      static double mp_bitwise_xor(_cimg_math_parser& mp) {
        return (double)((longT)_mp_arg(2) ^ (longT)_mp_arg(3));
      }
      static double mp_bitwise_xor(_cimg_math_parser& mp) {
        return (double)((longT)_mp_arg(2) ^ (longT)_mp_arg(3));
      }