On 09/12/2011 12:58 PM, Dmitry. A. Ashkadov wrote: > I found many classes which have functions like «queryInterface», > «acquire» and etc. implemented in a same way. Maybe is it better to > introduce a new helper class? I can do it. There are already more than enough helper classes for that! See cppuhelper/implbase1.hxx etc. -Stephan