Type Alias AckCallbackFn 

pub type AckCallbackFn = Box<dyn Fn(AckResult) -> Result<(), ClientError> + Send + Sync>;

Type alias for a function that acts as an acknowledgment callback. The function takes two optional arguments: an AckResult and an error.

This type alias is used to define a callback function that can be passed around and invoked when an acknowledgment operation completes.

The function must be Send and Sync to ensure it can be safely used across threads.

Aliased Type

pub struct AckCallbackFn(/* private fields */);