Range-based loop for std::queue

Well, the answer is actually pretty simple: there is no function begin() in std::queue and there isn't any overload of std::begin taking a std::queue either. You can have a look at the documentation.

The core problem is that std::queue is not meant to be iterated over. It exists to satisfy other needs. If you really need to iterate over it, you should just use the underlying container (by default std::deque) which supports iteration and for which your code would be valid.