main.rs

struct Network {
}

struct Handshake<'a> {
    net: &'a Network
}

struct Foo<'a> {
    net: Network,
    hs: Handshake<'a>
}

impl<'a> Foo<'a> {
    fn new() -> Self {
        let net = Network {};
        Self {
            net,
            hs: Handshake { net: &net }
        }
    }
}

fn main() {
}