How would you go about implementing `squeeze`?

squeeze.rs

#[cfg(test)]
mod test {
    use super::squeeze;

    #[test]
    fn test_squeeze() {
        // The idea here is that any non-() type would work.
        assert_eq!(squeeze(1i32, 2i32), (1, 2));
        assert_eq!(squeeze(true, false), (true, false));
        assert_eq!(squeeze("foo", Some("bar")), ("foo", Some("bar")));

        assert_eq!(squeeze(1i32, ()), 1);
        assert_eq!(squeeze("foo", ()), "foo");
        assert_eq!(squeeze(Some(1.3), ()), Some(1.3));

        assert_eq!(squeeze((), 2i32), 2);
        assert_eq!(squeeze((), "foo"), "foo");
        assert_eq!(squeeze((), Some(1.3)), Some(1.3));

        assert_eq!(squeeze((), ()), ());
    }
}