diff options
| -rw-r--r-- | compiler/rustc_transmute/src/layout/tree.rs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/compiler/rustc_transmute/src/layout/tree.rs b/compiler/rustc_transmute/src/layout/tree.rs index 4cc6292a3ee..6ce9969aefe 100644 --- a/compiler/rustc_transmute/src/layout/tree.rs +++ b/compiler/rustc_transmute/src/layout/tree.rs @@ -495,7 +495,10 @@ pub(crate) mod rustc { (ty, layout): (Ty<'tcx>, Layout<'tcx>), i: FieldIdx, ) -> Ty<'tcx> { - // FIXME: Why does this not just use `ty_and_layout_field`? + // We cannot use `ty_and_layout_field` to retrieve the field type, since + // `ty_and_layout_field` erases regions in the returned type. We must + // not erase regions here, since we may need to ultimately emit outlives + // obligations as a consequence of the transmutability analysis. match ty.kind() { ty::Adt(def, args) => { match layout.variants { |