Fixed #852.

4 files changed, 6 insertions, 3 deletions

diff --git a/src/library/scala/List.scala b/src/library/scala/List.scala
index 6f4b52b4fd..84560f2939 100644
--- a/src/library/scala/List.scala
+++ b/src/library/scala/List.scala
@@ -489,7 +489,7 @@ sealed abstract class List[+A] extends Seq[A] {
    *  @param x the element to append.
    *  @return  the list with <code>x</code> added at the end.
    */
-  def +[B >: A](x: B): List[B] =
+  override def +[B >: A](x: B): List[B] =
     if (isEmpty) List(x)
     else {
       val buf = new ListBuffer[B]
diff --git a/src/library/scala/Seq.scala b/src/library/scala/Seq.scala
index 6b545ae6e7..14001d1b0a 100644
--- a/src/library/scala/Seq.scala
+++ b/src/library/scala/Seq.scala
@@ -213,6 +213,9 @@ trait Seq[+A] extends AnyRef with PartialFunction[Int, A] with Collection[A] {
     buf.readOnly
   }
 
+  def +[B >: A](e: B): Seq[B] =
+    this ++ Seq.single(e)
+
   /** Is this partial function defined for the index <code>x</code>?
    *
    *  @param x ..
diff --git a/src/library/scala/collection/immutable/Queue.scala b/src/library/scala/collection/immutable/Queue.scala
index 738c7ab55e..01abc1a813 100644
--- a/src/library/scala/collection/immutable/Queue.scala
+++ b/src/library/scala/collection/immutable/Queue.scala
@@ -72,7 +72,7 @@ class Queue[+A](elem: A*) extends Seq[A] {
    *
    *  @param  elem        the element to insert
    */
-  def +[B >: A](elem: B) = mkQueue(elem :: in, out)
+  override def +[B >: A](elem: B) = mkQueue(elem :: in, out)
 
   /** Returns a new queue with all all elements provided by
    *  an <code>Iterable</code> object added at the end of
diff --git a/src/library/scala/collection/immutable/Stack.scala b/src/library/scala/collection/immutable/Stack.scala
index 75d6cb8b98..dcff24b51c 100644
--- a/src/library/scala/collection/immutable/Stack.scala
+++ b/src/library/scala/collection/immutable/Stack.scala
@@ -46,7 +46,7 @@ class Stack[+A] extends Seq[A] {
    *  @param   elem       the element to push on the stack.
    *  @return the stack with the new element on top.
    */
-  def +[B >: A](elem: B): Stack[B] = new Node(elem)
+  override def +[B >: A](elem: B): Stack[B] = new Node(elem)
 
   /** Push all elements provided by the given iterable object onto
    *  the stack. The last element returned by the iterable object