lib/chronoclocks.cpp

The following code example is taken from the book
C++20 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2021
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <iostream>
#include <chrono>

int main()
{
  using namespace std::literals;
  namespace chr = std::chrono;
  
  auto tpUtc = chr::clock_cast<chr::utc_clock>(chr::sys_days{2017y/1/1} - 1000ms);
  for (auto end = tpUtc + 2500ms; tpUtc <= end; tpUtc += 200ms) {
    auto tpSys = chr::clock_cast<chr::system_clock>(tpUtc);
    auto tpGps = chr::clock_cast<chr::gps_clock>(tpUtc);
    auto tpTai = chr::clock_cast<chr::tai_clock>(tpUtc);
    std::cout << std::format("{:%F %T} SYS  ", tpSys);
    std::cout << std::format("{:%F %T %Z}  ",  tpUtc);
    std::cout << std::format("{:%F %T %Z}  ",  tpGps);
    std::cout << std::format("{:%F %T %Z}\n",  tpTai);
  }
}