static public function isUnsignedInt($value)
{
  return (preg_match('#^[0-9]+$#', (string)$value) AND $value < 4294967296 AND $value >= 0);
}

/**
* Check for an integer validity (unsigned)
* Mostly used in database for auto-increment
*
* @param integer $id Integer to validate
* @return boolean Validity is ok or not
*/
static public function isUnsignedId($id)
{
  return self::isUnsignedInt($id); /* Because an id could be equal to zero when there is no association */
}