some template meta-hell fun

#include <iostream>
#include <string>
#include <typeinfo>
#include <boost/cstdint.hpp>

#include <boost/mpl/vector.hpp>
#include <boost/mpl/fold.hpp>
#include <boost/mpl/map.hpp>
#include <boost/mpl/pair.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/next.hpp>
#include <boost/mpl/insert.hpp>
#include <boost/mpl/at.hpp>

using namespace boost::mpl;

typedef vector<uint8_t, uint16_t, uint32_t, uint64_t> types_integral;
typedef vector<float, double, long double> types_floating;
typedef vector<std::string> types_string;

typedef vector<types_integral, types_floating, types_string> type_sets;

template<typename M1, typename M2>
struct merge_maps
{
    typedef typename fold<M1, M2, insert<_1, _2> >::type type;
};

template<typename S>
struct make_type_map
{
    typedef typename fold<
        S,
        map<>,
        insert<_1, pair<_2, S> > >::type type;
};

typedef fold<
    type_sets,
    map<>,
    merge_maps<_1, make_type_map<_2> > >::type map_t2s;

template<typename T>
struct get_comparable
{
    typedef typename at<map_t2s, T>::type type;
};

int main()
{
    std::cout << typeid(get_comparable<float>::type).name() << std::endl << std::endl;
    std::cout << typeid(get_comparable<std::string>::type).name() << std::endl << std::endl;
    std::cout << typeid(get_comparable<uint64_t>::type).name() << std::endl << std::endl;
    return 0;
}