template partitionIt*[T](s: openArray[T], pred: untyped): untyped =    # it's OK

template partitionIt*[T](s: openArray[T], pred: untyped): (openArray[T], openArray[T]) =    # problem

test_pykot.nim(204, 31) Error: type mismatch: got <tuple[t: seq[float], f: seq[float]]> but expected 'tuple of (openarray[float], openarray[float])'