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+++ b/lib/gl_rbtree_oset.h
@@ -0,0 +1,35 @@
+/* Ordered set data type implemented by a binary tree.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _GL_RBTREE_OSET_H
+#define _GL_RBTREE_OSET_H
+
+#include "gl_oset.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const struct gl_oset_implementation gl_rbtree_oset_implementation;
+#define GL_RBTREE_OSET &gl_rbtree_oset_implementation
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_RBTREE_OSET_H */