Hello, I have an implementation of generic cyclic visitor. It is available at https://github.com/janherrmann/visitor . With my implementation it is possible to create non-member, non-friend templates which behave like virtual functions. Additionally it can be used as a base for multimethod implementation. Moreover it can be used to build a extensible type information system. All test cases compile with msvc-10.0 and gcc-mingw-4.6.2. Is there need for such a library? Jan Herrmann