enum List<'a> {
    Cons(i32, &'a List<'a>),
    Nil,
}

fn main() {
    let x = List::Cons(3, &List::Nil);
}

fn list(x: i32) -> List<'static> {
    List::Cons(x, &List::Nil)
}

fn list2(x: i32, y: i32) -> List<'static> {
    List::Cons(x, &List::Cons(y, &List::Nil))
}