Fmt and test revert

[rust.git] / compiler / rustc_middle / src / ty / structural_impls.rs

diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 2da23b331e0cb19a41e5e64d0664988ba1b344d1..a969626b370f5d2dc6320f245d05112343aa60e8 100644 (file)
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -454,10 +454,16 @@ fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
     }
 }
 
-impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::Binder<T> {
-    type Lifted = ty::Binder<T::Lifted>;
+impl<'a, 'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::Binder<'a, T>
+where
+    <T as Lift<'tcx>>::Lifted: TypeFoldable<'tcx>,
+{
+    type Lifted = ty::Binder<'tcx, T::Lifted>;
     fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
-        self.map_bound(|v| tcx.lift(v)).transpose()
+        let bound_vars = tcx.lift(self.bound_vars());
+        tcx.lift(self.skip_binder())
+            .zip(bound_vars)
+            .map(|(value, vars)| ty::Binder::bind_with_vars(value, vars))
     }
 }
 
@@ -749,7 +755,7 @@ fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow
     }
 }
 
-impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::Binder<T> {
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::Binder<'tcx, T> {
     fn super_fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self {
         self.map_bound(|ty| ty.fold_with(folder))
     }
@@ -767,7 +773,7 @@ fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::Br
     }
 }
 
-impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::Binder<ty::ExistentialPredicate<'tcx>>> {
+impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>> {
     fn super_fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_poly_existential_predicates(v))
     }