Rust code shared from the playground

playground.rs

use std::rc::Rc;
use std::cell::{Ref, RefCell};

struct Node<T> {
    data: T,
}

struct Container<T> {
    nodes: Vec<Rc<RefCell<Node<T>>>>,
}

impl<T> Container<T> {
    fn new() -> Self {
        Container { nodes: Vec::new() }
    }

    fn iter<'a>(&'a self) -> NodeIter<'a, T> {
        NodeIter { iter: self.nodes.iter() }
    }
}

struct NodeIter<'a, T: 'a> {
    iter: std::slice::Iter<'a, Rc<RefCell<Node<T>>>>,
}

impl<'a, T: 'a> Iterator for NodeIter<'a, T> {
    type Item = Ref<'a, T>;

    fn next(&mut self) -> Option<Ref<'a, T>> {
        self.iter.next().map(|rc| {
            Ref::map(rc.borrow(), |node| &node.data)
        })
    }
}

fn main() {
    let c: Container<()> = Container::new();
    println!("Hello, world!");
}