基于C++实现高精度计时器

#include <iostream>
#include <chrono>
using namespace std;
using namespace std::chrono;
int main()
{
    cout << "system clock          : ";
    cout << system_clock::period::num << "/" << system_clock::period::den << " s" << endl;
    cout << "steady clock          : ";
    cout << steady_clock::period::num << "/" << steady_clock::period::den << " s" << endl;
    cout << "high resolution clock : ";
    cout << high_resolution_clock::period::num << "/"
         << high_resolution_clock::period::den << " s" << endl;
 
    return 0;
}

#include <iostream>
#include <chrono>
using namespace std;
using namespace std::chrono;
class HighResolutionClock
{
public:
    HighResolutionClock()
    {
        update();
    }
 
    ~HighResolutionClock()
    {
 
    }
 
    void update()
    {
        m_start = high_resolution_clock::now();
    }
    // 秒
    double getSecond()
    {
        return getMicroSec() * 0.000001;
    }
    // 毫秒
    double getMilliSec()
    {
        return getMicroSec()*0.001;
    }
    // 微妙
    long long getMicroSec()
    {
        // 如果你愿意，也可以用nanoseconds获取纳秒，其实微秒已经够用了
        return duration_cast<microseconds>(high_resolution_clock::now() - m_start).count();
    }
 
private:
    time_point<high_resolution_clock> m_start;
 
};
 
int main(int argc, char *argv[])
{
    HighResolutionClock hrClock;
    int sum = 0;
    hrClock.update();
 
    for (int i = 0; i < 100000; i++)
    {
        sum++;
    }
 
    cout << "cost time: " << hrClock.getMilliSec() <<" ms"<< endl;
    cout << "cost time: " << hrClock.getMicroSec() <<" us" << endl;
    return 0;
 
}