Breaking shared_ptr Cycles

#include <iostream>
#include <memory>
using namespace std;

class B;

class A {
public:
    // A owns B
    shared_ptr<B> b;

    ~A() {
        cout << "A destroyed" << endl;
    }
};

class B {
public:
    // B only needs to refer to A, not own it
    weak_ptr<A> a;

    ~B() {
        cout << "B destroyed" << endl;
    }
};

int main() {
    {
        auto objA = make_shared<A>();
        auto objB = make_shared<B>();

        // Ownership is one-directional
        objA->b = objB;

        // Non-owning reference back to A
        objB->a = objA;
    }

    // Both objects are destroyed correctly
    cout << "End of scope" << endl;
    return 0;
}

Solving Approach