Question

我想对我的代码发表意见。我需要一个自定义容器的随机访问迭代器。如果我阅读C ++ 2011标准，特别是第24章，我理解这是一个实现可能是以下几点：

class my_iterator : public std::iterator<std::random_access_iterator_tag, my_element>
{
    private:
       my_container *_ref;
       my_iterator_state state; // some useful state
    public:
       my_iterator ();
       my_iterator (const my_iterator &);
       my_iterator (my_iterator &&);
       ~my_iterator ();
       my_iterator &operator = (const my_iterator &);
       my_iterator &operator = (my_iterator &&);
       reference operator * ();
       my_iterator &operator ++ ();
       bool operator != (my_iterator);
       value_type operator * ();
       pointer operator -> ();
       my_iterator &operator * ();
       void operator ++ (int);
       value_type operator ++ (int);
       const my_iterator &operator ++ (int);
       reference operator ++ (int);
       my_iterator &operator -- ();
       const my_iterator operator -- (int);
       reference operator -- (int);
       my_iterator &operator += (difference_type);
       my_iterator operator + (difference_type);
       my_iterator operator - (difference_type);
       reference operator [] (difference_type);
       bool operator < (my_iterator);
       bool operator > (my_iterator);
       bool operator <= (my_iterator);
       bool operator >= (my_iterator);
       friend difference_type (my_iterator, my_iterator);
       friend my_iterator operator + (difference_type, my_iterator);
       friend void swap (iterator &, iterator &);
};

void swap (iterator &, iterator &);
difference_type (my_iterator, my_iterator);
my_iterator operator + (difference_type, my_iterator);

以上实施是否正确且功能齐全？还有成员？

Answer 1

通常，您不能使用相同的参数但返回类型不同的重载，因此您的几个成员不能存在。你应该保留以下内容：

reference operator * ();
my_iterator operator ++ (int);
my_iterator operator -- (int);

并删除虚假超载：

value_type operator * ();
void operator ++ (int);
value_type operator ++ (int);
const my_iterator &operator ++ (int);
reference operator ++ (int);
const my_iterator operator -- (int);
reference operator -- (int);

这没有任何意义：

friend difference_type (my_iterator, my_iterator);

我认为应该是：

friend difference_type operator-(my_iterator, my_iterator);

你似乎错过了operator-=

在C ++ 2011中创建自定义随机访问迭代器

1 个答案: