static double variance_fp_recurrence_result(double s, ulonglong count, bool is_sample_variance)
{
  if (count == 1)
    return 0.0;

  if (is_sample_variance)
    return s / (count - 1);

  /* else, is a population variance */
  return s / count;
}
static double variance_fp_recurrence_result(double s, ulonglong count, bool is_sample_variance)
{
  if (count == 1)
    return 0.0;

  if (is_sample_variance)
    return s / (count - 1);

   
  return s / count;
}