测量代码运行时间的模板

#include <iostream>
#include <chrono>
#include <ctime>

int main(){
using namespace std::chrono;
using namespace std;


using _time = steady_clock::time_point;

_time t1 = steady_clock::now();

/*code one*/

_time t2 = steady_clock::now();

duration<double> time_span1 = duration_cast<duration<double>>(t2 - t1);

std::cout << "It took me " << time_span1.count() << " seconds." << endl;

/*code two*/

_time t3 = steady_clock::now();
duration<double> time_span2 = duration_cast<duration<double>>(t3 - t2);
std::cout << "It took me " << time_span2.count() << " seconds." << endl;

return 0;
}