Add copyToArray and toArray to IArray

library/src/scala/IArray.scala

@@ -52,6 +52,18 @@ object opaques:
       // but we can use `exists` instead, which is how `ArrayOps#contains` itself is implemented:
       genericArrayOps(arr).exists(_ == elem)
 
+    /** Copy elements of this array to another array. */
+    extension [T, U >: T](arr: IArray[T]) def copyToArray(xs: Array[U]): Int =
+      genericArrayOps(arr).copyToArray(xs)
+
+    /** Copy elements of this array to another array. */
+    extension [T, U >: T](arr: IArray[T]) def copyToArray(xs: Array[U], start: Int): Int =
+      genericArrayOps(arr).copyToArray(xs, start)
+
+    /** Copy elements of this array to another array. */
+    extension [T, U >: T](arr: IArray[T]) def copyToArray(xs: Array[U], start: Int, len: Int): Int =
+      genericArrayOps(arr).copyToArray(xs, start, len)
+
     /** Counts the number of elements in this array which satisfy a predicate */
     extension [T](arr: IArray[T]) def count(p: T => Boolean): Int =
       genericArrayOps(arr).count(p)
@@ -247,6 +259,10 @@ object opaques:
     extension [T](arr: IArray[T]) def takeWhile(p: T => Boolean): IArray[T] =
       genericArrayOps(arr).takeWhile(p)
 
+    /** Returns a mutable copy of this immutable array. */
+    extension [T](arr: IArray[T]) def toArray: Array[T] =
+      arr.clone.asInstanceOf[Array[T]]
+
     /** Converts an array of pairs into an array of first elements and an array of second elements. */
     extension [U: ClassTag, V: ClassTag](arr: IArray[(U, V)]) def unzip: (IArray[U], IArray[V]) =
       genericArrayOps(arr).unzip

tests/run/iarrays.scala

@@ -70,4 +70,17 @@ object Test extends App {
   val cs: Array[Double] = bs.asInstanceOf[Array[Double]]
   cs(1) = 3.0
   assert(bs(1) == 3.0)
-}
+
+  // Check copyToArray
+  val ds: IArray[Int] = IArray(1, 2, 3)
+  val es: Array[Int] = new Array[Int](10)
+  ds.copyToArray(es, 5, 2)
+  assert(es.toList == List(0, 0, 0, 0, 0, 1, 2, 0, 0, 0))
+  val fs: Array[Any] = new Array[Any](10)
+  ds.copyToArray(fs, 5, 2)
+  assert(fs.toList == List(null, null, null, null, null, 1, 2, null, null, null))
+
+  // Check toArray
+  ds.toArray(0) = 0
+  assert(ds(0) == 1)
+}