#include <stdio.h>
#include <stddef.h>

int main(void){

  int    *i,    j = 1;
  char   *c,    h = 'a';
  double *d,    e = 2.0;
  void   *f;

  i = &e;  /* Error: i cannot point to a double */
  c = &h;  /* OK                                */
  d = &j;  /* Error: d cannot point to an int   */
  f = &j;  /* OK. f is a generic pointer        */

  printf("%d, %c, %f, %d\n", *i, 
                             *c,
                             *d,
                             *f   /* Error: dereferencing */ 
        );                        /*      pointer to void */
}