Get nth Fibonacci number in Rust

fibonacci.rs

fn fibonacci(term: u64) -> u64 {
    let (_, tot) = (0..=term).fold((0_u64, 1_u64), |acc, t| {
        match t {
            0 => (0_u64, 0_u64),
            1 => (0, 1_u64),
            2 => (1, 1_u64),
            _ => {
                let (prev, tot) = acc;
                (tot, tot + prev)
            }
        }
    });
    tot
}




fn main() {
    let n = 5;
    println!("{}th fibonacci value is {}", n, fibonacci(n));
}