/* compile using:  gcc -E ex02.c                */
/*           and:  gcc -E -D DEBUG_MODE ex02.c  */

#define M 100
#define K 400 + Q
#define SQUARE(X) (X) * (X)
#define Q 4
#define SWAP(TYPE, A, B) { TYPE tmp=A; A=B; B=tmp;}

/* example #2 */

#include <stdio.h>

int main()
{
 int x = M;
 int y = SQUARE( K );
 SWAP( int, x, y );
 double q = 4.56;

#ifdef DEBUG_MODE
 printf( "x is %d and y is %d and q is %lf\n", x, y, q );
#endif

 return 0;
}