#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash, PartialOrd)]
pub struct Point(pub i16, pub i16);

static EMPTY: &[Point] = &[];

#[derive(Debug)]
struct Bot1<'a> {
    path: Vec<Point>,
    cur_view: &'a [Point],
}

impl<'a> Bot1<'a> {
    fn new() -> Self {
        let path = Vec::new();
        let b = Bot1 {
            path: path,
            cur_view: &EMPTY[..],
        };
        b
    }
}

fn f1(_b: &mut Bot1) {}
fn f2(_b: Bot1) {}

fn main() {
    let mut b = Bot1::new();
    b.path = vec![Point(0, 0), Point(0, 1), Point(0, 2)];
    b.cur_view = &b.path[1..];

    println!("{:?}", &b);

    let mut b1 = Bot1::new();
    b1.path = vec![Point(-1, -1), Point(0, 1), Point(6, 2)];
    b1.cur_view = &b1.path[2..];

    println!("{:?}", &b1);

    f1(&mut b1);
    f2(b1);

    println!("{:?}", EMPTY);
}