MAINT: Adapt the `npt._GenericAlias` backport to Python 3.11 `types.GenericAlias` changes

1 files changed, 42 insertions, 7 deletions

diff --git a/numpy/_typing/_generic_alias.py b/numpy/_typing/_generic_alias.py
index 0541ad77f..d32814a72 100644
--- a/numpy/_typing/_generic_alias.py
+++ b/numpy/_typing/_generic_alias.py
@@ -64,7 +64,7 @@ def _reconstruct_alias(alias: _T, parameters: Iterator[TypeVar]) -> _T:
         args.append(value)
 
     cls = type(alias)
-    return cls(alias.__origin__, tuple(args))
+    return cls(alias.__origin__, tuple(args), alias.__unpacked__)
 
 
 class _GenericAlias:
@@ -80,7 +80,14 @@ class _GenericAlias:
 
     """
 
-    __slots__ = ("__weakref__", "_origin", "_args", "_parameters", "_hash")
+    __slots__ = (
+        "__weakref__",
+        "_origin",
+        "_args",
+        "_parameters",
+        "_hash",
+        "_starred",
+    )
 
     @property
     def __origin__(self) -> type:
@@ -95,14 +102,27 @@ class _GenericAlias:
         """Type variables in the ``GenericAlias``."""
         return super().__getattribute__("_parameters")
 
+    @property
+    def __unpacked__(self) -> bool:
+        return super().__getattribute__("_starred")
+
+    @property
+    def __typing_unpacked_tuple_args__(self) -> tuple[object, ...] | None:
+        # NOTE: This should return `__args__` if `__origin__` is a tuple,
+        # which should never be the case with how `_GenericAlias` is used
+        # within numpy
+        return None
+
     def __init__(
         self,
         origin: type,
         args: object | tuple[object, ...],
+        starred: bool = False,
     ) -> None:
         self._origin = origin
         self._args = args if isinstance(args, tuple) else (args,)
         self._parameters = tuple(_parse_parameters(self.__args__))
+        self._starred = starred
 
     @property
     def __call__(self) -> type[Any]:
@@ -110,10 +130,10 @@ class _GenericAlias:
 
     def __reduce__(self: _T) -> tuple[
         type[_T],
-        tuple[type[Any], tuple[object, ...]],
+        tuple[type[Any], tuple[object, ...], bool],
     ]:
         cls = type(self)
-        return cls, (self.__origin__, self.__args__)
+        return cls, (self.__origin__, self.__args__, self.__unpacked__)
 
     def __mro_entries__(self, bases: Iterable[object]) -> tuple[type[Any]]:
         return (self.__origin__,)
@@ -130,7 +150,11 @@ class _GenericAlias:
         try:
             return super().__getattribute__("_hash")
         except AttributeError:
-            self._hash: int = hash(self.__origin__) ^ hash(self.__args__)
+            self._hash: int = (
+                hash(self.__origin__) ^
+                hash(self.__args__) ^
+                hash(self.__unpacked__)
+            )
             return super().__getattribute__("_hash")
 
     def __instancecheck__(self, obj: object) -> NoReturn:
@@ -147,7 +171,8 @@ class _GenericAlias:
         """Return ``repr(self)``."""
         args = ", ".join(_to_str(i) for i in self.__args__)
         origin = _to_str(self.__origin__)
-        return f"{origin}[{args}]"
+        prefix = "*" if self.__unpacked__ else ""
+        return f"{prefix}{origin}[{args}]"
 
     def __getitem__(self: _T, key: object | tuple[object, ...]) -> _T:
         """Return ``self[key]``."""
@@ -169,9 +194,17 @@ class _GenericAlias:
             return NotImplemented
         return (
             self.__origin__ == value.__origin__ and
-            self.__args__ == value.__args__
+            self.__args__ == value.__args__ and
+            self.__unpacked__ == getattr(
+                value, "__unpacked__", self.__unpacked__
+            )
         )
 
+    def __iter__(self: _T) -> Generator[_T, None, None]:
+        """Return ``iter(self)``."""
+        cls = type(self)
+        yield cls(self.__origin__, self.__args__, True)
+
     _ATTR_EXCEPTIONS: ClassVar[frozenset[str]] = frozenset({
         "__origin__",
         "__args__",
@@ -181,6 +214,8 @@ class _GenericAlias:
         "__reduce_ex__",
         "__copy__",
         "__deepcopy__",
+        "__unpacked__",
+        "__typing_unpacked_tuple_args__",
     })
 
     def __getattribute__(self, name: str) -> Any: