On 14 October 2017 at 17:49, Ethan Furman <ethan@stoneleaf.us> wrote:
The problem with PEP 560 is that it doesn't allow the class definition protections that a metaclass does.

Since the discussion turned to PEP 560, I can say that I don't want this to be a general mechanism, the PEP rationale section gives
several specific examples why we don't want metaclasses to implement generic class machinery/internals.

Could you please elaborate more what is wrong with PEP 560 and what do you mean by "class definition protections"

--
Ivan