rustc: move cfg, infer, traits and ty from middle to top-level.

1 files changed, 815 insertions, 0 deletions

diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs
new file mode 100644
index 00000000000..6fca1eef701
--- /dev/null
+++ b/src/librustc/ty/structural_impls.rs
@@ -0,0 +1,815 @@
+// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use ty::subst::{self, VecPerParamSpace};
+use traits;
+use ty::{self, Lift, TraitRef, Ty, TyCtxt};
+use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
+
+use std::rc::Rc;
+use syntax::abi;
+use syntax::ptr::P;
+
+use rustc_front::hir;
+
+///////////////////////////////////////////////////////////////////////////
+// Lift implementations
+
+impl<'tcx, A: Lift<'tcx>, B: Lift<'tcx>> Lift<'tcx> for (A, B) {
+    type Lifted = (A::Lifted, B::Lifted);
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<Self::Lifted> {
+        tcx.lift(&self.0).and_then(|a| tcx.lift(&self.1).map(|b| (a, b)))
+    }
+}
+
+impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for [T] {
+    type Lifted = Vec<T::Lifted>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<Self::Lifted> {
+        // type annotation needed to inform `projection_must_outlive`
+        let mut result : Vec<<T as Lift<'tcx>>::Lifted>
+            = Vec::with_capacity(self.len());
+        for x in self {
+            if let Some(value) = tcx.lift(x) {
+                result.push(value);
+            } else {
+                return None;
+            }
+        }
+        Some(result)
+    }
+}
+
+impl<'tcx> Lift<'tcx> for ty::Region {
+    type Lifted = Self;
+    fn lift_to_tcx(&self, _: &TyCtxt<'tcx>) -> Option<ty::Region> {
+        Some(*self)
+    }
+}
+
+impl<'a, 'tcx> Lift<'tcx> for TraitRef<'a> {
+    type Lifted = TraitRef<'tcx>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<TraitRef<'tcx>> {
+        tcx.lift(&self.substs).map(|substs| TraitRef {
+            def_id: self.def_id,
+            substs: substs
+        })
+    }
+}
+
+impl<'a, 'tcx> Lift<'tcx> for ty::TraitPredicate<'a> {
+    type Lifted = ty::TraitPredicate<'tcx>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<ty::TraitPredicate<'tcx>> {
+        tcx.lift(&self.trait_ref).map(|trait_ref| ty::TraitPredicate {
+            trait_ref: trait_ref
+        })
+    }
+}
+
+impl<'a, 'tcx> Lift<'tcx> for ty::EquatePredicate<'a> {
+    type Lifted = ty::EquatePredicate<'tcx>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<ty::EquatePredicate<'tcx>> {
+        tcx.lift(&(self.0, self.1)).map(|(a, b)| ty::EquatePredicate(a, b))
+    }
+}
+
+impl<'tcx, A: Copy+Lift<'tcx>, B: Copy+Lift<'tcx>> Lift<'tcx> for ty::OutlivesPredicate<A, B> {
+    type Lifted = ty::OutlivesPredicate<A::Lifted, B::Lifted>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<Self::Lifted> {
+        tcx.lift(&(self.0, self.1)).map(|(a, b)| ty::OutlivesPredicate(a, b))
+    }
+}
+
+impl<'a, 'tcx> Lift<'tcx> for ty::ProjectionPredicate<'a> {
+    type Lifted = ty::ProjectionPredicate<'tcx>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<ty::ProjectionPredicate<'tcx>> {
+        tcx.lift(&(self.projection_ty.trait_ref, self.ty)).map(|(trait_ref, ty)| {
+            ty::ProjectionPredicate {
+                projection_ty: ty::ProjectionTy {
+                    trait_ref: trait_ref,
+                    item_name: self.projection_ty.item_name
+                },
+                ty: ty
+            }
+        })
+    }
+}
+
+impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::Binder<T> {
+    type Lifted = ty::Binder<T::Lifted>;
+    fn lift_to_tcx(&self, tcx: &TyCtxt<'tcx>) -> Option<Self::Lifted> {
+        tcx.lift(&self.0).map(|x| ty::Binder(x))
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////
+// TypeFoldable implementations.
+//
+// Ideally, each type should invoke `folder.fold_foo(self)` and
+// nothing else. In some cases, though, we haven't gotten around to
+// adding methods on the `folder` yet, and thus the folding is
+// hard-coded here. This is less-flexible, because folders cannot
+// override the behavior, but there are a lot of random types and one
+// can easily refactor the folding into the TypeFolder trait as
+// needed.
+
+macro_rules! CopyImpls {
+    ($($ty:ty),+) => {
+        $(
+            impl<'tcx> TypeFoldable<'tcx> for $ty {
+                fn super_fold_with<F:TypeFolder<'tcx>>(&self, _: &mut F) -> $ty {
+                    *self
+                }
+
+                fn super_visit_with<F: TypeVisitor<'tcx>>(&self, _: &mut F) -> bool {
+                    false
+                }
+            }
+        )+
+    }
+}
+
+CopyImpls! { (), hir::Unsafety, abi::Abi }
+
+impl<'tcx, T:TypeFoldable<'tcx>, U:TypeFoldable<'tcx>> TypeFoldable<'tcx> for (T, U) {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> (T, U) {
+        (self.0.fold_with(folder), self.1.fold_with(folder))
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.0.visit_with(visitor) || self.1.visit_with(visitor)
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Option<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        self.as_ref().map(|t| t.fold_with(folder))
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.iter().any(|t| t.visit_with(visitor))
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Rc<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        Rc::new((**self).fold_with(folder))
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        (**self).visit_with(visitor)
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Box<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        let content: T = (**self).fold_with(folder);
+        box content
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        (**self).visit_with(visitor)
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Vec<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        self.iter().map(|t| t.fold_with(folder)).collect()
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.iter().any(|t| t.visit_with(visitor))
+    }
+}
+
+impl<'tcx, T:TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::Binder<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.enter_region_binder();
+        let result = ty::Binder(self.0.fold_with(folder));
+        folder.exit_region_binder();
+        result
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_binder(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        visitor.enter_region_binder();
+        if self.0.visit_with(visitor) { return true }
+        visitor.exit_region_binder();
+        false
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for P<[T]> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        self.iter().map(|t| t.fold_with(folder)).collect()
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.iter().any(|t| t.visit_with(visitor))
+    }
+}
+
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for VecPerParamSpace<T> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+
+        // Things in the Fn space take place under an additional level
+        // of region binding relative to the other spaces. This is
+        // because those entries are attached to a method, and methods
+        // always introduce a level of region binding.
+
+        let result = self.map_enumerated(|(space, index, elem)| {
+            if space == subst::FnSpace && index == 0 {
+                // enter new level when/if we reach the first thing in fn space
+                folder.enter_region_binder();
+            }
+            elem.fold_with(folder)
+        });
+        if result.len(subst::FnSpace) > 0 {
+            // if there was anything in fn space, exit the region binding level
+            folder.exit_region_binder();
+        }
+        result
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        let mut entered_region_binder = false;
+        let result = self.iter_enumerated().any(|(space, index, t)| {
+            if space == subst::FnSpace && index == 0 {
+                visitor.enter_region_binder();
+                entered_region_binder = true;
+            }
+            t.visit_with(visitor)
+        });
+        if entered_region_binder {
+            visitor.exit_region_binder();
+        }
+        result
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TraitTy<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::TraitTy {
+            principal: self.principal.fold_with(folder),
+            bounds: self.bounds.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.principal.visit_with(visitor) || self.bounds.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for Ty<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        let sty = match self.sty {
+            ty::TyBox(typ) => ty::TyBox(typ.fold_with(folder)),
+            ty::TyRawPtr(ref tm) => ty::TyRawPtr(tm.fold_with(folder)),
+            ty::TyArray(typ, sz) => ty::TyArray(typ.fold_with(folder), sz),
+            ty::TySlice(typ) => ty::TySlice(typ.fold_with(folder)),
+            ty::TyEnum(tid, ref substs) => {
+                let substs = substs.fold_with(folder);
+                ty::TyEnum(tid, folder.tcx().mk_substs(substs))
+            }
+            ty::TyTrait(ref trait_ty) => ty::TyTrait(trait_ty.fold_with(folder)),
+            ty::TyTuple(ref ts) => ty::TyTuple(ts.fold_with(folder)),
+            ty::TyFnDef(def_id, substs, ref f) => {
+                let substs = substs.fold_with(folder);
+                let bfn = f.fold_with(folder);
+                ty::TyFnDef(def_id,
+                            folder.tcx().mk_substs(substs),
+                            folder.tcx().mk_bare_fn(bfn))
+            }
+            ty::TyFnPtr(ref f) => {
+                let bfn = f.fold_with(folder);
+                ty::TyFnPtr(folder.tcx().mk_bare_fn(bfn))
+            }
+            ty::TyRef(r, ref tm) => {
+                let r = r.fold_with(folder);
+                ty::TyRef(folder.tcx().mk_region(r), tm.fold_with(folder))
+            }
+            ty::TyStruct(did, ref substs) => {
+                let substs = substs.fold_with(folder);
+                ty::TyStruct(did, folder.tcx().mk_substs(substs))
+            }
+            ty::TyClosure(did, ref substs) => {
+                ty::TyClosure(did, substs.fold_with(folder))
+            }
+            ty::TyProjection(ref data) => ty::TyProjection(data.fold_with(folder)),
+            ty::TyBool | ty::TyChar | ty::TyStr | ty::TyInt(_) |
+            ty::TyUint(_) | ty::TyFloat(_) | ty::TyError | ty::TyInfer(_) |
+            ty::TyParam(..) => self.sty.clone(),
+        };
+        folder.tcx().mk_ty(sty)
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_ty(*self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        match self.sty {
+            ty::TyBox(typ) => typ.visit_with(visitor),
+            ty::TyRawPtr(ref tm) => tm.visit_with(visitor),
+            ty::TyArray(typ, _sz) => typ.visit_with(visitor),
+            ty::TySlice(typ) => typ.visit_with(visitor),
+            ty::TyEnum(_tid, ref substs) => substs.visit_with(visitor),
+            ty::TyTrait(ref trait_ty) => trait_ty.visit_with(visitor),
+            ty::TyTuple(ref ts) => ts.visit_with(visitor),
+            ty::TyFnDef(_, substs, ref f) => {
+                substs.visit_with(visitor) || f.visit_with(visitor)
+            }
+            ty::TyFnPtr(ref f) => f.visit_with(visitor),
+            ty::TyRef(r, ref tm) => r.visit_with(visitor) || tm.visit_with(visitor),
+            ty::TyStruct(_did, ref substs) => substs.visit_with(visitor),
+            ty::TyClosure(_did, ref substs) => substs.visit_with(visitor),
+            ty::TyProjection(ref data) => data.visit_with(visitor),
+            ty::TyBool | ty::TyChar | ty::TyStr | ty::TyInt(_) |
+            ty::TyUint(_) | ty::TyFloat(_) | ty::TyError | ty::TyInfer(_) |
+            ty::TyParam(..) => false,
+        }
+    }
+
+    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        visitor.visit_ty(self)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::BareFnTy<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::BareFnTy { sig: self.sig.fold_with(folder),
+                       abi: self.abi,
+                       unsafety: self.unsafety }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_bare_fn_ty(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.sig.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ClosureTy<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+       ty::ClosureTy {
+            sig: self.sig.fold_with(folder),
+            unsafety: self.unsafety,
+            abi: self.abi,
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_closure_ty(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.sig.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TypeAndMut<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::TypeAndMut { ty: self.ty.fold_with(folder), mutbl: self.mutbl }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_mt(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.ty.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::FnOutput<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        match *self {
+            ty::FnConverging(ref ty) => ty::FnConverging(ty.fold_with(folder)),
+            ty::FnDiverging => ty::FnDiverging
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_output(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        match *self {
+            ty::FnConverging(ref ty) => ty.visit_with(visitor),
+            ty::FnDiverging => false,
+        }
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::FnSig<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::FnSig { inputs: self.inputs.fold_with(folder),
+                    output: self.output.fold_with(folder),
+                    variadic: self.variadic }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_fn_sig(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.inputs.visit_with(visitor) || self.output.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TraitRef<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        let substs = self.substs.fold_with(folder);
+        ty::TraitRef {
+            def_id: self.def_id,
+            substs: folder.tcx().mk_substs(substs),
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_trait_ref(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.substs.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ImplHeader<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ImplHeader {
+            impl_def_id: self.impl_def_id,
+            self_ty: self.self_ty.fold_with(folder),
+            trait_ref: self.trait_ref.map(|t| t.fold_with(folder)),
+            predicates: self.predicates.iter().map(|p| p.fold_with(folder)).collect(),
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_impl_header(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.self_ty.visit_with(visitor) ||
+            self.trait_ref.map(|r| r.visit_with(visitor)).unwrap_or(false) ||
+            self.predicates.iter().any(|p| p.visit_with(visitor))
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::Region {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _folder: &mut F) -> Self {
+        *self
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_region(*self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> bool {
+        false
+    }
+
+    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        visitor.visit_region(*self)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for subst::Substs<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        subst::Substs { regions: self.regions.fold_with(folder),
+                        types: self.types.fold_with(folder) }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_substs(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.types.visit_with(visitor) || self.regions.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ClosureSubsts<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        let func_substs = self.func_substs.fold_with(folder);
+        ty::ClosureSubsts {
+            func_substs: folder.tcx().mk_substs(func_substs),
+            upvar_tys: self.upvar_tys.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.func_substs.visit_with(visitor) || self.upvar_tys.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ItemSubsts<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ItemSubsts {
+            substs: self.substs.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.substs.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::adjustment::AutoRef<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        match *self {
+            ty::adjustment::AutoPtr(r, m) => {
+                let r = r.fold_with(folder);
+                ty::adjustment::AutoPtr(folder.tcx().mk_region(r), m)
+            }
+            ty::adjustment::AutoUnsafe(m) => ty::adjustment::AutoUnsafe(m)
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_autoref(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        match *self {
+            ty::adjustment::AutoPtr(r, _m) => r.visit_with(visitor),
+            ty::adjustment::AutoUnsafe(_m) => false,
+        }
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::BuiltinBounds {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _folder: &mut F) -> Self {
+        *self
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> bool {
+        false
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ExistentialBounds<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ExistentialBounds {
+            region_bound: self.region_bound.fold_with(folder),
+            builtin_bounds: self.builtin_bounds,
+            projection_bounds: self.projection_bounds.fold_with(folder),
+        }
+    }
+
+    fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        folder.fold_existential_bounds(self)
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.region_bound.visit_with(visitor) || self.projection_bounds.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TypeParameterDef<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::TypeParameterDef {
+            name: self.name,
+            def_id: self.def_id,
+            space: self.space,
+            index: self.index,
+            default: self.default.fold_with(folder),
+            default_def_id: self.default_def_id,
+            object_lifetime_default: self.object_lifetime_default.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.default.visit_with(visitor) ||
+            self.object_lifetime_default.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ObjectLifetimeDefault {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        match *self {
+            ty::ObjectLifetimeDefault::Ambiguous =>
+                ty::ObjectLifetimeDefault::Ambiguous,
+
+            ty::ObjectLifetimeDefault::BaseDefault =>
+                ty::ObjectLifetimeDefault::BaseDefault,
+
+            ty::ObjectLifetimeDefault::Specific(r) =>
+                ty::ObjectLifetimeDefault::Specific(r.fold_with(folder)),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        match *self {
+            ty::ObjectLifetimeDefault::Specific(r) => r.visit_with(visitor),
+            _ => false,
+        }
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::RegionParameterDef {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::RegionParameterDef {
+            name: self.name,
+            def_id: self.def_id,
+            space: self.space,
+            index: self.index,
+            bounds: self.bounds.fold_with(folder)
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.bounds.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::Generics<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::Generics {
+            types: self.types.fold_with(folder),
+            regions: self.regions.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.types.visit_with(visitor) || self.regions.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::GenericPredicates<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::GenericPredicates {
+            predicates: self.predicates.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.predicates.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::Predicate<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        match *self {
+            ty::Predicate::Trait(ref a) =>
+                ty::Predicate::Trait(a.fold_with(folder)),
+            ty::Predicate::Equate(ref binder) =>
+                ty::Predicate::Equate(binder.fold_with(folder)),
+            ty::Predicate::RegionOutlives(ref binder) =>
+                ty::Predicate::RegionOutlives(binder.fold_with(folder)),
+            ty::Predicate::TypeOutlives(ref binder) =>
+                ty::Predicate::TypeOutlives(binder.fold_with(folder)),
+            ty::Predicate::Projection(ref binder) =>
+                ty::Predicate::Projection(binder.fold_with(folder)),
+            ty::Predicate::WellFormed(data) =>
+                ty::Predicate::WellFormed(data.fold_with(folder)),
+            ty::Predicate::ObjectSafe(trait_def_id) =>
+                ty::Predicate::ObjectSafe(trait_def_id),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        match *self {
+            ty::Predicate::Trait(ref a) => a.visit_with(visitor),
+            ty::Predicate::Equate(ref binder) => binder.visit_with(visitor),
+            ty::Predicate::RegionOutlives(ref binder) => binder.visit_with(visitor),
+            ty::Predicate::TypeOutlives(ref binder) => binder.visit_with(visitor),
+            ty::Predicate::Projection(ref binder) => binder.visit_with(visitor),
+            ty::Predicate::WellFormed(data) => data.visit_with(visitor),
+            ty::Predicate::ObjectSafe(_trait_def_id) => false,
+        }
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ProjectionPredicate<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ProjectionPredicate {
+            projection_ty: self.projection_ty.fold_with(folder),
+            ty: self.ty.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.projection_ty.visit_with(visitor) || self.ty.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ProjectionTy<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ProjectionTy {
+            trait_ref: self.trait_ref.fold_with(folder),
+            item_name: self.item_name,
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.trait_ref.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::InstantiatedPredicates<'tcx> {
+    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::InstantiatedPredicates {
+            predicates: self.predicates.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.predicates.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::EquatePredicate<'tcx> {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::EquatePredicate(self.0.fold_with(folder),
+                            self.1.fold_with(folder))
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.0.visit_with(visitor) || self.1.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TraitPredicate<'tcx> {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::TraitPredicate {
+            trait_ref: self.trait_ref.fold_with(folder)
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.trait_ref.visit_with(visitor)
+    }
+}
+
+impl<'tcx,T,U> TypeFoldable<'tcx> for ty::OutlivesPredicate<T,U>
+    where T : TypeFoldable<'tcx>,
+          U : TypeFoldable<'tcx>,
+{
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::OutlivesPredicate(self.0.fold_with(folder),
+                              self.1.fold_with(folder))
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.0.visit_with(visitor) || self.1.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::ClosureUpvar<'tcx> {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ClosureUpvar {
+            def: self.def,
+            span: self.span,
+            ty: self.ty.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.ty.visit_with(visitor)
+    }
+}
+
+impl<'a, 'tcx> TypeFoldable<'tcx> for ty::ParameterEnvironment<'a, 'tcx> where 'tcx: 'a {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::ParameterEnvironment {
+            tcx: self.tcx,
+            free_substs: self.free_substs.fold_with(folder),
+            implicit_region_bound: self.implicit_region_bound.fold_with(folder),
+            caller_bounds: self.caller_bounds.fold_with(folder),
+            selection_cache: traits::SelectionCache::new(),
+            evaluation_cache: traits::EvaluationCache::new(),
+            free_id_outlive: self.free_id_outlive,
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.free_substs.visit_with(visitor) ||
+            self.implicit_region_bound.visit_with(visitor) ||
+            self.caller_bounds.visit_with(visitor)
+    }
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ty::TypeScheme<'tcx>  {
+    fn super_fold_with<F:TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
+        ty::TypeScheme {
+            generics: self.generics.fold_with(folder),
+            ty: self.ty.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.generics.visit_with(visitor) || self.ty.visit_with(visitor)
+    }
+}