C++编程常用代码

计时：

#include<chrono>
chrono::steady_clock::time_point t1=chrono::steady_clock::now();
//do something
chrono::steady_clock::time_point t2=chrono::steady_clock::now();
chrono::duration<double> time_used=chrono::duration_cast<chrono::duration<double>>(t2-t1);

double time0=static_cast<double>(getTickCount());
//do something
time0=((double)getTickCount()-time0)/getTickFrequency();#include<chrono>
chrono::steady_cl