---

yaml
---
r: 145907
b: refs/heads/try2
c: 91abfd4
h: refs/heads/master
i:
  145905: f28c2b0
  145903: a4a91df
v: v3

Author: bors

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: e88064d18f681cc702baebeb8951d5dc6ed10fb9
+refs/heads/try2: 91abfd425d74af4cd083c3a6fc15bb39a4aa33da
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/libstd/vec.rs

@@ -840,6 +840,7 @@ pub trait ImmutableVector<'self, T> {
     fn window_iter(self, size: uint) -> WindowIter<'self, T>;
     fn chunk_iter(self, size: uint) -> ChunkIter<'self, T>;
 
+    fn get_opt(&self, index: uint) -> Option<&'self T>;
     fn head(&self) -> &'self T;
     fn head_opt(&self) -> Option<&'self T>;
     fn tail(&self) -> &'self [T];
@@ -1019,6 +1020,13 @@ impl<'self,T> ImmutableVector<'self, T> for &'self [T] {
         ChunkIter { v: self, size: size }
     }
 
+    /// Returns the element of a vector at the given index, or `None` if the
+    /// index is out of bounds
+    #[inline]
+    fn get_opt(&self, index: uint) -> Option<&'self T> {
+        if index < self.len() { Some(&self[index]) } else { None }
+    }
+
     /// Returns the first element of a vector, failing if the vector is empty.
     #[inline]
     fn head(&self) -> &'self T {
@@ -2574,6 +2582,16 @@ mod tests {
         assert_eq!(v2.len(), 2);
     }
 
+    #[test]
+    fn test_get_opt() {
+        let mut a = ~[11];
+        assert_eq!(a.get_opt(1), None);
+        a = ~[11, 12];
+        assert_eq!(a.get_opt(1).unwrap(), &12);
+        a = ~[11, 12, 13];
+        assert_eq!(a.get_opt(1).unwrap(), &12);
+    }
+
     #[test]
     fn test_head() {
         let mut a = ~[11];