Relax the safety condition for get_mut_unchecked

rust-lang · Aug 16, 2019 · 7a641f7 · 7a641f7
1 parent 810dfd7
commit 7a641f7
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git 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
@@ -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
     ///