Easy way to access the boost::tuple with phoenix

Question

I would like to access the boost::tuple element with phoenix(c++98)

#include <boost/tuple/tuple.hpp>
#include <boost/phoenix.hpp>

#include <algorithm>
#include <vector>

int main()
{
    using namespace boost::phoenix::placeholders;

    std::vector<boost::tuple<int> > vec;
    vec.push_back(boost::make_tuple(3));
    vec.push_back(boost::make_tuple(4));

    std::for_each(vec.begin(), vec.end(), std::cout<<boost::get<0>(arg1)<<std::endl);
}

But it cannot work, I have tried with std::pair and self define struct, but they cannot work either. Is it possible to access those element with some intuitive, easy solution?

Answer 1

Just find out you can use boost::phoenix::at_c to access tuple element

std::for_each(vec.begin(), vec.end(), std::cout<<boost::phoenix::at_c<0>(arg1)<<std::endl);

You can access std::pair with phoenix too, but need to include the header

#include <boost/fusion/adapted.hpp>

Still lack the example of access self define struct, if I can figure it out I would post it

Edit : you need to include

#include <boost/phoenix/fusion.hpp>

else at_c may not found