/*
 * C++ Operator Overloading
 * by Hans Schou
 *
 * Inspiration from
 * http://www.cplusplus.com/doc/tutorial/tut4-2.html
 *
 */

#include <iostream>
#include <sys/time.h>
using namespace std;

class CTimeval {
public:
	struct timeval tv;
	CTimeval () {};
	CTimeval (struct timeval *);
	CTimeval (int,int);
	CTimeval operator + (CTimeval);
	void operator += (CTimeval);
	CTimeval operator - (CTimeval);
	int operator > (CTimeval);
	int operator < (CTimeval);
};

CTimeval::CTimeval (struct timeval *a) {
	memcpy(&tv, a, sizeof(tv));
}

CTimeval::CTimeval (int sec, int usec) {
	tv.tv_sec = sec;
	tv.tv_usec = usec;
}

CTimeval CTimeval::operator + (CTimeval param) {
	CTimeval temp;
	temp.tv.tv_sec = tv.tv_sec + param.tv.tv_sec;
	temp.tv.tv_usec = tv.tv_usec + param.tv.tv_usec;
	if (temp.tv.tv_usec > 999999) {
		temp.tv.tv_usec -= 1000000;
		temp.tv.tv_sec++;
	}
	return (temp);
}

void CTimeval::operator += (CTimeval param) {
	tv.tv_sec += param.tv.tv_sec;
	tv.tv_usec += param.tv.tv_usec;
	if (tv.tv_usec > 999999) {
		tv.tv_usec -= 1000000;
		tv.tv_sec++;
	}
}

CTimeval CTimeval::operator - (CTimeval param) {
	CTimeval temp;
	temp.tv.tv_sec = tv.tv_sec - param.tv.tv_sec;
	temp.tv.tv_usec = tv.tv_usec - param.tv.tv_usec;
	if (temp.tv.tv_usec < 0)
		temp.tv.tv_usec += 1000000;
	return (temp);
}

int CTimeval::operator > (CTimeval param) {
	if (tv.tv_sec > param.tv.tv_sec) {
		return (1);
	} else {
		if (tv.tv_sec == param.tv.tv_sec && tv.tv_usec > param.tv.tv_usec)
			return (1);
		else
			return (0);
	}
}

int CTimeval::operator < (CTimeval param) {
	if (tv.tv_sec < param.tv.tv_sec) {
		return (1);
	} else {
		if (tv.tv_sec == param.tv.tv_sec && tv.tv_usec < param.tv.tv_usec)
			return (1);
		else
			return (0);
	}
}

int main (void) {
	CTimeval a ( &(struct timeval){3,3} );
	CTimeval b ( 2, 2 );
	CTimeval c;
	c = a + b;
	printf("%d.%06d\n", c.tv.tv_sec, c.tv.tv_usec);
	c = a - b;
	printf("%d.%06d\n", c.tv.tv_sec, c.tv.tv_usec);
	c = b - a;
	printf("%d.%06d\n", c.tv.tv_sec, c.tv.tv_usec);
	c = a;
	c += b;
	printf("%d.%06d\n", c.tv.tv_sec, c.tv.tv_usec);
	if (a > b)
		printf("a>b\n");
	else
		printf("b>a\n");
	if (a < b)
		printf("a<b\n");
	else
		printf("b<a\n");
	return 0;
}