fun box(): String {
  val a: DoubleArray = DoubleArray(size = 5)
  val x: DoubleIterator = a.iterator()
  var i: Int = 0
  while (x.hasNext()) { // BLOCK
    when {
      ieee754equals(arg0 = a.get(index = i), arg1 = x.next()).not() -> return "Fail " + i
    }
    { // BLOCK
      val tmp_0: Int = i
      i = tmp_0.inc()
      tmp_0
    } /*~> Unit */
  }
  return "OK"
}