Item 27: Use distance and advance to convert a container’s const_iterators to iterators

Item 26 points out that some container member functions that take iterators as parameters insist on iterators; const_iterators won’t do. So what do you do if you have a const_iterator in hand and you want to, say, insert a new value into a container at the position indicated by the iterator? Somehow you’ve got to turn your const_iterator into an iterator, and you have to take an active role in doing it, because, as Item 26 explains, there is no implicit conversion from const_iterator to iterator.

I know what you’re thinking. You’re thinking, “When all else fails, get a bigger hammer.” In the world of C++, that can mean only one thing: casting. Shame on you for such thoughts. Where do you get these ideas?