25 Time library [time]

25.8 The civil calendar [time.cal]

25.8.11 Class month_­weekday [time.cal.mwd]

25.8.11.1 Overview [time.cal.mwd.overview]

namespace std::chrono {
  class month_weekday {
    chrono::month           m_;         // exposition only
    chrono::weekday_indexed wdi_;       // exposition only
  public:
    constexpr month_weekday(const chrono::month& m, const chrono::weekday_indexed& wdi) noexcept;

    constexpr chrono::month           month()           const noexcept;
    constexpr chrono::weekday_indexed weekday_indexed() const noexcept;
    constexpr bool ok() const noexcept;
  };
}
month_­weekday represents the weekday of a month, of an as yet unspecified year.
To do this the month_­weekday stores a month and a weekday_­indexed.
[Example
:
constexpr auto mwd
    = February/Tuesday[3];               // mwd is the third Tuesday of February of an as yet unspecified year
static_assert(mwd.month() == February);
static_assert(mwd.weekday_indexed() == Tuesday[3]);
end example
]
month_­weekday is a trivially copyable and standard-layout class type.

25.8.11.2 Member functions [time.cal.mwd.members]

constexpr month_weekday(const chrono::month& m, const chrono::weekday_indexed& wdi) noexcept;
Effects: Constructs an object of type month_­weekday by initializing m_­ with m, and wdi_­ with wdi.
constexpr chrono::month month() const noexcept;
Returns: m_­.
constexpr chrono::weekday_indexed weekday_indexed() const noexcept;
Returns: wdi_­.
constexpr bool ok() const noexcept;
Returns: m_­.ok() && wdi_­.ok().

25.8.11.3 Non-member functions [time.cal.mwd.nonmembers]

constexpr bool operator==(const month_weekday& x, const month_weekday& y) noexcept;
Returns: x.month() == y.month() && x.weekday_­indexed() == y.weekday_­indexed().
template<class charT, class traits> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const month_weekday& mwd);
Returns: os << mwd.month() << '/' << mwd.weekday_­indexed().