SharedPointer by Marek Padlewski

#include <iostream>
#include <memory>

template <typename T>
class MySharedPointer{
public:
    explicit MySharedPointer(T* pointer = nullptr){
        counter = new unsigned int(0);
        my_ptr = pointer;
        if (pointer)
            (*counter)++;
    }

    MySharedPointer(MySharedPointer<T>& other_sptr){
        counter = other_sptr.counter;
        my_ptr = other_sptr.my_ptr;
        if (other_sptr.my_ptr)
            (*counter)++; //increase counter in all instances
    }

    MySharedPointer<T>& operator=(const MySharedPointer<T>& other_sptr){

        if (this != &other_sptr){
            counter = other_sptr.counter;
            my_ptr = other_sptr.my_ptr;
            if (other_sptr.my_ptr)
                (*counter)++;
        }

        return *this;
    }

    ~MySharedPointer(){
        if (*counter == 0){
            delete my_ptr;
            delete counter;
        }
        else
            (*counter)--;
    }

    unsigned int getCount(){
        return *counter;
    }

private:
    unsigned int* counter;
    T* my_ptr;
};


int main() {

    MySharedPointer<int> msp(new int(42));
    std::cout << msp.getCount() << std::endl;

    {
        MySharedPointer<int> msp2;
        msp2 = msp;
        std::cout << msp2.getCount() << std::endl;

        msp2 = MySharedPointer<int>(new int(17));
        std::cout << msp2.getCount() << std::endl;
        std::cout << msp.getCount() << std::endl;

    }

    std::cout << msp.getCount() << std::endl;

    return 0;
}