Hands-On Data Structures and Algorithms with Rust

Look up

The collections::LinkedList relies a lot on the Iterator trait to look up various items, which is great since it saves a lot of effort. This is achieved by extensively implementing various iterator traits using several structures, like the following:

• Iter
• IterMut
• IntoIter

Technically, DrainFilter also implements Iterator, but it's really a convenience wrapper. The following is the Iter structure declaration that the LinkedList uses:

#[stable(feature = "rust1", since = "1.0.0")]
pub struct Iter<'a, T: 'a> {
    head: Option<NonNull<Node<T>>>,
    tail: Option<NonNull<Node<T>>>,
    len: usize,
    marker: PhantomData<&'a Node<T>>,
}

If you remember the list's declaration earlier, it will become obvious that they are very similar! In fact, they are ...