    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);
    }