trait Trait: Sized {
    fn is_reference(self) -> bool;
}

impl<'a, T> Trait for &'a T {
    fn is_reference(self) -> bool {
        true
    }
}

fn main() {
    match 0.is_reference() {
        true => print!("1"),
        false => print!("0"),
    }

    match '?'.is_reference() {
        true => print!("1"),
        false => {
            impl Trait for char {
                fn is_reference(self) -> bool {
                    false
                }
            }
            print!("0")
        }
    }
}