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

From cppreference.com
< cpp ‎ | chrono ‎ | day
C++
Utilities library
General utilities
Relational operators (deprecated in C++20)
Date and time utilities
Time point
(C++11)
(C++20)
Duration
(C++11)
Clocks
(C++20)
(C++20)
(C++20)
Time of day
(C++20) (C++20)
(C++20) (C++20)
(C++20)

Calendar
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
Time zone
(C++20)
(C++20)
(C++20) (C++20) (C++20) (C++20)
(C++20)
chrono I/O
(C++20)
C-style date and time
std::chrono::day
constexpr std:: chrono :: day & operator + = ( const std:: chrono :: days & d ) noexcept ;
(1) (since C++20)
constexpr std:: chrono :: day & operator - = ( const std:: chrono :: days & d ) noexcept ;
(2) (since C++20)

Adds or subtracts d. count ( ) days from the day value.

1) Equivalent to * this = * this + d ; .
2) Equivalent to * this = * this - d ; .

Return value

A reference to this day after modification.

Notes

If the result would be outside the range [ ​ 0 ​ , 255 ] , the actual stored value is unspecified.

Example

Run this code 
#include <cassert>
#include <chrono>
 
int main()
{
    std::chrono::day d{15};
 
    d += std::chrono::days(2);
    assert(d == std::chrono::day(17));
 
    d -= std::chrono::days{3};
    assert(d == std::chrono::day(14));
}

See also

increments or decrements the day
(public member function)
(C++20)
adds or subtracts a number of days and a day , or find the difference between two day s
(function)
Retrieved from " https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/day/operator_arith&oldid=161524 "