http://boost-consulting.com/boost/libs/fusion/doc/html/fusion/extension.html... shows: namespace traits { template<typename Struct, int Pos> struct tag_of<boost::fusion::example_struct_iterator<Struct, Pos> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ { typedef example_struct_iterator_tag type; }; } Now, surely, the authors didn't intend example_struct_iterator to be defined in namespace boost::fusion. The example where it's defined doesn't show any namespace declaration. This sort of problem either has to be flushed out by an automated tool or it needs to be painstakingly weeded out by hand, usually in response to user complaints that the examples don't work. You *will* get complaints, but by then it will be too late to save users the pain. I will be more than happy to work with someone on adapting LitRE to BoostBook. -- Dave Abrahams Boost Consulting www.boost-consulting.com