[boost] Re: Progress on boost::enable_if?

From: David Abrahams (dave_at_[hidden])
Date: 2003-09-19 10:06:44

Eric Friedman <ebf_at_[hidden]> writes:

> Dave,
>
> David Abrahams wrote:
>
>> "Eric Friedman" <ebf_at_[hidden]> writes:
>> 
>>>Has there been any progress on providing a common enable_if facility for
>>>Boost? To workaround separete bugs in CodeWarrior and EDG compilers, I've
>>>introduced for Variant yet another implementation of enable_if.
>> boost/iterator/detail/enable_if.hpp works on both those compilers.
>> IIRC there was a problem on CW 8.0, but CW 8.1-8.3 have no trouble.
>> Did you fix CW 8.0?
>
> I don't know, sorry. I don't have access to 8.0.
>
> Anyhow, I want enable_if available only on platforms that support it...

That's fine; I was just trying to point out that you could peel out
the NO_SFINAE cases and be left with an implementation that works
everywhere SFINAE is known to work.  No need to reinvent the wheel.

>>>I'd be willing to write an boost/enable_if.hpp header with the requisite
>>>macros (enable_if(_c), disable_if(_c), etc.). I'd thought this was already
>>>happening though.
>>>
>>>Thanks,
>>>Eric
>>>
>>>P.S. Perhaps even more important is the need for a BOOST_NO_SFINAE defect
>>>macro. Is the attached test suitable?
>> Did you see boost/iterator/detail/config_def.hpp?
>
> Yes, in fact I actually used your config information. But IMO this
> should be a temporary solution, and I think we should add a config
> library test.

My point was that config_def.hpp already contains a test which could
be transplanted to the config library.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com