Modifying a data structure while iterating over it

Question

What happens when you add elements to a data structure such as a vector while iterating over it. Can I not do this?

I tried this and it breaks:

int m         


        

Answer 1

Iterators are invalidated by some operations that modify a std::vector.

Other containers have various rules about when iterators are and are not invalidated. This is a post (by yours truly) with details.

By the way, the entrypoint function main() MUST return int:

int main() { ... }