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generic mutable class attributes introduce a vent in the type system #11538

@KotlinIsland

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@KotlinIsland
from typing import Generic, TypeVar

T = TypeVar("T")


class A(Generic[T]):
    shared_attr: list[T] = []

a1 = A[str]()
a1.shared_attr.append("AMONGUS")

a2 = A[int]()
a2.shared_attr.append(1)

value = a2.class_attr[0]
reveal_type(value)  # revealed type: int, actual value: AMONGUS

In this example the shared attribute shared_attr is imposted upon by different instantiations of that class, causing a sus amongus to be appeared.

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