diff options
author | Gary V. Vaughan <gary@gnu.org> | 2003-09-04 14:02:05 +0000 |
---|---|---|
committer | Eric Blake <ebb9@byu.net> | 2007-10-05 22:00:25 -0600 |
commit | 2f90bc7a7b7dea8802df732359d2b154e6e3d64c (patch) | |
tree | 3bbbdf3328dbc2fd9c62bf1afbe9840f2a9ef6a6 /gnulib | |
parent | 3830cddcd8f9cc6fbdf9b95f6074c5379c10d000 (diff) | |
download | m4-2f90bc7a7b7dea8802df732359d2b154e6e3d64c.tar.gz |
forgot to cvs add this file in the last commit
Diffstat (limited to 'gnulib')
-rw-r--r-- | gnulib/lib/stdbool_.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/gnulib/lib/stdbool_.h b/gnulib/lib/stdbool_.h new file mode 100644 index 00000000..3dbb51b2 --- /dev/null +++ b/gnulib/lib/stdbool_.h @@ -0,0 +1,92 @@ +/* Copyright (C) 2001, 2002, 2003 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 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef _STDBOOL_H +#define _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. + + - 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'. + + 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 */ + +/* BeOS <sys/socket.h> already #defines false 0, true 1. We use the same + definitions below, but temporarily we have to #undef them. */ +#ifdef __BEOS__ +# undef false +# undef true +#endif + +/* For the sake of symbolic names in gdb, we define true and false as + enum constants, not only as macros. + It is tempting to write + typedef enum { false = 0, true = 1 } _Bool; + so that gdb prints values of type 'bool' symbolically. But if we do + this, values of type '_Bool' may promote to 'int' or 'unsigned int' + (see ISO C 99 6.7.2.2.(4)); however, '_Bool' must promote to 'int' + (see ISO C 99 6.3.1.1.(2)). So we add a negative value to the + enum; this ensures that '_Bool' promotes to 'int'. */ +#ifndef __cplusplus +# if !@HAVE__BOOL@ +# if defined __SUNPRO_C && (__SUNPRO_C < 0x550 || __STDC__ == 1) + /* Avoid stupid "warning: _Bool is a keyword in ISO C99". */ +# define _Bool signed char +enum { false = 0, true = 1 }; +# else +typedef enum { _Bool_must_promote_to_int = -1, false = 0, true = 1 } _Bool; +# endif +# endif +#else +typedef bool _Bool; +#endif +#define bool _Bool + +/* The other macros must be usable in preprocessor directives. */ +#define false 0 +#define true 1 +#define __bool_true_false_are_defined 1 + +#endif /* _STDBOOL_H */ |