#include <cstdlib>
#include <iostream>

using namespace std;

class BrakObiektu{};

template <class T>
class SmartPointer{
    public:
        SmartPointer(T *obj){
            ptr = obj;
        }
        ~SmartPointer(){
            delete ptr;
        }
        SmartPointer& operator=(SmartPointer& o){
            this->ptr = o.ptr;
            o.ptr = 0;
            return *this;
        }
        T* operator->(){
            if ( ptr==0 )
                throw BrakObiektu();
            else return ptr;  //zwracam wskaznik
        }

        T& operator*(){
            if ( ptr==0 )
                throw BrakObiektu();
            else return *ptr;  //zwracam zawartosc elementu(obiekt)
        }

    private:
        T* ptr;
};


class A{
public:
    void a(){
        cout<<"To ja klasa A\n";
    }
};



int main(int argc, char** argv) {
    cout<<"Hello World\n";

    SmartPointer<A> sp(new A);

    try
    {
        sp->a();

    (*sp).a();


        SmartPointer<A> sm(0);

               // sm->a();  wyskoczylby blad bo wskaznik pokazuje na 0
        sm = sp;

        sm->a();

        sp->a();  //wyrzuci blad bo teraz sp wskazuje na 0


    }catch (BrakObiektu& w)
    {
        cout<<"Blad";
    }




    return 0;
}