Issue #20912 has been updated by Eregon (Benoit Daloze). mame (Yusuke Endoh) wrote in #note-5:
I think it's a good idea to warn against redefining `__id__`, but I think we should keep warning against redefining `object_id` as well.
The reason is that it is relatively well known that "we should use `__send__` instead of `send` for unknown objects", but I think it is less well known that "we should use `__id__` instead of `object_id`". In fact, `object_id` is called far more often than `__id__`.
I agree and I think this a well thought out argument. In fact I used object_id plenty of times but almost never `__id__`.
He answered, "I didn't want to have to always use `__id__` because it would be ugly".
Same feeling here, I always prefer to use send/object_id when it's safe, because I think it looks much better/is more readable. Maybe it would even make sense to warn for `send` to discourage overriding it, but out of scope and probably not worth it (considering e.g. Socket#send in stdlib).
Is object_id really called that much?
It seems used a lot, yes: https://github.com/search?q=%2F%5C.object_id%5Cb%2F+language%3ARuby+&type=code&p=1 ---------------------------------------- Feature #20912: Move warning when redefining object_id to __id__ https://bugs.ruby-lang.org/issues/20912#change-110777 * Author: jhawthorn (John Hawthorn) * Status: Open ---------------------------------------- Currently if you create a class and redefine or remove either `object_id` or `__send__` it will issue a warning. There's no such warning on `__id__`. ``` ❯ ruby -we 'class << Object.new; def object_id = 1; end' -e:1: warning: redefining `object_id' may cause serious problems ❯ ruby -we 'class << Object.new; def __id__ = 1; end' ❯ ``` It makes sense that there's no warning on `send`, because we expect `__send__` to be the method reliably available. `__send__` is on `BasicObject`, `send` is only on `Kernel`. This seems a little inconsistent that `object_id` warns while `__id__` does not warn. `__id__` is the equivalent to `__send__` as it's also on `BasicObject`, where `object_id` is only on `Kernel`. This may be a more obvious problem in Ruby 3.4.0 as commit:cffd380390967d17899fde0a81f5151ae6ddd076 makes the warning print in more cases. I propose we change this warning to be emitted only when `__id__` is redefined and not when `object_id` is redefined: **Proposed behaviour:** ``` ❯ ruby -we 'class << Object.new; def object_id = 1; end' ❯ ruby -we 'class << Object.new; def __id__ = 1; end' -e:1: warning: redefining `__id__' may cause serious problems ❯ ``` -- https://bugs.ruby-lang.org/