(list)~NULL -> nullptr

C++ styling.

list.cpp

@@ -15,7 +15,7 @@ struct List
 
   ~List()
   {
-    if (next == NULL)
+    if (next == nullptr)
       return;
     delete next;
   }
@@ -25,31 +25,31 @@ template <typename T>
 List<T> *append(List<T> *lst, T value)
 {
   List<T> *node;
-  if (lst == NULL)
+  if (lst == nullptr)
   {
     node        = new List<T>;
     node->value = value;
-    node->next  = NULL;
+    node->next  = nullptr;
     return node;
   }
 
-  for (node = lst; node->next != NULL; node = node->next)
+  for (node = lst; node->next != nullptr; node = node->next)
     continue;
 
   node->next        = new List<T>;
   node->next->value = value;
-  node->next->next  = NULL;
+  node->next->next  = nullptr;
   return lst;
 }
 
 /** Reverse a list
  */
 template <typename T>
-List<T> *reverse(List<T> *lst, List<T> *prev = NULL)
+List<T> *reverse(List<T> *lst, List<T> *prev = nullptr)
 {
   auto next = lst->next;
   lst->next = prev;
-  if (next == NULL)
+  if (next == nullptr)
     return lst;
   return reverse(next, lst);
 }
@@ -65,7 +65,7 @@ std::ostream& operator<<(std::ostream& ostream, const List<T> *lst)
 
 int main(void)
 {
-  auto lst = append<int>(NULL, 1);
+  auto lst = append<int>(nullptr, 1);
   for (int i = 2; i < 10; ++i)
     lst = append(lst, i);
   std::cout << lst << std::endl;