Remove NoReturn overloads from pow() (#8568)

Author: AlexWaygood

stdlib/builtins.pyi

@@ -266,8 +266,6 @@ class int:
     @overload
     def __pow__(self, __x: int, __modulo: None = ...) -> Any: ...
     @overload
-    def __pow__(self, __x: int, __modulo: Literal[0]) -> NoReturn: ...
-    @overload
     def __pow__(self, __x: int, __modulo: int) -> int: ...
     def __rpow__(self, __x: int, __mod: int | None = ...) -> Any: ...
     def __and__(self, __n: int) -> int: ...
@@ -1548,8 +1546,8 @@ _SupportsSomeKindOfPow = (  # noqa: Y026  # TODO: Use TypeAlias once mypy bugs a
 )
 
 if sys.version_info >= (3, 8):
-    @overload
-    def pow(base: int, exp: int, mod: Literal[0]) -> NoReturn: ...
+    # TODO: `pow(int, int, Literal[0])` fails at runtime,
+    # but adding a `NoReturn` overload isn't a good solution for expressing that (see #8566).
     @overload
     def pow(base: int, exp: int, mod: int) -> int: ...
     @overload
@@ -1587,8 +1585,6 @@ if sys.version_info >= (3, 8):
     def pow(base: _SupportsSomeKindOfPow, exp: complex, mod: None = ...) -> complex: ...
 
 else:
-    @overload
-    def pow(__base: int, __exp: int, __mod: Literal[0]) -> NoReturn: ...
     @overload
     def pow(__base: int, __exp: int, __mod: int) -> int: ...
     @overload

test_cases/stdlib/builtins/test_pow.py

@@ -2,15 +2,19 @@
 
 from decimal import Decimal
 from fractions import Fraction
-from typing import Any, NoReturn
+from typing import Any
 from typing_extensions import Literal, assert_type
 
 # See #7163
 assert_type(pow(1, 0), Literal[1])
 assert_type(1**0, Literal[1])
 assert_type(pow(1, 0, None), Literal[1])
 
-assert_type(pow(2, 4, 0), NoReturn)
+# TODO: We don't have a good way of expressing the fact
+# that passing 0 for the third argument will lead to an exception being raised
+# (see discussion in #8566)
+#
+# assert_type(pow(2, 4, 0), NoReturn)
 
 assert_type(pow(2, 4), int)
 assert_type(2**4, int)