I am making a singly-linked list. When you delete a node, the previous node's next
should become the current node's next
(prev->next = curr->next;
) and return data
if the index matches. Otherwise, the previous node becomes the current node and the current node becomes the next node (prev = curr; curr = curr->next;
):
struct Node<T> {
data: T,
next: Option<Box<Node<T>>>,
}
struct LinkedList<T> {
head: Option<Box<Node<T>>>,
}
impl LinkedList<i64> {
fn remove(&mut self, index: usize) -> i64 {
if self.len() == 0 {
panic!("LinkedList is empty!");
}
if index >= self.len() {
panic!("Index out of range: {}", index);
}
let mut count = 0;
let mut head = &self.head;
let mut prev: Option<Box<Node<i64>>> = None;
loop {
match head {
None => {
panic!("LinkedList is empty!");
}
Some(c) => {
// I have borrowed here
if count == index {
match prev {
Some(ref p) => {
p.next = c.next;
// ^ cannot move out of borrowed content
}
_ => continue,
}
return c.data;
} else {
count += 1;
head = &c.next;
prev = Some(*c);
// ^^ cannot move out of borrowed content
}
}
}
}
}
fn len(&self) -> usize {
unimplemented!()
}
}
fn main() {}
error[E0594]: cannot assign to field `p.next` of immutable binding
--> src/main.rs:31:33
|
30 | Some(ref p) => {
| ----- consider changing this to `ref mut p`
31 | p.next = c.next;
| ^^^^^^^^^^^^^^^ cannot mutably borrow field of immutable binding
error[E0507]: cannot move out of borrowed content
--> src/main.rs:31:42
|
31 | p.next = c.next;
| ^ cannot move out of borrowed content
error[E0507]: cannot move out of borrowed content
--> src/main.rs:40:37
|
40 | prev = Some(*c);
| ^^ cannot move out of borrowed content
Playground Link for more info.
How can I do this? Is my approach wrong?