Exporting class from dll with nested class

[mtrudeau]

Hi. I'm trying to compile a dll. I'm exporting a class (called 'B') from it that contains as private data an instance (called A_object) of another class (called 'A')that is not exported.

Why do I get a warning C4251: 'A_object' : class 'A' needs to have dll-interface to be used by clients of class 'B' ?

Since the data is private, it will be invisible to any class derived from B. And any instance of class B in an .exe won't have problems using methods of B that call methods of A. I just don't see where the limitation could be...

 

[Cagliostro]

Is just a warning. In your case you may ignore it. In some cases your nested class could be used explicitly or implicitly by other modules, that is why you get this warning.

Ion Filipski