Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!hsdndev!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: Do you use stdarg, varargs or ya-args?
Message-ID: <16107@smoke.brl.mil>
Date: 10 May 91 23:30:21 GMT
References: <2755@muffin.cme.nist.gov>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 22

In article <2755@muffin.cme.nist.gov> libes@cme.nist.gov (Don Libes) writes:
>All the STDC (-like) compilers I use support varargs.

Not all the standard-conforming compilers that *I* use!

>Yes, programs that use varargs are not conforming, but we (and I'm
>speaking strictly for my coworkers here) are trying for maximal
>portability in unknown environments.  Either there is a curious irony
>here or I don't understand why STDC invented stdarg.

X3J11 invented ,...) and <stdarg.h> because there was a need for them
in some implementation environments, and the <varargs.h> va_start macro
did not have a slot for the crucial "hook" on a known parameter that is
needed by some reasonable implementations.

For portability, you need to code for three environments:
	(a) <stdarg.h> exists; you can rely on this #if __STDC__.
	(b) <varargs.h> exists; you can almost rely on this #if unix.
	(c) neither header exists; you might be able to provide your
	    own implementation of <varargs.h> for such an environment,
	    or you could try pretending that there are more arguments
	    than needed, which is a kludge that works in many cases.