C++ :: Inheriting One Variadic Class From Another?

I have a variadic base class with a pure-virtual function per type:

Code:
template <typename ... Types>
class Base;
template <typename T, typename ... Types>
class Base<T,Types...>: public Base<Types...>
{
public:
using Base<Types...>::doSomething;

[Code] ......

Now, I'd like to inherit from it using another variadic class, which provides implementations of doSomething(), but I run into trouble --- where do I indicate it derives from Base?

Code:
template <typename ... Types>
class Derived;
template <typename T, typename ... Types>
class Derived<T,Types...>: public Derived<Types...>

[code]....

I see two possible approaches:

First, virtual inheritance *might* get me what I want, but I don't know how bad a performance hit that might be.

Second, I could do some magic where the full set of types is captured in a tuple at the lowest level and continually passed up, then re-expanded in the base case to indicate Base inheritance. However, I'm not sure if that can be done in an unambigious manner; I can't have two variadic packs at once (Types... and the tuple contents), and I'm not sure if there's a way to use enable_if to check if an arbitrary template type is any kind of tuple.