Re: [boost] [utility/result_of] decltype-based implementation breaking valid code on msvc-10

Subject: Re: [boost] [utility/result_of] decltype-based implementation breaking valid code on msvc-10
From: Daniel Walker (daniel.j.walker_at_[hidden])
Date: 2010-04-05 21:09:53

On Mon, Apr 5, 2010 at 6:39 PM, Eric Niebler <eric_at_[hidden]> wrote:
> On 4/5/2010 2:59 PM, Eric Niebler wrote:
>>
>> I recently looked into some proto failures on msvc-10 and traced them
>> back to the use of decltype in the implementation of boost::result_of.
>> The program below demonstrates the problem:
>
> <snip>
>
> https://svn.boost.org/trac/boost/ticket/4072
>
> A patch is attached to the ticket. I've confirmed that it un-breaks proto on
> msvc-10, but have not tested it further.

Good catch. Seems reasonable to me. In general, if some vendor
releases an inadequate std:result_of or decltype, it would be good to
have boost::result_of as a functional fallback, which is yet another
reason to resolve the lambda/result_of issue. Enabling lambda to
support boost::result_of's signature protocol, as in ticket 864, would
do the trick. That way msvc-10 users would be able to enjoy
lambda/result_of compatibility, even if msvc-10 still has some
wrinkles.

~Daniel