make `IndexMut` a super trait over `Index`

[rust.git] / src / libcollections / btree / map.rs

diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index 1b6057d4c728660d1e046776ea5718c08064e854..aec50d5380880e24891e760d5247a3fbaad862f1 100644 (file)
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -910,8 +910,6 @@ fn index(&self, key: &Q) -> &V {
 impl<K: Ord, Q: ?Sized, V> IndexMut<Q> for BTreeMap<K, V>
     where Q: BorrowFrom<K> + Ord
 {
-    type Output = V;
-
     fn index_mut(&mut self, key: &Q) -> &mut V {
         self.get_mut(key).expect("no entry found for key")
     }