"David Abrahams" <david.abrahams@rcn.com> writes: > static int > type_is_gc(PyTypeObject *type) > { > return type->tp_flags & Py_TPFLAGS_HEAPTYPE; > } >> so, wouldn't it make more sense that the Python source always checks > Py_TPFLAGS_HEAPTYPE before tp_is_gc? No. Most GC objects do not have the HEAPTYPE flag (they actually aren't even type objects). Regards, Martin