class SuperSerializer {
  on(int64);
  on(float64);
  on(SGObject*);
}

class Cereal<Archive> : SuperSerializer {
}


class BaseAnyPolicy {
  void serialize(SuperSerializer*);
}

class ConcretePolicy<T> {
  void serialize(SuperSerializer* s) {
     // proper type
     s->on(value);
  }
}