Method operator+

inst/include/Rcpp/vector/MatrixRow.h:256–256

        }

        const_iterator operator+(difference_type n) const { return iterator( row, index + n ) ; }
        const_iterator operator-(difference_type n) const { return iterator( row, index - n ) ; }
        difference_type operator-(const const_iterator& other) const { return index - other.index ; }