diff options
| -rw-r--r-- | src/librustc_middle/ty/structural_impls.rs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/librustc_middle/ty/structural_impls.rs b/src/librustc_middle/ty/structural_impls.rs index c6ecb08615f..aa47c6b70a2 100644 --- a/src/librustc_middle/ty/structural_impls.rs +++ b/src/librustc_middle/ty/structural_impls.rs @@ -1019,7 +1019,11 @@ impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Const<'tcx> { fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { let ty = self.ty.fold_with(folder); let val = self.val.fold_with(folder); - folder.tcx().mk_const(ty::Const { ty, val }) + if ty != self.ty || val != self.val { + folder.tcx().mk_const(ty::Const { ty, val }) + } else { + *self + } } fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |