Module handler 

Helpers for event handlers.

These types are similar to Ref and RefMut but allow the handler to be replaced while it is borrowed. When this happens, the handler will be replaced before the next event is emitted.

Structs

HandlerMut

A mutable reference to a handler.

HandlerRef

A shared reference to a handler.

Enums

HandlerAccessError

An error returned when trying to access a handler.