Boxing a reference to &mut self

Question

I'm new to Rust, and as part of the learning process, I'm attempting to create a tree structure where each node has a vector of children and a reference to its parent. I want to create an addChild() function to the node, which takes the value of the new node (i32s for now), adds it to the child-list, and passes a reference to itself as a parent. Following Rust by Example's linked list example, I'm trying to reference the parent with a Box<>. Since I'm both modifying the parent and passing a reference to it, I got stuck, as the borrow checker doesn't want me to dereference the &mut self (see the code below).

From this I have two questions:

1. What is the correct way to keep a reference the parent in a tree structure? In C I would keep a simple pointer to the parent and some arbitrary collection for the children.

2. How are you supposed to both modify and pass a reference to an object in the same function in Rust?

Below is the full code for my enum and impl, with an additional test-function to modify self without passing it.

---

#[derive(Hash, Eq, PartialEq)]
enum Node {
    Elem {
        value: i32,
        parent: Box<Node>,
        children: Vec<Node>,
    },
    Nil,
}

impl Node {
    fn new(value: i32, parent: Box<Node>) -> Node {
        return Node::Elem {
            value: value,
            parent: parent,
            children: Vec::new(),
        };
    }

    // This function works fine
    fn setValue(&mut self, v: i32) {
        match self {
            &mut Node::Elem { ref mut value, .. } => *value = v,
            &mut Node::Nil => {}
        }
    }

    fn addChild(&mut self, value: i32) {
        match self {
            &mut Node::Elem { ref mut children, .. } => {
                (*children).push(Node::new(value, Box::new(*self)))
                // Produces E0507 (Cannot move out of borrowed context)
            } 
            &mut Node::Nil => println!("Failed to add children to empty node"),
        }
    }
}