TYP: Fix overlapping overloads issue in 2->1 ufuncs

numpy/_typing/_ufunc.pyi

@@ -4,32 +4,32 @@ The signatures of the ufuncs are too varied to reasonably type
 with a single class. So instead, `ufunc` has been expanded into
 four private subclasses, one for each combination of
 `~ufunc.nin` and `~ufunc.nout`.
-
 """
 
 from typing import (
     Any,
     Generic,
+    Literal,
     NoReturn,
-    TypedDict,
-    overload,
+    Protocol,
+    SupportsIndex,
     TypeAlias,
+    TypedDict,
     TypeVar,
-    Literal,
-    SupportsIndex,
-    Protocol,
+    overload,
     type_check_only,
 )
+
 from typing_extensions import LiteralString, Unpack
 
 import numpy as np
-from numpy import ufunc, _CastingKind, _OrderKACF
+from numpy import _CastingKind, _OrderKACF, ufunc
 from numpy.typing import NDArray
 
-from ._shape import _ShapeLike
-from ._scalars import _ScalarLike_co
 from ._array_like import ArrayLike, _ArrayLikeBool_co, _ArrayLikeInt_co
 from ._dtype_like import DTypeLike
+from ._scalars import _ScalarLike_co
+from ._shape import _ShapeLike
 
 _T = TypeVar("_T")
 _2Tuple: TypeAlias = tuple[_T, _T]
@@ -61,6 +61,13 @@ class _SupportsArrayUFunc(Protocol):
         **kwargs: Any,
     ) -> Any: ...
 
+@type_check_only
+class _UFunc3Kwargs(TypedDict, total=False):
+    where: _ArrayLikeBool_co | None
+    casting: _CastingKind
+    order: _OrderKACF
+    subok: bool
+    signature: _3Tuple[str | None] | str | None
 
 # NOTE: `reduce`, `accumulate`, `reduceat` and `outer` raise a ValueError for
 # ufuncs that don't accept two input arguments and return one output argument.
@@ -72,6 +79,8 @@ class _SupportsArrayUFunc(Protocol):
 # NOTE: If 2 output types are returned then `out` must be a
 # 2-tuple of arrays. Otherwise `None` or a plain array are also acceptable
 
+# pyright: reportIncompatibleMethodOverride=false
+
 @type_check_only
 class _UFunc_Nin1_Nout1(ufunc, Generic[_NameType, _NTypes, _IDType]):  # type: ignore[misc]
     @property
@@ -162,34 +171,61 @@ class _UFunc_Nin2_Nout1(ufunc, Generic[_NameType, _NTypes, _IDType]):  # type: i
     @property
     def signature(self) -> None: ...
 
-    @overload
+    @overload  # (scalar, scalar) -> scalar
     def __call__(
         self,
-        __x1: _ScalarLike_co,
-        __x2: _ScalarLike_co,
-        out: None = ...,
+        x1: _ScalarLike_co,
+        x2: _ScalarLike_co,
+        /,
+        out: None = None,
         *,
-        where: None | _ArrayLikeBool_co = ...,
-        casting: _CastingKind = ...,
-        order: _OrderKACF = ...,
-        dtype: DTypeLike = ...,
-        subok: bool = ...,
-        signature: str | _3Tuple[None | str] = ...,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
     ) -> Any: ...
-    @overload
+    @overload  # (array-like, array) -> array
     def __call__(
         self,
-        __x1: ArrayLike,
-        __x2: ArrayLike,
-        out: None | NDArray[Any] | tuple[NDArray[Any]] = ...,
+        x1: ArrayLike,
+        x2: NDArray[np.generic],
+        /,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
         *,
-        where: None | _ArrayLikeBool_co = ...,
-        casting: _CastingKind = ...,
-        order: _OrderKACF = ...,
-        dtype: DTypeLike = ...,
-        subok: bool = ...,
-        signature: str | _3Tuple[None | str] = ...,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any]: ...
+    @overload  # (array, array-like) -> array
+    def __call__(
+        self,
+        x1: NDArray[np.generic],
+        x2: ArrayLike,
+        /,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
+        *,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any]: ...
+    @overload  # (array-like, array-like, out=array) -> array
+    def __call__(
+        self,
+        x1: ArrayLike,
+        x2: ArrayLike,
+        /,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]],
+        *,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
     ) -> NDArray[Any]: ...
+    @overload  # (array-like, array-like) -> array | scalar
+    def __call__(
+        self,
+        x1: ArrayLike,
+        x2: ArrayLike,
+        /,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
+        *,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any] | Any: ...
 
     def at(
         self,
@@ -227,35 +263,61 @@ class _UFunc_Nin2_Nout1(ufunc, Generic[_NameType, _NTypes, _IDType]):  # type: i
         out: None | NDArray[Any] = ...,
     ) -> NDArray[Any]: ...
 
-    # Expand `**kwargs` into explicit keyword-only arguments
-    @overload
+    @overload  # (scalar, scalar) -> scalar
     def outer(
         self,
         A: _ScalarLike_co,
         B: _ScalarLike_co,
-        /, *,
-        out: None = ...,
-        where: None | _ArrayLikeBool_co = ...,
-        casting: _CastingKind = ...,
-        order: _OrderKACF = ...,
-        dtype: DTypeLike = ...,
-        subok: bool = ...,
-        signature: str | _3Tuple[None | str] = ...,
+        /,
+        *,
+        out: None = None,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
     ) -> Any: ...
-    @overload
-    def outer(  # type: ignore[misc]
+    @overload  # (array-like, array) -> array
+    def outer(
         self,
         A: ArrayLike,
+        B: NDArray[np.generic],
+        /,
+        *,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any]: ...
+    @overload  # (array, array-like) -> array
+    def outer(
+        self,
+        A: NDArray[np.generic],
         B: ArrayLike,
-        /, *,
-        out: None | NDArray[Any] | tuple[NDArray[Any]] = ...,
-        where: None | _ArrayLikeBool_co = ...,
-        casting: _CastingKind = ...,
-        order: _OrderKACF = ...,
-        dtype: DTypeLike = ...,
-        subok: bool = ...,
-        signature: str | _3Tuple[None | str] = ...,
+        /,
+        *,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
     ) -> NDArray[Any]: ...
+    @overload  # (array-like, array-like, out=array) -> array
+    def outer(
+        self,
+        A: ArrayLike,
+        B: ArrayLike,
+        /,
+        *,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]],
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any]: ...
+    @overload  # (array-like, array-like) -> array | scalar
+    def outer(
+        self,
+        A: ArrayLike,
+        B: ArrayLike,
+        /,
+        *,
+        out: NDArray[np.generic] | tuple[NDArray[np.generic]] | None = None,
+        dtype: DTypeLike | None = None,
+        **kwds: Unpack[_UFunc3Kwargs],
+    ) -> NDArray[Any] | Any: ...
 
 @type_check_only
 class _UFunc_Nin1_Nout2(ufunc, Generic[_NameType, _NTypes, _IDType]):  # type: ignore[misc]