使用?运算符来对Option进行解包

rust/src/design/q0297.rs

@@ -64,7 +64,7 @@ impl Codec {
     }
 
     fn deserialize_sub(&self, map: &mut Map<Chunks<u8>, fn(&[u8]) -> i32>) -> Option<Rc<RefCell<TreeNode>>> {
-        match map.next().unwrap() {
+        match map.next()? {
             i32::MAX => None,
             val => Some(Rc::new(RefCell::new(TreeNode { val, left: self.deserialize_sub(map), right: self.deserialize_sub(map) })))
         }

rust/src/implements/q0206.rs

@@ -1,7 +1,5 @@
 use crate::Solution;
 use crate::structure::ListNode;
-use std::option::Option::Some;
-use std::ptr::null;
 
 
 impl Solution {
@@ -38,7 +36,7 @@ impl Solution {
         let mut prev = None;
         let mut curr = head;
         while curr.is_some() {
-            let mut node = curr.take().unwrap();
+            let mut node = curr.take()?;
             curr = node.next.take();
             node.next = prev;
             prev = Some(node);