1 files changed, 8 insertions, 0 deletions
diff --git a/src/libcore/vec.rs b/src/libcore/vec.rs
index 3215f3b9f28..cddb1346c01 100644
--- a/src/libcore/vec.rs
+++ b/src/libcore/vec.rs
@@ -1096,6 +1096,14 @@ impl extensions<T> for [T] {
     #[inline]
     fn map<U>(f: fn(T) -> U) -> [U] { map(self, f) }
     #[doc = "
+    Apply a function to the index and value of each element in the vector
+    and return the results
+    "]
+    fn mapi<U>(f: fn(uint, T) -> U) -> [U] {
+        let mut i = 0u;
+        self.map { |e| i += 1u; f(i - 1u, e) }
+    }
+    #[doc = "
     Apply a function to each element of a vector and return a concatenation
     of each result vector
     "]