box smart pointer

exercises/19_smart_pointers/box1.rs

@@ -18,14 +18,16 @@
 //
 // Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(PartialEq, Debug)]
+
 pub enum List {
-    Cons(i32, List),
+    Cons(i32, Box<List>),
     Nil,
 }
 
+use crate::List::{Cons, Nil};
+
 fn main() {
     println!("This is an empty cons list: {:?}", create_empty_list());
     println!(
@@ -35,11 +37,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+   Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))))
 }
 
 #[cfg(test)]