namespace std::chrono { class weekday_last { chrono::weekday wd_; // exposition only public: constexpr explicit weekday_last(const chrono::weekday& wd) noexcept; constexpr chrono::weekday weekday() const noexcept; constexpr bool ok() const noexcept; }; }
constexpr auto wdl = Sunday[last]; // wdl is the last Sunday of an as yet unspecified month static_assert(wdl.weekday() == Sunday);— end example
constexpr explicit weekday_last(const chrono::weekday& wd) noexcept;
constexpr chrono::weekday weekday() const noexcept;
constexpr bool ok() const noexcept;
constexpr bool operator==(const weekday_last& x, const weekday_last& y) noexcept;
template<class charT, class traits>
basic_ostream<charT, traits>&
operator<<(basic_ostream<charT, traits>& os, const weekday_last& wdl);