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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: va_start without the first argument?
Date: Mon, 13 Mar 2017 11:21:39 -0700
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Xref: csiph.com comp.lang.c:105925

supercat@casperkitty.com writes:
[...]
> The main compiler I use supports an extension which I think debuted in gcc,
> which doesn't actually execute anything but returns 1 if an expression can
> be evaluated as a compile-time constant and zero if it cannot.  This makes
> it practical to have a macro which does an action one of two ways depending
> upon which is more efficient.  Being able to express such concepts more
> elegantly than via preprocessor macros would be nice, but the macros do work
> and the code is readable on the incocation side at least.
[...]

What compiler?  What is the name of the extension?

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"