std::chrono::year_month::operator+=, std::chrono::year_month::operator-=

 

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std::chrono::year_month

Member functions

year_month::year_month

year_month::yearyear_month::month

year_month::operator+=year_month::operator-=

year_month::ok

Nonmember functions

operator==operator<=>

operator+operator-

operator<<

from_stream

Helper classes

formatter<std::chrono::year_month>

hash<std::chrono::year_month> (C++26)

 

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

Run this code

#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

operator+operator- (C++20)

performs arithmetic on year_month (function)