Rust 标准库 1.63 增加了一个期待已久的功能：scoped thread（作用域线程）。

fn main() {
    println!("Hello, world!");
    use std::thread;

    let vals = vec![
        String::from("hi"),
        String::from("from"),
        String::from("the"),
        String::from("thread"),
    ];
    
    let v1 = &vals[0];
    use crossbeam_channel::unbounded;

    // Create a channel of unbounded capacity.
    let (tx, rx) = unbounded::<&String>();
    
    let mut a = vec![1, 2, 3];
    let mut x = 0;

    thread::scope(|s| {
    s.spawn( || {
            println!("hello from the first scoped thread");
            // borrow `a` here
            dbg!(&a);
        for word in &vals {
        tx.send(word);
        }
    });
    s.spawn( || {
            println!("hello from the second scoped thread");
            // mutably borrow `x`, because no other threads are using it
            x += a[0] + a[2];
        for recv in rx {
        println!("Got: {}", recv);
        }
    });
    println!("hello from the main thread");
    });

    // after the scope, can modify and access the variables again
    a.push(4);
    assert_eq!(x, a.len());
}

【 在 z16166 的大作中提到: 】
: 给send()传递ref是不行的，因为这个ref是在发送线程（或者说负责发送的闭包）里的，
: 一旦发送线程结束（或者说发送的闭包销毁了），ref即失效，此后接收线程收到这个ref后就是dangling reference。
: 这样去掉for带来的问题后，也是报错：
: ...................
--
FROM 117.147.20.*