TypeVisiting binders no longer requires TypeFolding its interior

Author: compiler-errors

compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs

@@ -9,8 +9,8 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::bug;
 use rustc_middle::ty::{
-    self as ty, IsSuggestable, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable, TypeVisitable,
-    TypeVisitableExt, TypeVisitor, Upcast,
+    self as ty, IsSuggestable, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
+    TypeVisitor, Upcast,
 };
 use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 use rustc_trait_selection::traits;
@@ -927,7 +927,7 @@ struct GenericParamAndBoundVarCollector<'a, 'tcx> {
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for GenericParamAndBoundVarCollector<'_, 'tcx> {
     type Result = ControlFlow<ErrorGuaranteed>;
 
-    fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         binder: &ty::Binder<'tcx, T>,
     ) -> Self::Result {

compiler/rustc_lint/src/impl_trait_overcaptures.rs

@@ -15,8 +15,7 @@ use rustc_middle::ty::relate::{
     Relate, RelateResult, TypeRelation, structurally_relate_consts, structurally_relate_tys,
 };
 use rustc_middle::ty::{
-    self, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
-    TypeVisitor,
+    self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint::FutureIncompatibilityReason;
@@ -210,7 +209,7 @@ where
     VarFn: FnOnce() -> FxHashMap<DefId, ty::Variance>,
     OutlivesFn: FnOnce() -> OutlivesEnvironment<'tcx>,
 {
-    fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) {
         // When we get into a binder, we need to add its own bound vars to the scope.
         let mut added = vec![];
         for arg in t.bound_vars() {

compiler/rustc_middle/src/ty/visit.rs

@@ -66,7 +66,7 @@ impl<'tcx> TyCtxt<'tcx> {
         {
             type Result = ControlFlow<()>;
 
-            fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+            fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
                 &mut self,
                 t: &Binder<'tcx, T>,
             ) -> Self::Result {
@@ -168,7 +168,7 @@ impl LateBoundRegionsCollector {
 }
 
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for LateBoundRegionsCollector {
-    fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, t: &Binder<'tcx, T>) {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &Binder<'tcx, T>) {
         self.current_index.shift_in(1);
         t.super_visit_with(self);
         self.current_index.shift_out(1);

compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs

@@ -1039,7 +1039,7 @@ where
 {
     type Result = ControlFlow<Result<(), NoSolution>>;
 
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
         self.universes.push(None);
         t.super_visit_with(self)?;
         self.universes.pop();

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -9,7 +9,7 @@ use rustc_macros::extension;
 pub use rustc_middle::traits::query::NormalizationResult;
 use rustc_middle::ty::{
     self, FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeSuperVisitable,
-    TypeVisitableExt, TypeVisitor, TypingMode,
+    TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode,
 };
 use rustc_span::DUMMY_SP;
 use tracing::{debug, info, instrument};
@@ -127,7 +127,7 @@ struct MaxEscapingBoundVarVisitor {
 }
 
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for MaxEscapingBoundVarVisitor {
-    fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) {
         self.outer_index.shift_in(1);
         t.super_visit_with(self);
         self.outer_index.shift_out(1);

compiler/rustc_ty_utils/src/ty.rs

@@ -7,8 +7,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{
-    self, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitor, Upcast,
-    fold_regions,
+    self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, Upcast, fold_regions,
 };
 use rustc_span::DUMMY_SP;
 use rustc_span::def_id::{CRATE_DEF_ID, DefId, LocalDefId};
@@ -186,7 +185,7 @@ struct ImplTraitInTraitFinder<'a, 'tcx> {
 }
 
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ImplTraitInTraitFinder<'_, 'tcx> {
-    fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, binder: &ty::Binder<'tcx, T>) {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, binder: &ty::Binder<'tcx, T>) {
         self.depth.shift_in(1);
         binder.super_visit_with(self);
         self.depth.shift_out(1);

compiler/rustc_type_ir/src/binder.rs

@@ -128,7 +128,7 @@ impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Binder<I, T> {
     }
 }
 
-impl<I: Interner, T: TypeFoldable<I>> TypeVisitable<I> for Binder<I, T> {
+impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Binder<I, T> {
     fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> V::Result {
         visitor.visit_binder(self)
     }
@@ -147,7 +147,7 @@ impl<I: Interner, T: TypeFoldable<I>> TypeSuperFoldable<I> for Binder<I, T> {
     }
 }
 
-impl<I: Interner, T: TypeFoldable<I>> TypeSuperVisitable<I> for Binder<I, T> {
+impl<I: Interner, T: TypeVisitable<I>> TypeSuperVisitable<I> for Binder<I, T> {
     fn super_visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> V::Result {
         self.as_ref().skip_binder().visit_with(visitor)
     }
@@ -292,7 +292,7 @@ impl<I: Interner> ValidateBoundVars<I> {
 impl<I: Interner> TypeVisitor<I> for ValidateBoundVars<I> {
     type Result = ControlFlow<()>;
 
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &Binder<I, T>) -> Self::Result {
         self.binder_index.shift_in(1);
         let result = t.super_visit_with(self);
         self.binder_index.shift_out(1);

compiler/rustc_type_ir/src/ty_kind/closure.rs

@@ -342,7 +342,7 @@ struct HasRegionsBoundAt {
 // FIXME: Could be optimized to not walk into components with no escaping bound vars.
 impl<I: Interner> TypeVisitor<I> for HasRegionsBoundAt {
     type Result = ControlFlow<()>;
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
         self.binder.shift_in(1);
         t.super_visit_with(self)?;
         self.binder.shift_out(1);

compiler/rustc_type_ir/src/visit.rs

@@ -52,7 +52,7 @@ use smallvec::SmallVec;
 use thin_vec::ThinVec;
 
 use crate::inherent::*;
-use crate::{self as ty, Interner, TypeFlags, TypeFoldable};
+use crate::{self as ty, Interner, TypeFlags};
 
 /// This trait is implemented for every type that can be visited,
 /// providing the skeleton of the traversal.
@@ -94,7 +94,7 @@ pub trait TypeVisitor<I: Interner>: Sized {
     #[cfg(not(feature = "nightly"))]
     type Result: VisitorResult;
 
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
         t.super_visit_with(self)
     }
 
@@ -401,7 +401,7 @@ impl std::fmt::Debug for HasTypeFlagsVisitor {
 impl<I: Interner> TypeVisitor<I> for HasTypeFlagsVisitor {
     type Result = ControlFlow<FoundFlags>;
 
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
         // If we're looking for the HAS_BINDER_VARS flag, check if the
         // binder has vars. This won't be present in the binder's bound
         // value, so we need to check here too.
@@ -510,7 +510,7 @@ struct HasEscapingVarsVisitor {
 impl<I: Interner> TypeVisitor<I> for HasEscapingVarsVisitor {
     type Result = ControlFlow<FoundEscapingVars>;
 
-    fn visit_binder<T: TypeFoldable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
+    fn visit_binder<T: TypeVisitable<I>>(&mut self, t: &ty::Binder<I, T>) -> Self::Result {
         self.outer_index.shift_in(1);
         let result = t.super_visit_with(self);
         self.outer_index.shift_out(1);

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

@@ -853,7 +853,7 @@ pub fn for_each_top_level_late_bound_region<B>(
                 ControlFlow::Continue(())
             }
         }
-        fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, t: &Binder<'tcx, T>) -> Self::Result {
+        fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &Binder<'tcx, T>) -> Self::Result {
             self.index += 1;
             let res = t.super_visit_with(self);
             self.index -= 1;