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

@@ -39,6 +39,10 @@
 #include <stdio.h>
 #include "bacdef.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
 #if DEBUG_ENABLED
 void debug_printf(
     const char *format,
@@ -52,4 +56,8 @@ static void debug_printf(
 }
 #endif
 
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
 #endif