namespace std {
    template <class charT,
              class traits = char_traits<charT> >
      class basic_ifstream;
    typedef basic_ifstream<char>    ifstream;
    typedef basic_ifstream<wchar_t> wifstream;

    template <class charT,
              class traits = char_traits<charT> >
      class basic_ofstream;
    typedef basic_ofstream<char>    ofstream;
    typedef basic_ofstream<wchar_t> wofstream;

    template <class charT,
              class traits = char_traits<charT> >
      class basic_fstream;
    typedef basic_fstream<char>    fstream;
    typedef basic_fstream<wchar_t> wfstream;

    template <class charT,
              class traits = char_traits<charT> >
      class basic_filebuf;
    typedef basic_filebuf<char>    filebuf;
    typedef basic_filebuf<wchar_t> wfilebuf;
}