Convert QList iterator to index

You can subtract iterator to beginning of your list from your iterator to get an index, since pointer arithmetic is defined on iterators:

int idx = iter-yourList.begin();

See QList-iterator-reference

As pointed out by @Frank Osterfeld's comment, you can use this:

const auto index = std::distance(yourList.begin(), currentIteratorOnYourList);

Checkout this article from Fluent{C++} blog.