184     type Output = Self;  typedef
186     fn add(self, rhs: Self) -> Self::Output {  in add()  argument
198     type Output = Self;  typedef
200     fn sub(self, rhs: Self) -> Self::Output {  in sub()  argument
212     type Output = Self;  typedef
214     fn mul(self, rhs: Self) -> Self::Output {  in mul()  argument
220     type Output = Self;  typedef
222     fn add(self, rhs: usize) -> Self::Output {  in add()  argument
234     type Output = Self;  typedef
236     fn sub(self, rhs: usize) -> Self::Output {  in sub()  argument
248     type Output = Self;  typedef
250     fn mul(self, rhs: usize) -> Self::Output {  in mul()  argument