Add ExactType to experimental

Based on python/mypy#8363 (comment)
sobolevn · Nov 10, 2024 · 6bb9c3d · 6bb9c3d
1 parent 305c66f
commit 6bb9c3d
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/useful_types/experimental.py b/useful_types/experimental.py
@@ -42,3 +42,11 @@ def __init_subclass__(cls):
                 "Use the @dataclass decorator to create dataclasses, "
                 "rather than subclassing dataclasses.DataclassLike"
             )
+
+
+# Based on: https://github.com/python/mypy/issues/8363#issuecomment-2462048345
+class ExactType(Protocol[T]):
+    @property
+    def __class__(self, /) -> type[T]: ...
+    @__class__.setter
+    def __class__(self, t: type[T], /) -> None: ...