Function select_two 

pub fn select_two<F1, F2, T1, T2>(future1: F1, future2: F2) -> SelectTwo<F1, F2> 
where
    F1: Future<Output = T1> + Unpin,
    F2: Future<Output = T2> + Unpin,

Select from two futures, returning the first that completes 从两个future中选择，返回第一个完成的

Example / 示例

use hiver_runtime::select::{select_two, SelectTwo};
use hiver_runtime::time::{sleep, Duration};

async fn example() {
    let sleep1 = sleep(Duration::from_millis(100));
    let sleep2 = sleep(Duration::from_millis(200));

    match select_two(sleep1, sleep2).await {
        SelectTwo::First(_) => println!("First completed"),
        SelectTwo::Second(_) => println!("Second completed"),
    }
}