Ex_4.14_swap_t_x_y.c

/* a macro swap(t,x,y) that interchanges two arguments of type t */

#include<stdio.h>

#define swap(t,x,y)	{ t _z; \
			 _z = x;\
			  x = y;\
			  y = _z; }

int main(void)
{
	char x,y;
	x='a';
	y='b';
	printf("x= %c \t y= %c\n",x,y);
	swap(char,x,y);
	printf("x=%c \t y=%c\n",x,y);
}