1 /* wchar_t type related definitions. 2 Copyright (C) 2000-2022 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 #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