std::timespec_getres

 

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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)

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C-style date and time utilities

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Time manipulation

difftime

time

clock

timespec_get (C++17)

timespec_getres (C++26)

Format conversions

asctime (deprecated in C++26)

ctime (deprecated in C++26)

strftime

wcsftime

gmtimegmtime_r (C++26)

localtimelocaltime_r (C++26)

mktime

timegm (C++26)

Constants

CLOCKS_PER_SEC

Types

tm

time_t

clock_t

timespec (C++17)

 

Defined in header <ctime>
int timespec_getres( std::timespec *ts, int base );		(since C++26)

If ts is non-null and base is supported by std::timespec_get, modifies *ts to hold the resolution of time provided by std::timespec_get for base. For each supported base, multiple calls to std::timespec_getres during the same program execution have identical results.

Parameters

ts	-	pointer to an object of type std::timespec
base	-	TIME_UTC or another nonzero integer value indicating the time base

Return value

The value of base if base is supported, zero otherwise.

Notes

The POSIX function clock_getres(clock_id, ts) may also be used to populate a std::timespec with the resolution of time identified by clock_id.

Example

Run this code

#include <cstdio>
#include <ctime>

int main()
{
    char buff[128];
    std::timespec ts;

    if (const int res = std::timespec_getres(&ts, TIME_UTC); res == TIME_UTC)
    {
        std::tm timer;
        std::strftime(buff, sizeof(buff), "%D %T", std::gmtime_r(&ts.tv_sec, &timer));
        std::printf("Time resolution info: %s.%09ld UTC\n", buff, ts.tv_nsec);
    }
    else
        std::printf("TIME_UTC base is not supported.");
}

Possible output:

Time resolution info: 01/01/70 00:00:00.000000001 UTC

See also

timespec (C++17)	time in seconds and nanoseconds (struct)
timespec_get (C++17)	returns the calendar time in seconds and nanoseconds based on a given time base (function)
time	returns the current time of the system as time since epoch (function)
C documentation for timespec_getres