std::chrono::operator+, std::chrono::operator- (std::chrono::weekday)

 

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Time point time_point (C++11) clock_time_conversion (C++20)   clock_cast (C++20) Duration duration (C++11) Clocks system_clock (C++11) steady_clock (C++11) is_clock (C++20) utc_clock (C++20) tai_clock (C++20) high_resolution_clock (C++11) gps_clock (C++20) file_clock (C++20) local_t (C++20) Time of day is_amis_pm (C++20)(C++20) make12make24 (C++20)(C++20) hh_mm_ss (C++20)

Calendar 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) chrono I/O parse (C++20)

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std::chrono::weekday

Member functions

weekday::weekday

weekday::operator++weekday::operator--

weekday::operator+=weekday::operator-=

weekday::c_encodingweekday::iso_encoding

weekday::ok

weekday::operator[]

Nonmember functions

operator==

operator+operator-

operator<<

from_stream

Helper classes

formatter<std::chrono::weekday>

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

 

Defined in header <chrono>
constexprstd::chrono::weekday operator+(conststd::chrono::weekday& wd,                                           conststd::chrono::days& d )noexcept;	(1)	(since C++20)
constexprstd::chrono::weekday operator+(conststd::chrono::days& d,                                           conststd::chrono::weekday& wd )noexcept;	(2)	(since C++20)
constexprstd::chrono::weekday operator-(conststd::chrono::weekday& wd,                                           conststd::chrono::days& d )noexcept;	(3)	(since C++20)
constexprstd::chrono::days operator-(conststd::chrono::weekday& wd1,                                        conststd::chrono::weekday& wd2 )noexcept;	(4)	(since C++20)

1,2) Adds d.count() days to wd. The weekday value held in the result is computed by first evaluating static_cast<longlong>(wd.c_encoding())+ d.count() and reducing it modulo 7 to an integer in the range [​0​, 6].

3) Subtracts d.count() days from wd. Equivalent to return wd +-d;.

4) If wd1.ok() and wd2.ok() are both true, returns a std::chrono::days value d such that d.count() is in the range [​0​, 6] and wd2 + d == wd1. Otherwise the returned value is unspecified.

Return value

1-3) A std::chrono::weekday holding a weekday value calculated as described above.

4) A std::chrono::days representing the distance between wd1 and wd2.

Notes

As long as the computation doesn't overflow, (1-3) always return a valid weekday even if wd.ok() is false.

Example

Run this code

#include <chrono>#include <iostream>   int main(){std::cout<<std::boolalpha;   std::chrono::weekday wd{4}; wd = wd +std::chrono::days(2);std::cout<<(wd ==std::chrono::weekday(6))<<' '<<(wd ==std::chrono::Saturday)<<' ';   wd = wd -std::chrono::days(3);std::cout<<(wd ==std::chrono::weekday(3))<<' '<<(wd ==std::chrono::Wednesday)<<' ';   wd =std::chrono::Tuesday; wd = wd +std::chrono::days{8};// (((2 + 8) == 10) % 7) == 3;std::cout<<(wd ==std::chrono::Wednesday)<<' ';   wd = wd +(std::chrono::Sunday-std::chrono::Thursday);// (3 + 3) == 6std::cout<<(wd ==std::chrono::Saturday)<<'\n';}

Output:

true true true true true true

See also

operator++operator++(int)operator--operator--(int)	increments or decrements the weekday (public member function)
operator+=operator-=	adds or subtracts a number of days (public member function)