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+/* Locale dependent string transformation for comparison.
+   Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Lesser General Public License as published
+   by the Free Software Foundation; either version 3 of the License, 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef ASTRXFRM_H
+#define ASTRXFRM_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Variant of strxfrm() with a calling convention that reduces the number
+   of strxfrm calls.  */
+
+/* Transform the string starting at S to a string, in such a way that
+   comparing S1 and S2 with strcoll() is equivalent to comparing astrxfrm(S1)
+   and astrxfrm(S2) with strcmp().
+   The result of this function depends on the LC_COLLATE category of the
+   current locale.
+   If successful: If resultbuf is not NULL and the result fits into *lengthp
+   bytes, it is put in resultbuf, and resultbuf is returned.  Otherwise, a
+   freshly allocated string is returned.  In both cases, *lengthp is set to the
+   length of the returned string.
+   Upon failure, return NULL, with errno set.  */
+extern char * astrxfrm (const char *s, char *resultbuf, size_t *lengthp);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ASTRXFRM_H */