1/* Internal header containing implementation of wcwidth() function.
2 Copyright (C) 1996-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <wchar.h>
21#include <wctype.h>
22#include "../wctype/wchar-lookup.h"
23#include "../locale/localeinfo.h"
24
25/* Table containing width information. */
26extern const char *__ctype32_width attribute_hidden;
27
28static __inline int
29internal_wcwidth (wchar_t wc)
30{
31 unsigned char res;
32
33 /* The tables have been prepared in such a way that
34 1. wc == L'\0' yields res = 0,
35 2. !iswprint (wc) implies res = '\xff'. */
36 res = wcwidth_table_lookup (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_WIDTH), wc);
37
38 return res == (unsigned char) '\xff' ? -1 : (int) res;
39}
40