bpo-44353: Implement typing.NewType __call__ method in C (#27262)

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Co-authored-by: Denis Laxalde <denis@laxalde.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/Lib/typing.py b/Lib/typing.py
index 1aff0a1..5c95a4d 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -31,6 +31,13 @@ import types
 import warnings
 from types import WrapperDescriptorType, MethodWrapperType, MethodDescriptorType, GenericAlias
 
+
+try:
+    from _typing import _idfunc
+except ImportError:
+    def _idfunc(_, x):
+        return x
+
 # Please keep __all__ alphabetized within each category.
 __all__ = [
     # Super-special typing primitives.
@@ -2375,6 +2382,8 @@ class NewType:
         num = UserId(5) + 1     # type: int
     """
 
+    __call__ = _idfunc
+
     def __init__(self, name, tp):
         self.__name__ = name
         self.__qualname__ = name
@@ -2384,9 +2393,6 @@ class NewType:
     def __repr__(self):
         return f'{self.__module__}.{self.__qualname__}'
 
-    def __call__(self, x):
-        return x
-
     def __or__(self, other):
         return Union[self, other]