boost - multi_index (2) - ranked_index 사용관련

boost 1.59 버전에서 새롭게 추가된 컨데이너...

랭킹 관련한 처리를 할때 이용하기 좋아보인다...

아래는 그냥 샘플 코드...

#include <iostream> #include "boost/shared_ptr.hpp" #include "boost/make_shared.hpp" #include "boost/multi_index_container.hpp" #include "boost/multi_index/member.hpp" #include "boost/multi_index/ordered_index.hpp" #include "boost/multi_index/ranked_index.hpp" struct Data { int uid; int value; Data(const int _uid, const int _value) : uid(_uid), value(_value) {} }; typedef boost::shared_ptr<Data> DataPtr; struct Indices : public boost::multi_index::indexed_by < boost::multi_index::ordered_unique<boost_MULTI_INDEX_MEMBER(Data, int, uid)> , boost::multi_index::ranked_non_unique<boost_MULTI_INDEX_MEMBER(Data, int, value), std::greater<int>> > { enum Index { IDX_UID, IDX_RANK, }; }; typedef boost::multi_index_container<DataPtr, Indices> Container; int main() { Container container; auto& uidContainer = container.get<Indices::IDX_UID>(); auto& rankContainer = container.get<Indices::IDX_RANK>(); container.insert(boost::make_shared<Data>(1, 100)); container.insert(boost::make_shared<Data>(2, 200)); container.insert(boost::make_shared<Data>(3, 300)); container.insert(boost::make_shared<Data>(4, 200)); container.insert(boost::make_shared<Data>(5, 500)); ////////////////////////////////////////////////////////////////////////// printf("=== 전체 랭킹\n"); for (auto it = rankContainer.begin(); it != rankContainer.end(); ++it) { printf("[rank:%d] uid:%d value:%d\n", static_cast<int>(rankContainer.rank(it)), (*it)->uid, (*it)->value); } printf("\n"); ////////////////////////////////////////////////////////////////////////// auto find_if = uidContainer.find(3); if (find_if == uidContainer.end()) return 0; auto find_user_rank = container.project<Indices::IDX_RANK>(find_if); if (find_user_rank == rankContainer.end()) return 0; printf("=== uid : 3번의 랭킹 정보 \n"); printf("[rank:%d] uid:%d value:%d\n", static_cast<int>(rankContainer.rank(find_user_rank)), (*find_user_rank)->uid, (*find_user_rank)->value); printf("\n"); return 0; }