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Diffstat (limited to 'gl/stdbool_.h')
| -rw-r--r-- | gl/stdbool_.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/gl/stdbool_.h b/gl/stdbool_.h new file mode 100644 index 00000000..efa80ba9 --- /dev/null +++ b/gl/stdbool_.h | |||
| @@ -0,0 +1,115 @@ | |||
| 1 | /* Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc. | ||
| 2 | Written by Bruno Haible <haible@clisp.cons.org>, 2001. | ||
| 3 | |||
| 4 | This program is free software; you can redistribute it and/or modify | ||
| 5 | it under the terms of the GNU General Public License as published by | ||
| 6 | the Free Software Foundation; either version 2, or (at your option) | ||
| 7 | any later version. | ||
| 8 | |||
| 9 | This program is distributed in the hope that it will be useful, | ||
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 12 | GNU General Public License for more details. | ||
| 13 | |||
| 14 | You should have received a copy of the GNU General Public License | ||
| 15 | along with this program; if not, write to the Free Software Foundation, | ||
| 16 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | ||
| 17 | |||
| 18 | #ifndef _STDBOOL_H | ||
| 19 | #define _STDBOOL_H | ||
| 20 | |||
| 21 | /* ISO C 99 <stdbool.h> for platforms that lack it. */ | ||
| 22 | |||
| 23 | /* Usage suggestions: | ||
| 24 | |||
| 25 | Programs that use <stdbool.h> should be aware of some limitations | ||
| 26 | and standards compliance issues. | ||
| 27 | |||
| 28 | Standards compliance: | ||
| 29 | |||
| 30 | - <stdbool.h> must be #included before 'bool', 'false', 'true' | ||
| 31 | can be used. | ||
| 32 | |||
| 33 | - You cannot assume that sizeof (bool) == 1. | ||
| 34 | |||
| 35 | - Programs should not undefine the macros bool, true, and false, | ||
| 36 | as C99 lists that as an "obsolescent feature". | ||
| 37 | |||
| 38 | Limitations of this substitute, when used in a C89 environment: | ||
| 39 | |||
| 40 | - <stdbool.h> must be #included before the '_Bool' type can be used. | ||
| 41 | |||
| 42 | - You cannot assume that _Bool is a typedef; it might be a macro. | ||
| 43 | |||
| 44 | - In C99, casts and automatic conversions to '_Bool' or 'bool' are | ||
| 45 | performed in such a way that every nonzero value gets converted | ||
| 46 | to 'true', and zero gets converted to 'false'. This doesn't work | ||
| 47 | with this substitute. With this substitute, only the values 0 and 1 | ||
| 48 | give the expected result when converted to _Bool' or 'bool'. | ||
| 49 | |||
| 50 | Also, it is suggested that programs use 'bool' rather than '_Bool'; | ||
| 51 | this isn't required, but 'bool' is more common. */ | ||
| 52 | |||
| 53 | |||
| 54 | /* 7.16. Boolean type and values */ | ||
| 55 | |||
| 56 | /* BeOS <sys/socket.h> already #defines false 0, true 1. We use the same | ||
| 57 | definitions below, but temporarily we have to #undef them. */ | ||
| 58 | #ifdef __BEOS__ | ||
| 59 | # include <OS.h> /* defines bool but not _Bool */ | ||
| 60 | # undef false | ||
| 61 | # undef true | ||
| 62 | #endif | ||
| 63 | |||
| 64 | /* For the sake of symbolic names in gdb, we define true and false as | ||
| 65 | enum constants, not only as macros. | ||
| 66 | It is tempting to write | ||
| 67 | typedef enum { false = 0, true = 1 } _Bool; | ||
| 68 | so that gdb prints values of type 'bool' symbolically. But if we do | ||
| 69 | this, values of type '_Bool' may promote to 'int' or 'unsigned int' | ||
| 70 | (see ISO C 99 6.7.2.2.(4)); however, '_Bool' must promote to 'int' | ||
| 71 | (see ISO C 99 6.3.1.1.(2)). So we add a negative value to the | ||
| 72 | enum; this ensures that '_Bool' promotes to 'int'. */ | ||
| 73 | #if defined __cplusplus || defined __BEOS__ | ||
| 74 | /* A compiler known to have 'bool'. */ | ||
| 75 | /* If the compiler already has both 'bool' and '_Bool', we can assume they | ||
| 76 | are the same types. */ | ||
| 77 | # if !@HAVE__BOOL@ | ||
| 78 | typedef bool _Bool; | ||
| 79 | # endif | ||
| 80 | #else | ||
| 81 | # if !defined __GNUC__ | ||
| 82 | /* If @HAVE__BOOL@: | ||
| 83 | Some HP-UX cc and AIX IBM C compiler versions have compiler bugs when | ||
| 84 | the built-in _Bool type is used. See | ||
| 85 | http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html | ||
| 86 | http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html | ||
| 87 | http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html | ||
| 88 | Similar bugs are likely with other compilers as well; this file | ||
| 89 | wouldn't be used if <stdbool.h> was working. | ||
| 90 | So we override the _Bool type. | ||
| 91 | If !@HAVE__BOOL@: | ||
| 92 | Need to define _Bool ourselves. As 'signed char' or as an enum type? | ||
| 93 | Use of a typedef, with SunPRO C, leads to a stupid | ||
| 94 | "warning: _Bool is a keyword in ISO C99". | ||
| 95 | Use of an enum type, with IRIX cc, leads to a stupid | ||
| 96 | "warning(1185): enumerated type mixed with another type". | ||
| 97 | The only benefit of the enum type, debuggability, is not important | ||
| 98 | with these compilers. So use 'signed char' and no typedef. */ | ||
| 99 | # define _Bool signed char | ||
| 100 | enum { false = 0, true = 1 }; | ||
| 101 | # else | ||
| 102 | /* With this compiler, trust the _Bool type if the compiler has it. */ | ||
| 103 | # if !@HAVE__BOOL@ | ||
| 104 | typedef enum { _Bool_must_promote_to_int = -1, false = 0, true = 1 } _Bool; | ||
| 105 | # endif | ||
| 106 | # endif | ||
| 107 | #endif | ||
| 108 | #define bool _Bool | ||
| 109 | |||
| 110 | /* The other macros must be usable in preprocessor directives. */ | ||
| 111 | #define false 0 | ||
| 112 | #define true 1 | ||
| 113 | #define __bool_true_false_are_defined 1 | ||
| 114 | |||
| 115 | #endif /* _STDBOOL_H */ | ||
