translate a macro to D

[teo]

On Thu, 07 Jul 2011 11:57:51 -0400, Steven Schveighoffer wrote:

> Well, I can't really say I understand the point of using this macro at
> all.  sizeof is a builtin, and part of the C spec.  Why not just use
> sizeof?
> 

Well, have a look please at ioctl.h (linux). You will find the following 
macros:


#define _IOC(dir,type,nr,size) \
        (((dir)  << _IOC_DIRSHIFT) | \
         ((type) << _IOC_TYPESHIFT) | \
         ((nr)   << _IOC_NRSHIFT) | \
         ((size) << _IOC_SIZESHIFT))

#define _IOC_TYPECHECK(t) (sizeof(t))

/* used to create numbers */
#define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
#define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK
(size)))
#define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),
(_IOC_TYPECHECK(size)))
#define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),
(_IOC_TYPECHECK(size)))


This is what I am after. However I thought that a simplified case will 
make it easier to describe the problem.