// test for pointer validity: defining conversion to unspecified_bool_type
// and not more obvious bool to avoid implicit conversions to integer types
typedef T *(wxObjectDataPtr<T>::*unspecified_bool_type)() const;
// test for pointer validity: defining conversion to unspecified_bool_type
// and not more obvious bool to avoid implicit conversions to integer types
typedef T *(wxObjectDataPtr<T>::*unspecified_bool_type)() const;