with pub-static methods should not warn on only private ctors

[Martin v. Loewis]

> It is quite common to define a class that can be created
> only via a static methods. Therefore, in the following
> I think the warning should not be issued.

Thanks for your report. This is a known bug and has been fixed in the
mainline. In your version of the compiler, you can use
-Wno-ctor-dtor-privacy after -Wall to kill the warning.

Regards,
Martin