Hi!
I tried to use multi_index_container as a drop in replacement for std::map and hoped that I could obtain non-const references to the values therein. Although returning a non-const reference might not be a problem for a multi_index_container with only 1 sorting criterium the lib and the compiler insist on const &. Workarounds beyond modify(...) available? Markus #include <boost/tuple/tuple.hpp> #include <boost/multi_index_container.hpp> #include <boost/multi_index/sequenced_index.hpp> #include <boost/multi_index/key_extractors.hpp> #include <boost/multi_index/ordered_index.hpp> #include <string> namespace bm = ::boost::multi_index; // http://lists.boost.org/boost-users/2005/12/16088.php template<typename Tuple,int N> struct tuple_member_extractor { typedef typename boost::tuples::element<N,Tuple>::type result_type; const result_type& operator()(const Tuple& t) const { return boost::tuples::get<N>(t); } }; typedef boost::tuple<std::string, std::string> element; typedef bm::multi_index_container< element, bm::indexed_by<bm::ordered_unique <tuple_member_extractor<element, 0> >
multi_t;
int main() { multi_t test; test.insert(boost::make_tuple("a", "aa")); // will not compile element & ref = test.find("a"); std::string & s = ref.get<1>(); }