Recognize Iterator as Hashable

Author: aryansk

mypy/typeshed/stdlib/typing.pyi

@@ -550,6 +550,7 @@ class Iterator(Iterable[_T_co], Protocol[_T_co]):
     @abstractmethod
     def __next__(self) -> _T_co: ...
     def __iter__(self) -> Iterator[_T_co]: ...
+    def __hash__(self) -> int: ...
 
 @runtime_checkable
 class Reversible(Iterable[_T_co], Protocol[_T_co]):

test-data/unit/check-protocols.test

@@ -1025,14 +1025,17 @@ main:15: note:         def [T2] a(self, other: P1[T2]) -> Any
 
 [case testHashable]
 
-from typing import Hashable, Iterable
+from typing import Hashable, Iterable, Iterator
 
 def f(x: Hashable) -> None:
     pass
 
 def g(x: Iterable[str]) -> None:
     f(x)   # E: Argument 1 to "f" has incompatible type "Iterable[str]"; expected "Hashable"
 
+def h(x: Iterator[str]) -> None:
+    f(x)
+
 [builtins fixtures/object_hashable.pyi]
 [typing fixtures/typing-full.pyi]
 

test-data/unit/fixtures/typing-full.pyi

@@ -84,6 +84,7 @@ class Iterable(Protocol[T_co]):
 class Iterator(Iterable[T_co], Protocol):
     @abstractmethod
     def __next__(self) -> T_co: pass
+    def __hash__(self) -> int: pass
 
 class Generator(Iterator[T_co], Generic[T_co, S_contra, R_co]):
     @abstractmethod