Rudimentary autograd implementation in Rust

Question

I am using Rust to build a simple autograd implementation based on Karpathy's micrograd as inspiration, which was written in Python. I am struggling in building the data structure to manage the children. The following is my initial attempt:

enum Op {
    Add,
    Sub,
    Mul,
    Div,
}

struct Value<T: Default> {
    data: T,
    grad: T,
    children: Vec<Rc<RefCell<Value<T>>>>,
    op: Option<Op>
}

The problem is that, when building the children type, copying is required. In C, I'd use a raw pointer in this situation. How do I go about doing this in Rust? I've tried using Vec<&mut Value<T>> instead, but this leads to hassle if I want to implement the Add traits.