std::chrono::weekday::weekday
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(1) | (since C++20) |
|
(2) | (since C++20) |
|
(3) | (since C++20) |
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(4) | (since C++20) |
Constructs a weekday object.
1) Default constructor leaves the weekday value uninitialized.
2) Constructs a
weekday object holding the weekday value wd. If wd == 7, the value held is 0. If wd > 255, the value held is unspecified.
3) Constructs a
weekday object representing the day of the week dp corresponds to. This constructor defines an implicit conversion from std::chrono::sys_days to weekday.
4) Constructs a
weekday object representing the day of the week dp corresponds to, as if by weekday(std::chrono::sys_days(dp.time_since_epoch())).
Example
#include <chrono>
#include <iomanip>
#include <iostream>
int main()
{
constexpr std::chrono::weekday friday{5}; // uses overload (2)
static_assert(friday == std::chrono::Friday);
for (int y{2020}; y <= 2023; ++y)
{
const std::chrono::year cur_year{y};
for (int cur_month{1}; cur_month != 13; ++cur_month)
{
const std::chrono::year_month_day ymd{cur_year/cur_month/13};
const std::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 Fri
2020-11-13 is Fri
2021-08-13 is Fri
2022-05-13 is Fri
2023-01-13 is Fri
2023-10-13 is Fri© cppreference.com
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https://en.cppreference.com/w/cpp/chrono/weekday/weekday