---

yaml
---
r: 23294
b: refs/heads/master
c: 6d7b143
h: refs/heads/master
v: v3

Author: pcwalton

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 0e3825d38cc459f9fcb24f1e95d4f6e867265300
+refs/heads/master: 6d7b143036e1d61c8f58864db3445d2a0ae4ad11
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: cd6f24f9d14ac90d167386a56e7a6ac1f0318195
 refs/heads/try: ffbe0e0e00374358b789b0037bcb3a577cd218be

trunk/src/libstd/cell.rs

@@ -39,6 +39,13 @@ impl<T> Cell<T> {
     fn is_empty() -> bool {
         self.value.is_none()
     }
+
+    // Calls a closure with a reference to the value.
+    fn with_ref(f: fn(v: &T)) {
+        let val = move self.take();
+        f(&val);
+        self.put_back(move val);
+    }
 }
 
 #[test]
@@ -66,4 +73,4 @@ fn test_take_empty() {
 fn test_put_back_non_empty() {
     let value_cell = Cell(~10);
     value_cell.put_back(~20);
-}
+}