bpo-46244: Remove __slots__ from typing.TypeVar, .ParamSpec

Lib/typing.py

@@ -729,6 +729,9 @@ def __repr__(self):
 
 class _TypeVarLike:
     """Mixin for TypeVar-like types (TypeVar and ParamSpec)."""
+
+    __slots__ = ('__name__', '__bound__', '__covariant__', '__contravariant__')
+
     def __init__(self, bound, covariant, contravariant):
         """Used to setup TypeVars and ParamSpec's bound, covariant and
         contravariant attributes.
@@ -805,8 +808,7 @@ def longest(x: A, y: A) -> A:
     Note that only type variables defined in global scope can be pickled.
     """
 
-    __slots__ = ('__name__', '__bound__', '__constraints__',
-                 '__covariant__', '__contravariant__', '__dict__')
+    __slots__ = ('__constraints__', '__dict__')
 
     def __init__(self, name, *constraints, bound=None,
                  covariant=False, contravariant=False):
@@ -907,8 +909,7 @@ def add_two(x: float, y: float) -> float:
     be pickled.
     """
 
-    __slots__ = ('__name__', '__bound__', '__covariant__', '__contravariant__',
-                 '__dict__')
+    __slots__ = ('__dict__', )
 
     @property
     def args(self):

Misc/NEWS.d/next/Library/2022-01-06-21-31-14.bpo-46244.hjyfJj.rst

@@ -0,0 +1,2 @@
+Add missing ``__slots__`` to ``typing._TypeVarLike``. Patch by Arie
+Bovenberg.