4.0 KiB
[time.cal.wdidx]
30 Time library [time]
30.8 The civil calendar [time.cal]
30.8.7 Class weekday_indexed [time.cal.wdidx]
30.8.7.1 Overview [time.cal.wdidx.overview]
namespace std::chrono {class weekday_indexed { chrono::weekday wd_; // exposition onlyunsigned char index_; // exposition onlypublic: weekday_indexed() = default; constexpr weekday_indexed(const chrono::weekday& wd, unsigned index) noexcept; constexpr chrono::weekday weekday() const noexcept; constexpr unsigned index() const noexcept; constexpr bool ok() const noexcept; };}
weekday_indexed represents a weekday and a small index in the range 1 to 5.
This class is used to represent the first, second, third, fourth, or fifth weekday of a month.
[Note 1:
A weekday_indexed object can be constructed by indexing a weekday with an unsigned.
â end note]
[Example 1: constexpr auto wdi = Sunday[2]; // wdi is the second Sunday of an as yet unspecified monthstatic_assert(wdi.weekday() == Sunday);static_assert(wdi.index() == 2); â end example]
weekday_indexed is a trivially copyable and standard-layout class type.
30.8.7.2 Member functions [time.cal.wdidx.members]
constexpr weekday_indexed(const chrono::weekday& wd, unsigned index) noexcept;
Effects: Initializes wd_ with wd and index_ with index.
The values held are unspecified if !wd.ok() or index is not in the range [0, 7].
constexpr chrono::weekday weekday() const noexcept;
Returns: wd_.
constexpr unsigned index() const noexcept;
Returns: index_.
constexpr bool ok() const noexcept;
Returns: wd_.ok() && 1 <= index_ && index_ <= 5.
30.8.7.3 Non-member functions [time.cal.wdidx.nonmembers]
constexpr bool operator==(const weekday_indexed& x, const weekday_indexed& y) noexcept;
Returns: x.weekday() == y.weekday() && x.index() == y.index().
template<class charT, class traits> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const weekday_indexed& wdi);
Effects: Equivalent to:auto i = wdi.index();return os << (i >= 1 && i <= 5 ? format(os.getloc(), STATICALLY-WIDEN("{:L}[{}]"), wdi.weekday(), i) : format(os.getloc(), STATICALLY-WIDEN("{:L}[{} is not a valid index]"), wdi.weekday(), i));