weird.c

/*============================================================================
  ----------------------------------------------------------------------------
  weird.c - Void pointer versatility...
                 (c) Damion 'Phr0z3n.Dev' Tapper, 2013.
                 Email: Phr0z3n.Dev@Gmail.com

  NOTE: void* - The 'pawn' of C Programming.
  ----------------------------------------------------------------------------
  ============================================================================*/
#define USE_SEC_API /* Comment this line if you do not have the secure libraries. */

#include <stdio.h>

void* retVal(void *); /* This is 'not so' weird... */
int main(void)
{
    int *a;

    a = retVal((void *)2);  /* ...but this is... */

#ifdef USE_SEC_API
    printf_s("%d", a); /* The secure printf function (good programming practice). */
#else
    /* If you are lacking the secure libraries. */
    printf("%d", a);
#endif

    return 0;
}

void* retVal(void *nada)  /* ...because of this. */
{
    return (int *)(2 * (int)nada);  /* Now this is really, really weird. */
}