30 Input/output library [input.output]

30.7 Formatting and manipulators [iostream.format]

30.7.2 Header <ostream> synopsis [ostream.syn]

namespace std {
  template <class charT, class traits = char_traits<charT>>
    class basic_ostream;

  using ostream  = basic_ostream<char>;
  using wostream = basic_ostream<wchar_t>;

  template <class charT, class traits>
    basic_ostream<charT, traits>& endl(basic_ostream<charT, traits>& os);
  template <class charT, class traits>
    basic_ostream<charT, traits>& ends(basic_ostream<charT, traits>& os);
  template <class charT, class traits>
    basic_ostream<charT, traits>& flush(basic_ostream<charT, traits>& os);

  template <class charT, class traits, class T>
    basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>&& os, const T& x);
}