Merge pull request rust-lang#737 from rkruppe/patch-2

repr(transparent): mention align=1 requirement
Centril · Jan 11, 2020 · a94b0ef · a94b0ef
2 parents 55a3f99 + 8055a35
commit a94b0ef
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/src/type-layout.md b/src/type-layout.md
@@ -332,9 +332,10 @@ Like all ways to create undefined behavior in safe Rust, this is a bug.
 
 ### The `transparent` Representation
 
-The `transparent` representation can only be used on `struct`s that have a
-single non-zero sized field and any number of zero-sized fields, including
-[`PhantomData<T>`].
+The `transparent` representation can only be used on `struct`s that have:
+
+- a single field with non-zero size, and
+- any number of fields with size 0 and alignment 1 (e.g. [`PhantomData<T>`]).
 
 Structs with this representation have the same layout and ABI as the single
 non-zero sized field.