std::chrono::year_month::operator+=, std::chrono::year_month::operator-=
constexpr std::chrono::year_month&
operator+=( const std::chrono::years& dy ) const noexcept;
| (1) | (since C++20) |
constexpr std::chrono::year_month&
operator+=( const std::chrono::months& dm ) const noexcept;
| (2) | (since C++20) |
constexpr std::chrono::year_month&
operator-=( const std::chrono::years& dy ) const noexcept;
| (3) | (since C++20) |
constexpr std::chrono::year_month&
operator-=( const std::chrono::months& dm ) const noexcept;
| (4) | (since C++20) |
Modifies the time point *this represents by the duration dy or dm.
1) Equivalent to
*this = *this + dy;.
2) Equivalent to
*this = *this + dm;.
3) Equivalent to
*this = *this - dy;.
4) Equivalent to
*this = *this - dm;.For durations that are convertible to both std::chrono::years and std::chrono::months, the years overloads (1,3) are preferred if the call would otherwise be ambiguous.
Example
#include <cassert>
#include <chrono>
int main()
{
auto ym{std::chrono::day(1)/7/2023};
ym -= std::chrono::years{2};
assert(ym.month() == std::chrono::July);
assert(ym.year() == std::chrono::year(2021));
ym += std::chrono::months{7};
assert(ym.month() == std::chrono::month(2));
assert(ym.year() == std::chrono::year(2022));
}See also
|
(C++20) | performs arithmetic on year_month (function) |
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