Move trait bound modifiers into hir::PolyTraitRef

32 files changed, 102 insertions, 100 deletions

diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 365924ef782..b19ccc59a71 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1225,7 +1225,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     itctx,
                     TraitBoundModifiers::NONE,
                 );
-                let bound = (bound, hir::TraitBoundModifier::None);
                 let bounds = this.arena.alloc_from_iter([bound]);
                 let lifetime_bound = this.elided_dyn_bound(t.span);
                 (bounds, lifetime_bound)
@@ -1328,8 +1327,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             // const trait bounds in trait object types.
                             GenericBound::Trait(ty, modifiers) => {
                                 let trait_ref = this.lower_poly_trait_ref(ty, itctx, *modifiers);
-                                let polarity = this.lower_trait_bound_modifiers(*modifiers);
-                                Some((trait_ref, polarity))
+                                Some(trait_ref)
                             }
                             GenericBound::Outlives(lifetime) => {
                                 if lifetime_bound.is_none() {
@@ -1958,21 +1956,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             span_ext: DUMMY_SP,
         });
 
-        hir::GenericBound::Trait(
-            hir::PolyTraitRef {
-                bound_generic_params: &[],
-                trait_ref: hir::TraitRef {
-                    path: self.make_lang_item_path(
-                        trait_lang_item,
-                        opaque_ty_span,
-                        Some(bound_args),
-                    ),
-                    hir_ref_id: self.next_id(),
-                },
-                span: opaque_ty_span,
+        hir::GenericBound::Trait(hir::PolyTraitRef {
+            bound_generic_params: &[],
+            modifiers: hir::TraitBoundModifier::None,
+            trait_ref: hir::TraitRef {
+                path: self.make_lang_item_path(trait_lang_item, opaque_ty_span, Some(bound_args)),
+                hir_ref_id: self.next_id(),
             },
-            hir::TraitBoundModifier::None,
-        )
+            span: opaque_ty_span,
+        })
     }
 
     #[instrument(level = "trace", skip(self))]
@@ -1982,10 +1974,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         itctx: ImplTraitContext,
     ) -> hir::GenericBound<'hir> {
         match tpb {
-            GenericBound::Trait(p, modifiers) => hir::GenericBound::Trait(
-                self.lower_poly_trait_ref(p, itctx, *modifiers),
-                self.lower_trait_bound_modifiers(*modifiers),
-            ),
+            GenericBound::Trait(p, modifiers) => {
+                hir::GenericBound::Trait(self.lower_poly_trait_ref(p, itctx, *modifiers))
+            }
             GenericBound::Outlives(lifetime) => {
                 hir::GenericBound::Outlives(self.lower_lifetime(lifetime))
             }
@@ -2194,7 +2185,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let bound_generic_params =
             self.lower_lifetime_binder(p.trait_ref.ref_id, &p.bound_generic_params);
         let trait_ref = self.lower_trait_ref(modifiers, &p.trait_ref, itctx);
-        hir::PolyTraitRef { bound_generic_params, trait_ref, span: self.lower_span(p.span) }
+        let modifiers = self.lower_trait_bound_modifiers(modifiers);
+        hir::PolyTraitRef {
+            bound_generic_params,
+            modifiers,
+            trait_ref,
+            span: self.lower_span(p.span),
+        }
     }
 
     fn lower_mt(&mut self, mt: &MutTy, itctx: ImplTraitContext) -> hir::MutTy<'hir> {
@@ -2634,10 +2631,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     Res::Def(DefKind::Trait | DefKind::TraitAlias, _) => {
                         let principal = hir::PolyTraitRef {
                             bound_generic_params: &[],
+                            modifiers: hir::TraitBoundModifier::None,
                             trait_ref: hir::TraitRef { path, hir_ref_id: hir_id },
                             span: self.lower_span(span),
                         };
-                        let principal = (principal, hir::TraitBoundModifier::None);
 
                         // The original ID is taken by the `PolyTraitRef`,
                         // so the `Ty` itself needs a different one.
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 39175b406a4..6333d59a1bc 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -254,7 +254,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         debug!(?hrtb_bounds);
 
         hrtb_bounds.iter().for_each(|bound| {
-            let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }, _) = bound else {
+            let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }) = bound else {
                 return;
             };
             diag.span_note(*trait_span, fluent::borrowck_limitations_implies_static);
@@ -277,7 +277,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     return;
                 };
                 bounds.iter().for_each(|bd| {
-                    if let Trait(PolyTraitRef { trait_ref: tr_ref, .. }, _) = bd
+                    if let Trait(PolyTraitRef { trait_ref: tr_ref, .. }) = bd
                         && let Def(_, res_defid) = tr_ref.path.res
                         && res_defid == trait_res_defid // trait id matches
                         && let TyKind::Path(Resolved(_, path)) = bounded_ty.kind
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_name.rs b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
index 1a5f9bdb154..b4b8373ac97 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_name.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
@@ -837,7 +837,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
                 hir_ty
             );
         };
-        if let hir::OpaqueTy { bounds: [hir::GenericBound::Trait(trait_ref, _)], .. } = opaque_ty
+        if let hir::OpaqueTy { bounds: [hir::GenericBound::Trait(trait_ref)], .. } = opaque_ty
             && let Some(segment) = trait_ref.trait_ref.path.segments.last()
             && let Some(args) = segment.args
             && let [constraint] = args.constraints
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 2ef6fa53f4e..1e9cbba94c7 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -520,7 +520,7 @@ pub enum TraitBoundModifier {
 
 #[derive(Clone, Copy, Debug, HashStable_Generic)]
 pub enum GenericBound<'hir> {
-    Trait(PolyTraitRef<'hir>, TraitBoundModifier),
+    Trait(PolyTraitRef<'hir>),
     Outlives(&'hir Lifetime),
     Use(&'hir [PreciseCapturingArg<'hir>], Span),
 }
@@ -528,7 +528,7 @@ pub enum GenericBound<'hir> {
 impl GenericBound<'_> {
     pub fn trait_ref(&self) -> Option<&TraitRef<'_>> {
         match self {
-            GenericBound::Trait(data, _) => Some(&data.trait_ref),
+            GenericBound::Trait(data) => Some(&data.trait_ref),
             _ => None,
         }
     }
@@ -2874,11 +2874,7 @@ pub enum TyKind<'hir> {
     OpaqueDef(&'hir OpaqueTy<'hir>, &'hir [GenericArg<'hir>]),
     /// A trait object type `Bound1 + Bound2 + Bound3`
     /// where `Bound` is a trait or a lifetime.
-    TraitObject(
-        &'hir [(PolyTraitRef<'hir>, TraitBoundModifier)],
-        &'hir Lifetime,
-        TraitObjectSyntax,
-    ),
+    TraitObject(&'hir [PolyTraitRef<'hir>], &'hir Lifetime, TraitObjectSyntax),
     /// Unused for now.
     Typeof(&'hir AnonConst),
     /// `TyKind::Infer` means the type should be inferred instead of it having been
@@ -3182,6 +3178,11 @@ pub struct PolyTraitRef<'hir> {
     /// The `'a` in `for<'a> Foo<&'a T>`.
     pub bound_generic_params: &'hir [GenericParam<'hir>],
 
+    /// The constness and polarity of the trait ref.
+    ///
+    /// The `async` modifier is lowered directly into a different trait for now.
+    pub modifiers: TraitBoundModifier,
+
     /// The `Foo<&'a T>` in `for<'a> Foo<&'a T>`.
     pub trait_ref: TraitRef<'hir>,
 
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index 58916d05865..ffe519b0e7d 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -905,7 +905,7 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) -> V::Resul
             try_visit!(visitor.visit_array_length(length));
         }
         TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
-            for (bound, _modifier) in bounds {
+            for bound in bounds {
                 try_visit!(visitor.visit_poly_trait_ref(bound));
             }
             try_visit!(visitor.visit_lifetime(lifetime));
@@ -1160,7 +1160,7 @@ pub fn walk_param_bound<'v, V: Visitor<'v>>(
     bound: &'v GenericBound<'v>,
 ) -> V::Result {
     match *bound {
-        GenericBound::Trait(ref typ, _modifier) => visitor.visit_poly_trait_ref(typ),
+        GenericBound::Trait(ref typ) => visitor.visit_poly_trait_ref(typ),
         GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
         GenericBound::Use(args, _) => {
             walk_list!(visitor, visit_precise_capturing_arg, args);
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 3a9d2640eee..1d78ea0c919 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -832,7 +832,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for GATArgsCollector<'tcx> {
 
 fn could_be_self(trait_def_id: LocalDefId, ty: &hir::Ty<'_>) -> bool {
     match ty.kind {
-        hir::TyKind::TraitObject([(trait_ref, _)], ..) => match trait_ref.trait_ref.path.segments {
+        hir::TyKind::TraitObject([trait_ref], ..) => match trait_ref.trait_ref.path.segments {
             [s] => s.res.opt_def_id() == Some(trait_def_id.to_def_id()),
             _ => false,
         },
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 6d30f7c7b9d..a87b29b3093 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -866,7 +866,7 @@ impl<'tcx> ItemCtxt<'tcx> {
     #[instrument(level = "trace", skip(self))]
     fn bound_defines_assoc_item(&self, b: &hir::GenericBound<'_>, assoc_name: Ident) -> bool {
         match b {
-            hir::GenericBound::Trait(poly_trait_ref, _) => {
+            hir::GenericBound::Trait(poly_trait_ref) => {
                 let trait_ref = &poly_trait_ref.trait_ref;
                 if let Some(trait_did) = trait_ref.trait_def_id() {
                     self.tcx.trait_may_define_assoc_item(trait_did, assoc_name)
diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index c8852a3a369..cb7f0901c7e 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -644,7 +644,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
                 debug!(?bounds, ?lifetime, "TraitObject");
                 let scope = Scope::TraitRefBoundary { s: self.scope };
                 self.with(scope, |this| {
-                    for (bound, _) in bounds {
+                    for bound in bounds {
                         this.visit_poly_trait_ref_inner(
                             bound,
                             NonLifetimeBinderAllowed::Deny("trait object types"),
@@ -1918,7 +1918,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                                 return None;
                             }
                             predicate.bounds.iter().find_map(|bound| {
-                                let hir::GenericBound::Trait(trait_, _) = bound else {
+                                let hir::GenericBound::Trait(trait_) = bound else {
                                     return None;
                                 };
                                 BoundVarContext::supertrait_hrtb_vars(
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
index 45cd46e3df2..8f7ca089c91 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
@@ -44,10 +44,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let mut unbounds: SmallVec<[_; 1]> = SmallVec::new();
         let mut search_bounds = |hir_bounds: &'tcx [hir::GenericBound<'tcx>]| {
             for hir_bound in hir_bounds {
-                let hir::GenericBound::Trait(ptr, modifier) = hir_bound else {
+                let hir::GenericBound::Trait(ptr) = hir_bound else {
                     continue;
                 };
-                match modifier {
+                match ptr.modifiers {
                     hir::TraitBoundModifier::Maybe => unbounds.push(ptr),
                     hir::TraitBoundModifier::Negative => {
                         if let Some(sized_def_id) = sized_def_id
@@ -156,8 +156,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     {
         for hir_bound in hir_bounds {
             match hir_bound {
-                hir::GenericBound::Trait(poly_trait_ref, modifier) => {
-                    let (constness, polarity) = match modifier {
+                hir::GenericBound::Trait(poly_trait_ref) => {
+                    let (constness, polarity) = match poly_trait_ref.modifiers {
                         hir::TraitBoundModifier::Const => {
                             (ty::BoundConstness::Const, ty::PredicatePolarity::Positive)
                         }
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
index 394a263fbb5..98822eec2ac 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
@@ -30,7 +30,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         &self,
         span: Span,
         hir_id: hir::HirId,
-        hir_trait_bounds: &[(hir::PolyTraitRef<'tcx>, hir::TraitBoundModifier)],
+        hir_trait_bounds: &[hir::PolyTraitRef<'tcx>],
         lifetime: &hir::Lifetime,
         representation: DynKind,
     ) -> Ty<'tcx> {
@@ -39,8 +39,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let mut bounds = Bounds::default();
         let mut potential_assoc_types = Vec::new();
         let dummy_self = self.tcx().types.trait_object_dummy_self;
-        for (trait_bound, modifier) in hir_trait_bounds.iter().rev() {
-            if *modifier == hir::TraitBoundModifier::Maybe {
+        for trait_bound in hir_trait_bounds.iter().rev() {
+            // FIXME: This doesn't handle `? const`.
+            if trait_bound.modifiers == hir::TraitBoundModifier::Maybe {
                 continue;
             }
             if let GenericArgCountResult {
@@ -263,7 +264,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 let args = tcx.mk_args(&args);
 
                 let span = i.bottom().1;
-                let empty_generic_args = hir_trait_bounds.iter().any(|(hir_bound, _)| {
+                let empty_generic_args = hir_trait_bounds.iter().any(|hir_bound| {
                     hir_bound.trait_ref.path.res == Res::Def(DefKind::Trait, trait_ref.def_id)
                         && hir_bound.span.contains(span)
                 });
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
index a735b8cc2a4..01768c89cca 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
@@ -718,7 +718,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         &self,
         associated_types: FxIndexMap<Span, FxIndexSet<DefId>>,
         potential_assoc_types: Vec<usize>,
-        trait_bounds: &[(hir::PolyTraitRef<'_>, hir::TraitBoundModifier)],
+        trait_bounds: &[hir::PolyTraitRef<'_>],
     ) {
         if associated_types.values().all(|v| v.is_empty()) {
             return;
@@ -764,12 +764,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // related to issue #91997, turbofishes added only when in an expr or pat
         let mut in_expr_or_pat = false;
         if let ([], [bound]) = (&potential_assoc_types[..], &trait_bounds) {
-            let grandparent = tcx.parent_hir_node(tcx.parent_hir_id(bound.0.trait_ref.hir_ref_id));
+            let grandparent = tcx.parent_hir_node(tcx.parent_hir_id(bound.trait_ref.hir_ref_id));
             in_expr_or_pat = match grandparent {
                 hir::Node::Expr(_) | hir::Node::Pat(_) => true,
                 _ => false,
             };
-            match bound.0.trait_ref.path.segments {
+            match bound.trait_ref.path.segments {
                 // FIXME: `trait_ref.path.span` can point to a full path with multiple
                 // segments, even though `trait_ref.path.segments` is of length `1`. Work
                 // around that bug here, even though it should be fixed elsewhere.
@@ -810,7 +810,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // and we can then use their span to indicate this to the user.
         let bound_names = trait_bounds
             .iter()
-            .filter_map(|(poly_trait_ref, _)| {
+            .filter_map(|poly_trait_ref| {
                 let path = poly_trait_ref.trait_ref.path.segments.last()?;
                 let args = path.args?;
 
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
index 11c0450bfe2..fd49e7e4439 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
@@ -50,7 +50,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 .ok()
                 .is_some_and(|s| s.trim_end().ends_with('<'));
 
-        let is_global = poly_trait_ref.0.trait_ref.path.is_global();
+        let is_global = poly_trait_ref.trait_ref.path.is_global();
 
         let mut sugg = vec![(
             self_ty.span.shrink_to_lo(),
@@ -211,7 +211,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // Check if trait object is safe for suggesting dynamic dispatch.
         let is_dyn_compatible = match self_ty.kind {
             hir::TyKind::TraitObject(objects, ..) => {
-                objects.iter().all(|(o, _)| match o.trait_ref.path.res {
+                objects.iter().all(|o| match o.trait_ref.path.res {
                     Res::Def(DefKind::Trait, id) => tcx.is_dyn_compatible(id),
                     _ => false,
                 })
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
index 9fe6a8ee342..9ebfd4f15ab 100644
--- a/compiler/rustc_hir_pretty/src/lib.rs
+++ b/compiler/rustc_hir_pretty/src/lib.rs
@@ -301,16 +301,13 @@ impl<'a> State<'a> {
                     self.word_space("dyn");
                 }
                 let mut first = true;
-                for (bound, modifier) in bounds {
+                for bound in bounds {
                     if first {
                         first = false;
                     } else {
                         self.nbsp();
                         self.word_space("+");
                     }
-                    if *modifier == TraitBoundModifier::Maybe {
-                        self.word("?");
-                    }
                     self.print_poly_trait_ref(bound);
                 }
                 if !lifetime.is_elided() {
@@ -679,6 +676,10 @@ impl<'a> State<'a> {
     }
 
     fn print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef<'_>) {
+        // FIXME: This isn't correct!
+        if t.modifiers == TraitBoundModifier::Maybe {
+            self.word("?");
+        }
         self.print_formal_generic_params(t.bound_generic_params);
         self.print_trait_ref(&t.trait_ref);
     }
@@ -2077,10 +2078,7 @@ impl<'a> State<'a> {
             }
 
             match bound {
-                GenericBound::Trait(tref, modifier) => {
-                    if modifier == &TraitBoundModifier::Maybe {
-                        self.word("?");
-                    }
+                GenericBound::Trait(tref) => {
                     self.print_poly_trait_ref(tref);
                 }
                 GenericBound::Outlives(lt) => {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 1df4d32f3cb..3e9e5326156 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -849,7 +849,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             hir::FnRetTy::Return(hir_ty) => {
                 if let hir::TyKind::OpaqueDef(op_ty, ..) = hir_ty.kind
                     // FIXME: account for RPITIT.
-                    && let [hir::GenericBound::Trait(trait_ref, _)] = op_ty.bounds
+                    && let [hir::GenericBound::Trait(trait_ref)] = op_ty.bounds
                     && let Some(hir::PathSegment { args: Some(generic_args), .. }) =
                         trait_ref.trait_ref.path.segments.last()
                     && let [constraint] = generic_args.constraints
@@ -1035,7 +1035,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // extract all bounds from the source code using their spans
         let all_matching_bounds_strs = predicates_from_where
             .filter_map(|bound| match bound {
-                GenericBound::Trait(_, _) => {
+                GenericBound::Trait(_) => {
                     self.tcx.sess.source_map().span_to_snippet(bound.span()).ok()
                 }
                 _ => None,
diff --git a/compiler/rustc_lint/src/traits.rs b/compiler/rustc_lint/src/traits.rs
index c0a01b0065e..5a3666dcbd4 100644
--- a/compiler/rustc_lint/src/traits.rs
+++ b/compiler/rustc_lint/src/traits.rs
@@ -112,10 +112,11 @@ impl<'tcx> LateLintPass<'tcx> for DropTraitConstraints {
 
     fn check_ty(&mut self, cx: &LateContext<'_>, ty: &'tcx hir::Ty<'tcx>) {
         let hir::TyKind::TraitObject(bounds, _lifetime, _syntax) = &ty.kind else { return };
-        for (bound, modifier) in &bounds[..] {
+        for bound in &bounds[..] {
             let def_id = bound.trait_ref.trait_def_id();
             if def_id.is_some_and(|def_id| cx.tcx.is_lang_item(def_id, LangItem::Drop))
-                && *modifier != hir::TraitBoundModifier::Maybe
+                // FIXME: ?Drop is not a thing.
+                && bound.modifiers != hir::TraitBoundModifier::Maybe
             {
                 let Some(def_id) = cx.tcx.get_diagnostic_item(sym::needs_drop) else { return };
                 cx.emit_span_lint(DYN_DROP, bound.span, DropGlue { tcx: cx.tcx, def_id });
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index 354ca746b46..4f408ee1574 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -192,7 +192,8 @@ fn suggest_changing_unsized_bound(
             .iter()
             .enumerate()
             .filter(|(_, bound)| {
-                if let hir::GenericBound::Trait(poly, hir::TraitBoundModifier::Maybe) = bound
+                if let hir::GenericBound::Trait(poly) = bound
+                    && poly.modifiers == hir::TraitBoundModifier::Maybe
                     && poly.trait_ref.trait_def_id() == def_id
                 {
                     true
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/find_anon_type.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/find_anon_type.rs
index 7a44c2ad661..2ecd28f4868 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/find_anon_type.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/find_anon_type.rs
@@ -86,7 +86,7 @@ impl<'tcx> Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
             }
 
             hir::TyKind::TraitObject(bounds, ..) => {
-                for (bound, _) in bounds {
+                for bound in bounds {
                     self.current_index.shift_in(1);
                     self.visit_poly_trait_ref(bound);
                     self.current_index.shift_out(1);
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
index a6ecd1cc987..8541621b23b 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
@@ -599,7 +599,7 @@ impl<'a, 'tcx> Visitor<'tcx> for HirTraitObjectVisitor<'a> {
             _,
         ) = t.kind
         {
-            for (ptr, _) in poly_trait_refs {
+            for ptr in poly_trait_refs {
                 if Some(self.1) == ptr.trait_ref.trait_def_id() {
                     self.0.push(ptr.span);
                 }
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
index cf0ab630f2e..62204f63dd0 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
@@ -894,7 +894,9 @@ fn foo(&self) -> Self::T { String::new() }
         // FIXME: we would want to call `resolve_vars_if_possible` on `ty` before suggesting.
 
         let trait_bounds = bounds.iter().filter_map(|bound| match bound {
-            hir::GenericBound::Trait(ptr, hir::TraitBoundModifier::None) => Some(ptr),
+            hir::GenericBound::Trait(ptr) if ptr.modifiers == hir::TraitBoundModifier::None => {
+                Some(ptr)
+            }
             _ => None,
         });
 
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs
index 709b6eb18e3..fc2d0ba36f0 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs
@@ -740,9 +740,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     ) if std::iter::zip(*last_bounds, *exp_bounds).all(|(left, right)| match (
                         left, right,
                     ) {
-                        (hir::GenericBound::Trait(tl, ml), hir::GenericBound::Trait(tr, mr))
+                        // FIXME: Suspicious
+                        (hir::GenericBound::Trait(tl), hir::GenericBound::Trait(tr))
                             if tl.trait_ref.trait_def_id() == tr.trait_ref.trait_def_id()
-                                && ml == mr =>
+                                && tl.modifiers == tr.modifiers =>
                         {
                             true
                         }
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
index becc1acfb66..ba57909fc23 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
@@ -439,7 +439,7 @@ pub fn report_dyn_incompatibility<'tcx>(
         if tcx.parent_hir_node(hir_id).fn_sig().is_some() {
             // Do not suggest `impl Trait` when dealing with things like super-traits.
             err.span_suggestion_verbose(
-                ty.span.until(trait_ref.0.span),
+                ty.span.until(trait_ref.span),
                 "consider using an opaque type instead",
                 "impl ",
                 Applicability::MaybeIncorrect,
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 87834c329e1..733baaa99e5 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -3074,11 +3074,11 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     match ty.kind {
                         hir::TyKind::TraitObject(traits, _, _) => {
                             let (span, kw) = match traits {
-                                [(first, _), ..] if first.span.lo() == ty.span.lo() => {
+                                [first, ..] if first.span.lo() == ty.span.lo() => {
                                     // Missing `dyn` in front of trait object.
                                     (ty.span.shrink_to_lo(), "dyn ")
                                 }
-                                [(first, _), ..] => (ty.span.until(first.span), ""),
+                                [first, ..] => (ty.span.until(first.span), ""),
                                 [] => span_bug!(ty.span, "trait object with no traits: {ty:?}"),
                             };
                             let needs_parens = traits.len() != 1;
@@ -5162,7 +5162,7 @@ pub fn suggest_desugaring_async_fn_to_impl_future_in_trait<'tcx>(
     let async_span = tcx.sess.source_map().span_extend_while_whitespace(async_span);
 
     let future = tcx.hir_node_by_def_id(opaque_def_id).expect_opaque_ty();
-    let [hir::GenericBound::Trait(trait_ref, _)] = future.bounds else {
+    let [hir::GenericBound::Trait(trait_ref)] = future.bounds else {
         // `async fn` should always lower to a single bound... but don't ICE.
         return None;
     };
diff --git a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
index 45e7de942fb..364a13b3a75 100644
--- a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
+++ b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
@@ -125,7 +125,7 @@ fn sized_trait_bound_spans<'tcx>(
     bounds: hir::GenericBounds<'tcx>,
 ) -> impl 'tcx + Iterator<Item = Span> {
     bounds.iter().filter_map(move |b| match b {
-        hir::GenericBound::Trait(trait_ref, hir::TraitBoundModifier::None)
+        hir::GenericBound::Trait(trait_ref)
             if trait_has_sized_self(
                 tcx,
                 trait_ref.trait_ref.trait_def_id().unwrap_or_else(|| FatalError.raise()),
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index fa73733360c..1ddad917b78 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -214,15 +214,15 @@ fn clean_generic_bound<'tcx>(
 ) -> Option<GenericBound> {
     Some(match *bound {
         hir::GenericBound::Outlives(lt) => GenericBound::Outlives(clean_lifetime(lt, cx)),
-        hir::GenericBound::Trait(ref t, modifier) => {
+        hir::GenericBound::Trait(ref t) => {
             // `T: ~const Destruct` is hidden because `T: Destruct` is a no-op.
-            if modifier == hir::TraitBoundModifier::MaybeConst
+            if t.modifiers == hir::TraitBoundModifier::MaybeConst
                 && cx.tcx.lang_items().destruct_trait() == Some(t.trait_ref.trait_def_id().unwrap())
             {
                 return None;
             }
 
-            GenericBound::TraitBound(clean_poly_trait_ref(t, cx), modifier)
+            GenericBound::TraitBound(clean_poly_trait_ref(t, cx), t.modifiers)
         }
         hir::GenericBound::Use(args, ..) => {
             GenericBound::Use(args.iter().map(|arg| arg.name()).collect())
@@ -1833,7 +1833,7 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
         }
         TyKind::Path(_) => clean_qpath(ty, cx),
         TyKind::TraitObject(bounds, lifetime, _) => {
-            let bounds = bounds.iter().map(|(bound, _)| clean_poly_trait_ref(bound, cx)).collect();
+            let bounds = bounds.iter().map(|bound| clean_poly_trait_ref(bound, cx)).collect();
             let lifetime =
                 if !lifetime.is_elided() { Some(clean_lifetime(lifetime, cx)) } else { None };
             DynTrait(bounds, lifetime)
diff --git a/src/tools/clippy/clippy_lints/src/implied_bounds_in_impls.rs b/src/tools/clippy/clippy_lints/src/implied_bounds_in_impls.rs
index 5f349d78053..590d9afd1b4 100644
--- a/src/tools/clippy/clippy_lints/src/implied_bounds_in_impls.rs
+++ b/src/tools/clippy/clippy_lints/src/implied_bounds_in_impls.rs
@@ -242,7 +242,8 @@ fn collect_supertrait_bounds<'tcx>(cx: &LateContext<'tcx>, bounds: GenericBounds
     bounds
         .iter()
         .filter_map(|bound| {
-            if let GenericBound::Trait(poly_trait, TraitBoundModifier::None) = bound
+            if let GenericBound::Trait(poly_trait) = bound
+                && let TraitBoundModifier::None = poly_trait.modifiers
                 && let [.., path] = poly_trait.trait_ref.path.segments
                 && poly_trait.bound_generic_params.is_empty()
                 && let Some(trait_def_id) = path.res.opt_def_id()
@@ -307,7 +308,8 @@ fn check<'tcx>(cx: &LateContext<'tcx>, bounds: GenericBounds<'tcx>) {
     // This involves some extra logic when generic arguments are present, since
     // simply comparing trait `DefId`s won't be enough. We also need to compare the generics.
     for (index, bound) in bounds.iter().enumerate() {
-        if let GenericBound::Trait(poly_trait, TraitBoundModifier::None) = bound
+        if let GenericBound::Trait(poly_trait) = bound
+            && let TraitBoundModifier::None = poly_trait.modifiers
             && let [.., path] = poly_trait.trait_ref.path.segments
             && let implied_args = path.args.map_or([].as_slice(), |a| a.args)
             && let implied_constraints = path.args.map_or([].as_slice(), |a| a.constraints)
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index 311bbce14bd..035ee40348c 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -310,7 +310,7 @@ fn extract_future_output<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<&
     if let ty::Alias(_, alias_ty) = ty.kind()
         && let Some(Node::OpaqueTy(opaque)) = cx.tcx.hir().get_if_local(alias_ty.def_id)
         && let OpaqueTyOrigin::AsyncFn { .. } = opaque.origin
-        && let [GenericBound::Trait(trait_ref, _)] = &opaque.bounds
+        && let [GenericBound::Trait(trait_ref)] = &opaque.bounds
         && let Some(segment) = trait_ref.trait_ref.path.segments.last()
         && let Some(generic_args) = segment.args
         && let [constraint] = generic_args.constraints
diff --git a/src/tools/clippy/clippy_lints/src/lifetimes.rs b/src/tools/clippy/clippy_lints/src/lifetimes.rs
index ec28671a061..a7c48eb216a 100644
--- a/src/tools/clippy/clippy_lints/src/lifetimes.rs
+++ b/src/tools/clippy/clippy_lints/src/lifetimes.rs
@@ -163,7 +163,7 @@ fn check_fn_inner<'tcx>(
                 if visitor.lts.iter().any(|lt| matches!(lt.res, LifetimeName::Param(_))) {
                     return;
                 }
-                if let GenericBound::Trait(ref trait_ref, _) = *bound {
+                if let GenericBound::Trait(ref trait_ref) = *bound {
                     let params = &trait_ref
                         .trait_ref
                         .path
@@ -438,7 +438,7 @@ impl<'tcx> Visitor<'tcx> for RefVisitor<'_, 'tcx> {
                 if !lt.is_elided() {
                     self.unelided_trait_object_lifetime = true;
                 }
-                for (bound, _) in bounds {
+                for bound in bounds {
                     self.visit_poly_trait_ref(bound);
                 }
             },
diff --git a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
index 81115cffdca..67255c1af79 100644
--- a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
@@ -107,7 +107,7 @@ fn future_trait_ref<'tcx>(
 ) -> Option<(&'tcx TraitRef<'tcx>, Vec<LifetimeName>)> {
     if let TyKind::OpaqueDef(opaque, bounds) = ty.kind
         && let Some(trait_ref) = opaque.bounds.iter().find_map(|bound| {
-            if let GenericBound::Trait(poly, _) = bound {
+            if let GenericBound::Trait(poly) = bound {
                 Some(&poly.trait_ref)
             } else {
                 None
diff --git a/src/tools/clippy/clippy_lints/src/needless_maybe_sized.rs b/src/tools/clippy/clippy_lints/src/needless_maybe_sized.rs
index bb44ff37b20..a56024f08d5 100644
--- a/src/tools/clippy/clippy_lints/src/needless_maybe_sized.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_maybe_sized.rs
@@ -40,7 +40,6 @@ struct Bound<'tcx> {
     ident: Ident,
 
     trait_bound: &'tcx PolyTraitRef<'tcx>,
-    modifier: TraitBoundModifier,
 
     predicate_pos: usize,
     bound_pos: usize,
@@ -65,11 +64,10 @@ fn type_param_bounds<'tcx>(generics: &'tcx Generics<'tcx>) -> impl Iterator<Item
                     .iter()
                     .enumerate()
                     .filter_map(move |(bound_pos, bound)| match bound {
-                        &GenericBound::Trait(ref trait_bound, modifier) => Some(Bound {
+                        &GenericBound::Trait(ref trait_bound) => Some(Bound {
                             param,
                             ident,
                             trait_bound,
-                            modifier,
                             predicate_pos,
                             bound_pos,
                         }),
@@ -120,13 +118,13 @@ impl LateLintPass<'_> for NeedlessMaybeSized {
         let maybe_sized_params: DefIdMap<_> = type_param_bounds(generics)
             .filter(|bound| {
                 bound.trait_bound.trait_ref.trait_def_id() == Some(sized_trait)
-                    && bound.modifier == TraitBoundModifier::Maybe
+                    && bound.trait_bound.modifiers == TraitBoundModifier::Maybe
             })
             .map(|bound| (bound.param, bound))
             .collect();
 
         for bound in type_param_bounds(generics) {
-            if bound.modifier == TraitBoundModifier::None
+            if bound.trait_bound.modifiers == TraitBoundModifier::None
                 && let Some(sized_bound) = maybe_sized_params.get(&bound.param)
                 && let Some(path) = path_to_sized_bound(cx, bound.trait_bound)
             {
diff --git a/src/tools/clippy/clippy_lints/src/trait_bounds.rs b/src/tools/clippy/clippy_lints/src/trait_bounds.rs
index 3c3973857e7..38befdee574 100644
--- a/src/tools/clippy/clippy_lints/src/trait_bounds.rs
+++ b/src/tools/clippy/clippy_lints/src/trait_bounds.rs
@@ -182,7 +182,7 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
 
             // Iterate the bounds and add them to our seen hash
             // If we haven't yet seen it, add it to the fixed traits
-            for (bound, _) in bounds {
+            for bound in bounds {
                 let Some(def_id) = bound.trait_ref.trait_def_id() else {
                     continue;
                 };
@@ -197,9 +197,9 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
             // If the number of unique traits isn't the same as the number of traits in the bounds,
             // there must be 1 or more duplicates
             if bounds.len() != unique_traits.len() {
-                let mut bounds_span = bounds[0].0.span;
+                let mut bounds_span = bounds[0].span;
 
-                for (bound, _) in bounds.iter().skip(1) {
+                for bound in bounds.iter().skip(1) {
                     bounds_span = bounds_span.to(bound.span);
                 }
 
@@ -229,7 +229,8 @@ impl TraitBounds {
     /// this MSRV? See <https://github.com/rust-lang/rust-clippy/issues/8772> for details.
     fn cannot_combine_maybe_bound(&self, cx: &LateContext<'_>, bound: &GenericBound<'_>) -> bool {
         if !self.msrv.meets(msrvs::MAYBE_BOUND_IN_WHERE)
-            && let GenericBound::Trait(tr, TraitBoundModifier::Maybe) = bound
+            && let GenericBound::Trait(tr) = bound
+            && let TraitBoundModifier::Maybe = tr.modifiers
         {
             cx.tcx.lang_items().get(LangItem::Sized) == tr.trait_ref.path.res.opt_def_id()
         } else {
@@ -375,11 +376,11 @@ impl Default for ComparableTraitRef {
 }
 
 fn get_trait_info_from_bound<'a>(bound: &'a GenericBound<'_>) -> Option<(Res, &'a [PathSegment<'a>], Span)> {
-    if let GenericBound::Trait(t, tbm) = bound {
+    if let GenericBound::Trait(t) = bound {
         let trait_path = t.trait_ref.path;
         let trait_span = {
             let path_span = trait_path.span;
-            if let TraitBoundModifier::Maybe = tbm {
+            if let TraitBoundModifier::Maybe = t.modifiers {
                 path_span.with_lo(path_span.lo() - BytePos(1)) // include the `?`
             } else {
                 path_span
@@ -430,7 +431,7 @@ fn rollup_traits(
     let mut repeated_res = false;
 
     let only_comparable_trait_refs = |bound: &GenericBound<'_>| {
-        if let GenericBound::Trait(t, _) = bound {
+        if let GenericBound::Trait(t) = bound {
             Some((into_comparable_trait_ref(&t.trait_ref), t.span))
         } else {
             None
diff --git a/src/tools/clippy/clippy_lints/src/types/borrowed_box.rs b/src/tools/clippy/clippy_lints/src/types/borrowed_box.rs
index 2fcfc71a8c7..eb7ffbbe360 100644
--- a/src/tools/clippy/clippy_lints/src/types/borrowed_box.rs
+++ b/src/tools/clippy/clippy_lints/src/types/borrowed_box.rs
@@ -82,7 +82,7 @@ pub(super) fn check(cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>, lt: &Lifetime, m
 // Returns true if given type is `Any` trait.
 fn is_any_trait(cx: &LateContext<'_>, t: &hir::Ty<'_>) -> bool {
     if let TyKind::TraitObject(traits, ..) = t.kind {
-        return traits.iter().any(|(bound, _)| {
+        return traits.iter().any(|bound| {
             if let Some(trait_did) = bound.trait_ref.trait_def_id()
                 && cx.tcx.is_diagnostic_item(sym::Any, trait_did)
             {
diff --git a/src/tools/clippy/clippy_lints/src/types/type_complexity.rs b/src/tools/clippy/clippy_lints/src/types/type_complexity.rs
index 0b64fddb447..b89bd6a8d05 100644
--- a/src/tools/clippy/clippy_lints/src/types/type_complexity.rs
+++ b/src/tools/clippy/clippy_lints/src/types/type_complexity.rs
@@ -55,7 +55,6 @@ impl<'tcx> Visitor<'tcx> for TypeComplexityVisitor {
             TyKind::TraitObject(param_bounds, _, _) => {
                 let has_lifetime_parameters = param_bounds.iter().any(|bound| {
                     bound
-                        .0
                         .bound_generic_params
                         .iter()
                         .any(|param| matches!(param.kind, GenericParamKind::Lifetime { .. }))