Re: [boost] [concept] forward declarations and `BOOST_CONCEPT_REQUIRES()`

Subject: Re: [boost] [concept] forward declarations and `BOOST_CONCEPT_REQUIRES()`
From: Dave Abrahams (dave_at_[hidden])
Date: 2010-08-10 18:28:49

On Tue, Aug 10, 2010 at 5:01 PM, Stefan van Kessel
<van_kessel_at_[hidden]> wrote:
> On 8/10/2010 10:05 PM, Lorenzo Caminiti wrote:
>>
>> On Mon, Aug 9, 2010 at 10:00 PM, Dave Abrahams<dave_at_[hidden]>  wrote:
>>>
>>> Just from looking at the error message this would seem to be a
>>> cut-and-dried case of bugs in the compiler.  The "overloads" it is
>>> saying are ambiguous are identical, meaning they're really just one
>>> thing.
>>
>> Yes, I noticed the same thing. I cannot try the code on other
>> compilers at the moment, it would be great if anyone from this mailing
>> list could do that and let me know...
>>
>> Even assuming this is a MSVC bug, is there a workaround for it?
>>
>
>
> For what it's worth. On MSVC10 your code only fails to build in Debug mode
> for me. There's a Workaround already in requires.hpp that only triggers if
> BOOST_MSVC < 1300 or #ifdef(NDEBUG). Adding  || BOOST_WORKAROUND(BOOST_MSVC,
> == 1600) (obviously 1600 is my _MSC_VER) gets rid of the problem for me. I
> don't know why the workaround has been disabled for debug builds and I don't
> know if enabling it that way wreaks havoc somewhere else.
>
> Have a nice day,
> Stefan
>
> #if defined(NDEBUG) || BOOST_WORKAROUND(BOOST_MSVC, < 1300) ||
> BOOST_WORKAROUND(BOOST_MSVC, == 1600)
>
> # define BOOST_CONCEPT_REQUIRES(models, result)            \
>    typename
> ::boost::parameter::aux::unaryfunptr_arg_type<void(*)result>::type

Could you please make note of this in a Trac ticket?  Otherwise it's
liable to get lost.

Thanks,

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com