Enum rustc_middle::ty::fast_reject::TreatParams

source ·

pub enum TreatParams {
    AsCandidateKey,
    ForLookup,
    NextSolverLookup,
}

Expand description

Generic parameters are pretty much just bound variables, e.g. the type of fn foo<'a, T>(x: &'a T) -> u32 { ... } can be thought of as for<'a, T> fn(&'a T) -> u32.

Typecheck of foo has to succeed for all possible generic arguments, so during typeck, we have to treat its generic parameters as if they were placeholders.

But when calling foo we only have to provide a specific generic argument. In that case the generic parameters are instantiated with inference variables. As we use simplify_type before that instantiation happens, we just treat generic parameters as if they were inference variables in that case.

Variants§

§

AsCandidateKey

Treat parameters as infer vars. This is the correct mode for caching an impl’s type for lookup.

§

ForLookup

Treat parameters as placeholders in the given environment. This is the correct mode for lookup, as during candidate selection.

This also treats projections with inference variables as infer vars since they could be further normalized.

§

NextSolverLookup

Treat parameters as placeholders in the given environment. This is the correct mode for lookup, as during candidate selection.

N.B. during deep rejection, this acts identically to ForLookup.

FIXME(-Ztrait-solver=next): Remove this variant and cleanup the code.

Enum rustc_middle::ty::fast_reject::TreatParams

Variants§

AsCandidateKey

ForLookup

NextSolverLookup

Trait Implementations§

impl Clone for TreatParams

fn clone(&self) -> TreatParams

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

impl Debug for TreatParams

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

impl PartialEq<TreatParams> for TreatParams

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

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

impl Copy for TreatParams

impl Eq for TreatParams

impl StructuralEq for TreatParams

impl StructuralPartialEq for TreatParams

Auto Trait Implementations§

impl RefUnwindSafe for TreatParams

impl Send for TreatParams

impl Sync for TreatParams

impl Unpin for TreatParams

impl UnwindSafe for TreatParams

Blanket Implementations§

impl<T> Aligned for T

const ALIGN: Alignment = _

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

fn type_id(&self) -> TypeId

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, 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<T> From<T> for T

fn from(t: T) -> T

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

fn into(self) -> U

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> ToOwned for Twhere T: Clone,

type Owned = T

fn to_owned(&self) -> T

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

impl<'tcx, T> ToPredicate<'tcx, T> for T

fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> 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>,

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

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

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

default fn from_cycle_error( tcx: Tcx, cycle: &[QueryInfo], _guar: ErrorGuaranteed ) -> T

Layout§