Simple Auto Pointer Impl

auto_ptr.cpp

std::unordered_map<void*, size_t> *auto_ref_cnt;

template<typename T>
class AutoPtr {
    T * data;
public:
    AutoPtr() = delete;
    AutoPtr(T* data): data(data) {
        if(auto_ref_cnt == nullptr) {
            auto_ref_cnt = new std::unordered_map<void*, size_t>;
        }
        auto_ref_cnt->operator[](data) += 1;
    }
    ~AutoPtr() {
        auto_ref_cnt->operator[](data) -= 1;
        if (auto_ref_cnt->operator[](data) == 0) {
            auto_ref_cnt->erase(data);
            if (auto_ref_cnt->empty()) {
                delete auto_ref_cnt;
                auto_ref_cnt = nullptr;
            }
        }
    }
};