我有一个用Rust创建冒泡排序的编程任务。我在Rust方面没有太多的经验，所以这对我来说有点困难：

fn main() {
    println!("Sort numbers ascending");
    let num:[i32; 10] = [4, 65, 2, -31, 0, 99, 2, 83, 782, 1];
    println!("Before: {:?}", num);
    bubble_sort( num);
    println!("After: {:?}\n", num);
}

fn swap( a: &mut i32, b: &mut i32){
    let tmp: i32 = *b;
    *b=*a;
    *a=tmp;
}

fn bubble_sort(mut arr: [i32; 10]) {
    for i in 0..arr.len() {
        for j in 0..arr.len() - 1 - i {
            if arr[j] > arr[j + 1] {
                swap( &mut arr[j], &mut arr[j + 1]);
            }
        }
    }
}

错误：

Compiling playground v0.0.1 (/playground)
error[E0499]: cannot borrow `arr[_]` as mutable more than once at a time
  --> src/main.rs:19:24
   |
19 |                 swap( &mut arr[j], &mut arr[j + 1]);
   |                 ----  -----------  ^^^^^^^^^^^^^^^ second mutable borrow occurs here
   |                 |     |
   |                 |     first mutable borrow occurs here
   |                 first borrow later used by call
   |
   = help: consider using `.split_at_mut(position)` or similar method to obtain two mutable non-overlapping sub-slices

For more information about this error, try `rustc --explain E0499`.
error: could not compile `playground` due to previous error