13   list_node_t* head;  member
72   return list->head->data;  in list_front()
111   node->next = list->head;  in list_prepend()
113   list->head = node;  in list_prepend()
114   if (list->tail == NULL) list->tail = list->head;  in list_prepend()
128     list->head = node;  in list_append()
144   if (list->head->data == data) {  in list_remove()
145     list_node_t* next = list_free_node_(list, list->head);  in list_remove()
146     if (list->tail == list->head) list->tail = next;  in list_remove()
147     list->head = next;  in list_remove()
151   for (list_node_t *prev = list->head, *node = list->head->next; node;  in list_remove()
164   for (list_node_t* node = list->head; node;)  in list_clear()
166   list->head = NULL;  in list_clear()
176   for (list_node_t* node = list->head; node;) {  in list_foreach()
186   return list->head;  in list_begin()