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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: is it possible to have functions with 0, 1, or 2 args?
Date: Sun, 11 Aug 2024 10:43:03 -0700
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ram@zedat.fu-berlin.de (Stefan Ram) writes:

> Mark Summerfield <mark@qtrac.eu> wrote or quoted:
>
>> This does *not* work for the `va_test()` call.  But if I supply 1 or 2 args
>> it works great.
>
>   Here's an
>
> SSCCE, a short self-contained correct compilable example, aka,
> MWE - minimal working example.
>
>   Some coders whip up these examples themselves for their post!
>
>   It's a quick and dirty demo that can be compiled and run to
>   show what's buggin' them.
>
>   In this case, it's hella clear the macros are trippin', thinkin'
>   the number of args is "1" when it's actually zilch, nada, zero.
>
>   main.c
>
> #include <stdio.h>
>
> #define NARGS(...)  NARGS_(__VA_ARGS__, 5, 4, 3, 2, 1, 0)
> #define NARGS_(_5, _4, _3, _2, _1, N, ...)  N
> #define va_test(...)  NARGS(__VA_ARGS__)
>
> int main( void ){ printf( "%d\n", va_test() ); }
>
>   transcript
>
> 1

It appears you have missed the point of the question.  What is being
sought is a way to distinguish between macro calls like va_test()
and macro calls like va_test(x).  The above definition of va_test()
doesn't do that.