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/* Copyright (C) 2001-2003, 2006-2017 Free Software Foundation, Inc.
Written by Bruno Haible <haible@clisp.cons.org>, 2001.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>. */
#ifndef _UNISTRING_STDBOOL_H
#define _UNISTRING_STDBOOL_H
/* ISO C 99 <stdbool.h> for platforms that lack it. */
/* Usage suggestions:
Programs that use <stdbool.h> should be aware of some limitations
and standards compliance issues.
Standards compliance:
- <stdbool.h> must be #included before 'bool', 'false', 'true'
can be used.
- You cannot assume that sizeof (bool) == 1.
- Programs should not undefine the macros bool, true, and false,
as C99 lists that as an "obsolescent feature".
Limitations of this substitute, when used in a C89 environment:
- <stdbool.h> must be #included before the '_Bool' type can be used.
- You cannot assume that _Bool is a typedef; it might be a macro.
- Bit-fields of type 'bool' are not supported. Portable code
should use 'unsigned int foo : 1;' rather than 'bool foo : 1;'.
- In C99, casts and automatic conversions to '_Bool' or 'bool' are
performed in such a way that every nonzero value gets converted
to 'true', and zero gets converted to 'false'. This doesn't work
with this substitute. With this substitute, only the values 0 and 1
give the expected result when converted to _Bool' or 'bool'.
- C99 allows the use of (_Bool)0.0 in constant expressions, but
this substitute cannot always provide this property.
Also, it is suggested that programs use 'bool' rather than '_Bool';
this isn't required, but 'bool' is more common. */
/* 7.16. Boolean type and values */
#ifdef __cplusplus
/* Assume the compiler has 'bool' and '_Bool'. */
#else
/* <stdbool.h> is known to exist and work with the following compilers:
- GNU C 3.0 or newer, on any platform,
- Intel C,
- MSVC 12 (Visual Studio 2013) or newer,
- Sun C, on Solaris, if _STDC_C99 is defined,
- AIX xlc, if _ANSI_C_SOURCE is defined,
- HP C, on HP-UX 11.31 or newer.
It is know not to work with:
- Sun C, on Solaris, if __C99FEATURES__ is defined but _STDC_C99 is not,
- MIPSpro C 7.30, on IRIX. */
# if (__GNUC__ >= 3) \
|| defined __INTEL_COMPILER \
|| (_MSC_VER >= 1800) \
|| (defined __SUNPRO_C && defined _STDC_C99) \
|| (defined _AIX && !defined __GNUC__ && defined _ANSI_C_SOURCE) \
|| defined __HP_cc
/* Assume the compiler has <stdbool.h>. */
# include <stdbool.h>
# else
/* Need to define _Bool ourselves. As 'signed char' or as an enum type?
Use of a typedef, with SunPRO C, leads to a stupid
"warning: _Bool is a keyword in ISO C99".
Use of an enum type, with IRIX cc, leads to a stupid
"warning(1185): enumerated type mixed with another type".
Even the existence of an enum type, without a typedef,
"Invalid enumerator. (badenum)" with HP-UX cc on Tru64.
The only benefit of the enum, debuggability, is not important
with these compilers. So use 'signed char' and no enum. */
# define _Bool signed char
# define bool _Bool
# endif
#endif
/* The other macros must be usable in preprocessor directives. */
#ifdef __cplusplus
# define false false
# define true true
#else
# undef false
# define false 0
# undef true
# define true 1
#endif
#define __bool_true_false_are_defined 1
#endif /* _UNISTRING_STDBOOL_H */
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