error_code() noexcept;
error_code(int val, const error_category& cat) noexcept;
template<class ErrorCodeEnum>
error_code(ErrorCodeEnum e) noexcept;
void assign(int val, const error_category& cat) noexcept;
template<class ErrorCodeEnum>
error_code& operator=(ErrorCodeEnum e) noexcept;
void clear() noexcept;
int value() const noexcept;
const error_category& category() const noexcept;
error_condition default_error_condition() const noexcept;
string message() const;
explicit operator bool() const noexcept;
error_code make_error_code(errc e) noexcept;
template<class charT, class traits>
basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const error_code& ec);