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Subject: Re: [boost] Alternative implementation for BOOST_PP_VARIADIC_SIZE
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-11-12 14:42:02

On 11/12/2011 6:52 AM, Gennadiy Rozental wrote:
> Lorenzo Caminiti<lorcaminiti<at>> writes:
>> On Thu, Nov 10, 2011 at 6:43 PM, Gennadiy Rozental<rogeeff<at>>>
>> Hi,
>>> Current implementation of subject macro have a very serious shortcoming -
>>> it does not work for empty __VA_ARGS__. After googling around a bit for
>>> some ideas I came up with the following alternative:
>> A while back there was a discussion about the
>> possibility/impossibility to handle empty macro parameters using
>> variadics:
>> (Make sure to address the concerns expressed by Paul in the replies to
>> the above thread.)
> Frankly, I do not have time to read through the whole discussion. I am not a
> language lawyer, but for what it worth my version works on all compilers I
> have tried and looks to be perfectly legal (to me). I do know about one
> limitation. It's where __VA_ARGS__ ends with macro function which produces
> comma when evaluated. It's very rare case though and even if it's possible
> to implement solution that deals with it (look here:
> ),
> I find the complication does not worth the trouble.
> If Edward or Paul care to comment it might be easier for them to point to any
> shortcomings in my solution (if any).

I have already commented in a direct reply to your OP. I don't see how
the link above gets around the function-like macro problem but I will
study it to see what is involved.

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