Hi Jens, On Thu, Aug 08, 2024 at 11:13:02AM GMT, Jens Gustedt wrote: > > but to maintain expectations, I think it would be better to do > > the same here. > > Just to compare, the recent additions in C23 typeof etc. only have the > parenthesized versions. So there would be precedent. And it really > eases transition
Hmmm, interesting. The good part of reusing sizeof syntax is that I can reuse internal code for sizeof. But I'll check if I can change it easily to only support parens. > > > I wouldn't be sure that we should continue that distinction from > > > `sizeof`. > > > > But then, what do we do? Allow lengthof with type names without parens? > > Or require parens? I'm not comfortable with that choice. > > > > > Also that prefix variant would be difficult to wrap in a > > > `lengthof` macro (without underscores) as we would probably like to > > > have it in the end. > > > > Do you mean that I should add _Lengthof? We're adding __lengthof__ to > > be a GNU extension with relative freedom from ISO. If I sent a patch > > adding _Lengthof, we'd have to send a proposal to ISO at the same time, > > and we'd be waiting for ISO to discuss it before I can merge it. And we > > couldn't bring prior art to ISO. > > > > With this approach instead, the plan is: > > > > - Merge __lengthof__ in GCC before ISO hears of it (well, there are > > already several WG14 members in this discussion, so you have actually > > heard of it, but we're free to do more or less what we want). > > > > - Propose _Lengthof to ISO C, with prior art in GCC as __lengthof__, > > proposing the same semantics. Also propose a lengthof macro defined > > in <stdlength.h> > > I don't really see why we should take a detour via _Lengthof, I would > hope we could directly propose lengthof as the standardization Hmmm, maybe programs already use lengthof for some other purpose. Hopefully not, but I don't know. In any case, I'm fine with both approaches. > > - When ISO C accepts _Lengthof and lengthof, map _Lengthof in GCC to > > the same internals as __lengthof__, so they are the same thing. > > > > Still, I'm interested in having some feedback from WG14, to prevent > > implementing something that will have modifications when merged to > > ISO C, so please CC anyone interested from WG14, if you know of any. > > I think that more important would be to have clang on board with this. Does anyone have any Clang maintainer in mind that would be interested in being CCed? If so, please let me know (and/or add it yourselves). > > In any case, thanks for doing this! :-) Cheers, Alex -- <https://www.alejandro-colomar.es/>
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