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authorSergey Poznyakoff <gray@gnu.org.ua>2005-02-24 12:18:40 (GMT)
committer Sergey Poznyakoff <gray@gnu.org.ua>2005-02-24 12:18:40 (GMT)
commit8ea093c83ec0eecbe9d5ffce741d3ec3e27fad83 (patch) (side-by-side diff)
treec452da6b6ae47962743478dd8367048582ab4d8b /lib
parent975038c912b76c56c552ae51bac8a36f0c3bd160 (diff)
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Added to the repository
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-rw-r--r--lib/stdbool.h93
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diff --git a/lib/stdbool.h b/lib/stdbool.h
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+/* 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__
+# include <OS.h> /* defines bool but not _Bool */
+# 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'. */
+#if !(defined __cplusplus || defined __BEOS__)
+# if !0
+# 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 */

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