C++ timing of fuctions

timer.cpp

#include <iostream>
#include <chrono>

long add(int a, int b) {
	return a + b;
}

int main() {
	auto start = std::chrono::steady_clock::now();
	std::cout << "9 + 10 = " << add(9, 10) << '\n';
	auto end = std::chrono::steady_clock::now();
	std::chrono::duration<double> elapsed_seconds = end - start;
	std::cout << "elapsed time: " << elapsed_seconds.count() << "s\n";

	std::cin.get();
	return 0;
}