1/* @title: Singly linked list */
2#define sll_add(q, thing) \
3 if (!q->head) { \
4 q->head = thing; \
5 q->tail = thing; \
6 } else { \
7 thing->next = NULL; \
8 q->tail->next = thing; \
9 q->tail = thing; \
10 }
11