/* File: bad_pointers.c

   This program uses pointers incorrectly.
   It won't compile.
*/

#include <stdio.h>
#include "genlib.h"
#include "simpio.h"

main () {
   int a = 1, b = 2, c = 3 ;
   double x = 3.1, y = 3.2, z = 3.3 ;

   /* These are pointer declarations */
   int *ptr1, *ptr2 ;
   double *dptr ;

   /* Can't assign integer expressions to pointers */
   ptr1 = a + 7 ;
   ptr1 = 5 ;

   /* Exception: you can assign zero to a pointer */
   ptr1 = 0 ;
   ptr1 = NULL ;

   /* Can't assign double address to integer pointer */ 
   ptr1 = &x ;
}