[boost] Re: MPL problems with como [repost]

From: David Abrahams (dave_at_[hidden])
Date: 2004-01-04 18:49:48

David Abrahams <dave_at_[hidden]> writes:

> "Jonathan Turkanis" <technews_at_[hidden]> writes:
>
>> [I posted this message last week. I know people are busy, so I don't expect
>> immediate bug fixes or long explanations, particularly since I found a
>> workaround some time ago for my intended application. But if I am wrong that
>> the described behavior represents a bug of some sort, I'd like to know.]
>>
>> I have found that some MPL algorithms and metafunctions fail to compile on
>> como 4.3.3 when applied to sequences containing certain lambda expressions.
>> The simplest example is:
>>
>>     BOOST_STATIC_ASSERT( !empty< list< deref<_> > >::value );
>>
>> Almost every computation I have tried on sequences containing deref<_> fail.
>> The output in the above case is shown below.
>
> I'm sorry, I tried to look at this one and was stumped.  I'll give it
> another shot in a minute.

As far as I can tell, this is a bug in the EDG front end (Intel/Linux
shows the same problem).  Having looked carefully, I can see no cause
for boost::mpl::deref<boost::mpl::_> to be instantiated.  I'll spend
a little time looking for a workaround, but I'm not overly optimistic.

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