Add @typing.type_check_only (#2679)

srittau · gvanrossum · commit bd10d8aad488 · 2019-04-12T15:32:22.000-07:00
Cf. python/typing#597
diff --git a/stdlib/2/typing.pyi b/stdlib/2/typing.pyi
@@ -63,6 +63,7 @@ _KT_co = TypeVar('_KT_co', covariant=True)  # Key type covariant containers.
 _VT_co = TypeVar('_VT_co', covariant=True)  # Value type covariant containers.
 _T_contra = TypeVar('_T_contra', contravariant=True)  # Ditto contravariant.
 _TC = TypeVar('_TC', bound=Type[object])
+_C = TypeVar("_C", bound=Callable)
 
 def runtime(cls: _TC) -> _TC: ...
 
@@ -462,3 +463,6 @@ class NamedTuple(tuple):
     def _replace(self: _T, **kwargs: Any) -> _T: ...
 
 def NewType(name: str, tp: Type[_T]) -> Type[_T]: ...
+
+# This itself is only available during type checking
+def type_check_only(func_or_cls: _C) -> _C: ...
diff --git a/stdlib/3/typing.pyi b/stdlib/3/typing.pyi
@@ -65,6 +65,7 @@ _KT_co = TypeVar('_KT_co', covariant=True)  # Key type covariant containers.
 _VT_co = TypeVar('_VT_co', covariant=True)  # Value type covariant containers.
 _T_contra = TypeVar('_T_contra', contravariant=True)  # Ditto contravariant.
 _TC = TypeVar('_TC', bound=Type[object])
+_C = TypeVar("_C", bound=Callable)
 
 def runtime(cls: _TC) -> _TC: ...
 
@@ -585,3 +586,6 @@ class NamedTuple(tuple):
     def _replace(self: _T, **kwargs: Any) -> _T: ...
 
 def NewType(name: str, tp: Type[_T]) -> Type[_T]: ...
+
+# This itself is only available during type checking
+def type_check_only(func_or_cls: _C) -> _C: ...
