Method operator ++

include/utf8cpp/unchecked.h:204–209

                return *this;
            }
            iterator operator ++ (int)
            {
                iterator temp = *this;
                ::std::advance(it, utf8::internal::sequence_length(it));
                return temp;
            }  
            iterator& operator -- ()
            {
                utf8::unchecked::prior(it);