NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/lang/c/18343

Text File | 1992-12-14 | 1.7 KB | 54 lines

Newsgroups: comp.lang.c
Path: sparky!uunet!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!cs.uiuc.edu!vela!pd-dom!agrafiot
From: [e-mail] (Dimitris Agrafiotis)
Subject: Re: questions on variable argument lists
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: Warner Lambert / Parke-Davis
References: <[e-mail]>
Distribution: usa
Date: Mon, 14 Dec 1992 20:34:22 GMT
Lines: 41

In article <[e-mail]> [e-mail] (Dimitris Agrafiotis) writes:
>
>I want to define a function, alpha(), that takes as arguments a pointer to a
>function, beta(), and the arguments to be passed to that function. Ideally,
>the function would be implemented as follows:
>
>void alpha(void (*beta)(...), ...)
>{
>   va_list arg;
>   va_start(arg, beta);
>   (*beta)(arg);
>   va_end(arg);
>}
>
>but that doesn't work for several reasons. First, the compiler seems to
>require at least one argument in the declaration of beta(). Is there
>an elegant way around that ? Second, even when you avoid this problem
>by introducing a dummy argument, you get garbage at run time (this was
>run on an SGI Indigo). What is the reason? What's the best alternative
>and how portable would it be?
>Thanks in advance,
>
>--
>Dimitris K. Agrafiotis
>Computer Assisted Drug Design
>Parke-Davis Pharmaceutical Research
>([e-mail])

I did some experiments and I think I found the solution to my problem
(at least on the SGI machines). The declaration would be something like:

void alpha(void (*beta)(va_list arg), ...);

and the rest is obvious. Sorry for waisting your time.


--
Dimitris K. Agrafiotis
Computer Assisted Drug Design
Parke-Davis Pharmaceutical Research
([e-mail])