#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#[derive(Debug)]
struct MyCollection(Vec<i32>);
impl MyCollection {
    fn new() -> MyCollection {
        MyCollection(Vec::new())
    }
    fn add(&mut self, elem: i32) {
        self.0.push(elem);
    }
}
impl IntoIterator for MyCollection {
    type Item = i32;
    type IntoIter = std::vec::IntoIter<Self::Item>;
    fn into_iter(self) -> Self::IntoIter {
        self.0.into_iter()
    }
}
fn main() {
    let mut c = MyCollection::new();
    c.add(0);
    c.add(1);
    c.add(2);
    for (i, n) in c.into_iter().enumerate() {
        assert_eq!(i as i32, n);
    }
}