Type Alias PredicateObligation

pub type PredicateObligation<'tcx> = Obligation<'tcx, Predicate<'tcx>>;

Aliased Type

struct PredicateObligation<'tcx> {
    pub cause: ObligationCause<'tcx>,
    pub param_env: ParamEnv<'tcx>,
    pub predicate: Predicate<'tcx>,
    pub recursion_depth: usize,
}

Fields

cause: ObligationCause<'tcx>

The reason we have to prove this thing.

param_env: ParamEnv<'tcx>

The environment in which we should prove this thing.

predicate: Predicate<'tcx>

The thing we are trying to prove.

recursion_depth: usize

If we started proving this as a result of trying to prove something else, track the total depth to ensure termination. If this goes over a certain threshold, we abort compilation – in such cases, we can not say whether or not the predicate holds for certain. Stupid halting problem; such a drag.

Implementations

impl<'tcx> PredicateObligation<'tcx>

pub fn flip_polarity( &self, tcx: TyCtxt<'tcx>, ) -> Option<PredicateObligation<'tcx>>

Flips the polarity of the inner predicate.

Given T: Trait predicate it returns T: !Trait and given T: !Trait returns T: Trait.

Trait Implementations

impl<'tcx> Elaboratable<TyCtxt<'tcx>> for PredicateObligation<'tcx>

For Obligation, a sub-obligation is combined with the current obligation’s param-env and cause code.

fn predicate(&self) -> Predicate<'tcx>

fn child(&self, clause: Clause<'tcx>) -> Self

fn child_with_derived_cause( &self, clause: Clause<'tcx>, span: Span, parent_trait_pred: PolyTraitPredicate<'tcx>, index: usize, ) -> Self

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