unique_ptr 的简单实现

 

template <typename T>
class poor_unique_ptr {
public:
    explicit poor_unique_ptr(T* ptr=nullptr): ptr_(ptr) {};
    ~poor_unique_ptr() {
        if (ptr_) {
            delete ptr_;
        }
    }

    // 删除拷贝构造和拷贝赋值
    poor_unique_ptr(const poor_unique_ptr&) = delete;
    poor_unique_ptr& operator=(const poor_unique_ptr&) = delete;

    // 移动拷贝和移动赋值
    poor_unique_ptr(poor_unique_ptr&& rhs): ptr_{rhs.release()} {}
    poor_unique_ptr& operator=(poor_unique_ptr&& rhs) {
        reset(rhs.release());
        return *this;
    }

    T* get() const {return ptr_;}
    T* release() {  // 并不会释放其指向的对象
        T *p = ptr_;
        ptr_ = nullptr;
        return p;
    }
    void reset(T* ptr) {
        delete ptr_;
        ptr_ = ptr;
    }
    void swap(poor_unique_ptr& rhs){
        std::swap(ptr_, rhs.ptr_);
    }

    T& operator*() {return *ptr_;}
    T* operator->() {return ptr_;}
    explicit operator bool() {return static_cast<bool>(ptr_);}

private:
    T* ptr_;
};