Merge pull request #1739 from jedesah/Array_opt

SI-5017 Poor performance of :+ operator on Arrays

1 files changed, 14 insertions, 0 deletions

diff --git a/src/library/scala/collection/mutable/ArrayOps.scala b/src/library/scala/collection/mutable/ArrayOps.scala
index bb938a7aeb..6b778b26f5 100644
--- a/src/library/scala/collection/mutable/ArrayOps.scala
+++ b/src/library/scala/collection/mutable/ArrayOps.scala
@@ -52,6 +52,20 @@ trait ArrayOps[T] extends Any with ArrayLike[T, Array[T]] with CustomParalleliza
       super.toArray[U]
   }
 
+  def :+[B >: T: scala.reflect.ClassTag](elem: B): Array[B] = {
+    val result = Array.ofDim[B](repr.length + 1)
+    Array.copy(repr, 0, result, 0, repr.length)
+    result(repr.length) = elem
+    result
+  }
+
+  def +:[B >: T: scala.reflect.ClassTag](elem: B): Array[B] = {
+    val result = Array.ofDim[B](repr.length + 1)
+    result(0) = elem
+    Array.copy(repr, 0, result, 1, repr.length)
+    result
+  }
+
   override def par = ParArray.handoff(repr)
 
   /** Flattens a two-dimensional array by concatenating all its rows