1  
       2  class basic_ios
       3  {
       4  public:
       5    virtual ~basic_ios();
       6    basic_ios();
       7  };
       8  
       9  class basic_ostream : virtual public basic_ios
      10  {
      11  public:
      12    basic_ostream();
      13    virtual ~basic_ostream();
      14  };