Fibo in Rust

fibo_test.rs

fn main() {
   println!("{}", fib(5));
   println!("{}", fib(9));
}

fn fib(n: i32) -> i32{
    let mut v = vec![n];
    loop {
        v = v.iter().fold(vec![], |mut acc, _v| {
            if *_v > 1 {
                acc.push(*_v - 1);
                acc.push(*_v - 2);
            } else {
                acc.push(*_v);
            }
            acc
        });

        if v.iter().find(|_v| **_v > 1).is_none() {
            return v.iter().fold(0, |acc, _v| { acc + *_v });
        }
        
    }
}