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use std::thread;

fn main() {
    let mut a = vec![1, 2, 3];
    let mut x = 0;

    scope_lock::lock_scope(|e| {
        thread::spawn({
            let f = e.extend_fn_once_box(|()| {
                println!("hello from the first scoped thread");
                // We can borrow `a` here.
                dbg!(&a);
            });
            move || f(())
        });
        thread::spawn({
            let f = e.extend_fn_once_box(|()| {
                println!("hello from the second scoped thread");
                // We can even mutably borrow `x` here,
                // because no other threads are using it.
                x += a[0] + a[2];
            });
            move || f(())
        });
        println!("hello from the main thread");
    });

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