namespace std {
  template<class charT> class char_traits;
  template<> class char_traits<char>;
  template<> class char_traits<char16_t>;
  template<> class char_traits<char32_t>;
  template<> class char_traits<wchar_t>;
  template<class T> class allocator;
  template <class charT, class traits = char_traits<charT> >
    class basic_ios;
  template <class charT, class traits = char_traits<charT> >
    class basic_streambuf;
  template <class charT, class traits = char_traits<charT> >
    class basic_istream;
  template <class charT, class traits = char_traits<charT> >
    class basic_ostream;
  template <class charT, class traits = char_traits<charT> >
    class basic_iostream;
  template <class charT, class traits = char_traits<charT>,
    class Allocator = allocator<charT> >
    class basic_stringbuf;
  template <class charT, class traits = char_traits<charT>,
    class Allocator = allocator<charT> >
    class basic_istringstream;
  template <class charT, class traits = char_traits<charT>,
    class Allocator = allocator<charT> >
    class basic_ostringstream;
  template <class charT, class traits = char_traits<charT>,
    class Allocator = allocator<charT> >
    class basic_stringstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_filebuf;
  template <class charT, class traits = char_traits<charT> >
    class basic_ifstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_ofstream;
  template <class charT, class traits = char_traits<charT> >
    class basic_fstream;
  template <class charT, class traits = char_traits<charT> >
    class istreambuf_iterator;
  template <class charT, class traits = char_traits<charT> >
    class ostreambuf_iterator;
  typedef basic_ios<char>       ios;
  typedef basic_ios<wchar_t>    wios;
  typedef basic_streambuf<char> streambuf;
  typedef basic_istream<char>   istream;
  typedef basic_ostream<char>   ostream;
  typedef basic_iostream<char>  iostream;
  typedef basic_stringbuf<char>     stringbuf;
  typedef basic_istringstream<char> istringstream;
  typedef basic_ostringstream<char> ostringstream;
  typedef basic_stringstream<char>  stringstream;
  typedef basic_filebuf<char>  filebuf;
  typedef basic_ifstream<char> ifstream;
  typedef basic_ofstream<char> ofstream;
  typedef basic_fstream<char>  fstream;
  typedef basic_streambuf<wchar_t> wstreambuf;
  typedef basic_istream<wchar_t>   wistream;
  typedef basic_ostream<wchar_t>   wostream;
  typedef basic_iostream<wchar_t>  wiostream;
  typedef basic_stringbuf<wchar_t>     wstringbuf;
  typedef basic_istringstream<wchar_t> wistringstream;
  typedef basic_ostringstream<wchar_t> wostringstream;
  typedef basic_stringstream<wchar_t>  wstringstream;
  typedef basic_filebuf<wchar_t>  wfilebuf;
  typedef basic_ifstream<wchar_t> wifstream;
  typedef basic_ofstream<wchar_t> wofstream;
  typedef basic_fstream<wchar_t> wfstream;
  template <class state> class fpos;
  typedef fpos<char_traits<char>::state_type>    streampos;
  typedef fpos<char_traits<wchar_t>::state_type> wstreampos;
}
