whats new note

Author: ianhi

doc/release/next_whats_new/callback_registry_disconnect_func.rst

@@ -0,0 +1,20 @@
+``CallbackRegistry.disconnect_func`` to disconnect callbacks by function
+-------------------------------------------------------------------------
+
+`.CallbackRegistry` now has a `~.CallbackRegistry.disconnect_func` method that
+allows disconnecting a callback by passing the signal and function directly,
+instead of needing to track the callback ID returned by
+`~.CallbackRegistry.connect`.
+
+.. code-block:: python
+
+    from matplotlib.cbook import CallbackRegistry
+
+    def my_callback(event):
+        print(event)
+
+    callbacks = CallbackRegistry()
+    callbacks.connect('my_signal', my_callback)
+
+    # Disconnect by function reference instead of callback ID
+    callbacks.disconnect_func('my_signal', my_callback)