--- /dev/null
+/*
+ * Copyright (c) 2004, 2007, 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _SUDO_REDBLACK_H
+#define _SUDO_REDBLACK_H
+
+enum rbcolor {
+ red,
+ black
+};
+
+enum rbtraversal {
+ preorder,
+ inorder,
+ postorder
+};
+
+struct rbnode {
+ struct rbnode *left, *right, *parent;
+ void *data;
+ enum rbcolor color;
+};
+
+struct rbtree {
+ int (*compar)(const void *, const void *);
+ struct rbnode root;
+ struct rbnode nil;
+};
+
+#define rbapply(t, f, c, o) rbapply_node((t), (t)->root.left, (f), (c), (o))
+#define rbisempty(t) ((t)->root.left == &(t)->nil && (t)->root.right == &(t)->nil)
+#define rbfirst(t) ((t)->root.left)
+#define rbroot(t) (&(t)->root)
+#define rbnil(t) (&(t)->nil)
+
+void *rbdelete(struct rbtree *, struct rbnode *);
+int rbapply_node(struct rbtree *, struct rbnode *,
+ int (*)(void *, void *), void *, enum rbtraversal);
+struct rbnode *rbfind(struct rbtree *, void *);
+struct rbnode *rbinsert(struct rbtree *, void *);
+struct rbtree *rbcreate(int (*)(const void *, const void *));
+void rbdestroy(struct rbtree *, void (*)(void *));
+
+#endif /* _SUDO_REDBLACK_H */