How could I extract and use the types defined in variable template arguments of a C++ class?

template <typename... T>
class SUTTestFixture
{
public:
    void SetUp(T... args)
    {
        _expected = args...[0];
        _data = args...[1]; // expected ‘;’ before ‘...’ token
    }

protected:
    vector<T...> _data; // XXX
    T... _expected; // error: expected unqualified-id before ‘...’ token
};