refactor query_outlives_constraints_into_obligations

Author: lcnr

src/librustc_infer/infer/canonical/query_response.rs

@@ -525,12 +525,10 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
  result_subst: &'a CanonicalVarValues<'tcx>,
  ) -> impl Iterator<Item = PredicateObligation<'tcx>> + 'a + Captures<'tcx> {
  unsubstituted_region_constraints.iter().map(move |constraint| {
- let constraint = substitute_value(self.tcx, result_subst, constraint);
+ let ty::OutlivesPredicate(k1, r2) =
+ *substitute_value(self.tcx, result_subst, constraint).skip_binder();
 
- let to_predicate = |ty::OutlivesPredicate(k1, r2): ty::OutlivesPredicate<
- GenericArg<'tcx>,
- ty::Region<'tcx>,
- >| match k1.unpack() {
+ let predicate = match k1.unpack() {
  GenericArgKind::Lifetime(r1) => {
  ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(r1, r2))
  .to_predicate(self.tcx)
@@ -541,16 +539,11 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
  }
  GenericArgKind::Const(..) => {
  // Consts cannot outlive one another, so we don't expect to
- // ecounter this branch.
+ // encounter this branch.
  span_bug!(cause.span, "unexpected const outlives {:?}", constraint);
  }
- };
-
- let predicate = if let Some(constraint) = constraint.no_bound_vars() {
- to_predicate(constraint)
- } else {
- ty::PredicateKind::ForAll(constraint.map_bound(to_predicate)).to_predicate(self.tcx)
- };
+ }
+ .potentially_quantified(self.tcx, ty::PredicateKind::ForAll);
 
  Obligation::new(cause.clone(), param_env, predicate)
  })