Function calc_size

src/tree/binary/bst.rs:278–282

Returns the number of key-value pairs

(x: Option<NonNull<Node<K, V>>>)

/// Returns the number of key-value pairs
pub fn calc_size<K, V>(x: Option<NonNull<Node<K, V>>>) -> usize {
    x.map_or(0, |x| unsafe {
        1 + calc_size(x.as_ref().left) + calc_size(x.as_ref().right)
    })
}

/// add the keys between lo and hi in the subtree rooted at x
/// to the queue