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Yes, it is possible to create your own shared pointer class in C++. Here is an example implementation using reference counting:

template<typename T>
class SharedPtr {
public:
    explicit SharedPtr(T* ptr = nullptr)
        : ptr_(ptr), ref_count_(new int(1))
    {}

    SharedPtr(const SharedPtr<T>& other)
        : ptr_(other.ptr_), ref_count_(other.ref_count_)
    {
        ++*ref_count_;
    }

    SharedPtr<T>& operator=(const SharedPtr<T>& other)
    {
        if (this != &other) {
            release();
            ptr_ = other.ptr_;
            ref_count_ = other.ref_count_;
            ++*ref_count_;
        }
        return *this;
    }

    ~SharedPtr()
    {
        release();
    }

    T* get() const { return ptr_; }
    T& operator*() const { return *ptr_; }
    T* operator->() const { return ptr_; }

private:
    void release()
    {
        if (--*ref_count_ == 0) {
            delete ptr_;
            delete ref_count_;
        }
    }

    T* ptr_;
    int* ref_count_;
};

This implementation uses a reference count to track the number of shared pointers pointing to the same object. When a new shared pointer is created or copied, the reference count is incremented. When a shared pointer is destroyed or assigned to a new object, the reference count is decremented. If the reference count reaches zero, the object is deleted along with the reference count.