test.cpp

#include <iostream>
#include <chrono>
#include <cstdint>

template<typename T = double>
T GetSeconds()
{
    typedef std::chrono::high_resolution_clock c;
    typedef c::time_point timepoint;
    typedef c::duration duration;

    typedef std::chrono::duration<T> my_duration;

    timepoint tp = c::now();
    duration d = tp.time_since_epoch();
    return std::chrono::duration_cast<my_duration>(d).count();
}

int main()
{
    double secs = GetSeconds();
    std::cout << "Seconds (double) = " << secs << std::endl;

    uint64_t isecs = GetSeconds<uint64_t>();
    std::cout << "Seconds (uint64) = " << isecs << std::endl;
}