c – 从std :: multimap <>删除项目后,我可以继续使用迭代
发布时间：2020-12-16 10:41:46 所属栏目：百科 来源：网络整理
导读：参见英文答案 What happens if you call erase() on a map element while iterating from begin to end?????????????????????????????????????3个 即使在调用multimap :: erase()之后,我还能继续使用多重映射迭代器吗？例如： Blah::iterator iter;for ( ite
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参见英文答案 >
What happens if you call erase() on a map element while iterating from begin to end?????????????????????????????????????3个
即使在调用multimap :: erase()之后,我还能继续使用多重映射迭代器吗？例如： Blah::iterator iter;
for ( iter = mm.begin();
iter != mm.end();
iter ++ )
{
if ( iter->second == something )
{
mm.erase( iter );
}
}
是否应该正确运行,或者在调用擦除后迭代器是否无效？像http://www.cplusplus.com/reference/stl/multimap/erase.html这样的参考站点在迭代器的生命周期或者建设性/破坏性方法对迭代器的影响这个主题上是非常安静的. 解决方法
http://www.sgi.com/tech/stl/Multimap.html
Multimap has the important property that inserting a new element into a multimap does not invalidate iterators that point to existing elements. Erasing an element from a multimap also does not invalidate any iterators,except,of course,for iterators that actually point to the element that is being erased. 所以看起来应该是这样的： Blah::iterator iter;
for ( iter = mm.begin();iter != mm.end();)
{
if ( iter->second == something )
{
mm.erase( iter++ );
// Use post increment. This increments the iterator but
// returns a copy of the original iterator to be used by
// the erase method
}
else
{
++iter; // Use Pre Increment for efficiency.
}
}
另见： 和 delete a specific entry in the map,but the iterator must point to the next element after the deletion （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |