1 use rustc::traits::query::CanonicalPredicateGoal;
3 EvaluationResult, Obligation, ObligationCause, OverflowError, SelectionContext, TraitQueryMode,
5 use rustc::ty::query::Providers;
6 use rustc::ty::{ParamEnvAnd, TyCtxt};
7 use syntax::source_map::DUMMY_SP;
9 crate fn provide(p: &mut Providers<'_>) {
16 fn evaluate_obligation<'tcx>(
17 tcx: TyCtxt<'_, 'tcx, 'tcx>,
18 canonical_goal: CanonicalPredicateGoal<'tcx>,
19 ) -> Result<EvaluationResult, OverflowError> {
20 tcx.infer_ctxt().enter_with_canonical(
23 |ref infcx, goal, _canonical_inference_vars| {
29 let mut selcx = SelectionContext::with_query_mode(&infcx, TraitQueryMode::Canonical);
30 let obligation = Obligation::new(ObligationCause::dummy(), param_env, predicate);
32 selcx.evaluate_obligation_recursively(&obligation)