Re: bitfields in structs
Reini Urban <[email protected]> Wed, 05 May 2004 00:42:25 +0200
| Newsgroups | gmane.lisp.uffi.general |
|---|---|
| Message-ID | <[email protected]> |
Kevin Rosenberg schrieb: > rif wrote: >>I assume there's no direct way to wrap this in UFFI? In fact, can >>this even be done on top of most UFFI's? Fortunately, I don't *think* >>I need to actually access any of the fields in this thing --- I think >>I can get by with just having the sxpinfo_struct contained an >>:unsigned-int, and I guess if I need bit access I could write >>accessors in C or something? > > > UFFI does not have any support for bit fields. As for other FFI's, you > can read their individual documentation to check. I don't know without > me doing similar research. I never came around such a special bitfield ffi helper in any FFI so far, since it's trivial to convert such a bitmask to shortint, longint, quad or similar native C type, pass it to the external function and convert it back then. > As for bit access, you could either use a C wrapper or treat the bit > fields as an conglomerated integer of some width and then twidlle the > bits with CL's myriad of bit accessors. -- Reini Urban http://xarch.tu-graz.ac.at/home/rurban/