Use defaults for _SingleDispatchCallable

Author: srittau

stdlib/functools.pyi

@@ -26,7 +26,8 @@ __all__ = [
 _T = TypeVar("_T")
 _T_co = TypeVar("_T_co", covariant=True)
 _S = TypeVar("_S")
-_P = ParamSpec("_P")
+_P = ParamSpec("_P", default=Any)
+_R = TypeVar("_R", default=Any)
 _PWrapped = ParamSpec("_PWrapped")
 _RWrapped = TypeVar("_RWrapped")
 _PWrapper = ParamSpec("_PWrapper")
@@ -191,68 +192,68 @@ class partialmethod(Generic[_T]):
     def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
 
 @type_check_only
-class _SingleDispatchCallable(Generic[_P, _T]):
+class _SingleDispatchCallable(Generic[_P, _R]):
     # First argument pf the callables in the registry is the type to dispatch on.
-    registry: types.MappingProxyType[Any, Callable[Concatenate[Any, _P], _T]]
-    def dispatch(self, cls: type[_S]) -> Callable[Concatenate[_S, _P], _T]: ...
+    registry: types.MappingProxyType[Any, Callable[Concatenate[Any, _P], _R]]
+    def dispatch(self, cls: type[_S]) -> Callable[Concatenate[_S, _P], _R]: ...
     if sys.version_info >= (3, 11):
         # @fun.register(complex | str)
         # def _(arg, verbose=False): ...
         @overload
         def register(
             self, cls: types.UnionType, func: None = None
-        ) -> Callable[[Callable[Concatenate[_S, _P], _T]], Callable[Concatenate[_S, _P], _T]]: ...
+        ) -> Callable[[Callable[Concatenate[_S, _P], _R]], Callable[Concatenate[_S, _P], _R]]: ...
     # @fun.register(complex)
     # def _(arg, verbose=False): ...
     @overload
     def register(  # type: ignore[overload-overlap]
         self, cls: type[_S], func: None = None
-    ) -> Callable[[Callable[Concatenate[_S, _P], _T]], Callable[Concatenate[_S, _P], _T]]: ...
+    ) -> Callable[[Callable[Concatenate[_S, _P], _R]], Callable[Concatenate[_S, _P], _R]]: ...
     # @fun.register
     # def _(arg: int, verbose=False):
     @overload
-    def register(self, cls: Callable[Concatenate[_S, _P], _T], func: None = None) -> Callable[Concatenate[_S, _P], _T]: ...
+    def register(self, cls: Callable[Concatenate[_S, _P], _R], func: None = None) -> Callable[Concatenate[_S, _P], _R]: ...
     if sys.version_info >= (3, 11):
         # fun.register(int, lambda x: x)
         @overload
         def register(
-            self, cls: types.UnionType, func: Callable[Concatenate[_S, _P], _T]
-        ) -> Callable[Concatenate[_S, _P], _T]: ...
+            self, cls: types.UnionType, func: Callable[Concatenate[_S, _P], _R]
+        ) -> Callable[Concatenate[_S, _P], _R]: ...
     # fun.register(int, lambda x: x)
     @overload
-    def register(self, cls: type[_S], func: Callable[Concatenate[_S, _P], _T]) -> Callable[Concatenate[_S, _P], _T]: ...
+    def register(self, cls: type[_S], func: Callable[Concatenate[_S, _P], _R]) -> Callable[Concatenate[_S, _P], _R]: ...
     def _clear_cache(self) -> None: ...
-    def __call__(self, arg: object, /, *args: _P.args, **kwargs: _P.kwargs) -> _T: ...
+    def __call__(self, arg: object, /, *args: _P.args, **kwargs: _P.kwargs) -> _R: ...
 
-def singledispatch(func: Callable[Concatenate[object, _P], _T]) -> _SingleDispatchCallable[_P, _T]: ...
+def singledispatch(func: Callable[Concatenate[object, _P], _R]) -> _SingleDispatchCallable[_P, _R]: ...
 
-class singledispatchmethod(Generic[_P, _T]):
-    dispatcher: _SingleDispatchCallable[_P, _T]
-    func: Callable[_P, _T]
-    def __init__(self, func: Callable[Concatenate[object, _P], _T]) -> None: ...
+class singledispatchmethod(Generic[_P, _R]):
+    dispatcher: _SingleDispatchCallable[_P, _R]
+    func: Callable[_P, _R]
+    def __init__(self, func: Callable[Concatenate[object, _P], _R]) -> None: ...
     @property
     def __isabstractmethod__(self) -> bool: ...
     if sys.version_info >= (3, 11):
         @overload
         def register(
             self, cls: types.UnionType, method: None = None
-        ) -> Callable[[Callable[Concatenate[_S, _P], _T]], Callable[Concatenate[_S, _P], _T]]: ...
+        ) -> Callable[[Callable[Concatenate[_S, _P], _R]], Callable[Concatenate[_S, _P], _R]]: ...
 
     @overload
     def register(  # type: ignore[overload-overlap]
         self, cls: type[_S], method: None = None
-    ) -> Callable[[Callable[Concatenate[_S, _P], _T]], Callable[Concatenate[_S, _P], _T]]: ...
+    ) -> Callable[[Callable[Concatenate[_S, _P], _R]], Callable[Concatenate[_S, _P], _R]]: ...
     @overload
-    def register(self, cls: Callable[Concatenate[_S, _P], _T], method: None = None) -> Callable[Concatenate[_S, _P], _T]: ...
+    def register(self, cls: Callable[Concatenate[_S, _P], _R], method: None = None) -> Callable[Concatenate[_S, _P], _R]: ...
     if sys.version_info >= (3, 11):
         @overload
         def register(
-            self, cls: types.UnionType, method: Callable[Concatenate[_S, _P], _T]
-        ) -> Callable[Concatenate[_S, _P], _T]: ...
+            self, cls: types.UnionType, method: Callable[Concatenate[_S, _P], _R]
+        ) -> Callable[Concatenate[_S, _P], _R]: ...
 
     @overload
-    def register(self, cls: type[_S], method: Callable[Concatenate[_S, _P], _T]) -> Callable[Concatenate[_S, _P], _T]: ...
-    def __get__(self, obj: _S, cls: type[_S] | None = None) -> Callable[Concatenate[_S, _P], _T]: ...
+    def register(self, cls: type[_S], method: Callable[Concatenate[_S, _P], _R]) -> Callable[Concatenate[_S, _P], _R]: ...
+    def __get__(self, obj: _S, cls: type[_S] | None = None) -> Callable[Concatenate[_S, _P], _R]: ...
 
 class cached_property(Generic[_T_co]):
     func: Callable[[Any], _T_co]