macro to cast one static instance to another class type. ATTENTION: no checks are done if the given class is really a parent of the instances class.

include/tr/class.h

@@ -138,6 +138,8 @@
 		{ __VA_ARGS__ }                    \
 	}
 
+#define TR_INSTANCE_CAST(class, name)	((class)&(_##name.data))
+
 /**
  * I initialize _ (the class's base or parent class)
  * with the identifier of that class.