    CImg<T>& operator<<=(const char *const expression) {
      return *this<<=(+*this)._fill(expression,true,1,0,0,"operator<<=",this);
    }
    CImg<T>& operator<<=(const char *const expression) {
      return *this<<=(+*this)._fill(expression,true,1,0,0,"operator<<=",this);
    }