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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Concatenated if and preprocessor
Date: Fri, 14 Mar 2025 15:29:36 -0700
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Richard Harnden <richard.nospam@gmail.invalid> writes:

> On 14/03/2025 21:10, Keith Thompson wrote:
>
>> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
>>
>>> Richard Harnden <richard.nospam@gmail.invalid> writes:
>>>
>>>> On 14/03/2025 16:44, Tim Rentsch wrote:
>>>>
>>>>>     for(  int just_once = 1;  just_once;  just_once = 0  ){
>>>>
>>>> Any reason not to say ...
>>>>
>>>> do {
>>>>      ...
>>>> } while (0);
>>>>
>>>> ... ?
>>>
>>> In fact using do/while(0) is what I first wrote.  But then
>>> I thought, oh wait, what if an overzealous compiler gives
>>> a warning because the while() expression is always false? :-/
>
> That would break a lot of macros :)
>
>> [...]
>
> Hmm, clang with -Weverything is okay with:
>   do { ... } while (0);
>
> But not with:
>   if ( 0 ) { ... }
>
> But it's okay with:
>   if ( (0) ) { ... }

These examples illustrate why I have the reaction I do.  That
plus the lack of clarity as to what the OP's actual requirements
are explains my decision to use a for() rather than do/while(0).