C++: owner_less

개요

• 값 기반이 아닌 소유자 기반 비교

예제

• 코드

    #include <iostream>
    #include <memory>
    #include <set>

    using namespace std;

    int main() {
    	shared_ptr<int> p1(new int(10));
    	shared_ptr<int> p2(p1, new int(20));

    	set<shared_ptr<int>> valueBased;
    	valueBased.insert(p1);
    	valueBased.insert(p2);
    	cout << valueBased.size() << endl;
    	for (const auto &iter : valueBased) {
    		cout << *iter << endl;
    	}

    	cout << "------" << endl;

    	set<shared_ptr<int>, owner_less<shared_ptr<int>>> ownerBased;
    	ownerBased.insert(p1);
    	ownerBased.insert(p2);
    	cout << ownerBased.size() << endl;
    	for (const auto &iter : ownerBased) {
    		cout << *iter << endl;
    	}

    	return 0;
    }

• 실행 결과

    2
    10
    20
    ------
    1
    10