Update data_types.md

markdown/libraries/data_types.md

@@ -30,3 +30,11 @@ variable except with the added benefit of one-liners in order to make your code
 # END RESULT:
 
 ``Hello Harry``
+
+# NOTE:
+
+It should be noted that while you can make the declrative of a macro anything such as an ``int, char, string, bool, double, float, const, etc``
+You CANNOT define a macro as a ``struct`` otherwise it will not work
+
+By all means, you can do what I did in the first screenshot and define a macro with the same name as the struct but it needs to explictially state 
+that it is a struct otherwise it will not work for some reason?!