C++ 科目二 智能指针 [weak_ptr] (解决shared_ptr的循环引用问题)

shared_ptr引入的重复计数问题，导致内存泄漏

using namespace std;
class CFather;
class CSon;

class CFather {
public:
    CFather()
    {}
    void Set(shared_ptr<CSon> pson)
    {
        Pson = pson;
    }

    shared_ptr<CSon> Pson;
};

class CSon {
public:
    CSon()
    {}
    void Set(shared_ptr<CFather> pfather)
    {
        Pfather = pfather;
    }

    shared_ptr<CFather> Pfather;
};

int main()
{
    CSon *pson = new CSon();
    CFather *pfather = new CFather();
    {
        shared_ptr<CFather> shared_father(pfather);
        shared_ptr<CSon> shared_son(pson);

        shared_father->Set(shared_son);
        shared_son->Set(shared_father);

        cout << shared_father.use_count() << endl;
        cout << shared_son.use_count() << endl;
    }
    cout << "It's good to see you!" << endl;
    return 0;
}

将CFather或者CSon的shared_ptr变成weak_ptr即可避免内存泄漏问题