phantom-lifetime.rs

struct Doc;

#[cfg(not(phantom))]
struct Node<'a> {
    doc: &'a Doc
}

#[cfg(phantom)]
struct Node<'a>;

impl Doc {
    #[cfg(phantom)]
    fn node<'a>(&'a self) -> Node<'a> {
        Node
    }

    #[cfg(not(phantom))]
    fn node<'a>(&'a self) -> Node<'a> {
        Node { doc: self }
    }
}

fn main() {
    let node;
    {
        let doc = Doc;
        node = doc.node();
    }
}