This enables a check that which a class which only inherits from immutable classes like str, tuple, and NamedTuple, also defined `__slots__` so they don't allocate memory unnecessarily. This also ensure contributors think about how they define their classes with subclass NamedTuples and str, of which we have many in our codebase
Pull Request resolved: https://github.com/pytorch/pytorch/pull/146276
Approved by: https://github.com/aorenste
Summary:
Making union types harder to use wrong:
1. Initialize unset fields still with None, but we don't assert on the uniqueness of not None field, since it's possible to set a real field to None.
2. Raise error on unset fields in union, reducing the error surface and enforcing type safety.
3. Serialize union type with only tag and omit all the unset fields, this makes the serialized model more readable and debuggable.
Test Plan:
buck test mode/opt caffe2/test:test_export
buck test mode/opt executorch/exir/...
buck test mode/opt mode/inplace aps_models/ads/icvr/tests:export_test
Differential Revision: D52446586
Pull Request resolved: https://github.com/pytorch/pytorch/pull/116511
Approved by: https://github.com/angelayi
