Overrode contains and apply in mutable.HashMap ...

Overrode contains and apply in mutable.HashMap to avoid allocating
an unnecessary Some on every call to either of them. Fruit looks a
little better defended in immutable.HashMap, so I deleted a bunch of old
debugging code instead. Closes #4469, no review.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/library/scala/collection/MapLike.scala b/src/library/scala/collection/MapLike.scala
index f6a5c57ddf..4850898ce8 100644
--- a/src/library/scala/collection/MapLike.scala
+++ b/src/library/scala/collection/MapLike.scala
@@ -141,10 +141,7 @@ self =>
    *  @param key the key
    *  @return    `true` if there is a binding for `key` in this map, `false` otherwise.
    */
-  def contains(key: A): Boolean = get(key) match {
-    case None => false
-    case Some(_) => true
-  }
+  def contains(key: A): Boolean = get(key).isDefined
 
   /** Tests whether this map contains a binding for a key. This method,
    *  which implements an abstract method of trait `PartialFunction`,