C++ specializing variadic template inside of a variadic template -

how specialize classes variadic template parameters inside of classes variadic template parameters? i.e.:

template < typename ... > struct test_class {     template < typename ... >     struct s { }; };  template < > template < typename ... ts > struct test_class< ts ... >::s< int > { }; // doesn't work 

is possible?

template <typename...> struct outsides {     // ... };  template </* ... */> struct outsides</* ... */> {     // ... };  template <typename... types> struct testclass {     template <typename... othertypes>     using s = outsides<othertypes...>; }; 

specializing in nested way not possible, can specialize nested template somewhere else.