Yeah, I immediately twitched when I saw the PartialEq implementation. Somebody is going to write code which finds the "correct" order and ends up allowing someone to order the same pizza but get yours, while you have to wait for it to be made and cooked again.

It's not difficult to write the predicate same_details_as() and then it's obvious to reviewers if that's what we meant and discourages weird ad-hoc code which might stop working when the PizzaDetails is redefined.