map_bound_ref -> rebind

5 files changed, 32 insertions, 37 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 96a0c339e18..867ecea04e4 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -651,10 +651,10 @@ impl AutoTraitFinder<'tcx> {
                     {
                         self.add_user_pred(computed_preds, predicate);
                     }
-                    predicates.push_back(bound_predicate.map_bound_ref(|_| p));
+                    predicates.push_back(bound_predicate.rebind(p));
                 }
                 ty::PredicateAtom::Projection(p) => {
-                    let p = bound_predicate.map_bound_ref(|_| p);
+                    let p = bound_predicate.rebind(p);
                     debug!(
                         "evaluate_nested_obligations: examining projection predicate {:?}",
                         predicate
@@ -784,13 +784,13 @@ impl AutoTraitFinder<'tcx> {
                     }
                 }
                 ty::PredicateAtom::RegionOutlives(binder) => {
-                    let binder = bound_predicate.map_bound_ref(|_| binder);
+                    let binder = bound_predicate.rebind(binder);
                     if select.infcx().region_outlives_predicate(&dummy_cause, binder).is_err() {
                         return false;
                     }
                 }
                 ty::PredicateAtom::TypeOutlives(binder) => {
-                    let binder = bound_predicate.map_bound_ref(|_| binder);
+                    let binder = bound_predicate.rebind(binder);
                     match (
                         binder.no_bound_vars(),
                         binder.map_bound_ref(|pred| pred.0).no_bound_vars(),
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 3c4394e7d03..2b95da4c5b9 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -258,7 +258,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                 let bound_predicate = obligation.predicate.bound_atom(self.tcx);
                 match bound_predicate.skip_binder() {
                     ty::PredicateAtom::Trait(trait_predicate, _) => {
-                        let trait_predicate = bound_predicate.map_bound_ref(|_| trait_predicate);
+                        let trait_predicate = bound_predicate.rebind(trait_predicate);
                         let trait_predicate = self.resolve_vars_if_possible(&trait_predicate);
 
                         if self.tcx.sess.has_errors() && trait_predicate.references_error() {
@@ -532,7 +532,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     }
 
                     ty::PredicateAtom::RegionOutlives(predicate) => {
-                        let predicate = bound_predicate.map_bound_ref(|_| predicate);
+                        let predicate = bound_predicate.rebind(predicate);
                         let predicate = self.resolve_vars_if_possible(&predicate);
                         let err = self
                             .region_outlives_predicate(&obligation.cause, predicate)
@@ -1082,7 +1082,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
         let bound_error = error.bound_atom(self.tcx);
         let (cond, error) = match (cond.skip_binders(), bound_error.skip_binder()) {
             (ty::PredicateAtom::Trait(..), ty::PredicateAtom::Trait(error, _)) => {
-                (cond, bound_error.map_bound_ref(|_| error))
+                (cond, bound_error.rebind(error))
             }
             _ => {
                 // FIXME: make this work in other cases too.
@@ -1094,7 +1094,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
             let bound_predicate = obligation.predicate.bound_atom(self.tcx);
             if let ty::PredicateAtom::Trait(implication, _) = bound_predicate.skip_binder() {
                 let error = error.to_poly_trait_ref();
-                let implication = bound_predicate.map_bound_ref(|_| implication.trait_ref);
+                let implication = bound_predicate.rebind(implication.trait_ref);
                 // FIXME: I'm just not taking associated types at all here.
                 // Eventually I'll need to implement param-env-aware
                 // `Γ₁ ⊦ φ₁ => Γ₂ ⊦ φ₂` logic.
@@ -1178,7 +1178,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                 let (data, _) = self.replace_bound_vars_with_fresh_vars(
                     obligation.cause.span,
                     infer::LateBoundRegionConversionTime::HigherRankedType,
-                    &bound_predicate.map_bound_ref(|_| data),
+                    &bound_predicate.rebind(data),
                 );
                 let mut obligations = vec![];
                 let normalized_ty = super::normalize_projection_type(
@@ -1463,7 +1463,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
         let mut err = match bound_predicate.skip_binder() {
             ty::PredicateAtom::Trait(data, _) => {
                 let self_ty = data.trait_ref.self_ty();
-                let trait_ref = bound_predicate.map_bound_ref(|_| data.trait_ref);
+                let trait_ref = bound_predicate.rebind(data.trait_ref);
                 debug!("self_ty {:?} {:?} trait_ref {:?}", self_ty, self_ty.kind(), trait_ref);
 
                 if predicate.references_error() {
@@ -1587,7 +1587,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                 self.emit_inference_failure_err(body_id, span, a.into(), ErrorCode::E0282)
             }
             ty::PredicateAtom::Projection(data) => {
-                let trait_ref = bound_predicate.map_bound_ref(|_| data).to_poly_trait_ref(self.tcx);
+                let trait_ref = bound_predicate.rebind(data).to_poly_trait_ref(self.tcx);
                 let self_ty = trait_ref.skip_binder().self_ty();
                 let ty = data.ty;
                 if predicate.references_error() {
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index 01217457eb4..495a250be7c 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -353,7 +353,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
                 // This means we need to pass it the bound version of our
                 // predicate.
                 ty::PredicateAtom::Trait(trait_ref, _constness) => {
-                    let trait_obligation = obligation.with(binder.map_bound_ref(|_| trait_ref));
+                    let trait_obligation = obligation.with(binder.rebind(trait_ref));
 
                     self.process_trait_obligation(
                         obligation,
@@ -362,7 +362,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
                     )
                 }
                 ty::PredicateAtom::Projection(data) => {
-                    let project_obligation = obligation.with(binder.map_bound_ref(|_| data));
+                    let project_obligation = obligation.with(binder.rebind(data));
 
                     self.process_projection_obligation(
                         project_obligation,
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 295ba6041fb..63e1fe4a38a 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -634,9 +634,9 @@ fn prune_cache_value_obligations<'a, 'tcx>(
                 // indirect obligations (e.g., we project to `?0`,
                 // but we have `T: Foo<X = ?1>` and `?1: Bar<X =
                 // ?0>`).
-                ty::PredicateAtom::Projection(data) => infcx
-                    .unresolved_type_vars(&bound_predicate.map_bound_ref(|_| data.ty))
-                    .is_some(),
+                ty::PredicateAtom::Projection(data) => {
+                    infcx.unresolved_type_vars(&bound_predicate.rebind(data.ty)).is_some()
+                }
 
                 // We are only interested in `T: Foo<X = U>` predicates, whre
                 // `U` references one of `unresolved_type_vars`. =)
@@ -910,7 +910,7 @@ fn assemble_candidates_from_predicates<'cx, 'tcx>(
         debug!(?predicate);
         let bound_predicate = predicate.bound_atom(infcx.tcx);
         if let ty::PredicateAtom::Projection(data) = predicate.skip_binders() {
-            let data = bound_predicate.map_bound_ref(|_| data);
+            let data = bound_predicate.rebind(data);
             let same_def_id = data.projection_def_id() == obligation.predicate.item_def_id;
 
             let is_match = same_def_id
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 29c9c29d208..d0f1af253eb 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -449,17 +449,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         }
 
         let result = ensure_sufficient_stack(|| {
-            let bound_predicate = obligation.predicate.bound_atom(self.infcx().tcx);
+            let bound_predicate =
+                obligation.predicate.bound_atom_with_opt_escaping(self.infcx().tcx);
             match bound_predicate.skip_binder() {
                 ty::PredicateAtom::Trait(t, _) => {
-                    let t = bound_predicate.map_bound_ref(|_| t);
+                    let t = bound_predicate.rebind(t);
                     debug_assert!(!t.has_escaping_bound_vars());
                     let obligation = obligation.with(t);
                     self.evaluate_trait_predicate_recursively(previous_stack, obligation)
                 }
 
                 ty::PredicateAtom::Subtype(p) => {
-                    let p = bound_predicate.map_bound_ref(|_| p);
+                    let p = bound_predicate.rebind(p);
                     // Does this code ever run?
                     match self.infcx.subtype_predicate(&obligation.cause, obligation.param_env, p) {
                         Some(Ok(InferOk { mut obligations, .. })) => {
@@ -503,7 +504,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 }
 
                 ty::PredicateAtom::Projection(data) => {
-                    let data = bound_predicate.map_bound_ref(|_| data);
+                    let data = bound_predicate.rebind(data);
                     let project_obligation = obligation.with(data);
                     match project::poly_project_and_unify_type(self, &project_obligation) {
                         Ok(Ok(Some(mut subobligations))) => {
@@ -1177,7 +1178,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             .filter_map(|(idx, bound)| {
                 let bound_predicate = bound.bound_atom(self.infcx.tcx);
                 if let ty::PredicateAtom::Trait(pred, _) = bound_predicate.skip_binder() {
-                    let bound = bound_predicate.map_bound_ref(|_| pred.trait_ref);
+                    let bound = bound_predicate.rebind(pred.trait_ref);
                     if self.infcx.probe(|_| {
                         match self.match_projection(
                             obligation,
@@ -1534,15 +1535,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             ty::Tuple(tys) => Where(
                 obligation
                     .predicate
-                    .map_bound_ref(|_| tys.last().into_iter().map(|k| k.expect_ty()).collect()),
+                    .rebind(tys.last().into_iter().map(|k| k.expect_ty()).collect()),
             ),
 
             ty::Adt(def, substs) => {
                 let sized_crit = def.sized_constraint(self.tcx());
                 // (*) binder moved here
-                Where(obligation.predicate.map_bound_ref(|_| {
-                    sized_crit.iter().map(|ty| ty.subst(self.tcx(), substs)).collect()
-                }))
+                Where(
+                    obligation.predicate.rebind({
+                        sized_crit.iter().map(|ty| ty.subst(self.tcx(), substs)).collect()
+                    }),
+                )
             }
 
             ty::Projection(_) | ty::Param(_) | ty::Opaque(..) => None,
@@ -1594,16 +1597,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
             ty::Array(element_ty, _) => {
                 // (*) binder moved here
-                Where(obligation.predicate.map_bound_ref(|_| vec![*element_ty]))
+                Where(obligation.predicate.rebind(vec![*element_ty]))
             }
 
             ty::Tuple(tys) => {
                 // (*) binder moved here
-                Where(
-                    obligation
-                        .predicate
-                        .map_bound_ref(|_| tys.iter().map(|k| k.expect_ty()).collect()),
-                )
+                Where(obligation.predicate.rebind(tys.iter().map(|k| k.expect_ty()).collect()))
             }
 
             ty::Closure(_, substs) => {
@@ -1613,11 +1612,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     // Not yet resolved.
                     Ambiguous
                 } else {
-                    Where(
-                        obligation
-                            .predicate
-                            .map_bound_ref(|_| substs.as_closure().upvar_tys().collect()),
-                    )
+                    Where(obligation.predicate.rebind(substs.as_closure().upvar_tys().collect()))
                 }
             }