#[derive(Debug)]
struct Foo<'a> {
    a: u32,
    b: &'a u32,
}

impl<'a> Foo<'a> {
    fn new() -> Self {
        let a = 123;
        Foo { a, b: &a }
    }
}

fn main() {
    let foo = Foo::new();
    println!("{}", foo.b);
}