fn iterative(root: &RefCell<TreeNode>, l: i32, r: i32) -> i32 {
    let mut stack = Vec::new();
    stack.push(root.borrow());
    let mut sum: i32 = 0;
    while let Some(node) = stack.pop() {
        if l <= node.val && node.val <= r {
            sum += node.val;
        }
        if node.val < l {
            match &node.left {
                Some(left) => {
                    let tmp: &RefCell<TreeNode> = left.borrow();
                    stack.push(tmp.borrow());
                }
                None => {}
            }
            //node.borrow().left.map(|left| stack.push(left));
        }
        if node.val > r {
            match &node.right {
                Some(right) => {
                    let tmp: &RefCell<TreeNode> = right.borrow();
                    stack.push(tmp.borrow())
                }
                None => {}
            }
            //node.borrow().right.map(|right| stack.push(&right));
        }
    }
    return sum;
}

error[E0597]: `node` does not live long enough
  --> src/main.rs:76:24
   |
76 |                 match &node.right {
   |                        ^^^^ borrowed value does not live long enough
...
85 |         }
   |         - `node` dropped here while still borrowed
86 |         return sum;
87 |     }
   |     - borrow might be used here, when `stack` is dropped and runs the `Drop` code for type `std::vec::Vec`
   |
   = note: values in a scope are dropped in the opposite order they are defined

error: aborting due to previous error

pub struct TreeNode {
    pub val: i32,
    pub left: Option<Rc<RefCell<TreeNode>>>,
    pub right: Option<Rc<RefCell<TreeNode>>>,
}

error[E0507]: cannot move out of dereference of `std::cell::Ref<'_, TreeNode>`
  --> src/main.rs:66:23
   |
66 |                 match node.left {
   |                       ^^^^^^^^^ help: consider borrowing here: `&node.left`
67 |                     Some(left) => {
   |                          ----
   |                          |
   |                          data moved here
   |                          move occurs because `left` has type `std::rc::Rc<std::cell::RefCell<TreeNode>>`, which does not implement the `Copy` trait

error[E0597]: `left` does not live long enough

[global.databases]
sqlite_logs = { url = "/path/to/database.sqlite" }

echo DATABASE_URL=postgres://username:password@localhost/diesel_demo > .env