c++ 计算函数运行时间

#pragma once
#include <iostream>
#include <chrono>
#include <thread>


class Time_test
{
   
private:
	static int64_t __start;
	static int64_t __end;

public:
	static void getdiffTime_ms_begin()
	{
   
		__start = (int64_t)(std::chrono::duration_cast<std::chrono