std::chrono::system_clock

Clock properties

realtime

It is intended to represent the real time, and thus it can be translated in some way to and from calendar representations (see to_time_t and from_time_t member functions).

signed count

Its time_point values can refer to times before the epoch (with negative values).

system-wide

All processes running on the system shall retrieve the same time_point values by using this clock.

Member types

Member constants

Static member functions

now

Get current time (public static member function )

to_time_t

Convert to time_t ( public static member function )

from_time_t

Convert from time_t ( public static member function )

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

// system_clock example
#include <iostream>
#include <ctime>
#include <ratio>
#include <chrono>

int main ()
{
  using std::chrono::system_clock;

  std::chrono::duration<int,std::ratio<60*60*24> > one_day (1);

  system_clock::time_point today = system_clock::now();
  system_clock::time_point tomorrow = today + one_day;

  std::time_t tt;

  tt = system_clock::to_time_t ( today );
  std::cout << "today is: " << ctime(&tt);

  tt = system_clock::to_time_t ( tomorrow );
  std::cout << "tomorrow will be: " << ctime(&tt);

  return 0;
}

today is: Wed May 30 12:25:03 2012
tomorrow will be: Thu May 31 12:25:03 2012