I'm not sure. In any case, I'm thinking I should learn more about the STL and about data structures/classes in C++ (and perhaps even Boost - there are some very basic graph structures available in ...

Code: union vec_union { std::vector ... data structures, plus a tag ID (if you're an R user, it's a SEXPREC). It seems like it should be easy just to convert the C struct into a C++ struct with ...