/*unique values per x co-ordinate*/ boost::multi_index::ordered_non_unique< boost::multi_index::composite_key< element_t, boost::multi_index::member< element_t, unsigned char, &element_t::x >, boost::multi_index::member< element_t, unsigned char, &element_t::value > > > > > matrix_t;
How would I define the "unique values per x co-ordinate" as there x co-ordinate is suppose to be non unique while value in this key should ONLY point to unique instances within that x co-ordinate?
Would this work? /*unique values per x co-ordinate*/ boost::multi_index::ordered_unique< boost::multi_index::composite_key< element_t, boost::multi_index::member< element_t, unsigned char, &element_t::x >, boost::multi_index::member< element_t, unsigned char, &element_t::value > > > As it is not clear in the documentation what the "boost::multi_index::ordered_unique" scope is. IE is it the combination of the defined members (member vs member) of is it based on the first and then on the second (first vs first, second vs second). Etienne