#include <iostream>
#include <sstream>
#include <memory>

class A {
public:
    A() {std::cout << "A::A()" << std::endl;}
    virtual ~A() {std::cout << "A::~A()" << std::endl;}
    virtual void f() {
        std::cout << "A::f()" << std::endl;
    }
};
class B : public A{
public:
    B() {std::cout << "B::B()" << std::endl;}
    ~B() {std::cout << "B::~B()" << std::endl;}
    void f() override {
        std::cout << "B::f()" << std::endl;
    }
};





int main() {
    {
        A* b = new B;
        b->f();
        delete b;
    }

    int* p4 = nullptr;
    std::shared_ptr<int> p5;
    {
        std::shared_ptr<int> p(new int);
        std::shared_ptr<int> p2;
        p2 = p;
        int* p3 = p2.get();
        p4 = p2.get();
        p5.swap(p2);
    }
    {
        std::unique_ptr<int> p(new int);
        std::unique_ptr<int> p2(p.get());

    }


    //line


}