Defined in header <chrono> | ||
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class year_month_day_last; | (since C++20) |
The class year_month_day_last
represents the last day of a specific year and month. It is a field-based time point, with a resolution of std::chrono::days
, subject to the limit that it can only represent the last day of a month.
std::chrono::years
- and std::chrono::months
-oriented arithmetic are supported directly. An implicit conversion to std::chrono::sys_days
allows std::chrono::days
-oriented arithmetic to be performed efficiently.
year_month_day_last
is a TriviallyCopyable StandardLayoutType.
constructs a year_month_day_last object (public member function) |
|
modifies the time point by some number of months or years (public member function) |
|
accesses the fields of this object (public member function) |
|
converts to a std::chrono::time_point (public member function) |
|
checks whether this object represents a valid date (public member function) |
(C++20) | compares two year_month_day_last values (function) |
(C++20) | adds or subtracts a year_month_day_last and some number of years or months (function) |
(C++20) | outputs a year_month_day_last into a stream (function template) |
(C++20) | formatting support for year_month_day_last (class template specialization) |
#include <chrono> #include <iostream> // until online compiler supports streaming the year_month_day_last: std::ostream& operator<<(std::ostream& os, std::chrono::year_month_day_last ymdl) { return os << static_cast<int>(ymdl.year()) << '/' << static_cast<unsigned>(ymdl.month()) << '/' << static_cast<unsigned>(ymdl.day()); } int main() { const auto ymd = std::chrono::year_month_day { std::chrono::floor<std::chrono::days>( std::chrono::system_clock::now()) }; const std::chrono::year_month_day_last ymdl { ymd.year(), ymd.month() / std::chrono::last }; std::cout << "The date of the last day of this month is: " << ymdl << '\n'; // The 'last' object can be placed wherever it is legal to place a 'day': using namespace std::chrono; constexpr std::chrono::year_month_day_last ymdl1 = 2023y / February / last, ymdl2 = last / February / 2023y, ymdl3 = February / last / 2023y; static_assert( ymdl1 == ymdl2 and ymdl2 == ymdl3 ); }
Possible output:
The date of the last day of this month is: 2023/6/30
(C++20) | represents a specific year , month , and day (class) |
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