Why doesn't __declspec(novtable) work on a template specialization?

Question

I have a base class for a generic callable that I'm marking __declspec(novtable):

template<class F> struct callable;
template<class R, class... T>
struct __declspec(novtable) callable<R(T...)>
{ virtual R operator()(T...) volatile { return R(); } };

but somehow this does not error like it's supposed to:

int main()
{
        auto temp = new callable<void()>();
        temp->operator()();
}

Why is novtable not working?

Answer 1

Apparently Visual C++ looks at __declspec(novtable) on the template, not its specializations!
This doesn't make sense to me (is it a bug?), but the "solution" is to write this:

template<class F> struct __declspec(novtable) callable;