1  /* wchar_t type related definitions.
       2     Copyright (C) 2000-2023 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  #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 */