generate mpl::vector from fusion::vector

Question

How to generate fusion::vector from mpl::vector? How to generate mpl::vector from fusion::vector?

BOOST_MPL_ASSERT((is_same<
                  fusion::vector<int, char>,
                  generate_fusion_vector<mpl::vector<int, char> >::type >));

BOOST_MPL_ASSERT((is_same<
                  mpl::vector<int, char>,
                  generate_mpl_vector<fusion::vector<int, char> >::type >));

I need generate_fusion_vector and generate_mpl_vector metafunctions. I can write my own metafunctions, but i suspect that they already exist.

I had an experience of generating fusion::map with help result_of::as_map before, but in current boost(trunk, 1.39 also) such error occur:

D:\Libraries\boost_trunk\boost/fusion/sequence/intrinsic/size.hpp(56) : error C2903: 'apply' : symbol is neither a class template nor a function template
        D:\Libraries\boost_trunk\boost/fusion/container/vector/convert.hpp(23) : see reference to class template instantiation 'boost::fusion::result_of::size' being compiled
        with
        [
            Sequence=boost::mpl::vector
        ]
        temp.cpp(71) : see reference to class template instantiation 'boost::fusion::result_of::as_vector' being compiled

I don't understand what is going on?

Answer 1

As fusion accepts mpl types as arguments to functions you could try this:

BOOST_MPL_ASSERT((is_same<
fusion::vector<int, char>,
fusion::result_of::as_vector<mpl::vector<int, char> >::type >));

Edit:

I think the reason this isn't working for you is that you have to include certain header files to enable mpl compatibility in fusion.

#include <boost/fusion/adapted/mpl.hpp>
#include <boost/fusion/include/mpl.hpp>

Answer 2

I generated fusion::map with help result_of::as_map before, but in current boost(trunk, 1.39 also) such error occur:

D:\Libraries\boost_trunk\boost/fusion/sequence/intrinsic/size.hpp(56) : error C2903: 'apply' : symbol is neither a class template nor a function template
        D:\Libraries\boost_trunk\boost/fusion/container/vector/convert.hpp(23) : see reference to class template instantiation 'boost::fusion::result_of::size' being compiled
        with
        [
            Sequence=boost::mpl::vector
        ]
        temp.cpp(71) : see reference to class template instantiation 'boost::fusion::result_of::as_vector' being compiled

I don't understand what is going on?

Answer 3

I don't know if you're still doing char,int but I ran into the same error and my problem was that I tried to make a length 11 vector, but FUSION_MAX_VECTOR_SIZE was 10.