迭代器失效规则

Rules for Iterator Invalidation(迭代器失效规则)

问题描述

在 STL 容器类(Vector、Dequeue、list、map、multimap、set、multiset)上操作时迭代器失效的通常规则是什么.是否可以对 C++ STL 程序员在使用容器及其迭代器时必须注意的一些一般规则/指南进行分类和总结?

What are the usual rules for Iterator invalidation when operating over STL container classes(Vector,Dequeue,list,map,multimap,set,multiset). Is it possible to categorize and sum up some general rules/guidelines that a C++ STL programmer must be aware of while working with containers and their Iterators?

推荐答案

这些规则是特定于容器的.事实上，这些都是决定您使用哪个容器的重要标准.

These rules are container specific. In fact, these are important criteria for deciding which container you use.

例如，std::vector 的迭代器可能会在插入对象时失效(取决于插入对象的位置以及是否发生重新分配)，并且在插入对象时它们会失效在迭代器之前被移除.std::list 没有这个问题.插入和移除对象(迭代器指向的对象除外)不会使迭代器失效.

For instance, iterators to an std::vector can get invalidated when an object is inserted (depends in where the object is inserted and if reallocation takes place), and they get invalidated when an object is removed before the iterator. An std::list does not have this problem. Inserting and removing objects (except for the object the iterator points to) does not invalidate the iterator.

SGI 提供了很好的文档.

SGI provides good documentation on this.

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