Dear all, I get a compile error when I want to export a class derived from boost variant, e.g.: struct __declspec(dllexport) BlaVariant : public boost::variant<bool> { BlaVariant() {} }; It gives C2666. What do I wrong... As a workaround I can aggregate it instead of derivation (although I think in my case it was a really an 'ISA' relationship) wkr, me