Remove unused `TypeFoldable`/`TypeVisitable` impls.

12 files changed, 12 insertions, 59 deletions

diff --git a/compiler/rustc_infer/src/traits/project.rs b/compiler/rustc_infer/src/traits/project.rs
index 8d0af738dd1..e375d611936 100644
--- a/compiler/rustc_infer/src/traits/project.rs
+++ b/compiler/rustc_infer/src/traits/project.rs
@@ -20,7 +20,7 @@ pub struct MismatchedProjectionTypes<'tcx> {
     pub err: ty::error::TypeError<'tcx>,
 }
 
-#[derive(Clone, TypeFoldable, TypeVisitable)]
+#[derive(Clone)]
 pub struct Normalized<'tcx, T> {
     pub value: T,
     pub obligations: Vec<PredicateObligation<'tcx>>,
diff --git a/compiler/rustc_middle/src/hir/place.rs b/compiler/rustc_middle/src/hir/place.rs
index 80b4c964ce4..8a22de931c3 100644
--- a/compiler/rustc_middle/src/hir/place.rs
+++ b/compiler/rustc_middle/src/hir/place.rs
@@ -66,7 +66,6 @@ pub struct Place<'tcx> {
 ///
 /// This is an HIR version of [`rustc_middle::mir::Place`].
 #[derive(Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable)]
-#[derive(TypeFoldable, TypeVisitable)]
 pub struct PlaceWithHirId<'tcx> {
     /// `HirId` of the expression or pattern producing this value.
     pub hir_id: HirId,
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index da86cfd4772..813e109c41e 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -234,7 +234,6 @@ pub enum StmtKind<'tcx> {
 }
 
 #[derive(Clone, Debug, Copy, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
-#[derive(TypeFoldable, TypeVisitable)]
 pub struct LocalVarId(pub hir::HirId);
 
 /// A THIR expression.
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 6a8ae525069..02433026266 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -569,7 +569,7 @@ pub struct DerivedObligationCause<'tcx> {
     pub parent_code: InternedObligationCauseCode<'tcx>,
 }
 
-#[derive(Clone, Debug, TypeFoldable, TypeVisitable, Lift)]
+#[derive(Clone, Debug, TypeVisitable, Lift)]
 pub enum SelectionError<'tcx> {
     /// The trait is not implemented.
     Unimplemented,
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index 1cc9fd526b4..f2dda003b99 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -103,7 +103,7 @@ pub type EvaluationCache<'tcx> = Cache<
 /// required for associated types to work in default impls, as the bounds
 /// are visible both as projection bounds and as where-clauses from the
 /// parameter environment.
-#[derive(PartialEq, Eq, Debug, Clone, TypeFoldable, TypeVisitable)]
+#[derive(PartialEq, Eq, Debug, Clone, TypeVisitable)]
 pub enum SelectionCandidate<'tcx> {
     /// A builtin implementation for some specific traits, used in cases
     /// where we cannot rely an ordinary library implementations.
diff --git a/compiler/rustc_middle/src/traits/solve.rs b/compiler/rustc_middle/src/traits/solve.rs
index fef2be133e8..6b7b910a59b 100644
--- a/compiler/rustc_middle/src/traits/solve.rs
+++ b/compiler/rustc_middle/src/traits/solve.rs
@@ -120,7 +120,7 @@ impl<'tcx> std::ops::Deref for ExternalConstraints<'tcx> {
 }
 
 /// Additional constraints returned on success.
-#[derive(Debug, PartialEq, Eq, Clone, Hash, Default, TypeFoldable, TypeVisitable)]
+#[derive(Debug, PartialEq, Eq, Clone, Hash, Default)]
 pub struct ExternalConstraintsData<'tcx> {
     // FIXME: implement this.
     pub region_constraints: QueryRegionConstraints<'tcx>,
diff --git a/compiler/rustc_middle/src/ty/error.rs b/compiler/rustc_middle/src/ty/error.rs
index aff6c77e039..1be61e16dbe 100644
--- a/compiler/rustc_middle/src/ty/error.rs
+++ b/compiler/rustc_middle/src/ty/error.rs
@@ -28,7 +28,7 @@ impl<T> ExpectedFound<T> {
 }
 
 // Data structures used in type unification
-#[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable, Lift, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, TypeVisitable, Lift, PartialEq, Eq)]
 #[rustc_pass_by_value]
 pub enum TypeError<'tcx> {
     Mismatch,
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index 1c1432ecd5a..2aced27f7bb 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -2690,7 +2690,7 @@ impl<'tcx> ty::PolyTraitPredicate<'tcx> {
     }
 }
 
-#[derive(Debug, Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
+#[derive(Debug, Copy, Clone, Lift)]
 pub struct PrintClosureAsImpl<'tcx> {
     pub closure: ty::ClosureSubsts<'tcx>,
 }
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index a2611022406..d4116a763e1 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -4,7 +4,6 @@
 //! to help with the tedium.
 
 use crate::mir::interpret;
-use crate::mir::ProjectionKind;
 use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
 use crate::ty::print::{with_no_trimmed_paths, FmtPrinter, Printer};
 use crate::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
@@ -373,16 +372,6 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ParamEnv<'a> {
 ///////////////////////////////////////////////////////////////////////////
 // Traversal implementations.
 
-/// AdtDefs are basically the same as a DefId.
-impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
-        self,
-        _folder: &mut F,
-    ) -> Result<Self, F::Error> {
-        Ok(self)
-    }
-}
-
 impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
     fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
         &self,
@@ -445,15 +434,6 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::Const<'tcx>> {
     }
 }
 
-impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ProjectionKind> {
-    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
-        self,
-        folder: &mut F,
-    ) -> Result<Self, F::Error> {
-        ty::util::fold_list(self, folder, |tcx, v| tcx.mk_projs(v))
-    }
-}
-
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
     fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 29ae42be096..aa658fc5e45 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -631,7 +631,7 @@ impl<'tcx> UpvarSubsts<'tcx> {
 /// type of the constant. The reason that `R` is represented as an extra type parameter
 /// is the same reason that [`ClosureSubsts`] have `CS` and `U` as type parameters:
 /// inline const can reference lifetimes that are internal to the creating function.
-#[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable)]
+#[derive(Copy, Clone, Debug)]
 pub struct InlineConstSubsts<'tcx> {
     /// Generic parameters from the enclosing item,
     /// concatenated with the inferred type of the constant.
diff --git a/compiler/rustc_transmute/src/lib.rs b/compiler/rustc_transmute/src/lib.rs
index 8be02c1d988..77c0526e3aa 100644
--- a/compiler/rustc_transmute/src/lib.rs
+++ b/compiler/rustc_transmute/src/lib.rs
@@ -62,7 +62,7 @@ mod rustc {
 
     use rustc_hir::lang_items::LangItem;
     use rustc_infer::infer::InferCtxt;
-    use rustc_macros::{TypeFoldable, TypeVisitable};
+    use rustc_macros::TypeVisitable;
     use rustc_middle::traits::ObligationCause;
     use rustc_middle::ty::Const;
     use rustc_middle::ty::ParamEnv;
@@ -70,7 +70,7 @@ mod rustc {
     use rustc_middle::ty::TyCtxt;
 
     /// The source and destination types of a transmutation.
-    #[derive(TypeFoldable, TypeVisitable, Debug, Clone, Copy)]
+    #[derive(TypeVisitable, Debug, Clone, Copy)]
     pub struct Types<'tcx> {
         /// The source type.
         pub src: Ty<'tcx>,
diff --git a/compiler/rustc_type_ir/src/structural_impls.rs b/compiler/rustc_type_ir/src/structural_impls.rs
index 54c1ab5a275..c513bde6ecf 100644
--- a/compiler/rustc_type_ir/src/structural_impls.rs
+++ b/compiler/rustc_type_ir/src/structural_impls.rs
@@ -6,11 +6,10 @@ use crate::fold::{FallibleTypeFolder, TypeFoldable};
 use crate::visit::{TypeVisitable, TypeVisitor};
 use crate::Interner;
 use rustc_data_structures::functor::IdFunctor;
+use rustc_data_structures::sync::Lrc;
 use rustc_index::{Idx, IndexVec};
 
 use std::ops::ControlFlow;
-use std::rc::Rc;
-use std::sync::Arc;
 
 ///////////////////////////////////////////////////////////////////////////
 // Atomic structs
@@ -106,25 +105,13 @@ impl<I: Interner, T: TypeVisitable<I>, E: TypeVisitable<I>> TypeVisitable<I> for
     }
 }
 
-impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Rc<T> {
+impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Lrc<T> {
     fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
         self.try_map_id(|value| value.try_fold_with(folder))
     }
 }
 
-impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Rc<T> {
-    fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
-        (**self).visit_with(visitor)
-    }
-}
-
-impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Arc<T> {
-    fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
-        self.try_map_id(|value| value.try_fold_with(folder))
-    }
-}
-
-impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Arc<T> {
+impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Lrc<T> {
     fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         (**self).visit_with(visitor)
     }
@@ -160,18 +147,6 @@ impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for &[T] {
     }
 }
 
-impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Box<[T]> {
-    fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
-        self.try_map_id(|t| t.try_fold_with(folder))
-    }
-}
-
-impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Box<[T]> {
-    fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
-        self.iter().try_for_each(|t| t.visit_with(visitor))
-    }
-}
-
 impl<I: Interner, T: TypeFoldable<I>, Ix: Idx> TypeFoldable<I> for IndexVec<Ix, T> {
     fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
         self.try_map_id(|x| x.try_fold_with(folder))