Generating one class member per variadic template argument

Question

I have a template class where each template argument stands for one type of value the internal computation can handle. Templates (instead of function overloading) are needed

Answer 1

One way to do such a thing, as mentioned in πάντα-ῥεῖ's comment is to use a tuple. What he didn't explain (probably to save you from yourself) is how that might look.

Here is an example:

using namespace std;

// define the abomination    
template
struct thing
{
    thing(std::vector... args)
    : _x { std::move(args)... }
    {}

    void print()
    {
        do_print_vectors(std::index_sequence_for());
    }

private:
    template
    void do_print_vectors(std::index_sequence)
    {
        using swallow = int[];
        (void)swallow{0, (print_one(std::get(_x)), 0)...};
    }

    template
    void print_one(const Vector& v)
    {
        copy(begin(v), end(v), ostream_iterator(cout, ","));
        cout << endl;
    }

private:
    tuple...> _x;
};


// test it
BOOST_AUTO_TEST_CASE(play_tuples)
{
    thing t {
        { 1, 2, 3, },
        { 1.1, 2.2, 3.3 },
        { "one"s, "two"s, "three"s }
    };

    t.print();
}

expected output:

1,2,3,
1.1,2.2,3.3,
one,two,three,