include/nut_bool.h

   1 /*
   2  * nut_bool.h - Network UPS Tools boolean type definitions
   3  *              which should ensure a "nut_bool_t" name with
   4  *              lower-case values "true" and "false"
   5  *
   6  * Inspired by earlier efforts and numerous definitions in NUT codebase.
   7  * Copyright (C) 2024 Jim Klimov <jimklimov+nut@gmail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #ifndef NUT_BOOL_H_SEEN
  25 #define NUT_BOOL_H_SEEN 1
  26
  27 #ifdef __cplusplus
  28 /* *INDENT-OFF* */
  29 extern "C" {
  30 /* *INDENT-ON* */
  31 #endif
  32
  33 /* "config.h" is generated by autotools and lacks a header guard, so
  34  * we use an unambiguously named macro we know we must have, as one.
  35  * It must be the first header: be sure to know all about system config.
  36  */
  37 #ifndef NUT_NETVERSION
  38 # include "config.h"
  39 #endif
  40
  41 /* See also https://en.cppreference.com/w/cpp/header/cstdbool for more
  42  * info about what should be available where per standard approach. */
  43 #ifdef __cplusplus
  44 # if defined HAVE_CSTDBOOL_H || defined HAVE_CSTDBOOL
  45 #  include <cstdbool>
  46 # else
  47 #  ifdef HAVE_STDBOOL_H
  48 #   include <stdbool.h>
  49 #  endif
  50 # endif
  51 #else
  52 /* plain C */
  53 #  ifdef HAVE_STDBOOL_H
  54 #   include <stdbool.h>
  55 #  endif
  56 #endif
  57
  58 /* Is the goal achieved by the system headers or compiler itself,
  59  * so we can just alias to existing type and its values? */
  60 #if defined __bool_true_false_are_defined && __bool_true_false_are_defined
  61         typedef bool nut_bool_t;
  62 #elif defined FOUND__BOOL_TYPE && defined HAVE__BOOL_VALUE_LOWERCASE
  63         typedef FOUND__BOOL_TYPE nut_bool_t;
  64 #elif defined FOUND_BOOL_TYPE && defined HAVE_BOOL_VALUE_LOWERCASE
  65         typedef FOUND_BOOL_TYPE nut_bool_t;
  66 #elif defined FOUND_BOOLEAN_TYPE && defined HAVE_BOOLEAN_VALUE_LOWERCASE
  67         typedef FOUND_BOOLEAN_TYPE nut_bool_t;
  68 #elif defined FOUND_BOOL_T_TYPE && defined HAVE_BOOL_T_VALUE_LOWERCASE
  69         typedef FOUND_BOOL_T_TYPE nut_bool_t;
  70 #else
  71         /* Need a new type; can we use an enum with lower-case values? */
  72 # if (defined true && defined false) || defined HAVE__BOOL_VALUE_LOWERCASE || defined HAVE_BOOL_VALUE_LOWERCASE || defined HAVE_BOOLEAN_VALUE_LOWERCASE || defined HAVE_BOOL_T_VALUE_LOWERCASE
  73         /* Lower-case true/false are known */
  74 #  if defined FOUND__BOOL_TYPE
  75         /* Got a C99 built-in mandated by the standard */
  76         typedef FOUND__BOOL_TYPE nut_bool_t;
  77 #  else
  78         typedef int nut_bool_t;
  79 #  endif
  80 # elif defined FOUND__BOOL_VALUE_TRUE && defined FOUND__BOOL_VALUE_FALSE
  81         typedef enum nut_bool_enum { false = FOUND__BOOL_VALUE_FALSE, true = FOUND__BOOL_VALUE_TRUE } nut_bool_t;
  82 # elif defined FOUND_BOOL_VALUE_TRUE && defined FOUND_BOOL_VALUE_FALSE
  83         typedef enum nut_bool_enum { false = FOUND_BOOL_VALUE_FALSE, true = FOUND_BOOL_VALUE_TRUE } nut_bool_t;
  84 # elif defined FOUND_BOOLEAN_VALUE_TRUE && defined FOUND_BOOLEAN_VALUE_FALSE
  85         typedef enum nut_bool_enum { false = FOUND_BOOLEAN_VALUE_FALSE, true = FOUND_BOOLEAN_VALUE_TRUE } nut_bool_t;
  86 # elif defined FOUND_BOOL_T_VALUE_TRUE && defined FOUND_BOOL_T_VALUE_FALSE
  87         typedef enum nut_bool_enum { false = FOUND_BOOL_T_VALUE_FALSE, true = FOUND_BOOL_T_VALUE_TRUE } nut_bool_t;
  88 # else
  89         typedef enum nut_bool_enum { false = 0, true = 1 } nut_bool_t;
  90 # endif
  91 #endif
  92
  93 #ifdef __cplusplus
  94 /* *INDENT-OFF* */
  95 }
  96 /* *INDENT-ON* */
  97 #endif
  98
  99 #endif  /* NUT_BOOL_H_SEEN */