      static bool is_inf(const double val) {
#ifdef isinf
        return (bool)isinf(val);
#else
        return !is_nan(val) && (val<cimg::type<double>::min() || val>cimg::type<double>::max());
#endif
      }
      static bool is_inf(const double val) {
#ifdef isinf
        return (bool)isinf(val);
#else
        return !is_nan(val) && (val<cimg::type<double>::min() || val>cimg::type<double>::max());
#endif
      }