<分区>
我可以在调用 multimap::erase() 之后继续使用 multimap 迭代器吗？例如:
Blah::iterator iter;
for ( iter = mm.begin();
iter != mm.end();
iter ++ )
{
if ( iter->second == something )
{
mm.erase( iter );
}
}
这是否应该正确运行，或者迭代器是否在调用删除后失效？引用网站，如 http://www.cplusplus.com/reference/stl/multimap/erase.html在迭代器的生命周期或构造性/破坏性方法对迭代器的影响这个话题上出奇地安静。
最佳答案
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.
所以它应该是这样的:
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: What happens if you call erase() on a map element while iterating from begin to end?
和
关于c++ - 从 std::multimap<> 中删除项目后，我可以继续使用迭代器吗？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/446205/