X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=library%2Fcore%2Fsrc%2Fmarker.rs;h=1326fc9ab096f03d6edde634db009dc697c17c15;hb=6e969ea85eb8f5e504c1a0a06c0a63c515fadf3b;hp=c0fb954ce2d9d39c0a291902a021894ca820db2d;hpb=7c991868c60a4afc1ee6334b912ea96061a2c98d;p=rust.git

diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index c0fb954ce2d..1326fc9ab09 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -623,6 +623,12 @@ impl<T: ?Sized> !Sync for *mut T {}
 /// (ideally) or `PhantomData<*const T>` (if no lifetime applies), so
 /// as not to indicate ownership.
 ///
+/// ## Layout
+///
+/// For all `T`, the following are guaranteed:
+/// * `size_of::<PhantomData<T>>() == 0`
+/// * `align_of::<PhantomData<T>>() == 1`
+///
 /// [drop check]: ../../nomicon/dropck.html
 #[lang = "phantom_data"]
 #[stable(feature = "rust1", since = "1.0.0")]