Make InstantiatedPredicates impl IntoIterator

5 files changed, 27 insertions, 33 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
index df57c0f60fa..0419bb3f724 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
@@ -82,9 +82,7 @@ pub fn recompute_applicable_impls<'tcx>(
 
     let predicates =
         tcx.predicates_of(obligation.cause.body_id.owner.to_def_id()).instantiate_identity(tcx);
-    for obligation in
-        elaborate_predicates_with_span(tcx, std::iter::zip(predicates.predicates, predicates.spans))
-    {
+    for obligation in elaborate_predicates_with_span(tcx, predicates.into_iter()) {
         let kind = obligation.predicate.kind();
         if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = kind.skip_binder()
             && param_env_candidate_may_apply(kind.rebind(trait_pred))
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 5211f873a1e..6e2341a823b 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -2070,7 +2070,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
             // Find another predicate whose self-type is equal to the expected self type,
             // but whose substs don't match.
-            let other_pred = std::iter::zip(&predicates.predicates, &predicates.spans)
+            let other_pred = predicates.into_iter()
                 .enumerate()
                 .find(|(other_idx, (pred, _))| match pred.kind().skip_binder() {
                     ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred))
@@ -2095,7 +2095,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             // If we found one, then it's very likely the cause of the error.
             if let Some((_, (_, other_pred_span))) = other_pred {
                 err.span_note(
-                    *other_pred_span,
+                    other_pred_span,
                     "closure inferred to have a different signature due to this bound",
                 );
             }
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 13aa067844a..531aa23d6ea 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -115,14 +115,12 @@ pub fn predicates_for_generics<'tcx>(
     param_env: ty::ParamEnv<'tcx>,
     generic_bounds: ty::InstantiatedPredicates<'tcx>,
 ) -> impl Iterator<Item = PredicateObligation<'tcx>> {
-    std::iter::zip(generic_bounds.predicates, generic_bounds.spans).enumerate().map(
-        move |(idx, (predicate, span))| Obligation {
-            cause: cause(idx, span),
-            recursion_depth: 0,
-            param_env,
-            predicate,
-        },
-    )
+    generic_bounds.into_iter().enumerate().map(move |(idx, (predicate, span))| Obligation {
+        cause: cause(idx, span),
+        recursion_depth: 0,
+        param_env,
+        predicate,
+    })
 }
 
 /// Determines whether the type `ty` is known to meet `bound` and
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 15320916fbe..9c655aff0ba 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -2259,25 +2259,23 @@ fn confirm_impl_trait_in_trait_candidate<'tcx>(
         tcx.predicates_of(impl_fn_def_id).instantiate(tcx, impl_fn_substs),
         &mut obligations,
     );
-    obligations.extend(std::iter::zip(predicates.predicates, predicates.spans).map(
-        |(pred, span)| {
-            Obligation::with_depth(
-                tcx,
-                ObligationCause::new(
-                    obligation.cause.span,
-                    obligation.cause.body_id,
-                    if span.is_dummy() {
-                        super::ItemObligation(impl_fn_def_id)
-                    } else {
-                        super::BindingObligation(impl_fn_def_id, span)
-                    },
-                ),
-                obligation.recursion_depth + 1,
-                obligation.param_env,
-                pred,
-            )
-        },
-    ));
+    obligations.extend(predicates.into_iter().map(|(pred, span)| {
+        Obligation::with_depth(
+            tcx,
+            ObligationCause::new(
+                obligation.cause.span,
+                obligation.cause.body_id,
+                if span.is_dummy() {
+                    super::ItemObligation(impl_fn_def_id)
+                } else {
+                    super::BindingObligation(impl_fn_def_id, span)
+                },
+            ),
+            obligation.recursion_depth + 1,
+            obligation.param_env,
+            pred,
+        )
+    }));
 
     let ty = normalize_with_depth_to(
         selcx,
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index fec4047ff49..2cebad64c43 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -736,7 +736,7 @@ impl<'tcx> WfPredicates<'tcx> {
         trace!("{:#?}", predicates);
         debug_assert_eq!(predicates.predicates.len(), origins.len());
 
-        iter::zip(iter::zip(predicates.predicates, predicates.spans), origins.into_iter().rev())
+        iter::zip(predicates, origins.into_iter().rev())
             .map(|((mut pred, span), origin_def_id)| {
                 let code = if span.is_dummy() {
                     traits::ItemObligation(origin_def_id)