use bool type where it's available

when using gcc, compile as C99

src/CMakeLists.txt

@@ -3,6 +3,7 @@ project (eressea C)
 
 IF(CMAKE_COMPILER_IS_GNUCC)
     SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic -Wall -Werror -Wno-unknown-pragmas -Wstrict-prototypes -Wpointer-arith -Wno-char-subscripts -Wno-long-long")
+    SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -DHAVE__BOOL")
 ELSE(CMAKE_COMPILER_IS_GNUCC)
     MESSAGE(STATUS "Unknown compiler ${CMAKE_C_COMPILER_ID}")
 ENDIF(CMAKE_COMPILER_IS_GNUCC)

src/platform.h

@@ -246,21 +246,8 @@ extern char *strdup(const char *s);
 # define unused(a) (a)
 #endif /* ghs || __GNUC__ || ..... */
 
-/****                      ****
- ** The Eressea boolean type **
- ****                      ****/
-#if defined(BOOLEAN)
-# define boolean BOOLEAN
-#else
-typedef int boolean;            /* not bool! wrong size. */
-#endif
-#ifndef __cplusplus
-# define false ((boolean)0)
-# define true ((boolean)!false)
-#endif
-#ifdef __cplusplus
-}
-#endif
+#include "util/bool.h"
+typedef bool boolean;
   
 #ifndef INLINE_FUNCTION
 # define INLINE_FUNCTION

src/util/bool.h

@@ -0,0 +1,15 @@
+#if HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# if ! HAVE__BOOL
+#  ifdef __cplusplus
+typedef bool _Bool;
+#  else
+typedef unsigned char _Bool;
+#  endif
+# endif
+# define bool _Bool
+# define false 0
+# define true 1
+# define __bool_true_false_are_defined 1
+#endif