    CImg<T>& operator&=(const t value) {
      if (is_empty()) return *this;
      cimg_openmp_for(*this,(longT)*ptr & (longT)value,32768);
      return *this;
    }
    CImg<T>& operator&=(const t value) {
      if (is_empty()) return *this;
      cimg_openmp_for(*this,(longT)*ptr & (longT)value,32768);
      return *this;
    }