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>(
18 canonical_goal: CanonicalPredicateGoal<'tcx>,
19 ) -> Result<EvaluationResult, OverflowError> {
20 debug!("evaluate_obligation(canonical_goal={:#?})", canonical_goal);
21 tcx.infer_ctxt().enter_with_canonical(
24 |ref infcx, goal, _canonical_inference_vars| {
25 debug!("evaluate_obligation: goal={:#?}", goal);
31 let mut selcx = SelectionContext::with_query_mode(&infcx, TraitQueryMode::Canonical);
32 let obligation = Obligation::new(ObligationCause::dummy(), param_env, predicate);
34 selcx.evaluate_root_obligation(&obligation)