• clock_t, clock tick
• size_t, unsigned integeral type
• time_t, time type
• struct tm, time structure

//clock_t
#include <iostream>
#include <ctime>
#include <cmath>

void run()
{
	for(int i = 0; i < 100000000; i++)
		double temp = std::sqrt(i);
}

int main(int argc, char *argv[])
{
	//clock
	clock_t t = clock();
	run();
	t = clock()-t;

	//CLOCKS_PER_SEC
	std::cout<<"Clicks: "<<t<<std::endl;
	std::cout<<"Time: "<<float(t)/CLOCKS_PER_SEC<<" seconds ..."<<std::endl;

	return 0;
}
			

//time_t
#include <iostream>
#include <ctime>
#include <cmath>

void run()
{
	for(int i = 0; i < 100000000; i++)
		double temp = std::sqrt(i);
}

int main(int argc, char *argv[])
{
	//time
	time_t t, t2;
	time(&t);//get the current time
	run();
	time(&t2);

	//difftime
	std::cout<<(t2-t)<<" seconds ..."<<std::endl;
	std::cout<<difftime(t2, t)<<" seconds ..."<<std::endl;

	return 0;
}
		

//struct tm
#include <iostream>
#include <ctime>
#include <cmath>

int main(int argc, char *argv[])
{
	struct tm m;
	m.tm_hour = 0;
	m.tm_min = 0;
	m.tm_sec = 0;
	m.tm_year = 100;
	m.tm_mon = 0;
	m.tm_mday = 1;

	time_t t = mktime(&m);

	//ctime
	std::cout<<ctime(&t)<<std::endl;

	return 0;
}
	

//time_t to struct tm
#include <iostream>
#include <ctime>

int main(int argc, char *argv[])
{
	time_t t;
	struct tm *timeInfo;

	//localtime
	time(&t);
	timeInfo = localtime(&t);

	//asctime
	std::cout<<asctime(timeInfo)<<std::endl;

	return 0;
}
	

• cplusplus.com