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std::chrono::time_zone::to_sys

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< cpp‎ | chrono‎ | time zone

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Date and time library

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clock_time_conversion

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get_tzdbget_tzdb_listreload_tzdbremote_version

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nonexistent_local_time

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leap_second_info

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get_leap_second_info

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C-style date and time

std::chrono::time_zone

Member functions

time_zone::name

time_zone::get_info

time_zone::to_sys

time_zone::to_local

Nonmember functions

operator==operator<=>

template< class Duration >

auto to_sys( const std::chrono::local_time <Duration>& tp ) const

-> std::chrono::sys_time <std::common_type_t <Duration, std::chrono::seconds >>;

(1) (since C++20)

template< class Duration >

auto to_sys( const std::chrono::local_time <Duration>& tp, std::chrono::choose z ) const

-> std::chrono::sys_time <std::common_type_t <Duration, std::chrono::seconds >>;

(2) (since C++20)

Converts the local_time tp in this time zone to the corresponding sys_time.

1) Throws an exception if the conversion is ambiguous or if tp represents a nonexistent time.

2) Resolves ambiguity according to the value of z:

If z == std::chrono::choose::earliest, returns the earlier sys_time.
If z == std::chrono::choose::latest, returns the later sys_time.

If tp represents a nonexistent time between two UTC time_points, those two time_points will be the same, and that time_point will be returned.

Contents

[edit] Return value

The UTC equivalent of tp according to the rules of this time zone.

[edit] Exceptions

1) Throws:

std::chrono::ambiguous_local_time if the conversion is ambiguous,
std::chrono::nonexistent_local_time if tp represents a nonexistent time.

[edit] Notes

The precision of the result is at least std::chrono::seconds , and will be finer if the argument has finer precision.

Ambiguous and nonexistent local times can occur as a result of time zone transitions (such as daylight saving time). For example, "2016年03月13日 02:30:00" does not exist in the "America/New_York" time zone, while "2016年11月06日 01:30:00" in that time zone can correspond to two UTC time points: 2016-11-06 05:30:00 UTC and 2016-11-06 06:30:00 UTC.

[edit] Example

This section is incomplete
Reason: no example

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