include <chrono>
auto start = std::chrono::high_resolution_clock::now();
end = std::chrono::high_resolution_clock::now();
timing = std::chrono::duration<double, std::milli>(end - start);
std::cout << timing.count() << " ms " << std::endl;
auto start = std::chrono::high_resolution_clock::now();
end = std::chrono::high_resolution_clock::now();
timing = std::chrono::duration<double, std::milli>(end - start);
std::cout << timing.count() << " ms " << std::endl;