How to use self in a for loop in Rust

I am pretty new to Rust and just starting doing a little "compiler" and after having used the pointer system I encountered a problem with the move system:

for constraint in constraints {
    self.get_or_create_node(constraint.0.to_string(), 0, &constraint.1);
}

This system uses a recursive function which create a tree for a path that I call a constraint but I use Strings to name my nodes so my struct cannot be copied. So the self in the loop throws a move error, how could I prevent it?

Edit here’s the get_or_create_node method:

fn get_or_create_node(mut self, node_name: String, current_level: i32, value: &String) {
    let path: Vec<&str> = node_name.split('.').collect();
    if current_level + 1 == path.len().try_into().unwrap() {
        self.value = value.to_string();
    } else {
        for node in self.nodes {
            if path.get(current_level as usize).expect("Path in if statement is false") == &node.value.as_str() {
                node.get_or_create_node(node_name.clone(), current_level + 1, value);
            }
        }
    }
}

>Solution :

As I mentioned in the comments, you’re taking self by value (hence taking ownership) when you really don’t need it. Take a &mut self argument instead.

fn get_or_create_node(&mut self, node_name: String, current_level: i32, value: &String)