#include <stdio.h>
//#define func(x)  x*x-2          /* 一部NG */
//define func(x) ( x*x-2 )      /* 一部NG */
//#define func(x) (x)*(x) - 2    /* 一部NG */
#define func(x) ((x)*(x) - 2)    /* OK */

int main()
{
  int a = 2;
  double b = 1.5;

  printf("a=%d, b=%f\n", a, b);
  printf("func(a) = %d\n", func(a));
  printf("func(a+2) = %d\n", func(a + 2));
  printf("func(a)*4 = %d\n", func(a) * 4);
  printf("func(b) = %f\n", func(b));
  printf("func(b+2.5) = %f\n", func(b + 2.5));

  return 0;
}