struct IteratorResult<'a,T>  where T: 'a {
    pub value: Option<&'a T>,
    pub done: bool

}

struct JsIterator<T,Item> where T: Iterator<Item=Item> {
    iter: T

}

impl<T,Item> JsIterator<T,Item> where T: Iterator<Item=Item>
{

    fn next(&self) -> IteratorResult<Item>
    {
        match self.iter.next() {
            Some(ref v) => IteratorResult { value: Some(&v), done: false },
            None => IteratorResult { value: None, done: true }
        }
    }

}
fn main() {
}