If the expr is not a Rat or Flt then the result is NaN. If the expr is a Rat and an integer and in safe range for EcmaScript number then a number is returned. If the expr is a Flt and an integer then the number is returned.
If the expr is not a Rat or Flt then the result is NaN. If the expr is a Rat and an integer and in safe range for EcmaScript number then a number is returned. If the expr is a Flt and an integer then the number is returned.