'iterator' 可以只键入'const_iterator' 的子类吗?
在关于迭代器的另一个问题之后我对自定义容器有一些疑问.在我的容器中，iterator 是 const_iterator 的子类，因此我可以免费"从非 const 转换为 const.但这是否允许，或者这样的设置是否有任何缺点或不工作的情况?
After another question about iterators I'm having some doubts about custom containers. In my container, iterator is a subclass of const_iterator, so that I get conversion from non-const to const "for free". But is this allowed or are there any drawbacks or non-working scenarios for such a setup?
推荐答案
是的，这很好.例如，这就是 VC10 的 vector 迭代器实现的结构.请参阅 _Vector_iterator 和 _Vector_const_iterator.
Yes, this is fine. This is how VC10's implementation of the iterators for vector are structured, for example. See _Vector_iterator and _Vector_const_iterator in <vector>.
顺便说一句，编写迭代器很困难.值得您花时间学习和使用 boost::iterator 库.
By the way, writing iterators is hard. It's worth your time to learn and use the boost::iterator library.
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