Hi Aleksei, If I'm not mistaken, I believe you need more than a forward declaration to VariablesImpl in the header file. That is to say, you need the fully specified declaration of VariablesImpl BEFORE the "static VariablesImpl m_Impl;" declaration in the header file. One way around this would be to use "static VariablesImpl* m_Impl;" in the header file, instead. HTH, --Eljay
