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

 

C++

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Date and time utilities

Time point
time_point (C++11)	clock_time_conversion (C++20)	clock_cast (C++20)
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duration (C++11)
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Time of day
is_amis_pm (C++20)(C++20)	make12make24 (C++20)(C++20)	hh_mm_ss (C++20)
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day (C++20) month (C++20) year (C++20) weekday (C++20) operator/ (C++20) year_month_day (C++20)	year_month_day_last (C++20) year_month_weekday (C++20) year_month_weekday_last (C++20)   weekday_indexed (C++20) weekday_last (C++20) month_day (C++20)	month_day_last (C++20) month_weekday (C++20) month_weekday_last (C++20) year_month (C++20) last_speclast (C++20)(C++20)
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chrono I/O
parse (C++20)
C-style date and time

 

std::chrono::day

Member functions

day::day

day::operator++day::operator--

day::operator+=day::operator-=

day::operator unsigned

day::ok

Nonmember functions

operator==operator<=>

operator+operator-

operator<<

from_stream

operator""d

Helper classes

formatter<std::chrono::day>

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

 

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

operator++operator++(int)operator--operator--(int)	increments or decrements the day (public member function)
operator+operator- (C++20)	adds or subtracts a number of days and a day, or find the difference between two days (function)