[Boost-users] [iterator] readable and writable transform_iterator

I can't figure out how to make a writable transform_iterator work. Here is what I have: #include #include #include <vector> template< int N > struct Get { template<typename T> struct result; template struct result { typedef typename boost::reference_wrapper::type>::type type; }; template<typename Tup> typename result::type operator()(Tup& t) { return boost::tuples::get<N>(t); } }; int main() { std::vector > v1; v1.push_back(boost::make_tuple(1,2.2f)); v1.push_back(boost::make_tuple(2,3.2f)); std::vector > v2(2); std::copy(boost::make_transform_iterator(v1.begin(),Get<0>()), boost::make_transform_iterator(v1.end(),Get<0>()), boost::make_transform_iterator(v2.begin(),Get<0>())); } g++ seems to get hung up on figuring out the result type of Get<0>. Any help would be greatly appreciated. Chris