+/*----- doubly linked lists -----*/
+
+#define ISNODE(T) struct { T *succ, *pred; } node /* must be at start */
+#define DEFLIST(T) typedef struct { T *head, *tail, *tp; int count; } T##List
+
+#define NODE(n) (assert((void*)&(n)->node == &(n)), \
+ (struct node*)&(n)->node)
+
+#define LIST_CHECKCANHAVENODE(l,n) \
+ ((void)((n) == ((l).head))) /* just for the type check */
+
+#define LIST_ADDSOMEHOW(l,n,list_addsomehow) \
+ ( LIST_CHECKCANHAVENODE(l,n), \
+ list_addsomehow((struct list*)&(l), NODE((n))), \
+ (void)(l).count++ \
+ )
+
+#define LIST_REMSOMEHOW(l,list_remsomehow) \
+ ( (typeof((l).head)) \
+ ( (l).count \
+ ? ( (l).count--, \
+ list_remsomehow((struct list*)&(l)) ) \
+ : 0 \
+ ) \
+ )
+
+
+#define LIST_ADDHEAD(l,n) LIST_ADDSOMEHOW((l),(n),list_addhead)
+#define LIST_ADDTAIL(l,n) LIST_ADDSOMEHOW((l),(n),list_addtail)
+#define LIST_REMHEAD(l) LIST_REMSOMEHOW((l),list_remhead)
+#define LIST_REMTAIL(l) LIST_REMSOMEHOW((l),list_remtail)
+
+#define LIST_REMOVE(l,n) \
+ ( LIST_CHECKCANHAVENODE(l,n), \
+ list_remove(NODE((n))), \
+ (void)(l).count-- \
+ )
+
+#define LIST_INSERT(l,n,pred) \
+ ( LIST_CHECKCANHAVENODE(l,n), \
+ LIST_CHECKCANHAVENODE(l,pred), \
+ list_insert((struct list*)&(l), NODE((n)), NODE((pred))), \
+ (void)(l).count++ \
+ )
+
+/*----- type predeclarations -----*/
+