+#define RB_MAX(name, x) name##_RB_MINMAX(x, RB_INF)
+
+#define RB_FOREACH(x, name, head) \
+ for ((x) = RB_MIN(name, head); \
+ (x) != NULL; \
+ (x) = name##_RB_NEXT(x))
+
+#define RB_FOREACH_FROM(x, name, y) \
+ for ((x) = (y); \
+ ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
+ (x) = (y))
+
+#define RB_FOREACH_SAFE(x, name, head, y) \
+ for ((x) = RB_MIN(name, head); \
+ ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
+ (x) = (y))
+
+#define RB_FOREACH_REVERSE(x, name, head) \
+ for ((x) = RB_MAX(name, head); \
+ (x) != NULL; \
+ (x) = name##_RB_PREV(x))
+
+#define RB_FOREACH_REVERSE_FROM(x, name, y) \
+ for ((x) = (y); \
+ ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
+ (x) = (y))
+
+#define RB_FOREACH_REVERSE_SAFE(x, name, head, y) \
+ for ((x) = RB_MAX(name, head); \
+ ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
+ (x) = (y))
+
+#endif /* _SYS_TREE_H_ */