9 Iterators library [iterators]

9.7 Iterator adaptors [iterators.predef]

9.7.1 Reverse iterators [iterators.reverse]

9.7.1.2 reverse_iterator operations [reverse.iter.ops]

9.7.1.2.6 operator++ [reverse.iter.op++]

constexpr reverse_iterator& operator++();

1

Effects: -- current;

2

Returns: *this.

constexpr reverse_iterator operator++(int);

3

Effects: 

reverse_iterator tmp = *this;
--current;
return tmp;