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| Member functions | ||||
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| Helper classes | ||||
| Deduction guides |
Defined in header <chrono> | ||
template< class Duration, | (since C++20) | |
using zoned_seconds= std::chrono::zoned_time<std::chrono::seconds>; | (since C++20) | |
The classzoned_time represents a logical pairing of a time zone and astd::chrono::time_point whose resolution isDuration.
An invariant ofzoned_time is that it always refers to a valid time zone and represents an existing and unambiguous time point in that time zone. Consistent with this invariant,zoned_time has no move constructor or move assignment operator; attempts to move azoned_time will perform a copy.
The program is ill-formed ifDuration is not a specialization ofstd::chrono::duration.
The template parameterTimeZonePtr allows users to supply their own time zone pointer types and further customize the behavior ofzoned_time viastd::chrono::zoned_traits. Custom time zone types need not support all the operations supported bystd::chrono::time_zone, only those used by the functions actually called on thezoned_time.
TimeZonePtr must beMoveConstructible. Move-onlyTimeZonePtrs are allowed but difficult to use, as thezoned_time will be immovable and it is not possible to access the storedTimeZonePtr.
Contents |
| Member type | Definition |
duration | std::common_type_t<Duration,std::chrono::seconds> |
constructs azoned_time(public member function)[edit] | |
assigns value to azoned_time(public member function)[edit] | |
| obtains a copy of the time zone pointer (public member function)[edit] | |
obtains the stored time point as alocal_time(public member function)[edit] | |
obtains the stored time point as asys_time(public member function)[edit] | |
| obtain information about the time zone at the stored time point (public member function)[edit] |
(C++20) | compares twozoned_time values(function template)[edit] |
(C++20) | outputs azoned_time into a stream(function template)[edit] |
formatting support forzoned_time(class template specialization)[edit] | |
| hash support forstd::chrono::zoned_time (class template specialization) |
template<class Duration> constexprbool enable_nonlocking_formatter_optimization | (since C++23) | |
This specialization ofstd::enable_nonlocking_formatter_optimization enables efficient implementation ofstd::print andstd::println for printing achrono::zoned_time object.
#include <algorithm>#include <chrono>#include <iomanip>#include <iostream>#include <stdexcept>#include <string_view> int main(){constexprstd::string_view locations[]={"Africa/Casablanca","America/Argentina/Buenos_Aires","America/Barbados","America/Indiana/Petersburg","America/Tarasco_Bar","Antarctica/Casey","Antarctica/Vostok","Asia/Magadan","Asia/Manila","Asia/Shanghai","Asia/Tokyo","Atlantic/Bermuda","Australia/Darwin","Europe/Isle_of_Man","Europe/Laputa","Indian/Christmas","Indian/Cocos","Pacific/Galapagos",}; constexprauto width= std::ranges::max_element(locations,{},[](constauto& s){return s.length();})->length(); for(constauto location: locations)try{// may throw if 'location' is not in the time zone databaseconst std::chrono::zoned_time zt{location,std::chrono::system_clock::now()};std::cout<<std::setw(width)<< location<<" - Zoned Time: "<< zt<<'\n';}catch(std::runtime_error& ex){std::cout<<"Error: "<< ex.what()<<'\n';}}
Possible output:
Africa/Casablanca - Zoned Time: 2023-06-29 20:58:34.697449319 +01America/Argentina/Buenos_Aires - Zoned Time: 2023-06-29 16:58:34.709957354 -03 America/Barbados - Zoned Time: 2023-06-29 15:58:34.709977888 AST America/Indiana/Petersburg - Zoned Time: 2023-06-29 15:58:34.709998072 EDTError: tzdb: cannot locate zone: America/Tarasco_Bar Antarctica/Casey - Zoned Time: 2023-06-30 06:58:34.710093685 +11 Antarctica/Vostok - Zoned Time: 2023-06-30 01:58:34.710107932 +06 Asia/Magadan - Zoned Time: 2023-06-30 06:58:34.710121831 +11 Asia/Manila - Zoned Time: 2023-06-30 03:58:34.710134751 PST Asia/Shanghai - Zoned Time: 2023-06-30 03:58:34.710153259 CST Asia/Tokyo - Zoned Time: 2023-06-30 04:58:34.710172815 JST Atlantic/Bermuda - Zoned Time: 2023-06-29 16:58:34.710191043 ADT Australia/Darwin - Zoned Time: 2023-06-30 05:28:34.710236720 ACST Europe/Isle_of_Man - Zoned Time: 2023-06-29 20:58:34.710256834 BSTError: tzdb: cannot locate zone: Europe/Laputa Indian/Christmas - Zoned Time: 2023-06-30 02:58:34.710360409 +07 Indian/Cocos - Zoned Time: 2023-06-30 02:28:34.710377520 +0630 Pacific/Galapagos - Zoned Time: 2023-06-29 13:58:34.710389952 -06
(C++20) | represents a time zone (class)[edit] |
