22 Diagnostics library [diagnostics]

22.5 System error support [syserr]

22.5.3 Class error_­code [syserr.errcode]

22.5.3.5 Class error_­code 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: As if by: os << ec.category().name() << ':' << ec.value();