Re: [Boost-bugs] [Boost C++ Libraries] #3226: boost::fusion sequence fails to work in boost::mpl::fold

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3226: boost::fusion sequence fails to work in boost::mpl::fold
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-06-27 04:48:56

#3226: boost::fusion sequence fails to work in boost::mpl::fold
---------------------------------------------------+------------------------
 Reporter:  Jeffrey Hellrung <jhellrung@…>         |       Owner:         
     Type:  Bugs                                   |      Status:  new    
Milestone:  Boost 1.40.0                           |   Component:  None   
  Version:  Boost 1.39.0                           |    Severity:  Problem
 Keywords:                                         |  
---------------------------------------------------+------------------------

Comment(by Jeffrey Hellrung <jhellrung@…>):

 Here's a similar example using a somewhat simpler boost::mpl metafunction:

 {{{

 #include <boost/fusion/container/vector.hpp>
 #include <boost/mpl/assert.hpp>
 #include <boost/mpl/front.hpp>
 #include <boost/mpl/vector.hpp>
 #include <boost/type_traits/is_void.hpp>

 int main(int argc, char* argv[])
 {
     typedef boost::fusion::vector< void > fusion_vector_type;
     typedef boost::mpl::vector< void > mpl_vector_type;
     //typedef boost::mpl::front< fusion_vector_type >::type void1_type;
     typedef boost::mpl::front< mpl_vector_type >::type void2_type;
     BOOST_MPL_ASSERT((boost::is_void< void2_type >));
     return 0;
 }

 }}}

 FWIW, boost::mpl::find_if appears to work fine on boost::fusion
 sequences...

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3226#comment:1>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.