/*------------------------------------------------------------------*/
/* voidpointers.c (Void Pointers)                                   */
/*------------------------------------------------------------------*/

#include <stdio.h>

int main(int argc, char *argv[])
{
   int i = 5;
   double d = 5.5;
   int *pi;
   double* pd;
   void *pv;

   pi = &i;                       /* OK */
   printf("%d\n", *pi);           /* OK */

   pd = &d;                       /* OK */
   printf("%f\n", *pd);           /* OK */

   pi = &d;                       /* Compiletime warning */
   pd = &i;                       /* Compiletime warning */

   pv = &i;                       /* OK */
   printf("%d\n", *pv);           /* Compiletime error */
   printf("%d\n", *(int*)pv);     /* OK */

   pv = &d;                       /* OK */
   printf("%f\n", *pv);           /* Compiletime error */
   printf("%f\n", *(double*)pv);  /* OK */

   pv = &i;                       /* OK */
   d = *(double*)pv;              /* Runtime error */
   
   return 0;
}


/*

$ gcc -Wall -ansi -pedantic -o voidpointers voidpointers.c
voidpointers.c: In function `main':
voidpointers.c:21: warning: assignment from incompatible pointer type
voidpointers.c:22: warning: assignment from incompatible pointer type
voidpointers.c:25: warning: dereferencing `void *' pointer
voidpointers.c:25: invalid use of void expression
voidpointers.c:29: warning: dereferencing `void *' pointer
voidpointers.c:29: invalid use of void expression

*/