Constructor

Returns the element in the current position

Inserts a chain into the queue to the part after current position

Checks if there is more in the queue

Removes the part after the current position

Iterates to a a position of an element in the queue

Sets to first position

Update the current position, after update if the current position becomes empty after update - the current position will be the first in the queue, else the next in the queue

Operator ++ move to the next position in the queue