1 | /* wchar_t type related definitions. |
2 | Copyright (C) 2000-2018 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 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #ifndef _BITS_WCHAR_H |
20 | #define _BITS_WCHAR_H 1 |
21 | |
22 | /* The fallback definitions, for when __WCHAR_MAX__ or __WCHAR_MIN__ |
23 | are not defined, give the right value and type as long as both int |
24 | and wchar_t are 32-bit types. Adding L'\0' to a constant value |
25 | ensures that the type is correct; it is necessary to use (L'\0' + |
26 | 0) rather than just L'\0' so that the type in C++ is the promoted |
27 | version of wchar_t rather than the distinct wchar_t type itself. |
28 | Because wchar_t in preprocessor #if expressions is treated as |
29 | intmax_t or uintmax_t, the expression (L'\0' - 1) would have the |
30 | wrong value for WCHAR_MAX in such expressions and so cannot be used |
31 | to define __WCHAR_MAX in the unsigned case. */ |
32 | |
33 | #ifdef __WCHAR_MAX__ |
34 | # define __WCHAR_MAX __WCHAR_MAX__ |
35 | #elif L'\0' - 1 > 0 |
36 | # define __WCHAR_MAX (0xffffffffu + L'\0') |
37 | #else |
38 | # define __WCHAR_MAX (0x7fffffff + L'\0') |
39 | #endif |
40 | |
41 | #ifdef __WCHAR_MIN__ |
42 | # define __WCHAR_MIN __WCHAR_MIN__ |
43 | #elif L'\0' - 1 > 0 |
44 | # define __WCHAR_MIN (L'\0' + 0) |
45 | #else |
46 | # define __WCHAR_MIN (-__WCHAR_MAX - 1) |
47 | #endif |
48 | |
49 | #endif /* bits/wchar.h */ |
50 | |