std::chrono::year_month_day_last::operator sys_days, std::chrono::year_month_day_last::operator local_days
From cppreference.net
constexpr operator std::chrono::sys_days() const noexcept;
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(1) | (since C++20) |
constexpr explicit operator std::chrono::local_days() const noexcept;
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(2) | (since C++20) |
Converts *this to a std::chrono::time_point representing the same date as this year_month_day_last. This is equivalent to composing a year_month_day from year(), month() and day() and converting that year_month_day to the destination type.
1) Equivalent to
std::chrono::sys_days(year()/month()/day()).2) Equivalent to
std::chrono::local_days(year()/month()/day()).Example
Run this code
#include <array>
#include <chrono>
#include <iostream>
#include <string_view>
using namespace std::chrono;
using namespace std::literals;
int main()
{
constexpr std::chrono::year y{2023y};
constexpr std::array quarters{"1st"sv, "2nd"sv, "3rd"sv, "4th"sv};
constexpr auto mq{12 / 4}; // months per quarter
std::cout << "In year " << static_cast<int>(y) << '\n';
for (auto q = 1; q < 5; ++q)
{
const auto ls = y / std::chrono::month(q * mq) / Sunday[last];
const auto ld = y / std::chrono::month(q * mq) / last;
// subtract last Sunday from last day for day of week
const auto index = (sys_days(ld) - sys_days(ls)).count();
std::cout << "The " << quarters[q - 1] << " quarter ends on a "
<< std::chrono::weekday(index) << '\n';
}
}
Output:
In year 2023
The 1st quarter ends on a Fri
The 2nd quarter ends on a Fri
The 3rd quarter ends on a Sat
The 4th quarter ends on a Sun
See also
| converts to a std::chrono::time_point (public member function of std::chrono::year_month_day)
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