Как пользоваться shared_ptr (совместно с priority_queue)

class A{
public:
    A(int a, int b):a(a),b(b){}
    int a;
    int b;
};
 
struct min_a {
    bool operator()(shared_ptr<A> const& p1, shared_ptr<A> const& p2)
    {
        return (p1 -> a > p2 -> a);
    }
};
 
struct min_b {
    bool operator()(shared_ptr<A> const& p1, shared_ptr<A> const& p2)
    {
        return (p1 -> b > p2->b);
    }
};

int main(){
    auto a2 = make_shared<A>(2,3);
    auto a3 = make_shared<A>(3,2);
 
    std::priority_queue<shared_ptr<A>, vector<shared_ptr<A>>, min_a> Q1;
    std::priority_queue<shared_ptr<A>, vector<shared_ptr<A>>, min_b> Q2;
 
    Q1.push(a2);
    Q1.push(a3);
 
    Q2.push(a2);
    Q2.push(a3);
 
    cout<<Q1.top()->a<<" "<<Q1.top()->b<<endl;
    Q1.pop();
    cout<<Q1.top()->a<<" "<<Q1.top()->b<<endl<<endl;
    Q1.pop();
 
    cout<<Q2.top()->a<<" "<<Q2.top()->b<<endl;
    Q2.pop();
    cout<<Q2.top()->a<<" "<<Q2.top()->b<<endl<<endl;
    Q2.pop();
 
    cout<<a2->a<<endl;
    cout<<a3->a<<endl;
}

a2.reset(NULL);
a3.reset(NULL);
поможет?

    cout<<a2->a<<endl;
    cout<<a3->a<<endl;