boost - multi_index (2) - ranked

프로그래밍/boost

boost - multi_index (2) - ranked_index 사용관련

널부러 2016. 4. 19. 13:06

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;  
}

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