std::chrono::weekday_indexed

From cppreference.com

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros(C++20)
Language support library
Concepts library(C++20)
Diagnostics library
Memory management library
Metaprogramming library(C++11)
General utilities library
Containers library
Iterators library
Ranges library(C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library(C++17)
Concurrency support library(C++11)
Execution control library(C++26)
Technical specifications
Symbols index
External libraries

[edit]

Date and time library

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)

Time zone
tzdb (C++20)
tzdb_list (C++20)
get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20)
sys_info (C++20)
local_info (C++20)
nonexistent_local_time (C++20)
ambiguous_local_time (C++20)
locate_zone (C++20)
current_zone (C++20)
time_zone (C++20)
choose (C++20)
zoned_traits (C++20)
zoned_time (C++20)
time_zone_link (C++20)
leap_second (C++20)
leap_second_info (C++20)
get_leap_second_info (C++20)
C-style date and time

[edit]

std::chrono::weekday_indexed

Member functions
weekday_indexed::weekday_indexed
weekday_indexed::weekday
weekday_indexed::index
weekday_indexed::ok
Nonmember functions
operator==
operator<<
Helper classes
formatter<std::chrono::weekday_indexed>
hash<std::chrono::weekday_indexed> (C++26)

[edit]

Defined in header`<chrono>`
class weekday_indexed;		(since C++20)

The classweekday_indexed combines aweekday, representing a day of the week in theproleptic Gregorian calendar, with a small indexn in the range[1, 5]. It represents the first, second, third, fourth, or fifth weekday of some month.

weekday_indexed is aTriviallyCopyable StandardLayoutType.

[edit]Member functions

(constructor)	constructs a`weekday_indexed` (public member function)[edit]
weekday	access the stored`weekday` (public member function)[edit]
index	access the stored index (public member function)[edit]
ok	checks if the weekday and index are both valid (public member function)[edit]

[edit]Nonmember functions

operator== (C++20)	compares two`weekday_indexed` values (function)[edit]
operator<< (C++20)	outputs a`weekday_indexed` into a stream (function template)[edit]

[edit]Helper classes

std::formatter<std::chrono::weekday_indexed> (C++20)	formatting support for`weekday_indexed` (class template specialization)[edit]
std::hash<std::chrono::weekday_indexed> (C++26)	hash support for`std::chrono::weekday_indexed` (class template specialization)

[edit]Example

Run this code

#include <chrono>#include <iostream> int main(){usingnamespace std::chrono; constexpr weekday_indexed wi= Friday[2]; // Indexed weekday can be used at any place where chrono::day can be used:constexpr year_month_weekday ymwd= 2021y/ August/ wi;    static_assert(ymwd== August/ wi/ 2021y&&                  ymwd== wi/ August/ 2021y);std::cout<< ymwd<<'\n'; constexpr year_month_day ymd{ymwd};// a conversion    static_assert(ymd== 2021y/8/13);std::cout<< ymd<<'\n';}