Am 16.04.26 um 12:34 schrieb Kevin J. McCarthy:
On Thu, Apr 16, 2026 at 08:38:50AM +0200, Matthias Andree via Mutt-dev
wrote:
Am 16.04.26 um 06:52 schrieb Kevin J. McCarthy:
So... I guess this is C23. Which I know almost nothing about :-D.
In any case, we're a long ways away from getting to that level of C
standard support in Mutt.
It's actually a C11 feature that is finally leveraged in the C23
stdlib.h, see https://en.cppreference.com/w/c/language/generic.html
or
https://stackoverflow.com/questions/9804371/syntax-and-sample-usage-of-generic-in-c11
or
https://learn.microsoft.com/en-us/cpp/c-language/generic-selection?view=msvc-170
Thank you, Matthias. Those links are really helpful. Starts to turn
line noise into something I can understand!
Hi Kevin,
My pleasure, glad to have helped -- and the "magic" is one major selling
point for upgrading from C99 or older to at least C11 that I learned
earlier today, and tells me the const correctness problem that fraught
some of the stdlib.h functions is also a good reason to not wait for C23
for too long if you can assume up-to-date toolchains on the consumer side.
(I had been more focused on tackling C++ version differences in the
11/14/17/20 range migrations lately, I didn't follow C much, also
because the type generic stuff in C99/C11 is most prominently documented
in the tgmath.h area where a generic function name works for float,
double, long double so you needn't mess with whether you need fabs for a
double, fabsf for float or fabsl for long double... had missed that it
would also help with the void * vs. const void *).
1. C23 CHANGES INCOMPATIBLY how a function _declaration_ without
arguments is interpreted.
As of C23, int func() means the same as int func(void), must/will not
take arguments, where C18 and before interpreted "has no prototype,
any number of arguments is fine", although that had been deprecated
since C99 or so.
It wasn't that long ago that I start converting some func()
declarations inside mutt to func(void). I'll count myself lucky that
we didn't happen to have those kinds of problems in our configure.ac too!
Yep, that cleanup pretty much avoided the impenetrable "fails to compile
on <moderndistro>" reports or "fails to compile on GCC15".
Cheers,
Matthias
