[Boost-users] shared pointer problem - can't destruct

I've gotten myself into a situation. I've got a class A that created class Bs class B needs to register callbacks to the class A that created it. So I made member variables in class B that are boost::function type class A binds the method to be called and hands that to class B on construction So, not class A always has a reference count and cannot be destoryed. I tried passing a weak_ptr to boost::bind instead and it won't compile. what to do?