diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc_middle/ty/structural_impls.rs | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/librustc_middle/ty/structural_impls.rs b/src/librustc_middle/ty/structural_impls.rs index cee0afacb68..f6f5dfd6516 100644 --- a/src/librustc_middle/ty/structural_impls.rs +++ b/src/librustc_middle/ty/structural_impls.rs @@ -987,7 +987,8 @@ impl<'tcx> TypeFoldable<'tcx> for ty::Region<'tcx> { impl<'tcx> TypeFoldable<'tcx> for ty::Predicate<'tcx> { fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { - folder.tcx().mk_predicate(ty::PredicateKind::super_fold_with(self.kind, folder)) + let new = ty::PredicateKind::super_fold_with(self.kind, folder); + if new != *self.kind { folder.tcx().mk_predicate(new) } else { *self } } fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |