Path: utzoo!attcan!uunet!hsi!stpstn!lerman
From: lerman@stpstn.UUCP (Ken Lerman)
Newsgroups: comp.lang.c
Subject: Re: varargs...help appreciated
Keywords: varargs
Message-ID: <5773@stpstn.UUCP>
Date: 5 Nov 90 21:13:49 GMT
References: <1990Nov2.170614@madmax.Viewlogic.COM> <27416@mimsy.umd.edu>
Reply-To: lerman@stpstn.UUCP (Ken Lerman)
Organization: The Stepstone Corporation, Sandy Hook, CT 06482
Lines: 34

In article <27416@mimsy.umd.edu> chris@mimsy.umd.edu (Chris Torek) writes:
...
[->> has lost attribution.]
->>p.s.  Anyone got any varargs macros, portable between
->>      traditional varargs and ANSI stdarg?
->
->If you mean what I think you mean, it cannot be done.  The reason
->is that `va_start' has the same name in <varargs.h> and <stdarg.h>
->but the former version (used above) has only one parameter while the
->latter has two.  It is thus impossible to write a single implementation.
->
->If you mean the other thing I think you mean, it can be done, but it
->looks horrible (and I will not even give an example).
->-- 
->In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 405 2750)
->Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris

I generally put the following in my code (by #include):

#if defined(__STDC__) && __STDC__ != 0
#include <stdarg.h>
#define VA_START(ap,last) va_start(ap,last)
#else
#include <varargs.h>
#define VA_START(ap,last) va_start(ap)
#endif

Then I can write VA_START(ap, lastArg) in my code as if I'm using the
ANSI style of va_start.

While this is not a single va_start which does both, I think it meets
the portablility goals which were stated.

Ken