---

yaml
---
r: 13655
b: refs/heads/master
c: 5cf99e0
h: refs/heads/master
i:
  13653: 5065bec
  13651: eb9ab43
  13647: 4ef7e4f
v: v3

Author: eholk

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 3246723bf79ffc20e91936440cebc71ddcfd0a66
+refs/heads/master: 5cf99e02b5f430812e8bce64bcf55c2194ace3ca
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
 refs/heads/try: 2898dcc5d97da9427ac367542382b6239d9c0bbf

trunk/src/libcore/vec.rs

@@ -396,6 +396,15 @@ fn shift<T>(&v: [T]) -> T {
     }
 }
 
+#[doc = "Prepend an element to the vector"]
+fn unshift<T>(&v: [T], +x: T) {
+    let mut vv = [x];
+    v <-> vv;
+    while len(vv) > 0 {
+        push(v, shift(vv));
+    }
+}
+
 #[doc = "Remove the last element from a vector and return it"]
 fn pop<T>(&v: [const T]) -> T unsafe {
     let ln = len(v);
@@ -2197,6 +2206,13 @@ mod tests {
         assert addr == addr_imm;
     }
 
+    #[test]
+    fn test_unshift() {
+        let mut x = [1, 2, 3];
+        unshift(x, 0);
+        assert x == [0, 1, 2, 3];
+    }
+
     #[test]
     fn test_capacity() {
         let mut v = [0u64];