Fix type generics in InheritanceIterable

model_utils/managers.py

@@ -7,6 +7,7 @@ from django.core.exceptions import ObjectDoesNotExist
 from django.db import connection, models
 from django.db.models.constants import LOOKUP_SEP
 from django.db.models.fields.related import OneToOneField, OneToOneRel
+from django.db.models.query import ModelIterable, QuerySet
 from django.db.models.sql.datastructures import Join
 
 ModelT = TypeVar('ModelT', bound=models.Model, covariant=True)
@@ -15,19 +16,10 @@ if TYPE_CHECKING:
     from collections.abc import Iterator
 
     from django.db.models.query import BaseIterable
-    from django.db.models.query import ModelIterable as ModelIterableGeneric
-    from django.db.models.query import QuerySet as QuerySetGeneric
-
-    ModelIterable = ModelIterableGeneric[ModelT]
-    QuerySet = QuerySetGeneric[ModelT]
-else:
-    from django.db.models.query import ModelIterable, QuerySet
 
 
-class InheritanceIterable(ModelIterable):
-    def __iter__(self) -> Iterator[ModelT]:
-        queryset = self.queryset
-        iter: ModelIterableGeneric[ModelT] = ModelIterable(queryset)
+def _iter_inheritance_queryset(queryset: QuerySet[ModelT]) -> Iterator[ModelT]:
+    iter: ModelIterable[ModelT] = ModelIterable(queryset)
     if hasattr(queryset, 'subclasses'):
         assert hasattr(queryset, '_get_sub_obj_recurse')
         extras = tuple(queryset.query.extra.keys())
@@ -55,6 +47,22 @@ class InheritanceIterable(ModelIterable):
         yield from iter
 
 
+if TYPE_CHECKING:
+    class InheritanceIterable(ModelIterable[ModelT]):
+        queryset: QuerySet[ModelT]
+
+        def __init__(self, queryset: QuerySet[ModelT], *args: Any, **kwargs: Any):
+            ...
+
+        def __iter__(self) -> Iterator[ModelT]:
+            ...
+
+else:
+    class InheritanceIterable(ModelIterable):
+        def __iter__(self):
+            return _iter_inheritance_queryset(self.queryset)
+
+
 class InheritanceQuerySetMixin(Generic[ModelT]):
 
     model: type[ModelT]