Example of std::chrono durations.

chrono-durations.cpp

#include <chrono>
#include <iostream>

using namespace std::literals::chrono_literals;

int main() {

  {
    // Implicit casting down
    auto hours = 24h;
    std::chrono::minutes minutes = hours;
    std::chrono::seconds seconds = hours;
    std::chrono::microseconds microseconds = hours;
    std::chrono::nanoseconds nanoseconds = hours;

    std::cout << hours.count() << "h" << std::endl
        << minutes.count() << "min" << std::endl
        << seconds.count() << "s" << std::endl
        << microseconds.count() << "ms" << std::endl
        << nanoseconds.count() << "ns" << std::endl
        << std::endl;
  }

  {
    // Explicit casting up
    std::chrono::seconds seconds{2400};
    std::chrono::minutes minutes = std::chrono::duration_cast<std::chrono::minutes>(seconds);
    std::cout << minutes.count() << "min" << std::endl << std::endl;
  }

  {
    // Duration arithmetic
    auto sum = 3h + 52min + 40s - 2ns; // will return ns as most precise
    std::cout << "3h + 52min + 40s - 2ns = " << sum.count() << "ns" << std::endl << std::endl;
  }
}