需要计算程序运行的时间，格式为 X天XX小时X分X秒，可以用这个类，在启动时初始化，需要时调用即可获得。

timeduration.h

//timeduration.h

#pragma once
#include <chrono>
#include <string>

using namespace std::chrono;

class Timeduration
{
	
public:
	Timeduration() : m_begin(high_resolution_clock::now()){}
	void reset() { m_begin = high_resolution_clock::now(); }


	//默认输出秒
	double elapsed() const
	{
		return duration_cast<duration<double>>(high_resolution_clock::now() - m_begin).count();
	}
	//默认输出毫秒
	//int64_t elapsed() const
	//{
	//return duration_cast<chrono::milliseconds>(high_resolution_clock::now() - m_begin).count();
	//}

	//微秒
	int64_t elapsed_micro() const
	{
		return duration_cast<microseconds>(high_resolution_clock::now() - m_begin).count();
	}

	//纳秒
	int64_t elapsed_nano() const
	{
		return duration_cast<nanoseconds>(high_resolution_clock::now() - m_begin).count();
	}

	//秒
	int64_t elapsed_seconds() const
	{
		return duration_cast<seconds>(high_resolution_clock::now() - m_begin).count();
	}

	//分
	int64_t elapsed_minutes() const
	{
		return duration_cast<minutes>(high_resolution_clock::now() - m_begin).count();
	}

	//时
	int64_t elapsed_hours() const
	{
		return duration_cast<hours>(high_resolution_clock::now() - m_begin).count();
	}
	//天
	int64_t elapsed_days() const
	{
		typedef duration<int, std::ratio<86400,1> > days;
		return duration_cast<days>(high_resolution_clock::now() - m_begin).count();
	}
	std::string elapsedString()
	{
		std::string  retStr;
		auto seconds = elapsed_seconds();
		auto minutes = elapsed_minutes();
		auto hours = elapsed_hours();
		auto days = elapsed_days();

		auto hour = hours - days * 24;
		auto minute = minutes - hours * 60;
		auto second = seconds - minutes * 60;

		retStr = std::to_string(days) + "天"
			+ std::to_string(hour) + "小时"
			+ std::to_string(minute) + "分"
			+ std::to_string(second) + "秒";

		return std::move(retStr);
	}

private:
	time_point<high_resolution_clock> m_begin;
};

main.cpp

#include  "timeduration.h"


#include <iostream>
#include <string>
#include <Windows.h>

Timeduration t_start;
using namespace std;

int main()
{
	Sleep(2000);

	std::cout<<t_start.elapsedString();
	getchar();
	return 0;
}

输出：

0天0小时0分2秒