once

evno

Function once 

Source 
pub fn once<E, F>(f: F) -> Once<E, F>
where
    Once<E, F>: Listener,
Examples found in repository?
examples/base.rs (lines 26-28)
22async fn main() {
23    let bus = Bus::new(2);
24
25    // Register EventA listener
26    let handle1 = bus.bind::<EventA>(once(|_| async {
27        println!("Handled  Event A");
28    }));
29
30    // Register EventB listener
31    let handle2 = bus.bind(on(|_: EventB| async {
32        println!("Handled  Event B");
33    }));
34
35    // Register EventC listener
36    let handle3 = bus.bind(many(3, event_c_listener));
37
38    // Emit events
39    bus.emit(EventA).await;
40    bus.emit(EventB).await;
41    bus.emit(EventC).await;
42    bus.emit(EventD).await;
43
44    // Cancel EventB listener and register EventD listener
45    handle2.cancel();
46    tokio::time::sleep(Duration::from_millis(1)).await;
47    let handle4 = bus.bind(on(|_: EventD| async {
48        println!("Handled  Event D");
49    }));
50
51    // Emit again
52    bus.emit(EventA).await;
53    bus.emit(EventB).await;
54    bus.clone().emit(EventD).await;
55
56    drop(bus);
57
58    let _ = join!(handle1, handle3, handle4);
59}