namespace std { template<class charT, class traits = char_traits<charT>> class basic_istream; using istream = basic_istream<char>; using wistream = basic_istream<wchar_t>; template<class charT, class traits = char_traits<charT>> class basic_iostream; using iostream = basic_iostream<char>; using wiostream = basic_iostream<wchar_t>; template<class charT, class traits> basic_istream<charT, traits>& ws(basic_istream<charT, traits>& is); template<class charT, class traits, class T> basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>&& is, T&& x); }