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weekday::weekday | ||||
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(C++26) |
weekday()=default; | (1) | (since C++20) |
constexprexplicit weekday(unsigned wd)noexcept; | (2) | (since C++20) |
constexpr weekday(conststd::chrono::sys_days& sd)noexcept; | (3) | (since C++20) |
constexprexplicit weekday(conststd::chrono::local_days& ld)noexcept; | (4) | (since C++20) |
Constructs aweekday object.
weekday object holding the weekday valuewd. Ifwd==7, the value held is0. Ifwd>255, the value held is unspecified.weekday object representing the day of the weeksd corresponds to. This constructor defines an implicit conversion fromstd::chrono::sys_days toweekday.weekday object representing the day of the weekld corresponds to, as if byweekday(std::chrono::sys_days(ld.time_since_epoch())).| wd | - | a weekday value |
| sd | - | a system days object |
| ld | - | a local days object |
#include <chrono>#include <iomanip>#include <iostream> int main(){constexprstd::chrono::weekday friday{5};// uses overload (2) static_assert(friday==std::chrono::Friday); for(int y{2020}; y<=2024;++y){conststd::chrono::year cur_year{y};for(int cur_month{1}; cur_month!=13;++cur_month){conststd::chrono::year_month_day ymd{cur_year/cur_month/13};conststd::chrono::weekday cur_weekday{std::chrono::sys_days(ymd)};// (3)if(cur_weekday== friday)std::cout<< ymd<<" is "<< friday<<'\n';}}}
Output:
2020-03-13 is Fri2020-11-13 is Fri2021-08-13 is Fri2022-05-13 is Fri2023-01-13 is Fri2023-10-13 is Fri2024-09-13 is Fri2024-12-13 is Fri
