplSource<'tcx, ()>

source§

impl<'tcx, N> TypeFoldable<TyCtxt<'tcx>> for ImplSource<'tcx, N>
where N: TypeFoldable<TyCtxt<'tcx>>,

source§

fn try_fold_with<__F>( self, __folder: &mut __F, ) -> Result<ImplSource<'tcx, N>, <__F as FallibleTypeFolder<TyCtxt<'tcx>>>::Error>
where __F: FallibleTypeFolder<TyCtxt<'tcx>>,

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>(self, folder: &mut F) -> Self
where F: TypeFolder<I>,

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, N> TypeVisitable<TyCtxt<'tcx>> for ImplSource<'tcx, N>
where N: TypeVisitable<TyCtxt<'tcx>>,

source§

fn visit_with<__V>( &self, __visitor: &mut __V, ) -> <__V as TypeVisitor<TyCtxt<'tcx>>>::Result
where __V: TypeVisitor<TyCtxt<'tcx>>,

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

impl<'tcx, N> Eq for ImplSource<'tcx, N>
where N: Eq,

source§

impl<'tcx, N> StructuralPartialEq for ImplSource<'tcx, N>

Auto Trait Implementations§

§

impl<'tcx, N> Freeze for ImplSource<'tcx, N>

§

impl<'tcx, N> !RefUnwindSafe for ImplSource<'tcx, N>

§

impl<'tcx, N> Send for ImplSource<'tcx, N>
where N: Send,

§

impl<'tcx, N> Sync for ImplSource<'tcx, N>
where N: Sync,

§

impl<'tcx, N> Unpin for ImplSource<'tcx, N>
where N: Unpin,

§

impl<'tcx, N> !UnwindSafe for ImplSource<'tcx, N>

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<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
source§

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

source§

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<_>>()).

source§

type Output = R

source§

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

source§

default fn fingerprint_style() -> FingerprintStyle

source§

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).
source§

default fn to_debug_str(&self, _: Tcx) -> String

source§

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> 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.
source§

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

source§

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

source§

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.
source§

fn error_reported(&self) -> Result<(), <I as Interner>::ErrorGuaranteed>

source§

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

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
source§

fn has_aliases(&self) -> bool

source§

fn has_opaque_types(&self) -> bool

source§

fn has_coroutines(&self) -> bool

source§

fn references_error(&self) -> bool

source§

fn has_non_region_param(&self) -> bool

source§

fn has_infer_regions(&self) -> bool

source§

fn has_infer_types(&self) -> bool

source§

fn has_non_region_infer(&self) -> bool

source§

fn has_infer(&self) -> bool

source§

fn has_placeholders(&self) -> bool

source§

fn has_non_region_placeholders(&self) -> bool

source§

fn has_param(&self) -> bool

source§

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.
source§

fn has_erased_regions(&self) -> bool

source§

fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.
source§

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

True if there are any late-bound regions
source§

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

True if there are any bound variables
source§

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 T
where U: UpcastFrom<I, T>,

source§

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

source§

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

source§

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

source§

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

source§

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

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: 48 bytes

Size for each variant:

  • UserDefined: 40 bytes
  • Param: 24 bytes
  • Builtin: 40 bytes