智能指针的自我/自己的实现

我正在尝试编写自己的共享指针实现(为了好玩/挑战(，但是在无法使构造函数接受任何(自动(类型的指针变量后，我陷入了死胡同。问题是，目前我只能使自己的智能指针指向某个数据类型(类 P(，但我希望它能够指向任何数据类型，但问题是我需要在构造函数参数中指定数据类型。

法典：

    #include <iostream>
    #include <memory>
    class P //dummy class
    {
        int x;
    public:
        P() : x(42) {}
        ~P() {}
        void print()
        {
            std::cout<<"Address = "<< this << "n";
        }
    };
    class P2 //dummy class 2
    {
    public:
        P2() {}
        ~P2() {}
        void print()
        {
            std::cout<<"Address = "<< this << "n";
        }
    };
    class SmartP
    {
        P *ptr;
    public:
        SmartP(P *p) : ptr(p) {}
        ~SmartP()
        {
            delete ptr;
        }
        P& operator* ()
        {
            return *ptr;
        }
        P* operator-> ()
        {    
            return ptr;
        }
    };
    void rawPointer()
    {
        P *p(new P);
        p->print();
        delete p;   //when removed, next allocated address will be different
    }
    void smartPointerOwn()
    {
        SmartP spo(SmartP(new P));
        //This should also work but currently it does not: SmartP spo(SmartP(new P2));
        spo->print();
        //Do not need a delete
    }
    void smartPointer()
    {
        std::unique_ptr<P> sp(new P);
        sp->print();
        //Do not need a delete
    }
    int main()
    {
        rawPointer();
        smartPointerOwn();
        smartPointer();
        std::cin.get(); //Prevent exiting console prematurely
        return 0;
    }

谢谢！