1 files changed, 29 insertions, 13 deletions
diff --git a/compiler/rustc_transmute/src/layout/mod.rs b/compiler/rustc_transmute/src/layout/mod.rs
index f8d05bc89..76d97e0e6 100644
--- a/compiler/rustc_transmute/src/layout/mod.rs
+++ b/compiler/rustc_transmute/src/layout/mod.rs
@@ -30,33 +30,49 @@ impl fmt::Debug for Byte {
 }
 
 pub(crate) trait Def: Debug + Hash + Eq + PartialEq + Copy + Clone {}
-pub trait Ref: Debug + Hash + Eq + PartialEq + Copy + Clone {}
+pub trait Ref: Debug + Hash + Eq + PartialEq + Copy + Clone {
+    fn min_align(&self) -> usize;
+
+    fn is_mutable(&self) -> bool;
+}
 
 impl Def for ! {}
-impl Ref for ! {}
+impl Ref for ! {
+    fn min_align(&self) -> usize {
+        unreachable!()
+    }
+    fn is_mutable(&self) -> bool {
+        unreachable!()
+    }
+}
 
 #[cfg(feature = "rustc")]
-pub(crate) mod rustc {
+pub mod rustc {
     use rustc_middle::mir::Mutability;
-    use rustc_middle::ty;
-    use rustc_middle::ty::Region;
-    use rustc_middle::ty::Ty;
+    use rustc_middle::ty::{self, Ty};
 
     /// A reference in the layout.
     #[derive(Debug, Hash, Eq, PartialEq, PartialOrd, Ord, Clone, Copy)]
     pub struct Ref<'tcx> {
-        lifetime: Region<'tcx>,
-        ty: Ty<'tcx>,
-        mutability: Mutability,
+        pub lifetime: ty::Region<'tcx>,
+        pub ty: Ty<'tcx>,
+        pub mutability: Mutability,
+        pub align: usize,
     }
 
-    impl<'tcx> super::Ref for Ref<'tcx> {}
+    impl<'tcx> super::Ref for Ref<'tcx> {
+        fn min_align(&self) -> usize {
+            self.align
+        }
 
-    impl<'tcx> Ref<'tcx> {
-        pub fn min_align(&self) -> usize {
-            todo!()
+        fn is_mutable(&self) -> bool {
+            match self.mutability {
+                Mutability::Mut => true,
+                Mutability::Not => false,
+            }
         }
     }
+    impl<'tcx> Ref<'tcx> {}
 
     /// A visibility node in the layout.
     #[derive(Debug, Hash, Eq, PartialEq, Clone, Copy)]