Re: [Boost-bugs] [Boost C++ Libraries] #1315: iterator_adaptor does not work with incomplete Value types

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #1315: iterator_adaptor does not work with incomplete Value types
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-10-13 22:51:21

#1315: iterator_adaptor does not work with incomplete Value types
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  Reporter:  joaquin                  |       Owner:  witt    
      Type:  Feature Requests         |      Status:  new     
 Milestone:  To Be Determined         |   Component:  iterator
   Version:  Boost Development Trunk  |    Severity:  Problem 
Resolution:                           |    Keywords:          
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Comment (by Duncan Exon Smith <duncanphilipnorman@…>):

 Replying to [comment:7 Duncan Exon Smith <duncanphilipnorman@…>]:
 > This feature worked in GCC only because of a bug prior to v4.4 (e.g.,
 you could use abstract types in v4.3.4).  However, this bug -- to do with
 the intrinsics `__is_abstract` and `__is_pod` -- was fixed:
 >  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39475

 >
 > GCC v4.4.3 now gives the same as MSVC.  In particular,
 `iterator_facade<>` cannot be used to wrap pointers to abstract types any
 longer.  With a large codebase that accidentally relied on this
 misbehaviour, we cannot upgrade past GCC v4.3 without this feature.

 BTW, in case anyone else is searching for it, there's a similar problem
 with `boost::iterator_range<>`, from Boost.RangeEx, since it uses
 `is_abstract<>`.  Incomplete types cannot be used there, either.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/1315#comment:8>
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