#include <chrono>
#include <iostream>
using namespace std::chrono_literals;
template <class Rep, class Period>
constexpr double seconds(const std::chrono::duration<Rep,Period>& d)
{
using namespace std::chrono_literals;
// How many seconds? Divide by one second!
return d / 1.0s;
}
int main()
{
auto duration = 125ms;
auto milliseconds = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
auto seconds = static_cast<double>(milliseconds) / 1000.0;
std::cout << seconds << "s\n";
std::cout << duration/1.0s << "s\n";
return 0;
}