Trait rustc_trait_selection::infer::canonical::CanonicalExt

pub trait CanonicalExt<'tcx, V> {
    // Required methods
    fn substitute(
        &self,
        tcx: TyCtxt<'tcx>,
        var_values: &CanonicalVarValues<'tcx>
    ) -> V
       where V: TypeFoldable<TyCtxt<'tcx>>;
    fn substitute_projected<T>(
        &self,
        tcx: TyCtxt<'tcx>,
        var_values: &CanonicalVarValues<'tcx>,
        projection_fn: impl FnOnce(&V) -> T
    ) -> T
       where T: TypeFoldable<TyCtxt<'tcx>>;
}

FIXME(-Ztrait-solver=next): This or public because it is shared with the new trait solver implementation. We should deduplicate canonicalization.

Required Methods

fn substitute( &self, tcx: TyCtxt<'tcx>, var_values: &CanonicalVarValues<'tcx> ) -> Vwhere V: TypeFoldable<TyCtxt<'tcx>>,

Instantiate the wrapped value, replacing each canonical value with the value given in var_values.

fn substitute_projected<T>( &self, tcx: TyCtxt<'tcx>, var_values: &CanonicalVarValues<'tcx>, projection_fn: impl FnOnce(&V) -> T ) -> Twhere T: TypeFoldable<TyCtxt<'tcx>>,

Allows one to apply a substitute to some subset of self.value. Invoke projection_fn with self.value to get a value V that is expressed in terms of the same canonical variables bound in self (usually this extracts from subset of self). Apply the substitution var_values to this value V, replacing each of the canonical variables.

Implementors