cross platform unix timestamp in c++

unix_timestamp.cpp

#include <iostream>
#include <chrono>

int main(int argc, char *argv[])
{
	auto tp = std::chrono::system_clock::now();
	auto dur = tp.time_since_epoch();

	auto seconds = std::chrono::duration_cast<std::chrono::seconds>(dur).count();
	
	std::cout << "Timestamp: " << seconds << std::endl;
}

Thanks.