Variadic template deduction in variadic template template

Question

I am not sure if the title makes much sense, but the example is actually quite staightforward:

// A converter struct with a generic constructor.
template 

        

Answer 1

This is not the solution, but might help you or others to figure out what the problem is. The following compiles:

template <template <typename ...> class TT>
struct converter2
{
    template <typename Arg0, typename ... Args>    
    converter2(const TT<Arg0, Args ...> &);
};

// ...

converter2<foo_variadic2>(foo_variadic2<int>{});

I have to admit I don't understand why this is necessary and why your code doesn't work.