Function virtual_cast

library/include/DataDefs.h:489–491

    template<class T>
    inline T *virtual_cast(virtual_ptr ptr) {
        return T::_identity.is_instance(ptr) ? static_cast<T*>(ptr) : NULL;
    }

#define VIRTUAL_CAST_VAR(var,type,input) type *var = virtual_cast<type>(input)