std::chrono::zoned_time 的推导指引

 

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std::chrono::zoned_time

成员函数

zoned_time::zoned_time

zoned_time::operator=

zoned_time::get_time_zone

zoned_time::get_sys_timezoned_time::operator sys_time

zoned_time::get_local_timezoned_time::operator local_time

zoned_time::get_info

非成员函数

operator==

operator<<

辅助类

formatter<std::chrono::zoned_time>

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

推导指引

 

zoned_time() -> zoned_time<std::chrono::seconds>;	(1)	(C++20 起)
template< class Duration > zoned_time( std::chrono::sys_time<Duration> )     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;	(2)	(C++20 起)
template< class TimeZonePtrOrName > zoned_time( TimeZonePtrOrName&& ) -> zoned_time<std::chrono::seconds, /* 见下文 */>;	(3)	(C++20 起)
template< class TimeZonePtrOrName, class Duration > zoned_time( TimeZonePtrOrName&&, std::chrono::sys_time<Duration> )     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, /* 见下文 */>;	(4)	(C++20 起)
template< class TimeZonePtrOrName, class Duration > zoned_time( TimeZonePtrOrName&&, std::chrono::local_time<Duration>,             std::chrono::choose = std::chrono::choose::earliest )     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, /* 见下文 */>;	(5)	(C++20 起)
template< class TimeZonePtrOrName, class Duration, class TimeZonePtr2 > zoned_time( TimeZonePtrOrName&&, std::chrono::zoned_time<Duration, TimeZonePtr2>,             std::chrono::choose = std::chrono::choose::earliest )     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, /* 见下文 */>;	(6)	(C++20 起)

为 zoned_time 提供六个推导指引。它们把 Duration 正规化为最小分辨率为 std::chrono::seconds，并提供用对可转换成 std::string_view 的类型的指定时区名的正确处理。

3-6) 若 std::is_convertible_v<TimeZonePtrOrName, std::string_view> 为 true，则推导的第二模板实参为 const std::chrono::time_zone*。否则为 std::remove_cvref_t<TimeZonePtrOrName>。