19 Diagnostics library [diagnostics]

19.5 System error support [syserr]

19.5.4 Class error_code [syserr.errcode]

19.5.4.5 Non-member functions [syserr.errcode.nonmembers]

error_code make_error_code(errc e) noexcept;
Returns: error_code(static_cast<int>(e), generic_category()).
template<class charT, class traits> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const error_code& ec);
Effects: Equivalent to: return os << ec.category().name() << ':' << ec.value();