Borrowing

struct test {
    list: Vec<i32>,
    a: i32
}

impl test {
    pub fn new() -> Self {
        test { list:vec![1,2,3,4,5,6,7], a:0 }
    }

    pub fn run(&mut self) {
        for i in 0..self.list.len() {
            self.do_something(self.list[i])
        }

    }

    pub fn do_something(&mut self, n: i32) {
        self.a = n;
    }
}

fn main() {}