如何将 Sender 对象从可变引用移到字符串和 Sender 对象元组的向量？

这并不能解决我的问题。建议的答案是用Nones 替换值。我确实需要减小向量的大小。

口粮：

use tokio::sync::mpsc;

#[tokio::main]
async fn main() {

    // Pits the singers against each other...
    // Please do not get confused by the type of the sender used in here.
    // This still will showcase the same problem.
    fn pit(singers: &mut Vec<(String, mpsc::Sender<String>)>) {
        use rand::Rng;
        let mut rng = rand::thread_rng();
        let i1 = rng.gen_range(0..singers.len());
        let i2 = rng.gen_range(0..singers.len());
        // This will add dunsel "singers" to the vector who will get
        // pitted against one another. The actual code makes sure that
        // there are at least 2 singers in queue. What is does not do - 
        // and neither should it - is check if they are dummy objects.
        // Rust did not like me using singers[i1].take().unwrap() and
        // complained about iterators not being implemented for Sender?
        let (dunsel, _) = mpsc::channel::<String>(1);
        let s1 = std::mem::replace(&mut singers[i1], (String::new(), dunsel.clone()));
        let s2 = std::mem::replace(&mut singers[i2], (String::new(), dunsel.clone()));
        // returns s1, s2... not needed for MRE
    }

    let mut v = vec![];
    let (tx, _) = mpsc::channel::<String>(256); // receiver is not needed for MRE
    for name in vec!["name1".to_string(), "name2".to_string(), "name3".to_string()] {
        // In the actual code, the singer clients are sent this tx
        // and they send their transmitter channels via this tx, which
        // is then pushed to the vector. Here, it just accepts `String`s
        // So, tx is of the type mpsc::Sender<mpsc::Sender<String>>!!
        v.push((name.clone(), tx.clone()));
    }
    tokio::spawn(async move {
        let mut v = v;
        pit(&mut v); 
    });
}