Corrected a problem that debug_printf could not be implemented from c++ code because it did not contain the de-munging of c++ names. Thank you to Cameron C.!

bacnet-stack/include/debug.h

@@ -38,6 +38,10 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include "bacdef.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
 
 #if DEBUG_ENABLED
 void debug_printf(
@@ -51,5 +55,9 @@ static void debug_printf(
     format = format;
 }
 #endif
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
 
 #endif