[Boost-users] boost::variant compile error

Hi, i'd like to build a heterogenous container based on the boost::variant datastructure. My code looks like this: // forward-Deklarationen: class fExport FB_Ordered; class fExport FB_Dictionary; // Typedefs typedef boost::variant keydicttype; typedef boost::variant< int, std::string, date, ptime, boost::recursive_wrapper, boost::recursive_wrapper> valuedicttype; typedef boost::container::map basedict; C:\dev\boost_1_52_0\boost/checked_delete.hpp(32) : error C2027: use of undefined Type "FB_Ordered" what i want to do is to create a container fb_dictionary which can hold datatypes that are listed in the valuedicttype and which can accept keyvalues of int and string (see above). fb_ordered is another container defined in a diferent header file so i need the forward declarations. Could anybody please give me a hint in the right direction? I am using vs2008. Thanks for help, Georg