C++ iterator with weak pointers to container elements

Question

I have a generic tree container and I would like to implement an iterator to traverse his elements. In the main container I used shared pointers to connect the various nodes of the tree.

Does it make sense to implement an iterator using weak pointers?

The point is: if I remove a node from the tree while I am using the iterator, the node resources will be deallocated only when the iterator is destructed (if I use shared pointers). With weak pointers, I presume that the resources are deallocated at once (maybe making the iterator inconsistent, but this is not important).

Can you think of other solutions to this problem?

Answer 1

First, iterators contains only a pointer to container element, not element itself. So no matter it was weak_ptr or not.

So if you remove element from a container, iterator can become invalid . This means it can point to trash memory, freed memory, not-your-memory, another element (not which you think) and so on.

This is error-prone way and will lead to problems.