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From: Richard Harnden <richard.nospam@gmail.invalid>
Newsgroups: comp.lang.c
Subject: Re: is it possible to have functions with 0, 1, or 2 args?
Date: Mon, 12 Aug 2024 11:37:39 +0100
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On 12/08/2024 10:28, Tim Rentsch wrote:
> Richard Harnden <richard.nospam@gmail.invalid> writes:
> 
>> On 12/08/2024 06:20, Tim Rentsch wrote:
>>
>>> Michael S <already5chosen@yahoo.com> writes:
>>>
>>>> On Mon, 05 Aug 2024 08:26:04 +0000
>>>> Mark Summerfield <mark@qtrac.eu> wrote:
>>>>
>>>> According to my understanding, vararg functions without arguments will
>>>> become possible in C23.  But since fully functional C23 compilers do not
>>>> exist yet, right now the answer to your question is "No".
>>>
>>> Even in C99 varargs functions can be called without arguments.
>>> The question here is more subtle.  In fact it is possible even
>>> in C99 and C11 to do what he wants, but it isn't easy, and it
>>> is far from obvious how to go about it.  Still, if the question
>>> is "can this be done?", the answer is Yes even now.
>>
>> How does va_start know where to, um, start from if there's no last
>> named argument?
> 
> Sorry, I meant to say macros, not functions (using ... and __VA_ARGS__).
> The original question is about macro definitions, not function
> definitions, and I didn't read carefully enough.

No worries.

So ... how can you do it with macros?

And, even if it's possible, is it a good idea?