1/* Internal header containing implementation of wcwidth() function.
2 Copyright (C) 1996-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <wchar.h>
20#include <wctype.h>
21#include "../wctype/wchar-lookup.h"
22#include "../locale/localeinfo.h"
23
24/* Table containing width information. */
25extern const char *__ctype32_width attribute_hidden;
26
27static __inline int
28internal_wcwidth (wchar_t wc)
29{
30 unsigned char res;
31
32 /* The tables have been prepared in such a way that
33 1. wc == L'\0' yields res = 0,
34 2. !iswprint (wc) implies res = '\xff'. */
35 res = wcwidth_table_lookup (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_WIDTH), wc);
36
37 return res == (unsigned char) '\xff' ? -1 : (int) res;
38}
39