X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=include%2Fcommon.h;h=6ac756a70b1c795530a674f5346a17da14399dff;hb=4499a0ea0cecd41b7053ce5768a85efdfc48848a;hp=99c43829ec755b5a4da3dca641fdf6f277909ac5;hpb=be20bc40619598a5c9af8234ae81ce0a6899651f;p=smdp.git

diff --git a/include/common.h b/include/common.h
index 99c4382..6ac756a 100644
--- a/include/common.h
+++ b/include/common.h
@@ -21,11 +21,30 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  *
  *
+ * type: bool variable stores only true or false.
+ *
  * macro: MAX returns the higher one of two input variables
  * macro: MIN returns the lower one of two input variables
  *
  */
 
+#if defined( __STDC__ )  // for standard C compiler
+#if __STDC_VERSION__ >= 199901L    // for C99 and later
+#include <stdbool.h>
+#else    // __STDC_VERSION__ >= 199901L
+#if !defined( bool )
+typedef enum {
+    false = 0,
+    true  = 1
+} bool;
+#endif   // !defined( bool )
+#endif   // __STDC_VERSION__ >= 199901L
+#else    // defined( __STDC__ )
+#define bool    int
+#define true    1
+#define false   0
+#endif   // defined( __STDC__ )
+
 #define MAX(a, b) ({ typeof(a) _a = a; typeof(b) _b = b; _a > _b? _a : _b; })
 #define MIN(a, b) ({ typeof(a) _a = a; typeof(b) _b = b; _a < _b? _a : _b; })