NAME

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

Synopsis

constexpr std::chrono::year& operator+=( const std::chrono::years& (1) (since C++20)
y ) noexcept;
constexpr std::chrono::year& operator-=( const std::chrono::years& (2) (since C++20)
y ) noexcept;

Adds or subtracts y.count() years from the year value.

1) Equivalent to *this = *this + y;
2) Equivalent to *this = *this - y;

Return value

A reference to this year after modification.

Notes

If the result would be outside the range [-32767, 32767], the actual stored value is
unspecified.

Example

// Run this code

#include <iostream>
#include <chrono>

int main()
{
using namespace std::literals::chrono_literals;
std::cout << std::boolalpha;

std::chrono::year y {2020};

y += std::chrono::years(12);
std::cout << (y == 2032y) << ' ';

y -= std::chrono::years(33);
std::cout << (y == 1999y) << '\n';
}

Output:

true true

See also

operator++
operator++(int) increments or decrements the year
operator-- (public member function)
operator--(int)
operator+ performs arithmetic on years
operator- (function)
(C++20)