> I would like to add:
> 
>     /* No intptr_t dependency here */
>     #define __UNCONST(a) ((void *)(unsigned long)(const void *)(a))
> 
> in <sys/cdefs.h>
> 
> Any objections?

FreeBSD has __DECONST.
please follow it unless there's a compelling reason.

YAMAMOTO Takashi