/* passing arguments by reference */

#include<stdio.h>

/* oh no!  pointers!! */
int summ_it(int *var1, int *var2);

int main()
{

	int a, b, c;

	a = 5;
	b = 7;

	/* we now use the address operator to pass the
		memory address of the variable to the
		function */
	c = summ_it(&a, &b);

	printf("%d plus %d equals %d\n", a, b, c);
}

int summ_it(int *var1, int *var2)
{
	int answer;

	answer = *var1 + *var2;

	printf("inside the function, var1 is %d, and var2 is %d\n", *var1, *var2);

	*var1 = *var1 + 20;
	*var2 = *var2 + 20;

	printf("still inside the function, we've changed this to\n");
	printf("var1 = %d, var2 = %d\n", *var1, *var2);

	return answer;
}