BOOST MPL

//Exemplo official do Boost::MPL Sequencer

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

namespace fusion = boost::fusion;
namespace mpl = boost::mpl;

auto main() -> int
{
    mpl::vector_c<int, 123, 456> vec_c;
    fusion::vector3<int, long, long> v(vec_c);
    std::cout << fusion::at_c<0>(v) << std::endl;
    std::cout << fusion::at_c<1>(v) << std::endl;

    v = mpl::vector_c<int, 456, 789>();
    std::cout << fusion::at_c<0>(v) << std::endl;
    std::cout << fusion::at_c<1>(v) << std::endl;

    return EXIT_SUCCESS;
}