---

yaml
---
r: 29894
b: refs/heads/incoming
c: 6d7b143
h: refs/heads/master
v: v3

Author: pcwalton

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: d324a424d8f84b1eb049b12cf34182bda91b0024
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: d0c6ce338884ee21843f4b40bf6bf18d222ce5df
-refs/heads/incoming: 0e3825d38cc459f9fcb24f1e95d4f6e867265300
+refs/heads/incoming: 6d7b143036e1d61c8f58864db3445d2a0ae4ad11
 refs/heads/dist-snap: 2f32a1581f522e524009138b33b1c7049ced668d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/incoming/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);
-}
+}