Rust 使用 struct 外部的属性来改变 struct 的原始方式

如果你需要同时访问inners和max，你需要它们在不同的Mutex中，Mutex应该是around the current type of inners, (in your example max is only accessed immutably so it doesn't need a Mutex) not around the whole Outer struct.换句话说:对于需要同时访问的every字段，您需要一个different Mutex，这里只有inners个成员:

#[derive(Debug)]
struct Outer {
    inners: Mutex<Vec<Inner>>,
    max: Max,
}

fn main() {
    let s = Outer {
        inners: Mutex::new(vec![
            Inner { n: 1, factor: 2 },
            Inner { n: 2, factor: 2 },
            Inner { n: 3, factor: 3 },
            Inner { n: 4, factor: 3 },
        ]),
        max: Max { v: 5 },
    };
    
    s.inners.lock().unwrap().retain(|i| i.n * i.factor < s.max.v);

    println!("{:?}", s);
}

或者，如果字段对您可见(它们是pub或Outer是本地类型)，则可以拆分borrow :

fn main() {
    let mutex_s = Mutex::new(Outer {
        inners: vec![
            Inner { n: 1, factor: 2 },
            Inner { n: 2, factor: 2 },
            Inner { n: 3, factor: 3 },
            Inner { n: 4, factor: 3 },
        ],
        max: Max { v: 5 },
    });

    let mut s = mutex_s.lock().unwrap();

    // splitting the borrow into `inners` and `max` so only `max` is captured in the closure.
    let Outer { inners, max } = &mut *s;

    // or for more control over the mutability:
    let Outer {
        ref mut inners,
        ref max,
    } = *s;

    inners.retain(|i| i.n * i.factor < max.v);

    println!("{:?}", s);
}