Shared via Rust Playground

playground.rs

fn f(a: u8) -> Option<u16> { unimplemented!() }
fn g(b: u16) -> Option<u32> { unimplemented!() }
fn h(c: u32) -> Option<u64> { unimplemented!() }
fn do_something_with(a: u8, b: u16, c: u32, d: u64) -> Option<()> { unimplemented!() }

macro_rules! get(
    ($e:expr) => (match $e { Some(e) => e, None => return None })
);

fn blah1() {
    let a = 123;
    f(a).and_then(|b| {
        g(b).and_then(|c| {
            h(c).map(|d| {
                do_something_with(a, b, c, d)
            })
        })
    });
}

fn blah2() -> Option<()> {
    let a = 123;
    let b = get!(f(a));
    let c = get!(g(b));
    let d = get!(h(c));
    do_something_with(a, b, c, d)
}

fn main() {}