Smart Pointer

When ever you create a object of class, deconstructor will be called automatically,

but when you make pointer of that class, the deconstructor won't be automatically  called. So you have to use smart pointer to de-allocate the memory.

MyInt my_int(10);  // This will call the destructor

MyInt *my_int = new MyInt(10); // this won't automatically call the destructor

Unique Pointer: 

#include <memory>

    class MyInt {
    private:
        int x;

    public:
        MyInt(int p) { x = p; }

        ~MyInt() {
            std::cout << " deconstructor " << std::endl;
        }

        int getData() {
            return x;
        }
    };

    int main() {
//    MyInt my_int(10);
//    std::cout << "My Int " << my_int.getData() << std::endl;

        std::unique_ptr<MyInt> p(new MyInt(10));  // Here the p will be created on stack not on heap
        std::cout << p->getData();                    // This is the one way of declaring unique pointer

        std::unique_ptr<MyInt> pp = std::make_unique<MyInt>(20); // 2nd way of creating unique pointer

        // p = pp // FAIL: This will fail as ownership cannot be copied
        std::unique_ptr<MyInt> ppp = std::move(p); // this will move the ownership

//    MyInt *my_int = new MyInt(10);
//    std::cout << my_int->getData();

        MyInt *in = p.get(); // returns the pointer of that pointer
        MyInt *inn = p.release(); // release the pointer


        std::cout << "Before finishing: " << std::endl;

        return 0;
    }


    std::cout << "Before finishing: " << std::endl;

    return 0;
}