---

yaml
---
r: 89992
b: refs/heads/master
c: c6ca9ab
h: refs/heads/master
v: v3

Author: sfackler

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 48cd8c646ace585153d6ed25baccdd8420742e42
+refs/heads/master: c6ca9abcc651423fe85f522cbd20f1e64463c36f
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: a6d3e57dca68fde4effdda3e4ae2887aa535fcd6
 refs/heads/try: b160761e35efcd1207112b3b782c06633cf441a8

trunk/src/libstd/rc.rs

@@ -21,6 +21,7 @@ use unstable::intrinsics::transmute;
 use ops::Drop;
 use kinds::{Freeze, Send};
 use clone::{Clone, DeepClone};
+use mutable::Mut;
 
 struct RcBox<T> {
     value: T,
@@ -54,6 +55,16 @@ impl<T: Send> Rc<T> {
     }
 }
 
+impl<T: Freeze> Rc<Mut<T>> {
+    /// Construct a new reference-counted box from a `Mut`-wrapped `Freeze` value
+    #[inline]
+    pub fn from_mut(value: Mut<T>) -> Rc<Mut<T>> {
+        unsafe {
+            Rc::new_unchecked(value)
+        }
+    }
+}
+
 impl<T> Rc<T> {
     /// Unsafety construct a new reference-counted box from any value.
     ///
@@ -146,4 +157,10 @@ mod test_rc {
         let x = Rc::from_send(~5);
         assert_eq!(**x.borrow(), 5);
     }
+
+    #[test]
+    fn test_from_mut() {
+        let a = 10;
+        let _x = Rc::from_mut(Mut::new(&a));
+    }
 }