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]

9.7.1.2.7 operator-- [reverse.iter.op--]

constexpr reverse_iterator& operator--();

Effects: ++current

Returns: *this.

constexpr reverse_iterator operator--(int);

Effects:

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