From 7a641f7c516ac666c72bf9edfbec8648aa0160c7 Mon Sep 17 00:00:00 2001
From: Simon Sapin <simon.sapin@exyr.org>
Date: Fri, 16 Aug 2019 17:45:44 +0200
Subject: [PATCH] Relax the safety condition for get_mut_unchecked

---
 src/liballoc/rc.rs   | 6 ++++--
 src/liballoc/sync.rs | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index abb09684260d..1509afa48893 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -719,8 +719,10 @@ impl<T: ?Sized> Rc<T> {
     ///
     /// # Safety
     ///
-    /// There must be no other `Rc` or [`Weak`] pointers to the same value.
-    /// This is the case for example immediately after `Rc::new`.
+    /// Any other `Rc` or [`Weak`] pointers to the same value must not be dereferenced
+    /// for the duration of the returned borrow.
+    /// This is trivially the case if no such pointer exist,
+    /// for example immediately after `Rc::new`.
     ///
     /// # Examples
     ///
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index bb4d1499014c..078ddc27da9b 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -1104,8 +1104,10 @@ impl<T: ?Sized> Arc<T> {
     ///
     /// # Safety
     ///
-    /// There must be no other `Arc` or [`Weak`] pointers to the same value.
-    /// This is the case for example immediately after `Rc::new`.
+    /// Any other `Arc` or [`Weak`] pointers to the same value must not be dereferenced
+    /// for the duration of the returned borrow.
+    /// This is trivially the case if no such pointer exist,
+    /// for example immediately after `Arc::new`.
     ///
     /// # Examples
     ///