Move copyToArrayImpl implementation to Common source set

libraries/stdlib/js/src/kotlin/collectionJs.kt

@@ -36,26 +36,10 @@ internal fun <T> copyToArray(collection: Collection<T>): Array<T> {
 }
 
 @JsName("copyToArrayImpl")
-internal actual fun copyToArrayImpl(collection: Collection<*>): Array<Any?> {
-    val array = emptyArray<Any?>()
-    val iterator = collection.iterator()
-    while (iterator.hasNext())
-        array.asDynamic().push(iterator.next())
-    return array
-}
+internal actual fun copyToArrayImpl(collection: Collection<*>): Array<Any?> = collectionToArrayCommonImpl(collection)
 
 @JsName("copyToExistingArrayImpl")
-internal actual fun <T> copyToArrayImpl(collection: Collection<*>, array: Array<T>): Array<T> {
-    if (array.size < collection.size)
-        return copyToArrayImpl(collection).unsafeCast<Array<T>>()
-
-    val iterator = collection.iterator()
-    var index = 0
-    while (iterator.hasNext()) {
-        array[index++] = iterator.next().unsafeCast<T>()
-    }
-    return terminateCollectionToArray(collection.size, array)
-}
+internal actual fun <T> copyToArrayImpl(collection: Collection<*>, array: Array<T>): Array<T> = collectionToArrayCommonImpl(collection, array)
 
 internal actual fun <T> terminateCollectionToArray(collectionSize: Int, array: Array<T>): Array<T> = array
 

libraries/stdlib/native-wasm/src/kotlin/collections/Arrays.kt

@@ -84,14 +84,9 @@ internal fun <T> Array<out T>?.contentDeepHashCodeImpl(): Int {
 @Suppress("UNCHECKED_CAST")
 internal actual fun <T> arrayOfNulls(reference: Array<T>, size: Int): Array<T> = arrayOfNulls<Any>(size) as Array<T>
 
-internal actual fun copyToArrayImpl(collection: Collection<*>): Array<Any?> {
-    val array = arrayOfUninitializedElements<Any?>(collection.size)
-    val iterator = collection.iterator()
-    var index = 0
-    while (iterator.hasNext())
-        array[index++] = iterator.next()
-    return array
-}
+internal actual fun copyToArrayImpl(collection: Collection<*>): Array<Any?> = collectionToArrayCommonImpl(collection)
+
+internal actual fun <T> copyToArrayImpl(collection: Collection<*>, array: Array<T>): Array<T> = collectionToArrayCommonImpl(collection, array)
 
 internal actual fun <T> terminateCollectionToArray(collectionSize: Int, array: Array<T>): Array<T> = array
 

libraries/stdlib/src/kotlin/collections/Collections.kt

@@ -479,6 +479,40 @@ internal fun throwIndexOverflow() { throw ArithmeticException("Index overflow ha
 @SinceKotlin("1.3")
 internal fun throwCountOverflow() { throw ArithmeticException("Count overflow has happened.") }
 
+
+internal fun collectionToArrayCommonImpl(collection: Collection<*>): Array<Any?> {
+    if (collection.isEmpty()) return emptyArray<Any?>()
+
+    val destination = arrayOfNulls<Any>(collection.size)
+
+    val iterator = collection.iterator()
+    var index = 0
+    while (iterator.hasNext()) {
+        destination[index++] = iterator.next()
+    }
+
+    return destination
+}
+
+internal fun <T> collectionToArrayCommonImpl(collection: Collection<*>, array: Array<T>): Array<T> {
+    if (collection.isEmpty()) return terminateCollectionToArray(0, array)
+
+    val destination = if (array.size < collection.size) {
+        arrayOfNulls(array, collection.size)
+    } else {
+        array
+    }
+
+    val iterator = collection.iterator()
+    var index = 0
+    while (iterator.hasNext()) {
+        @Suppress("UNCHECKED_CAST")
+        destination[index++] = iterator.next() as T
+    }
+
+    return terminateCollectionToArray(collection.size, destination)
+}
+
 /**
  * In JVM if the size of [array] is bigger than [collectionSize], sets `array[collectionSize] = null`.
  * In other platforms does nothing.

libraries/stdlib/wasm/src/kotlin/collections/ArraysWasm.kt

@@ -22,17 +22,4 @@ internal fun <T> copyToArray(collection: Collection<T>): Array<T> =
         //TODO: Find more proper way to call abstract collection's toArray
         @Suppress("INVISIBLE_MEMBER") collection.toArray() as Array<T>
     else
-        copyToArrayImpl(collection) as Array<T>
-
-@Suppress("UNCHECKED_CAST")
-internal actual fun <T> copyToArrayImpl(collection: Collection<*>, array: Array<T>): Array<T> {
-    if (array.size < collection.size)
-        return copyToArrayImpl(collection) as Array<T>
-
-    val iterator = collection.iterator()
-    var index = 0
-    while (iterator.hasNext()) {
-        array[index++] = iterator.next() as T
-    }
-    return terminateCollectionToArray(collection.size, array)
-}
+        copyToArrayImpl(collection) as Array<T>