cake-monotone c6efa93cf7 [red-knot] Handle special case returning NotImplemented (#17034) ... ## Summary Closes #16661 This PR includes two changes: - `NotImplementedType` is now a member of `KnownClass` - We skip `is_assignable_to` checks for `NotImplemented` when checking return types ### Limitation ```py def f(cond: bool) -> int: return 1 if cond else NotImplemented ``` The implementation covers cases where `NotImplemented` appears inside a `Union`. However, for more complex types (ex. `Intersection`) it will not worked. In my opinion, supporting such complexity is unnecessary at this point. ## Test Plan Two `mdtest` files were updated: - `mdtest/function/return_type.md` - `mdtest/type_properties/is_singleton.md` To test `KnownClass`, run: ```bash cargo test -p red_knot_python_semantic -- types::class:: ```		2025-03-30 11:06:12 -07:00
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parameters.md	[red-knot] function parameter types (#14802)	2024-12-06 12:55:56 -08:00
return_type.md	[red-knot] Handle special case returning NotImplemented (#17034)	2025-03-30 11:06:12 -07:00