Hi everyone (my apologies if this shows as a report), In the following example is there a more efficient way to retrieve the unique keys of a non-unique index? #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/hashed_index.hpp> #include <boost/tuple/tuple.hpp> #include <algorithm> #include <iostream> #include <iterator> #include <string> using boost::multi_index_container; using namespace boost::multi_index; struct name {}; struct value {}; struct guid {}; struct TaggedNodeEntry { int name; int value; std::string guid; TaggedNodeEntry(int name_, int value_, std::string guid_) : name(name_), value(value_), guid(guid_) {} friend std::ostream& operator<<(std::ostream& os, const TaggedNodeEntry& e) { os << e.name << " " << e.value << " " << e.guid; return os; } }; typedef multi_index_container< TaggedNodeEntry, indexed_by< hashed_non_unique< tag<name>, BOOST_MULTI_INDEX_MEMBER(TaggedNodeEntry, int, name) >, hashed_non_unique< tag<value>, BOOST_MULTI_INDEX_MEMBER(TaggedNodeEntry, int, value) >, hashed_non_unique< tag<guid>, BOOST_MULTI_INDEX_MEMBER(TaggedNodeEntry, std::string, guid) >

TaggedNodes;

int main() { TaggedNodes taggedNodes; taggedNodes.insert(TaggedNodeEntry(1, 1, "one-one")); taggedNodes.insert(TaggedNodeEntry(1, 2, "one-two")); taggedNodes.insert(TaggedNodeEntry(1, 3, "one-three")); taggedNodes.insert(TaggedNodeEntry(2, 1, "two-one")); taggedNodes.insert(TaggedNodeEntry(2, 2, "two-two")); taggedNodes.insert(TaggedNodeEntry(3, 6, "three-six")); std::cout << std::endl << "Unique names :-" << std::endl; boost::multi_index::index<TaggedNodes, name>::type::iterator ic0 = get<name>(taggedNodes).begin(); boost::multi_index::index<TaggedNodes, name>::type::iterator ic1 = get<name>(taggedNodes).end(); while (ic0 != ic1) { std::cout << ic0->name << std::endl; ic0 = get<name>(taggedNodes).equal_range(ic0->name).second; } return 0; }