constexpr year_month_weekday_last(const chrono::year& y, const chrono::month& m,
const chrono::weekday_last& wdl) noexcept;
constexpr year_month_weekday_last& operator+=(const months& m) noexcept;
constexpr year_month_weekday_last& operator-=(const months& m) noexcept;
constexpr year_month_weekday_last& operator+=(const years& y) noexcept;
constexpr year_month_weekday_last& operator-=(const years& y) noexcept;
constexpr chrono::year year() const noexcept;
constexpr chrono::month month() const noexcept;
constexpr chrono::weekday weekday() const noexcept;
constexpr chrono::weekday_last weekday_last() const noexcept;
constexpr operator sys_days() const noexcept;
constexpr explicit operator local_days() const noexcept;
constexpr bool ok() const noexcept;
constexpr bool operator==(const year_month_weekday_last& x,
const year_month_weekday_last& y) noexcept;
constexpr year_month_weekday_last
operator+(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
constexpr year_month_weekday_last
operator+(const months& dm, const year_month_weekday_last& ymwdl) noexcept;
constexpr year_month_weekday_last
operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
constexpr year_month_weekday_last
operator+(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
constexpr year_month_weekday_last
operator+(const years& dy, const year_month_weekday_last& ymwdl) noexcept;
constexpr year_month_weekday_last
operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
template<class charT, class traits>
basic_ostream<charT, traits>&
operator<<(basic_ostream<charT, traits>& os, const year_month_weekday_last& ymwdl);