/**
 * CSE 374 example program
 * Demonstration of using preprocessor macros (poorly).
 */
#include <stdio.h>

#define TWICE_AWFUL(x) x*2
#define TWICE_BAD(x) ((x)+(x))
#define TWICE_OK(x) ((x)*2)

int main(int argc, char **argv) {
  int x = 1;
  int y = 2;

  // This gives 5 instead of 6 (y*2 is executed before adding x)
  printf("Twice of 1+2 should be 6, is %d\n", TWICE_AWFUL(x+y));

  // This gives 3 instead of 2 (the x++ is executed twice).
  printf("Twice of 1 should be 2, is %d\n", TWICE_BAD(x++));

  // This works.
  printf("Twice of 2+2 should be 8, is %d\n", TWICE_OK(y+y));

  return 0;
}