From 957307b785d7b55d9234e484a33250179ce1f347 Mon Sep 17 00:00:00 2001
From: David Fisher <ddf1991@gmail.com>
Date: Thu, 15 Dec 2016 17:53:38 -0800
Subject: [PATCH] Make filter work properly with Optional elements (#775)

---
 stdlib/2/__builtin__.pyi | 4 ++++
 stdlib/3/builtins.pyi    | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/stdlib/2/__builtin__.pyi b/stdlib/2/__builtin__.pyi
index b6de92b57..ee7b572d5 100644
--- a/stdlib/2/__builtin__.pyi
+++ b/stdlib/2/__builtin__.pyi
@@ -680,6 +680,10 @@ def divmod(a: int, b: int) -> Tuple[int, int]: ...
 @overload
 def divmod(a: float, b: float) -> Tuple[float, float]: ...
 def exit(code: int = ...) -> None: ...
+@overload
+def filter(function: None,
+           iterable: Iterable[Optional[_T]]) -> List[_T]: ...
+@overload
 def filter(function: Callable[[_T], Any],
            iterable: Iterable[_T]) -> List[_T]: ...
 def format(o: object, format_spec: str = '') -> str: ...  # TODO unicode
diff --git a/stdlib/3/builtins.pyi b/stdlib/3/builtins.pyi
index 3847506a8..0f3c12b97 100644
--- a/stdlib/3/builtins.pyi
+++ b/stdlib/3/builtins.pyi
@@ -696,7 +696,10 @@ def eval(source: str, globals: Dict[str, Any] = None,
 def exec(object: str, globals: Dict[str, Any] = None,
          locals: Mapping[str, Any] = None) -> Any: ...  # TODO code object as source
 def exit(code: int = None) -> None: ...
-def filter(function: Optional[Callable[[_T], Any]], iterable: Iterable[_T]) -> Iterator[_T]: ...
+@overload
+def filter(function: None, iterable: Iterable[Optional[_T]]) -> Iterator[_T]: ...
+@overload
+def filter(function: Callable[[_T], Any], iterable: Iterable[_T]) -> Iterator[_T]: ...
 def format(o: object, format_spec: str = '') -> str: ...
 def getattr(o: Any, name: str, default: Any = ...) -> Any: ...
 def globals() -> Dict[str, Any]: ...