try to implement join

src/utility/list.rs

@@ -9,11 +9,10 @@ use std::ptr;
 /// These methods wrap unsafe instructions because it doesn't respect borrow rules per example
 /// but everything has been tested with miri to assure there's no Undefined Behaviour (use-after-free, double free, etc.)
 /// or memory leak
-#[derive(PartialEq)]
-#[derive(Clone)]
+#[derive(PartialEq, Clone, Debug)]
 pub struct List<T: PartialEq> {
     head: Link<T>,
-    tail: *mut Node<T>,
+    tail: Link<T>,
 }
 
 type Link<T> = *mut Node<T>;