C++高精度计时器

#ifndef _CELL_TIMESTAMP_HPP_
#define _CELL_TIMESTAMP_HPP_

#include<chrono>
using namespace std::chrono;
class CELLTimestamp
{
public:
    CELLTimestamp()
    {
        update();
    }
    ~CELLTimestamp()
    {
    }

    void update()
    {
        _begin = high_resolution_clock::now();
    }

    //获取当前秒
    double getElapsedSecond()
    {
        return getElapsedTimeInMicroSec()*0.000001;
    }

    //获取毫秒
    double getElapsedTimeInMilliSec()
    {
        return getElapsedTimeInMicroSec()*0.001;
    }

    //获取微妙
    long long getElapsedTimeInMicroSec()
    {
        return duration_cast<microseconds>(high_resolution_clock::now() - _begin).count();
    }
private:
protected:
    time_point<high_resolution_clock> _begin;

};
#endif