Add @disjoint_base decorator in the stdlib (#14599)

And fix some other new stubtest finds.

stdlib/itertools.pyi

@@ -3,7 +3,7 @@ from _typeshed import MaybeNone
 from collections.abc import Callable, Iterable, Iterator
 from types import GenericAlias
 from typing import Any, Generic, Literal, SupportsComplex, SupportsFloat, SupportsIndex, SupportsInt, TypeVar, overload
-from typing_extensions import Self, TypeAlias
+from typing_extensions import Self, TypeAlias, disjoint_base
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")
@@ -27,6 +27,7 @@ _Predicate: TypeAlias = Callable[[_T], object]
 
 # Technically count can take anything that implements a number protocol and has an add method
 # but we can't enforce the add method
+@disjoint_base
 class count(Generic[_N]):
     @overload
     def __new__(cls) -> count[int]: ...
@@ -37,11 +38,13 @@ class count(Generic[_N]):
     def __next__(self) -> _N: ...
     def __iter__(self) -> Self: ...
 
+@disjoint_base
 class cycle(Generic[_T]):
     def __new__(cls, iterable: Iterable[_T], /) -> Self: ...
     def __next__(self) -> _T: ...
     def __iter__(self) -> Self: ...
 
+@disjoint_base
 class repeat(Generic[_T]):
     @overload
     def __new__(cls, object: _T) -> Self: ...
@@ -51,6 +54,7 @@ class repeat(Generic[_T]):
     def __iter__(self) -> Self: ...
     def __length_hint__(self) -> int: ...
 
+@disjoint_base
 class accumulate(Generic[_T]):
     @overload
     def __new__(cls, iterable: Iterable[_T], func: None = None, *, initial: _T | None = ...) -> Self: ...
@@ -59,6 +63,7 @@ class accumulate(Generic[_T]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
+@disjoint_base
 class chain(Generic[_T]):
     def __new__(cls, *iterables: Iterable[_T]) -> Self: ...
     def __next__(self) -> _T: ...
@@ -68,21 +73,25 @@ class chain(Generic[_T]):
     def from_iterable(cls: type[Any], iterable: Iterable[Iterable[_S]], /) -> chain[_S]: ...
     def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
 
+@disjoint_base
 class compress(Generic[_T]):
     def __new__(cls, data: Iterable[_T], selectors: Iterable[Any]) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
+@disjoint_base
 class dropwhile(Generic[_T]):
     def __new__(cls, predicate: _Predicate[_T], iterable: Iterable[_T], /) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
+@disjoint_base
 class filterfalse(Generic[_T]):
     def __new__(cls, function: _Predicate[_T] | None, iterable: Iterable[_T], /) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
+@disjoint_base
 class groupby(Generic[_T_co, _S_co]):
     @overload
     def __new__(cls, iterable: Iterable[_T1], key: None = None) -> groupby[_T1, _T1]: ...
@@ -91,6 +100,7 @@ class groupby(Generic[_T_co, _S_co]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[_T_co, Iterator[_S_co]]: ...
 
+@disjoint_base
 class islice(Generic[_T]):
     @overload
     def __new__(cls, iterable: Iterable[_T], stop: int | None, /) -> Self: ...
@@ -99,18 +109,20 @@ class islice(Generic[_T]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
+@disjoint_base
 class starmap(Generic[_T_co]):
     def __new__(cls, function: Callable[..., _T], iterable: Iterable[Iterable[Any]], /) -> starmap[_T]: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
+@disjoint_base
 class takewhile(Generic[_T]):
     def __new__(cls, predicate: _Predicate[_T], iterable: Iterable[_T], /) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 def tee(iterable: Iterable[_T], n: int = 2, /) -> tuple[Iterator[_T], ...]: ...
-
+@disjoint_base
 class zip_longest(Generic[_T_co]):
     # one iterable (fillvalue doesn't matter)
     @overload
@@ -189,6 +201,7 @@ class zip_longest(Generic[_T_co]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
+@disjoint_base
 class product(Generic[_T_co]):
     @overload
     def __new__(cls, iter1: Iterable[_T1], /) -> product[tuple[_T1]]: ...
@@ -274,6 +287,7 @@ class product(Generic[_T_co]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
+@disjoint_base
 class permutations(Generic[_T_co]):
     @overload
     def __new__(cls, iterable: Iterable[_T], r: Literal[2]) -> permutations[tuple[_T, _T]]: ...
@@ -288,6 +302,7 @@ class permutations(Generic[_T_co]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
+@disjoint_base
 class combinations(Generic[_T_co]):
     @overload
     def __new__(cls, iterable: Iterable[_T], r: Literal[2]) -> combinations[tuple[_T, _T]]: ...
@@ -302,6 +317,7 @@ class combinations(Generic[_T_co]):
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
+@disjoint_base
 class combinations_with_replacement(Generic[_T_co]):
     @overload
     def __new__(cls, iterable: Iterable[_T], r: Literal[2]) -> combinations_with_replacement[tuple[_T, _T]]: ...
@@ -317,12 +333,14 @@ class combinations_with_replacement(Generic[_T_co]):
     def __next__(self) -> _T_co: ...
 
 if sys.version_info >= (3, 10):
+    @disjoint_base
     class pairwise(Generic[_T_co]):
         def __new__(cls, iterable: Iterable[_T], /) -> pairwise[tuple[_T, _T]]: ...
         def __iter__(self) -> Self: ...
         def __next__(self) -> _T_co: ...
 
 if sys.version_info >= (3, 12):
+    @disjoint_base
     class batched(Generic[_T_co]):
         if sys.version_info >= (3, 13):
             def __new__(cls, iterable: Iterable[_T_co], n: int, *, strict: bool = False) -> Self: ...