27 Iterators library [iterators]

27.5 Iterator adaptors [predef.iterators]

27.5.1 Reverse iterators [reverse.iterators]

27.5.1.3 reverse_­iterator operations [reverse.iter.ops]

27.5.1.3.20 operator+ [reverse.iter.opsum]

template <class Iterator> constexpr reverse_iterator<Iterator> operator+( typename reverse_iterator<Iterator>::difference_type n, const reverse_iterator<Iterator>& x);

Returns: reverse_­iterator<Iterator> (x.current - n).