Storing iterators inside containers

Question

I am building a DLL that another application would use. I want to store the current state of some data globally in the DLL's memory before returning from the function call so that I could reuse state on the next call to the function.

For doing this, I'm having to save some iterators. I'm using a std::stack to store all other data, but I wasn't sure if I could do that with the iterators also.

Is it safe to put list iterators inside container classes? If not, could you suggest a way to store a pointer to an element in a list so that I can use it later?

I know using a vector to store my data instead of a list would have allowed me to store the subscript and reuse it very easily, but unfortunately I'm having to use only an std::list.

Answer 1

Iterators to list are invalidated only if the list is destroyed or the "pointed" element is removed from the list.

Answer 2

Yes, it'll work fine.

Since so many other answers go on about this being a special quality of list iterators, I have to point out that it'd work with any iterators, including vector ones. The fact that vector iterators get invalidated if the vector is modified is hardly relevant to a question of whether it is legal to store iterators in another container -- it is. Of course the iterator can get invalidated if you do anything that invalidates it, but that has nothing to do with whether or not the iterator is stored in a stack (or any other data structure).