fn main() {
    let s: &[Item] = &[Item::One, Item::Two, Item::Three];
    let v = foo(s);
    let v2 = foo(&[Item::One, Item::Two, Item::Three]);
}

fn foo(slice: impl Into<Vec<Item>>) -> Vec<Item> {
    slice.into()
}

#[derive(Clone, Copy)]
enum Item {
    One,
    Two,
    Three,
}