Re: [boost] [accumulators] broken on msvc

Subject: Re: [boost] [accumulators] broken on msvc
From: Edward Diener (eldiener_at_[hidden])
Date: 2014-06-16 07:09:25

On 6/16/2014 2:38 AM, Eric Niebler wrote:
> On 6/15/2014 10:36 PM, Eric Niebler wrote:
>> On 6/15/2014 2:20 PM, Andrey Semashev wrote:
>>> On Sunday 15 June 2014 21:18:12 Jürgen Hunold wrote:
>>>> The question remains: Who fixes this where?
>>>
>>> As far as I can see, is_empty.hpp does not use BOOST_PP_CAT when it doesn't
>>> include it, so the header is correct. Accumulators should include cat.hpp
>>> whenever it uses BOOST_PP_CAT, so at least accumulators_fwd.hpp has a bug.
>>
>> I've added the missing #include on develop. Hopefully, that fixes things.
>
> Looks like it doesn't fix things. If Edward's is indeed the problematic
> commit, I wonder if he'd be willing to look into this. Edward?
>
> This is the commit:
>
> https://github.com/boostorg/preprocessor/commit/c66ea5871fd44274f681f02323c4d46bdf394c7c
>
> *All* msvc accumulators tests are currently broken on develop by this.

I had added a variadic version of the undocumented is_empty macro to 
Boost PP on the 'develop' branch. Since the macro is undocumented and 
the variadic version is much better than the pre-existing non-variadic 
version I did not foresee this causing any problems. However I have now 
updated the 'develop' branch to remove the use of the variadic version.

Is Boost accumulators really using Boost PP is_empty ? Otherwise I 
cannot see where my change could have caused the breakage in accumulators.