Name boolean arguments in src/library.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/library/scala/collection/immutable/TreeSet.scala b/src/library/scala/collection/immutable/TreeSet.scala
index 26c3d44bbb..e25d16408a 100644
--- a/src/library/scala/collection/immutable/TreeSet.scala
+++ b/src/library/scala/collection/immutable/TreeSet.scala
@@ -109,7 +109,7 @@ class TreeSet[A] private (tree: RB.Tree[A, Unit])(implicit val ordering: Orderin
    *  @param elem    a new element to add.
    *  @return        a new $coll containing `elem` and all the elements of this $coll.
    */
-  def + (elem: A): TreeSet[A] = newSet(RB.update(tree, elem, (), false))
+  def + (elem: A): TreeSet[A] = newSet(RB.update(tree, elem, (), overwrite = false))
 
   /** A new `TreeSet` with the entry added is returned,
    *  assuming that elem is <em>not</em> in the TreeSet.
@@ -119,7 +119,7 @@ class TreeSet[A] private (tree: RB.Tree[A, Unit])(implicit val ordering: Orderin
    */
   def insert(elem: A): TreeSet[A] = {
     assert(!RB.contains(tree, elem))
-    newSet(RB.update(tree, elem, (), false))
+    newSet(RB.update(tree, elem, (), overwrite = false))
   }
 
   /** Creates a new `TreeSet` with the entry removed.