# std::chrono::operator+, std::chrono::operator- (std::chrono::year_month_weekday)

From cppreference.com
< cpp‎ | chrono‎ | year month weekday

constexpr std::chrono::year_month_weekday operator+(const std::chrono::year_month_weekday& ymwd, const std::chrono::months& dm) noexcept; | (1) | (since C++20)
constexpr std::chrono::year_month_weekday operator+(const std::chrono::months& dm, const std::chrono::year_month_weekday& ymwd) noexcept; | (2) | (since C++20)
constexpr std::chrono::year_month_weekday operator+(const std::chrono::year_month_weekday& ymwd, const std::chrono::years& dy) noexcept; | (3) | (since C++20)
constexpr std::chrono::year_month_weekday operator+(const std::chrono::years& dy, const std::chrono::year_month_weekday& ymwd) noexcept; | (4) | (since C++20)
constexpr std::chrono::year_month_weekday operator-(const std::chrono::year_month_weekday& ymwd, const std::chrono::months& dm) noexcept; | (5) | (since C++20)
constexpr std::chrono::year_month_weekday operator-(const std::chrono::year_month_weekday& ymwd, const std::chrono::years& dy) noexcept; | (6) | (since C++20)

1-2) Adds dm.count() months to the date represented by `ymwd`. The result has the same `year()` and `month()` as std::chrono::year_month(ymwd.year(), ymwd.month()) + dm and the same `weekday()` and `index()` as `ymwd`.
3-4) Adds dy.count() years to the date represented by `ymwd`. The result is equivalent to std::chrono::year_month_weekday(ymwd.year() + dy, ymwd.month(), ymwd.weekday_indexed()).
5) Subtracts dm.count() months from the date represented by `ymwd`. Equivalent to ymwd + -dm.
6) Subtracts dy.count() years from the date represented by `ymwd`. Equivalent to ymwd + -dy.

### Notes

Even if `ymwd.ok()` is true, the resulting `year_month_weekday` may not represent a valid date if ymwd.index() is 5.

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/year_month_weekday/operator_arith_2&oldid=104839"