STL: reverse_iterator / iterator 关系以及 erase 相关(C++)

最新推荐文章于 2024-02-29 22:02:19 发布

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最新推荐文章于 2024-02-29 22:02:19 发布 · 1.1k 阅读

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#C++ #STL #iterator #reverse_iterator #erase

本文探讨了C++ STL中反向迭代器reverse_iterator与普通迭代器iterator的关系，强调在使用反向迭代器进行元素删除时需要注意的细节。通过实例说明反向迭代器在调用erase函数前需要先前进一位再转换为正向迭代器，以确保正确删除目标元素。

反向迭代器

相信大家对正向迭代器应该都很熟悉，然而对于反向迭代器的使用确是有几处需要注意的地方，在此记录一下。先看STL源码处注释如下：

  /**
   *  Bidirectional and random access iterators have corresponding reverse
   *  %iterator adaptors that iterate through the data structure in the
   *  opposite direction.  They have the same signatures as the corresponding
   *  iterators.  The fundamental relation between a reverse %iterator and its
   *  corresponding %iterator @c i is established by the identity:
   *  @code
   *      &*(reverse_iterator(i)) == &*(i - 1)
   *  @endcode
   *
   *  <em>This mapping is dictated by the fact that while there is always a
   *  pointer past the end of an array, there might not be a valid pointer
   *  before the beginning of an array.</em> [24.4.1]/1,2
   *
   *  Reverse iterators can be tricky and surprising at first.  Their
   *  semantics make sense, however, an