LinkedList: Make sure the contained type inherits from DoublyLinkedListNode<T>

luna/include/luna/LinkedList.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <luna/Option.h>
+#include <luna/TypeTraits.h>
 
 template <typename T> inline Option<T*> nonnull_or_error(T* ptr)
 {
@@ -57,6 +58,8 @@ template <typename T> class DoublyLinkedList
 {
     using Node = DoublyLinkedListNode<T>;
 
+    static_assert(IsBaseOf<DoublyLinkedListNode<T>, T>);
+
   public:
     void append(T* ptr)
     {