std::chrono::file_clock::to_sys, std::chrono::file_clock::from_sys

 

C++

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

 

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

 

std::chrono::file_clock

Member functions

file_clock::now

file_clock::to_sysfile_clock::from_sys (optional*)

file_clock::to_utcfile_clock::from_utc (optional*)

Time point I/O

operator<<

formatter<std::chrono::file_time>

from_stream

 

template<class Duration > staticstd::chrono::sys_time</*see below*/>     to_sys(conststd::chrono::file_time<Duration>& t );	(1)	(since C++20) (optional*)
template<class Duration > staticstd::chrono::file_time</*see below*/>     from_sys(conststd::chrono::sys_time<Duration>& t );	(2)	(since C++20) (optional*)

1) Converts the file_timet to a sys_time representing the same point in time.

2) Converts the sys_timet to a file_time representing the same point in time.

The duration of the return type is computed from Duration in an unspecified manner.

These function templates are optional: an implementation may choose to instead provide to_utc() and from_utc().

Return value

1) A sys_time representing the same point in time as the argument.

2) A file_time representing the same point in time as the argument.

Notes

User code should usually use std::chrono::clock_cast, which provides a generic interface to convert time points between clocks, rather than call these functions directly.

See also

to_utcfrom_utc [static](optional)	converts between file_time and utc_time (public static member function)
clock_cast (C++20)	convert time points of one clock to another (function template)