vector实现（待补充）

template<class T>
class vector
{
public:
    //ctor
    vector()
        : data_(NULL), size_(0)
    {
    }

    explicit vector( size_t n, const T& value = T())
    {
        data_ = new T[n];
        for (size_t i = 0; i < n; i++)
        {
            data_[0] = value;
        }
    }

    vector<T>& operator=(const vector<T>& rhs)
    {
        data_ = rhs.data_;
        size_ = rhs.size_;
    }

    //dtor
    ~vector()
    {
        if (data_)
        {
            delete data_;
        }
    }

    //get
    size_t size() const
    {
        return size_;
    }

    // set & get
    T& operator[](size_t index);

    // set
    void push_back(const T& element);
    void pop_back(const T& element);
    void resize();
    void reserve();
    void clear();
    void empty();

private:
    T*      data_;
    size_t  size_;
};