kc3-lang/libbsd

diff --git a/COPYING b/COPYING
index 8a99303..32a1130 100644
--- a/COPYING
+++ b/COPYING
@@ -8,7 +8,6 @@ License: BSD-3-clause
 
 Files:
  man/arc4random.3bsd
- man/tree.3bsd
 Copyright:
  Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
  All rights reserved.
@@ -348,6 +347,7 @@ License: BSD-2-clause-verbatim
 Files:
  include/bsd/sys/tree.h
  man/fparseln.3bsd
+ man/tree.3bsd
  src/fparseln.c
 Copyright:
  Copyright © 1997 Christos Zoulas.
diff --git a/man/tree.3bsd b/man/tree.3bsd
index 6800c74..9433394 100644
--- a/man/tree.3bsd
+++ b/man/tree.3bsd
@@ -1,36 +1,29 @@
-.\"	$OpenBSD: tree.3,v 1.7 2002/06/12 01:09:20 provos Exp $
-.\"
-.\" Copyright 2002 Niels Provos <provos@citi.umich.edu>
-.\" All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\"    notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\"    notice, this list of conditions and the following disclaimer in the
-.\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\"    must display the following acknowledgement:
-.\"      This product includes software developed by Niels Provos.
-.\" 4. The name of the author may not be used to endorse or promote products
-.\"    derived from this software without specific prior written permission.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-.\"
-.\" $FreeBSD$
-.\"
-.Dd December 27, 2007
+.\"	$OpenBSD: tree.3,v 1.30 2019/05/10 13:13:14 florian Exp $
+.\"/*
+.\" * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+.\" * All rights reserved.
+.\" *
+.\" * Redistribution and use in source and binary forms, with or without
+.\" * modification, are permitted provided that the following conditions
+.\" * are met:
+.\" * 1. Redistributions of source code must retain the above copyright
+.\" *    notice, this list of conditions and the following disclaimer.
+.\" * 2. Redistributions in binary form must reproduce the above copyright
+.\" *    notice, this list of conditions and the following disclaimer in the
+.\" *    documentation and/or other materials provided with the distribution.
+.\" *
+.\" * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+.\" * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+.\" * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+.\" * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+.\" * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+.\" * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\" */
+.Dd May 10 2019
 .Dt TREE 3bsd
 .Os
 .Sh NAME
@@ -70,7 +63,9 @@
 .Nm RB_RIGHT ,
 .Nm RB_PARENT ,
 .Nm RB_FOREACH ,
+.Nm RB_FOREACH_SAFE ,
 .Nm RB_FOREACH_REVERSE ,
+.Nm RB_FOREACH_REVERSE_SAFE ,
 .Nm RB_INIT ,
 .Nm RB_INSERT ,
 .Nm RB_REMOVE
@@ -84,88 +79,92 @@
 (See
 .Xr libbsd 7
 for include usage.)
-.Fn SPLAY_PROTOTYPE NAME TYPE FIELD CMP
-.Fn SPLAY_GENERATE NAME TYPE FIELD CMP
-.Fn SPLAY_ENTRY TYPE
-.Fn SPLAY_HEAD HEADNAME TYPE
+.Pp
+.Fn SPLAY_PROTOTYPE "NAME" "TYPE" "FIELD" "CMP"
+.Fn SPLAY_GENERATE "NAME" "TYPE" "FIELD" "CMP"
+.Fn SPLAY_ENTRY "TYPE"
+.Fn SPLAY_HEAD "HEADNAME" "TYPE"
 .Ft "struct TYPE *"
 .Fn SPLAY_INITIALIZER "SPLAY_HEAD *head"
 .Fn SPLAY_ROOT "SPLAY_HEAD *head"
-.Ft bool
+.Ft "int"
 .Fn SPLAY_EMPTY "SPLAY_HEAD *head"
 .Ft "struct TYPE *"
-.Fn SPLAY_NEXT NAME "SPLAY_HEAD *head" "struct TYPE *elm"
+.Fn SPLAY_NEXT "NAME" "SPLAY_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn SPLAY_MIN NAME "SPLAY_HEAD *head"
+.Fn SPLAY_MIN "NAME" "SPLAY_HEAD *head"
 .Ft "struct TYPE *"
-.Fn SPLAY_MAX NAME "SPLAY_HEAD *head"
+.Fn SPLAY_MAX "NAME" "SPLAY_HEAD *head"
 .Ft "struct TYPE *"
-.Fn SPLAY_FIND NAME "SPLAY_HEAD *head" "struct TYPE *elm"
+.Fn SPLAY_FIND "NAME" "SPLAY_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
 .Fn SPLAY_LEFT "struct TYPE *elm" "SPLAY_ENTRY NAME"
 .Ft "struct TYPE *"
 .Fn SPLAY_RIGHT "struct TYPE *elm" "SPLAY_ENTRY NAME"
-.Fn SPLAY_FOREACH VARNAME NAME "SPLAY_HEAD *head"
+.Fn SPLAY_FOREACH "VARNAME" "NAME" "SPLAY_HEAD *head"
 .Ft void
 .Fn SPLAY_INIT "SPLAY_HEAD *head"
 .Ft "struct TYPE *"
-.Fn SPLAY_INSERT NAME "SPLAY_HEAD *head" "struct TYPE *elm"
+.Fn SPLAY_INSERT "NAME" "SPLAY_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn SPLAY_REMOVE NAME "SPLAY_HEAD *head" "struct TYPE *elm"
-.Fn RB_PROTOTYPE NAME TYPE FIELD CMP
-.Fn RB_PROTOTYPE_STATIC NAME TYPE FIELD CMP
-.Fn RB_GENERATE NAME TYPE FIELD CMP
-.Fn RB_GENERATE_STATIC NAME TYPE FIELD CMP
-.Fn RB_ENTRY TYPE
-.Fn RB_HEAD HEADNAME TYPE
+.Fn SPLAY_REMOVE "NAME" "SPLAY_HEAD *head" "struct TYPE *elm"
+.Pp
+.Fn RB_PROTOTYPE "NAME" "TYPE" "FIELD" "CMP"
+.Fn RB_PROTOTYPE_STATIC "NAME" "TYPE" "FIELD" "CMP"
+.Fn RB_GENERATE "NAME" "TYPE" "FIELD" "CMP"
+.Fn RB_GENERATE_STATIC "NAME" "TYPE" "FIELD" "CMP"
+.Fn RB_ENTRY "TYPE"
+.Fn RB_HEAD "HEADNAME" "TYPE"
 .Fn RB_INITIALIZER "RB_HEAD *head"
 .Ft "struct TYPE *"
 .Fn RB_ROOT "RB_HEAD *head"
-.Ft "bool"
+.Ft "int"
 .Fn RB_EMPTY "RB_HEAD *head"
 .Ft "struct TYPE *"
-.Fn RB_NEXT NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_NEXT "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn RB_PREV NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_PREV "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn RB_MIN NAME "RB_HEAD *head"
+.Fn RB_MIN "NAME" "RB_HEAD *head"
 .Ft "struct TYPE *"
-.Fn RB_MAX NAME "RB_HEAD *head"
+.Fn RB_MAX "NAME" "RB_HEAD *head"
 .Ft "struct TYPE *"
-.Fn RB_FIND NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_FIND "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn RB_NFIND NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_NFIND "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
 .Fn RB_LEFT "struct TYPE *elm" "RB_ENTRY NAME"
 .Ft "struct TYPE *"
 .Fn RB_RIGHT "struct TYPE *elm" "RB_ENTRY NAME"
 .Ft "struct TYPE *"
 .Fn RB_PARENT "struct TYPE *elm" "RB_ENTRY NAME"
-.Fn RB_FOREACH VARNAME NAME "RB_HEAD *head"
-.Fn RB_FOREACH_REVERSE VARNAME NAME "RB_HEAD *head"
+.Fn RB_FOREACH "VARNAME" "NAME" "RB_HEAD *head"
+.Fn RB_FOREACH_SAFE "VARNAME" "NAME" "RB_HEAD *head" "TEMP_VARNAME"
+.Fn RB_FOREACH_REVERSE "VARNAME" "NAME" "RB_HEAD *head"
+.Fn RB_FOREACH_REVERSE_SAFE "VARNAME" "NAME" "RB_HEAD *head" "TEMP_VARNAME"
 .Ft void
 .Fn RB_INIT "RB_HEAD *head"
 .Ft "struct TYPE *"
-.Fn RB_INSERT NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_INSERT "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Ft "struct TYPE *"
-.Fn RB_REMOVE NAME "RB_HEAD *head" "struct TYPE *elm"
+.Fn RB_REMOVE "NAME" "RB_HEAD *head" "struct TYPE *elm"
 .Sh DESCRIPTION
 These macros define data structures for different types of trees:
 splay trees and red-black trees.
 .Pp
 In the macro definitions,
 .Fa TYPE
-is the name tag of a user defined structure that must contain a field of type
-.Vt SPLAY_ENTRY ,
+is the name tag of a user defined structure that must contain a field named
+.Fa FIELD ,
+of type
+.Li SPLAY_ENTRY
 or
-.Vt RB_ENTRY ,
-named
-.Fa ENTRYNAME .
+.Li RB_ENTRY .
 The argument
 .Fa HEADNAME
 is the name tag of a user defined structure that must be declared
 using the macros
-.Fn SPLAY_HEAD ,
+.Fn SPLAY_HEAD
 or
 .Fn RB_HEAD .
 The argument
@@ -173,46 +172,38 @@ The argument
 has to be a unique name prefix for every tree that is defined.
 .Pp
 The function prototypes are declared with
-.Fn SPLAY_PROTOTYPE ,
-.Fn RB_PROTOTYPE ,
+.Li SPLAY_PROTOTYPE ,
+.Li RB_PROTOTYPE ,
 or
-.Fn RB_PROTOTYPE_STATIC .
+.Li RB_PROTOTYPE_STATIC .
 The function bodies are generated with
-.Fn SPLAY_GENERATE ,
-.Fn RB_GENERATE ,
+.Li SPLAY_GENERATE ,
+.Li RB_GENERATE ,
 or
-.Fn RB_GENERATE_STATIC .
+.Li RB_GENERATE_STATIC .
 See the examples below for further explanation of how these macros are used.
 .Sh SPLAY TREES
 A splay tree is a self-organizing data structure.
 Every operation on the tree causes a splay to happen.
-The splay moves the requested
-node to the root of the tree and partly rebalances it.
+The splay moves the requested node to the root of the tree and partly
+rebalances it.
 .Pp
 This has the benefit that request locality causes faster lookups as
 the requested nodes move to the top of the tree.
 On the other hand, every lookup causes memory writes.
 .Pp
-The Balance Theorem bounds the total access time for
-.Ar m
-operations and
-.Ar n
-inserts on an initially empty tree as
-.Fn O "\*[lp]m + n\*[rp]lg n" .
-The
-amortized cost for a sequence of
-.Ar m
-accesses to a splay tree is
-.Fn O "lg n" .
+The Balance Theorem bounds the total access time for m operations
+and n inserts on an initially empty tree as O((m + n)lg n).
+The amortized cost for a sequence of m accesses to a splay tree is O(lg n).
 .Pp
 A splay tree is headed by a structure defined by the
 .Fn SPLAY_HEAD
 macro.
 A
+.Fa SPLAY_HEAD
 structure is declared as follows:
-.Bd -ragged -offset indent
-.Fn SPLAY_HEAD HEADNAME TYPE
-.Va head ;
+.Bd -literal -offset indent
+SPLAY_HEAD(HEADNAME, TYPE) head;
 .Ed
 .Pp
 where
@@ -251,16 +242,15 @@ macro, but should be used only once.
 Finally,
 the
 .Fa CMP
-argument is the name of a function used to compare tree nodes
+argument is the name of a function used to compare trees' nodes
 with each other.
 The function takes two arguments of type
-.Vt "struct TYPE *" .
+.Fa "struct TYPE *" .
 If the first argument is smaller than the second, the function returns a
 value smaller than zero.
 If they are equal, the function returns zero.
 Otherwise, it should return a value greater than zero.
-The compare
-function defines the order of the tree elements.
+The compare function defines the order of the tree elements.
 .Pp
 The
 .Fn SPLAY_INIT
@@ -270,11 +260,8 @@ macro initializes the tree referenced by
 The splay tree can also be initialized statically by using the
 .Fn SPLAY_INITIALIZER
 macro like this:
-.Bd -ragged -offset indent
-.Fn SPLAY_HEAD HEADNAME TYPE
-.Va head
-=
-.Fn SPLAY_INITIALIZER &head ;
+.Bd -literal -offset indent
+SPLAY_HEAD(HEADNAME, TYPE) head = SPLAY_INITIALIZER(&head);
 .Ed
 .Pp
 The
@@ -282,6 +269,11 @@ The
 macro inserts the new element
 .Fa elm
 into the tree.
+Upon success,
+.Va NULL
+is returned.
+If a matching element already exists in the tree, the insertion is
+aborted, and a pointer to the existing element is returned.
 .Pp
 The
 .Fn SPLAY_REMOVE
@@ -289,6 +281,11 @@ macro removes the element
 .Fa elm
 from the tree pointed by
 .Fa head .
+Upon success, a pointer to the removed element is returned.
+.Va NULL
+is returned if
+.Fa elm
+is not present in the tree.
 .Pp
 The
 .Fn SPLAY_FIND
@@ -296,7 +293,7 @@ macro can be used to find a particular element in the tree.
 .Bd -literal -offset indent
 struct TYPE find, *res;
 find.key = 30;
-res = SPLAY_FIND(NAME, head, &find);
+res = SPLAY_FIND(NAME, &head, &find);
 .Ed
 .Pp
 The
@@ -313,8 +310,8 @@ for (np = SPLAY_MIN(NAME, &head); np != NULL; np = SPLAY_NEXT(NAME, &head, np))
 Or, for simplicity, one can use the
 .Fn SPLAY_FOREACH
 macro:
-.Bd -ragged -offset indent
-.Fn SPLAY_FOREACH np NAME head
+.Bd -literal -offset indent
+SPLAY_FOREACH(np, NAME, &head)
 .Ed
 .Pp
 The
@@ -324,29 +321,28 @@ macro should be used to check whether a splay tree is empty.
 A red-black tree is a binary search tree with the node color as an
 extra attribute.
 It fulfills a set of conditions:
-.Bl -enum -offset indent
+.Pp
+.Bl -enum -compact -offset indent
 .It
-Every search path from the root to a leaf consists of the same number of
-black nodes.
+every search path from the root to a leaf consists of the same number of
+black nodes,
 .It
-Each red node (except for the root) has a black parent.
+each red node (except for the root) has a black parent,
 .It
-Each leaf node is black.
+each leaf node is black.
 .El
 .Pp
-Every operation on a red-black tree is bounded as
-.Fn O "lg n" .
-The maximum height of a red-black tree is
-.Fn 2lg "n + 1" .
+Every operation on a red-black tree is bounded as O(lg n).
+The maximum height of a red-black tree is 2lg (n+1).
 .Pp
 A red-black tree is headed by a structure defined by the
 .Fn RB_HEAD
 macro.
 A
+.Fa RB_HEAD
 structure is declared as follows:
-.Bd -ragged -offset indent
-.Fn RB_HEAD HEADNAME TYPE
-.Va head ;
+.Bd -literal -offset indent
+RB_HEAD(HEADNAME, TYPE) head;
 .Ed
 .Pp
 where
@@ -364,7 +360,7 @@ their prototypes need to be declared with the
 .Fn RB_PROTOTYPE
 or
 .Fn RB_PROTOTYPE_STATIC
-macro,
+macros,
 where
 .Fa NAME
 is a unique identifier for this particular tree.
@@ -381,7 +377,7 @@ The function bodies are generated with the
 .Fn RB_GENERATE
 or
 .Fn RB_GENERATE_STATIC
-macro.
+macros.
 These macros take the same arguments as the
 .Fn RB_PROTOTYPE
 and
@@ -391,16 +387,15 @@ macros, but should be used only once.
 Finally,
 the
 .Fa CMP
-argument is the name of a function used to compare tree nodes
+argument is the name of a function used to compare trees' nodes
 with each other.
 The function takes two arguments of type
-.Vt "struct TYPE *" .
+.Fa "struct TYPE *" .
 If the first argument is smaller than the second, the function returns a
 value smaller than zero.
 If they are equal, the function returns zero.
 Otherwise, it should return a value greater than zero.
-The compare
-function defines the order of the tree elements.
+The compare function defines the order of the tree elements.
 .Pp
 The
 .Fn RB_INIT
@@ -410,11 +405,8 @@ macro initializes the tree referenced by
 The red-black tree can also be initialized statically by using the
 .Fn RB_INITIALIZER
 macro like this:
-.Bd -ragged -offset indent
-.Fn RB_HEAD HEADNAME TYPE
-.Va head
-=
-.Fn RB_INITIALIZER &head ;
+.Bd -literal -offset indent
+RB_HEAD(HEADNAME, TYPE) head = RB_INITIALIZER(&head);
 .Ed
 .Pp
 The
@@ -422,6 +414,11 @@ The
 macro inserts the new element
 .Fa elm
 into the tree.
+Upon success,
+.Va NULL
+is returned.
+If a matching element already exists in the tree, the insertion is
+aborted, and a pointer to the existing element is returned.
 .Pp
 The
 .Fn RB_REMOVE
@@ -429,16 +426,24 @@ macro removes the element
 .Fa elm
 from the tree pointed by
 .Fa head .
+.Fn RB_REMOVE
+returns
+.Fa elm .
 .Pp
 The
 .Fn RB_FIND
 and
 .Fn RB_NFIND
 macros can be used to find a particular element in the tree.
+.Fn RB_FIND
+finds the node with the same key as
+.Fa elm .
+.Fn RB_NFIND
+finds the first node greater than or equal to the search key.
 .Bd -literal -offset indent
 struct TYPE find, *res;
 find.key = 30;
-res = RB_FIND(NAME, head, &find);
+res = RB_FIND(NAME, &head, &find);
 .Ed
 .Pp
 The
@@ -449,26 +454,119 @@ The
 and
 .Fn RB_PREV
 macros can be used to traverse the tree:
-.Pp
-.Dl "for (np = RB_MIN(NAME, &head); np != NULL; np = RB_NEXT(NAME, &head, np))"
+.Bd -literal -offset indent
+for (np = RB_MIN(NAME, &head); np != NULL; np = RB_NEXT(NAME, &head, np))
+.Ed
 .Pp
 Or, for simplicity, one can use the
 .Fn RB_FOREACH
 or
 .Fn RB_FOREACH_REVERSE
-macro:
-.Bd -ragged -offset indent
-.Fn RB_FOREACH np NAME head
+macros:
+.Bd -literal -offset indent
+RB_FOREACH(np, NAME, &head)
 .Ed
 .Pp
+The macros
+.Fn RB_FOREACH_SAFE
+and
+.Fn RB_FOREACH_REVERSE_SAFE
+traverse the tree referenced by head
+in a forward or reverse direction respectively,
+assigning each element in turn to np.
+However, unlike their unsafe counterparts,
+they permit both the removal of np
+as well as freeing it from within the loop safely
+without interfering with the traversal.
+.Pp
 The
 .Fn RB_EMPTY
 macro should be used to check whether a red-black tree is empty.
+.Sh EXAMPLES
+The following example demonstrates how to declare a red-black tree
+holding integers.
+Values are inserted into it and the contents of the tree are printed
+in order.
+Lastly, the internal structure of the tree is printed.
+.Bd -literal -offset 3n
+#include <sys/tree.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+struct node {
+	RB_ENTRY(node) entry;
+	int i;
+};
+
+int	intcmp(struct node *, struct node *);
+void	print_tree(struct node *);
+
+int
+intcmp(struct node *e1, struct node *e2)
+{
+	return (e1->i < e2->i ? -1 : e1->i > e2->i);
+}
+
+RB_HEAD(inttree, node) head = RB_INITIALIZER(&head);
+RB_PROTOTYPE(inttree, node, entry, intcmp)
+RB_GENERATE(inttree, node, entry, intcmp)
+
+int testdata[] = {
+	20, 16, 17, 13, 3, 6, 1, 8, 2, 4, 10, 19, 5, 9, 12, 15, 18,
+	7, 11, 14
+};
+
+void
+print_tree(struct node *n)
+{
+	struct node *left, *right;
+
+	if (n == NULL) {
+		printf("nil");
+		return;
+	}
+	left = RB_LEFT(n, entry);
+	right = RB_RIGHT(n, entry);
+	if (left == NULL && right == NULL)
+		printf("%d", n->i);
+	else {
+		printf("%d(", n->i);
+		print_tree(left);
+		printf(",");
+		print_tree(right);
+		printf(")");
+	}
+}
+
+int
+main(void)
+{
+	int i;
+	struct node *n;
+
+	for (i = 0; i < sizeof(testdata) / sizeof(testdata[0]); i++) {
+		if ((n = malloc(sizeof(struct node))) == NULL)
+			err(1, NULL);
+		n->i = testdata[i];
+		RB_INSERT(inttree, &head, n);
+	}
+
+	RB_FOREACH(n, inttree, &head) {
+		printf("%d\en", n->i);
+	}
+	print_tree(RB_ROOT(&head));
+	printf("\en");
+	return (0);
+}
+.Ed
+.Sh SEE ALSO
+.Xr queue 3bsd
 .Sh NOTES
 Trying to free a tree in the following way is a common error:
 .Bd -literal -offset indent
-SPLAY_FOREACH(var, NAME, head) {
-	SPLAY_REMOVE(NAME, head, var);
+SPLAY_FOREACH(var, NAME, &head) {
+	SPLAY_REMOVE(NAME, &head, var);
 	free(var);
 }
 free(head);
@@ -476,36 +574,17 @@ free(head);
 .Pp
 Since
 .Va var
-is freed, the
+is free'd, the
 .Fn FOREACH
 macro refers to a pointer that may have been reallocated already.
 Proper code needs a second variable.
 .Bd -literal -offset indent
-for (var = SPLAY_MIN(NAME, head); var != NULL; var = nxt) {
-	nxt = SPLAY_NEXT(NAME, head, var);
-	SPLAY_REMOVE(NAME, head, var);
+for (var = SPLAY_MIN(NAME, &head); var != NULL; var = nxt) {
+	nxt = SPLAY_NEXT(NAME, &head, var);
+	SPLAY_REMOVE(NAME, &head, var);
 	free(var);
 }
 .Ed
-.Pp
-Both
-.Fn RB_INSERT
-and
-.Fn SPLAY_INSERT
-return
-.Dv NULL
-if the element was inserted in the tree successfully, otherwise they
-return a pointer to the element with the colliding key.
-.Pp
-Accordingly,
-.Fn RB_REMOVE
-and
-.Fn SPLAY_REMOVE
-return the pointer to the removed element otherwise they return
-.Dv NULL
-to indicate an error.
-.Sh SEE ALSO
-.Xr queue 3bsd
 .Sh AUTHORS
 The author of the tree macros is
 .An Niels Provos .