Some property macros do not use $crate:: access

[HeroicKatora]

This issue affects code that declares classes with properties through py_class!/@property. In slots.rs some of the macros use bare names instead of $crate::_ when using others. This makes it necessary to manually import the referred to names on use. In particular, there are bare uses of py_class_prop_getter, py_class_prop_setter, py_class_call_slot_impl_with_ref and potentially others.

[markbt]

Thanks for the report! I've created #235 to fix them. I think I got them all, but let me know if you find any more.