From f7256d28d1c2f8340ab5b99df4bdb15aa232f3f3 Mon Sep 17 00:00:00 2001
From: Ross MacArthur <ross@macarthur.io>
Date: Sat, 21 Dec 2019 13:16:18 +0200
Subject: Require issue = "none" over issue = "0" in unstable attributes

---
 src/liballoc/sync.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'src/liballoc/sync.rs')

diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index a99564c0dac..88027d48e8a 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -206,7 +206,7 @@ unsafe impl<T: ?Sized + Sync + Send> Sync for Arc<T> {}
 #[unstable(feature = "coerce_unsized", issue = "27732")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Arc<U>> for Arc<T> {}
 
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Arc<U>> for Arc<T> {}
 
 impl<T: ?Sized> Arc<T> {
@@ -263,7 +263,7 @@ unsafe impl<T: ?Sized + Sync + Send> Sync for Weak<T> {}
 
 #[unstable(feature = "coerce_unsized", issue = "27732")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Weak<U>> for Weak<T> {}
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Weak<U>> for Weak<T> {}
 
 #[stable(feature = "arc_weak", since = "1.4.0")]
@@ -993,7 +993,7 @@ impl<T: ?Sized> Deref for Arc<T> {
     }
 }
 
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized> Receiver for Arc<T> {}
 
 impl<T: Clone> Arc<T> {
@@ -2032,7 +2032,7 @@ impl<T> From<Vec<T>> for Arc<[T]> {
     }
 }
 
-#[unstable(feature = "boxed_slice_try_from", issue = "0")]
+#[unstable(feature = "boxed_slice_try_from", issue = "none")]
 impl<T, const N: usize> TryFrom<Arc<[T]>> for Arc<[T; N]>
 where
     [T; N]: LengthAtMost32,
-- 
cgit 1.4.1-3-g733a5


From a34c2677afeee2747d680536f302a8c5665a65f4 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Sat, 21 Dec 2019 20:35:41 -0500
Subject: Warn against relying on ?Sized being last

---
 src/liballoc/rc.rs   | 2 ++
 src/liballoc/sync.rs | 2 ++
 2 files changed, 4 insertions(+)

(limited to 'src/liballoc/sync.rs')

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 42a278de98b..00c4b5462be 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -2106,6 +2106,8 @@ impl<T: ?Sized> Unpin for Rc<T> { }
 unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
     // Align the unsized value to the end of the `RcBox`.
     // Because it is ?Sized, it will always be the last field in memory.
+    // Note: This is a detail of the current implementation of the compiler,
+    // and is not a guaranteed language detail. Do not rely on it outside of std.
     data_offset_align(align_of_val(&*ptr))
 }
 
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index a99564c0dac..37995a7ec79 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -2161,6 +2161,8 @@ impl<T: ?Sized> Unpin for Arc<T> { }
 unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
     // Align the unsized value to the end of the `ArcInner`.
     // Because it is `?Sized`, it will always be the last field in memory.
+    // Note: This is a detail of the current implementation of the compiler,
+    // and is not a guaranteed language detail. Do not rely on it outside of std.
     data_offset_align(align_of_val(&*ptr))
 }
 
-- 
cgit 1.4.1-3-g733a5