---

yaml
---
r: 11959
b: refs/heads/master
c: b1eb457
h: refs/heads/master
i:
  11957: 5d5c793
  11955: 6f4717c
  11951: 600ec4f
v: v3

Author: brson

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: d6ded6788dbf24a6545f579a23a92553efae1c2e
+refs/heads/master: b1eb4579c695871f75c995b7792ec5f100fbabf9
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
 refs/heads/try: 2898dcc5d97da9427ac367542382b6239d9c0bbf

trunk/src/libcore/vec.rs

@@ -773,11 +773,19 @@ fn iter_between<T>(v: [const T], start: uint, end: uint, f: fn(T)) {
     }
 }
 
-#[doc = "Iterates over two vectors in parallel"]
+#[doc = "
+Iterates over two vectors simultaneously
+
+# Failure
+
+Both vectors must have the same length
+"]
 #[inline]
-fn iter2<U, T>(v: [ U], v2: [const T], f: fn(U, T)) {
-    let mut i = 0;
-    for elt in v { f(elt, v2[i]); i += 1; }
+fn iter2<U, T>(v1: [const U], v2: [const T], f: fn(U, T)) {
+    assert len(v1) == len(v2);
+    uint::range(0u, len(v1)) {|i|
+        f(v1[i], v2[i])
+    }
 }
 
 #[doc = "