c32tolower: New module.

* lib/uchar.in.h (c32tolower): New declaration.
* lib/c32tolower.c: New file.
* lib/c32to-impl.h: New file, based on lib/c32is-impl.h.
* modules/c32tolower: New file.
* m4/uchar_h.m4 (gl_UCHAR_H_REQUIRE_DEFAULTS): Initialize
GNULIB_C32TOLOWER.
* modules/uchar (Makefile.am): Substitute GNULIB_C32TOLOWER.

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/c32tolower.c b/lib/c32tolower.c
new file mode 100644
index 0000000000..447016214e
--- /dev/null
+++ b/lib/c32tolower.c
@@ -0,0 +1,34 @@
+/* Map a 32-bit wide character to lowercase.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is free software.
+   It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
+   You can redistribute it and/or modify it under either
+     - the terms of the GNU Lesser General Public License as published
+       by the Free Software Foundation, either version 3, or (at your
+       option) any later version, or
+     - 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, or
+     - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
+
+   This file 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 and the GNU General Public License
+   for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License and of the GNU General Public License along with this
+   program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#define IN_C32TOLOWER
+/* Specification.  */
+#include <uchar.h>
+
+#define FUNC c32tolower
+#define WCHAR_FUNC towlower
+#define UCS_FUNC uc_tolower
+#include "c32to-impl.h"