added -= method to Buffer

2 files changed, 13 insertions, 2 deletions

diff --git a/src/library/scala/collection/mutable/Buffer.scala b/src/library/scala/collection/mutable/Buffer.scala
index 86bc87d046..5cec902cff 100644
--- a/src/library/scala/collection/mutable/Buffer.scala
+++ b/src/library/scala/collection/mutable/Buffer.scala
@@ -97,6 +97,16 @@ trait Buffer[A] extends AnyRef
      */
     def +:(elem: A): Buffer[A];
 
+    /** Removes a single element from this buffer, at its first occurrence.
+     *  If the list does not contain that element, it is unchanged
+     *
+     *  @param x  the element to remove.
+     */
+    def -= (x: A): unit = {
+      val i = indexOf(x)
+      if(i != -1) remove(i)
+    }
+
     /** Prepends a number of elements provided by an iterable object
      *  via its <code>elements</code> method. The identity of the
      *  buffer is returned.
diff --git a/src/library/scala/collection/mutable/ListBuffer.scala b/src/library/scala/collection/mutable/ListBuffer.scala
index eabeabeaa1..66c5dbae27 100644
--- a/src/library/scala/collection/mutable/ListBuffer.scala
+++ b/src/library/scala/collection/mutable/ListBuffer.scala
@@ -60,14 +60,15 @@ final class ListBuffer[A] extends Buffer[A] {
    *
    *  @param x  the element to remove.
    */
-  def -= (x: A): unit = {
+  override def -= (x: A): unit = {
     if (exported) copy()
     if (start.isEmpty) {}
     else if (start.head == x) start = start.tail
     else {
       var cursor = start
       while (!cursor.tail.isEmpty && cursor.tail.head != x) { cursor = cursor.tail }
-      if (!cursor.tail.isEmpty) cursor.asInstanceOf[scala.::[A]].tl = cursor.tail.tail
+      if (!cursor.tail.isEmpty)
+	cursor.asInstanceOf[scala.::[A]].tl = cursor.tail.tail
     }
   }