Shared via Rust Playground

playground.rs

#[derive(Clone, Copy)]
struct Comp;
struct USB;
struct Card;

impl USB {
    fn get_version(&self) -> Option<f64> {
        Some(1.2)
    }
}

impl Card {
    fn get_usb(&self) -> Option<USB> {
        Some(USB)
    }
}

impl Comp {
    fn get_soundcard(&self, number: i32) -> Option<Card> {
        match number {
            0 => Some(Card),
            _ => None,
        }
    }
}

fn get_version(computer: Comp, card_number: i32) -> Option<f64> {
    computer.get_soundcard(card_number)
            .and_then(|card| card.get_usb())
            .and_then(|usb| usb.get_version())
}

fn main() {
    let computer = Comp;

    let version = get_version(computer, 0);
    println!("{:?}", version);
    
    let version = get_version(computer, 1);
    println!("{:?}", version);
}