change usages of explicit_item_bounds to bound_explicit_item_bounds

compiler/rustc_hir_analysis/src/check/check.rs

@@ -319,9 +319,12 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
             selftys: vec![],
         };
         let prohibit_opaque = tcx
-            .explicit_item_bounds(def_id)
+            .bound_explicit_item_bounds(def_id.to_def_id())
-            .iter()
+            .transpose_iter()
-            .try_for_each(|(predicate, _)| predicate.visit_with(&mut visitor));
+            .try_for_each(|bound| {
+                let predicate = bound.map_bound(|&(predicate, _)| predicate).subst_identity();
+                predicate.visit_with(&mut visitor)
+            });
 
         if let Some(ty) = prohibit_opaque.break_value() {
             visitor.visit_item(&item);

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -360,7 +360,10 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                             tcx,
                             param_env,
                             item_def_id,
-                            tcx.explicit_item_bounds(item_def_id).to_vec(),
+                            tcx.bound_explicit_item_bounds(item_def_id.to_def_id())
+                                .transpose_iter()
+                                .map(|bound| bound.map_bound(|b| *b).subst_identity())
+                                .collect::<Vec<_>>(),
                             &FxIndexSet::default(),
                             gat_def_id.def_id,
                             gat_generics,
@@ -1122,10 +1125,11 @@ fn check_trait(tcx: TyCtxt<'_>, item: &hir::Item<'_>) {
 /// Assuming the defaults are used, check that all predicates (bounds on the
 /// assoc type and where clauses on the trait) hold.
 fn check_associated_type_bounds(wfcx: &WfCheckingCtxt<'_, '_>, item: ty::AssocItem, span: Span) {
-    let bounds = wfcx.tcx().explicit_item_bounds(item.def_id);
+    let bounds = wfcx.tcx().bound_explicit_item_bounds(item.def_id);
 
     debug!("check_associated_type_bounds: bounds={:?}", bounds);
-    let wf_obligations = bounds.iter().flat_map(|&(bound, bound_span)| {
+    let wf_obligations = bounds.transpose_iter().flat_map(|b| {
+        let (bound, bound_span) = b.map_bound(|b| *b).subst_identity();
         let normalized_bound = wfcx.normalize(span, None, bound);
         traits::wf::predicate_obligations(
             wfcx.infcx,

compiler/rustc_hir_analysis/src/collect/item_bounds.rs

@@ -130,9 +130,10 @@ pub(super) fn item_bounds(
     tcx: TyCtxt<'_>,
     def_id: DefId,
 ) -> ty::EarlyBinder<&'_ ty::List<ty::Predicate<'_>>> {
-    let bounds = tcx.mk_predicates_from_iter(util::elaborate(
+    tcx.bound_explicit_item_bounds(def_id).map_bound(|bounds| {
+        tcx.mk_predicates_from_iter(util::elaborate(
             tcx,
-        tcx.explicit_item_bounds(def_id).iter().map(|&(bound, _span)| bound),
+            bounds.iter().map(|&(bound, _span)| bound),
-    ));
+        ))
-    ty::EarlyBinder(bounds)
+    })
 }

compiler/rustc_hir_typeck/src/generator_interior/mod.rs

@@ -571,7 +571,8 @@ fn check_must_not_suspend_ty<'tcx>(
         // FIXME: support adding the attribute to TAITs
         ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
             let mut has_emitted = false;
-            for &(predicate, _) in fcx.tcx.explicit_item_bounds(def) {
+            for bound in fcx.tcx.bound_explicit_item_bounds(def).transpose_iter() {
+                let predicate = bound.map_bound(|&(predicate, _)| predicate).subst_identity();
                 // We only look at the `DefId`, so it is safe to skip the binder here.
                 if let ty::PredicateKind::Clause(ty::Clause::Trait(ref poly_trait_predicate)) =
                     predicate.kind().skip_binder()

compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs

@@ -74,7 +74,9 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound {
         // For every projection predicate in the opaque type's explicit bounds,
         // check that the type that we're assigning actually satisfies the bounds
         // of the associated type.
-        for &(pred, pred_span) in cx.tcx.explicit_item_bounds(def_id) {
+        for bound in cx.tcx.bound_explicit_item_bounds(def_id).transpose_iter() {
+            let (pred, pred_span) = bound.map_bound(|b| *b).subst_identity();
+
             // Liberate bound regions in the predicate since we
             // don't actually care about lifetimes in this check.
             let predicate = cx.tcx.liberate_late_bound_regions(def_id, pred.kind());

compiler/rustc_lint/src/unused.rs

@@ -254,7 +254,13 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
                 }
                 ty::Adt(def, _) => is_def_must_use(cx, def.did(), span),
                 ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
-                    elaborate(cx.tcx, cx.tcx.explicit_item_bounds(def).iter().cloned())
+                    elaborate(
+                        cx.tcx,
+                        cx.tcx
+                            .bound_explicit_item_bounds(def)
+                            .transpose_iter()
+                            .map(|bound| bound.map_bound(|b| *b).subst_identity()),
+                    )
                     // We only care about self bounds for the impl-trait
                     .filter_only_self()
                     .find_map(|(pred, _span)| {

compiler/rustc_middle/src/ty/context.rs

@@ -1611,7 +1611,7 @@ impl<'tcx> TyCtxt<'tcx> {
         let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = ty.kind() else { return false };
         let future_trait = self.require_lang_item(LangItem::Future, None);
 
-        self.explicit_item_bounds(def_id).iter().any(|(predicate, _)| {
+        self.bound_explicit_item_bounds(*def_id).skip_binder().iter().any(|(predicate, _)| {
             let ty::PredicateKind::Clause(ty::Clause::Trait(trait_predicate)) = predicate.kind().skip_binder() else {
                 return false;
             };

compiler/rustc_mir_transform/src/generator.rs

@@ -1800,7 +1800,9 @@ fn check_must_not_suspend_ty<'tcx>(
         // FIXME: support adding the attribute to TAITs
         ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
             let mut has_emitted = false;
-            for &(predicate, _) in tcx.explicit_item_bounds(def) {
+            for bound in tcx.bound_explicit_item_bounds(def).transpose_iter() {
+                let predicate = bound.map_bound(|&(pred, _)| pred).subst_identity();
+
                 // We only look at the `DefId`, so it is safe to skip the binder here.
                 if let ty::PredicateKind::Clause(ty::Clause::Trait(ref poly_trait_predicate)) =
                     predicate.kind().skip_binder()

compiler/rustc_privacy/src/lib.rs

@@ -269,7 +269,7 @@ where
                     // and are visited by shallow visitors.
                     self.visit_predicates(ty::GenericPredicates {
                         parent: None,
-                        predicates: tcx.explicit_item_bounds(def_id),
+                        predicates: tcx.bound_explicit_item_bounds(def_id).skip_binder(),
                     })?;
                 }
             }
@@ -1784,7 +1784,10 @@ impl SearchInterfaceForPrivateItemsVisitor<'_> {
     fn bounds(&mut self) -> &mut Self {
         self.visit_predicates(ty::GenericPredicates {
             parent: None,
-            predicates: self.tcx.explicit_item_bounds(self.item_def_id),
+            predicates: self
+                .tcx
+                .bound_explicit_item_bounds(self.item_def_id.to_def_id())
+                .skip_binder(),
         });
         self
     }

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -297,8 +297,9 @@ fn bounds_reference_self(tcx: TyCtxt<'_>, trait_def_id: DefId) -> SmallVec<[Span
     tcx.associated_items(trait_def_id)
         .in_definition_order()
         .filter(|item| item.kind == ty::AssocKind::Type)
-        .flat_map(|item| tcx.explicit_item_bounds(item.def_id))
+        .flat_map(|item| tcx.bound_explicit_item_bounds(item.def_id).transpose_iter())
-        .filter_map(|pred_span| predicate_references_self(tcx, *pred_span))
+        .map(|bound| bound.map_bound(|b| *b).subst_identity())
+        .filter_map(|pred_span| predicate_references_self(tcx, pred_span))
         .collect()
 }
 

src/librustdoc/clean/mod.rs

@@ -421,9 +421,9 @@ fn clean_projection<'tcx>(
     if cx.tcx.is_impl_trait_in_trait(ty.skip_binder().def_id) {
         let bounds = cx
             .tcx
-            .explicit_item_bounds(ty.skip_binder().def_id)
+            .bound_explicit_item_bounds(ty.skip_binder().def_id)
-            .iter()
+            .subst_iter_copied(cx.tcx, ty.skip_binder().substs)
-            .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, ty.skip_binder().substs))
+            .map(|(pred, _)| pred)
             .collect::<Vec<_>>();
         return clean_middle_opaque_bounds(cx, bounds);
     }
@@ -1315,10 +1315,13 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
             }
 
             if let ty::TraitContainer = assoc_item.container {
-                let bounds = tcx.explicit_item_bounds(assoc_item.def_id);
+                let bounds = tcx
+                    .bound_explicit_item_bounds(assoc_item.def_id)
+                    .transpose_iter()
+                    .map(|bound| bound.map_bound(|b| *b).subst_identity());
                 let predicates = tcx.explicit_predicates_of(assoc_item.def_id).predicates;
                 let predicates =
-                    tcx.arena.alloc_from_iter(bounds.into_iter().chain(predicates).copied());
+                    tcx.arena.alloc_from_iter(bounds.chain(predicates.iter().copied()));
                 let mut generics = clean_ty_generics(
                     cx,
                     tcx.generics_of(assoc_item.def_id),
@@ -1844,9 +1847,9 @@ pub(crate) fn clean_middle_ty<'tcx>(
             // by looking up the bounds associated with the def_id.
             let bounds = cx
                 .tcx
-                .explicit_item_bounds(def_id)
+                .bound_explicit_item_bounds(def_id)
-                .iter()
+                .subst_iter_copied(cx.tcx, substs)
-                .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, substs))
+                .map(|(bound, _)| bound)
                 .collect::<Vec<_>>();
             clean_middle_opaque_bounds(cx, bounds)
         }

src/tools/clippy/clippy_lints/src/future_not_send.rs

@@ -4,7 +4,7 @@ use rustc_hir::intravisit::FnKind;
 use rustc_hir::{Body, FnDecl};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{self, AliasTy, Clause, EarlyBinder, PredicateKind};
+use rustc_middle::ty::{self, AliasTy, Clause, PredicateKind};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::{sym, Span};
@@ -64,10 +64,9 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
         }
         let ret_ty = return_ty(cx, cx.tcx.hir().local_def_id_to_hir_id(fn_def_id).expect_owner());
         if let ty::Alias(ty::Opaque, AliasTy { def_id, substs, .. }) = *ret_ty.kind() {
-            let preds = cx.tcx.explicit_item_bounds(def_id);
+            let preds = cx.tcx.bound_explicit_item_bounds(def_id);
             let mut is_future = false;
-            for &(p, _span) in preds {
+            for (p, _span) in preds.subst_iter_copied(cx.tcx, substs) {
-                let p = EarlyBinder(p).subst(cx.tcx, substs);
                 if let Some(trait_pred) = p.to_opt_poly_trait_pred() {
                     if Some(trait_pred.skip_binder().trait_ref.def_id) == cx.tcx.lang_items().future_trait() {
                         is_future = true;

src/tools/clippy/clippy_utils/src/ty.rs

@@ -90,7 +90,8 @@ pub fn contains_ty_adt_constructor_opaque<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'
                         return false;
                     }
 
-                    for &(predicate, _span) in cx.tcx.explicit_item_bounds(def_id) {
+                    for bound in cx.tcx.bound_explicit_item_bounds(def_id).transpose_iter() {
+                        let (predicate, _span) = bound.map_bound(|b| *b).subst_identity();
                         match predicate.kind().skip_binder() {
                             // For `impl Trait<U>`, it will register a predicate of `T: Trait<U>`, so we go through
                             // and check substituions to find `U`.
@@ -267,7 +268,7 @@ pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
         },
         ty::Tuple(substs) => substs.iter().any(|ty| is_must_use_ty(cx, ty)),
         ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) => {
-            for (predicate, _) in cx.tcx.explicit_item_bounds(*def_id) {
+            for (predicate, _) in cx.tcx.bound_explicit_item_bounds(*def_id).skip_binder() {
                 if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_predicate)) = predicate.kind().skip_binder() {
                     if cx.tcx.has_attr(trait_predicate.trait_ref.def_id, sym::must_use) {
                         return true;