Attempt to narrow tuple.__hash__ to flag unhashable entries in the tuple

stdlib/@tests/test_cases/builtins/check_tuple.py

@@ -1,13 +1,27 @@
 from __future__ import annotations
 
-from typing import Tuple
+import sys
+from typing import Any
 from typing_extensions import assert_type
 
 
 # Empty tuples, see #8275
-class TupleSub(Tuple[int, ...]):
+class TupleSub(tuple[int, ...]):
     pass
 
 
 assert_type(TupleSub(), TupleSub)
 assert_type(TupleSub([1, 2, 3]), TupleSub)
+
+# Hashability shenanigans, see #15852
+t: tuple[int, int] = (1, 3)
+hash(t)
+u: tuple[int, ...] = tuple(b"spam")
+hash(u)
+v: tuple[str] = ("",)
+hash(v)
+w: tuple[()] = ()
+hash(w)
+hash(tuple(sys.platform))
+x: tuple[Any, Any] = ((), ())
+hash(x)

stdlib/builtins.pyi

@@ -30,7 +30,7 @@ from _typeshed import (
     SupportsRichComparisonT,
     SupportsWrite,
 )
-from collections.abc import Awaitable, Callable, Iterable, Iterator, MutableSet, Set as AbstractSet, Sized
+from collections.abc import Awaitable, Callable, Hashable, Iterable, Iterator, MutableSet, Set as AbstractSet, Sized
 from io import BufferedRandom, BufferedReader, BufferedWriter, FileIO, TextIOWrapper
 from os import PathLike
 from types import CellType, CodeType, EllipsisType, GenericAlias, NotImplementedType, TracebackType, UnionType
@@ -1163,7 +1163,7 @@ class tuple(Sequence[_T_co]):
     def __gt__(self, value: tuple[_T_co, ...], /) -> bool: ...
     def __ge__(self, value: tuple[_T_co, ...], /) -> bool: ...
     def __eq__(self, value: object, /) -> bool: ...
-    def __hash__(self) -> int: ...
+    def __hash__(self: tuple[Hashable, ...]) -> int: ...
 
     @overload
     def __add__(self, value: tuple[_T_co, ...], /) -> tuple[_T_co, ...]: ...