Martin Ecker wrote:

I need something like the following (somewhat contrived) example to work with boost::fusion::transform on a boost::fusion::vector or other vector types that have reference types. Note that the following doesn't compile.

<snip original example> The following code allows references to pass through, as I believe you want. It just uses a slight modification to your function object to allow it to cope with references correctly. namespace { struct pass_through { template<typename Sig> struct result; template<typename T> struct result { typedef T& type; }; template<typename T> T& operator()(T& t) const { return t; } }; } int main() { typedef fusion::vector vec; int i = 202; vec v1(i); vec v2(fusion::transform(v1, pass_through())); std::cout << fusion::at_c<0>(v2) << std::endl; // Output 202 } Is this ok for your needs? Cheers Dan ___________________________________________________________ Yahoo! Answers - Got a question? Someone out there knows the answer. Try it now. http://uk.answers.yahoo.com/