Added an override to immutable.IndexedSeq#toInd...

Added an override to immutable.IndexedSeq#toIndexedSeq which returns
itself. Closes #3732, no review.

2 files changed, 11 insertions, 0 deletions

diff --git a/src/library/scala/collection/immutable/IndexedSeq.scala b/src/library/scala/collection/immutable/IndexedSeq.scala
index 3db217a5f3..ba432517ff 100644
--- a/src/library/scala/collection/immutable/IndexedSeq.scala
+++ b/src/library/scala/collection/immutable/IndexedSeq.scala
@@ -22,6 +22,7 @@ trait IndexedSeq[+A] extends Seq[A]
                     with GenericTraversableTemplate[A, IndexedSeq]
                     with IndexedSeqLike[A, IndexedSeq[A]] {
   override def companion: GenericCompanion[IndexedSeq] = IndexedSeq
+  override def toIndexedSeq[B >: A]: IndexedSeq[B] = this
 }
 
 /** $factoryInfo
diff --git a/test/files/run/indexedSeq.scala b/test/files/run/indexedSeq.scala
new file mode 100644
index 0000000000..19308e1d8c
--- /dev/null
+++ b/test/files/run/indexedSeq.scala
@@ -0,0 +1,10 @@
+object Test {
+  import scala.collection.{ mutable, immutable, generic }
+
+  def checkIdentity[A](xs: immutable.IndexedSeq[A]) = assert(xs.toIndexedSeq eq xs)
+
+  def main(args: Array[String]): Unit = {
+    checkIdentity(immutable.Vector(1 to 10: _*))
+    checkIdentity(1 to 10 toIndexedSeq)
+  }
+}