fn main() {
    println!("Hello, world!");
    let mut test = String::from("12345");
    let mut obj1 = Object {
        text: test.as_mut_str(),
        next: None,
    };
    for i in 0..5 {
        obj1.split_text(4 - i);
        if let Some(obj) = obj1.next.as_ref() {
            println!("{}", obj.text);
        }
    }
}

struct Object<'a> {
    text: &'a mut str,
    next: Option<Box<Object<'a>>>,
}

impl<'a> Object<'a> {
    fn split_text(&'a mut self, count: usize) {
        let tmp = &mut self.text;
        let (part1, part2) = tmp.split_at_mut(count);
        self.text = part1;
        let obj2 = Object {
            text: part2,
            next: None,
        };
        self.next = Some(Box::new(obj2));
    }
}