#include <initializer_list>
#include <iostream>
#include <vector>

namespace aux {

template <typename Element>
class initializer_list_holder
{
private:
    typename std::initializer_list<Element>::iterator data;
    typename std::initializer_list<Element>::size_type size;
    std::vector<Element> elems;

    void init(void)
    {
        // Yes, vector<T>::data() is non-standard
        data = elems.data();
        size = elems.size();
    }
public:
    initializer_list_holder(std::vector<Element>&& tmp)
     : elems(std::move(tmp))
    {
        init();
    }

    template <typename StdRange>
    initializer_list_holder(const StdRange& src)
     : elems(src.begin(), src.end())
    {
        init();
    }

    operator std::initializer_list<Element>() const
    {
        return reinterpret_cast<
            std::initializer_list<Element> const &
        >(*this);
    }
};

} // namespace aux

template <typename T>
class container
{
public:
    container(std::initializer_list<T> init)
    {
        // TODO: do something more useful here
        for(auto i=init.begin(), e=init.end(); i!=e; ++i)
        {
            std::cout << *i << std::endl;
        }
    }
};

aux::initializer_list_holder<int> convert_input_data(void)
{
    std::vector<int> data;
    // TODO: here (instead doing this) get the data 
    // from an external representation: XML, JSON, database,
    // GUI, etc.
    data.push_back(1);
    data.push_back(2);
    data.push_back(3);
    data.push_back(4);
    return std::move(data);
}

container<int> make_int_container(void)
{
    // Use the initializer-list-constructor here
    return container<int>(convert_input_data());
}

int main(void)
{
    // make the container from external data
    container<int> c = make_int_container();
    return 0;
}