Allow passing only item_type to create_memory_object_stream() (agronh…

…olm#473)

docs/versionhistory.rst

@@ -26,6 +26,7 @@ This library adheres to `Semantic Versioning 2.0 <http:https://semver.org/>`_.
  - The ``TaskStatus`` class is now generic, and should be parametrized to indicate the
  type of the value passed to ``task_status.started()``
  - The ``Listener`` class is now covariant in its stream type
+ - ``create_memory_object_stream()`` now allows passing only ``item_type``
 - Fixed ``CapacityLimiter`` on the asyncio backend to order waiting tasks in the FIFO
  order (instead of LIFO) (PR by Conor Stevenson)
 - Fixed ``CancelScope.cancel()`` not working on asyncio if called before entering the

src/anyio/_core/_streams.py

@@ -14,15 +14,15 @@
 
 @overload
 def create_memory_object_stream(
- max_buffer_size: float, item_type: type[T_Item]
-) -> tuple[MemoryObjectSendStream[T_Item], MemoryObjectReceiveStream[T_Item]]:
+ max_buffer_size: float = 0,
+) -> tuple[MemoryObjectSendStream[Any], MemoryObjectReceiveStream[Any]]:
  ...
 
 
 @overload
 def create_memory_object_stream(
- max_buffer_size: float = 0,
-) -> tuple[MemoryObjectSendStream[Any], MemoryObjectReceiveStream[Any]]:
+ max_buffer_size: float = 0, item_type: type[T_Item] = ...
+) -> tuple[MemoryObjectSendStream[T_Item], MemoryObjectReceiveStream[T_Item]]:
  ...