How can I pass a value to a function without moving ownership, just by passing the value in Rust?

This is just example code.

fn main() {
    let mut vec = vec![4, 3, 6, 7, 5, 8, 1, 2, 9, 0, 1];

    println!("{:?}", solution(&mut vec));
}

fn solution(vec: &mut std::vec::Vec<i32>) -> (i32, i32, i32) {
    let mut copy = vec;

    copy.sort();
    println!("{:?}",copy);

    let mut len: i32 = match copy.len().try_into() {
        Ok(v) => v,
        Err(_) => panic!("Error!"),
    };

    let avg = (copy.last().unwrap() + copy.first().unwrap()) / 2;

    let median = copy[copy.len() / 2];

    let mode = {
        let mut hmap = HashMap::new();
        for element in copy {
            let count = hmap.entry(element).or_insert(0);
            *count += 1;
        }
        let mut max = 0;
        for i in hmap.keys() {
            if hmap[i] > max {
                max = **i;
            }
        }
        max
    };

    (avg, median, mode)
}

In this code, I copied vec variable in solution function to caculate something because of Ownership rules. But In this case, solution function need just a value of vec variable. As a result, the vec variable’s values can change. I want to transfer ownership or just pass a value when passing it to a function.

>Solution :

It’s quite Simple.

1. copy variable when pass to function. use {var}.copy()
2. If you want modify value, just assign a return to variable

fn main() {
    let mut vec 
    ...
    vec2 = foo(vec.copy());
    ...
}
fn foo(vec: std::vec::Vec<T>) -> V {
    ...
    return something
}

In this case, You finally no transfer ownership, pass only values to function.