flo-task

Async task utilities.

SpawnScope

RAII guard used to notify child tasks that the parent has been dropped. One use-case of this is to implement gracefully shut down a group of child tasks.

```rust

[tokio::test]

async fn testinitialvalue() { use std::future::Future; use std::time::Duration; use tokio::time::delay_for; let scope = SpawnScope::new();

fn get_task(mut scope: SpawnScopeHandle) -> impl Future<Output = i32> {
    async move {
        let mut n = 0;
        loop {
            tokio::select! {
              _ = scope.left() => {
                return n
              }
              _ = delay_for(Duration::from_millis(50)) => {
                n = n + 1
              }
            }
        }
    }
}

let t1 = tokio::spawn(get_task(scope.handle()));
let t2 = tokio::spawn(get_task(scope.handle()));
let t3 = tokio::spawn(get_task(scope.handle()));

delay_for(Duration::from_millis(100)).await;
drop(scope);

let (v1, v2, v3) = tokio::try_join!(t1, t2, t3).unwrap();
assert!(v1 > 0);
assert!(v2 > 0);
assert!(v3 > 0);

} ```