Defined in header
template< class InputIt, class Distance >
void advance( InputIt& it, Distance n );
Increments given iterator
n is negative, the iterator is decremented. In this case,
InputIt must meet the requirements of
BidirectionalIterator, otherwise the behavior is undefined.
|it||-||iterator to be advanced|
|n||-|| number of elements |
 Return value
InputIt additionally meets the requirements of
RandomAccessIterator, complexity is constant.
 See also
| returns the distance between two iterators |