208     type Output = Self;  typedef
210     fn add(self, rhs: Self) -> Self::Output {  in add()  argument
222     type Output = Self;  typedef
224     fn sub(self, rhs: Self) -> Self::Output {  in sub()  argument
236     type Output = Self;  typedef
238     fn mul(self, rhs: Self) -> Self::Output {  in mul()  argument
244     type Output = Self;  typedef
246     fn add(self, rhs: usize) -> Self::Output {  in add()  argument
258     type Output = Self;  typedef
260     fn sub(self, rhs: usize) -> Self::Output {  in sub()  argument
272     type Output = Self;  typedef
274     fn mul(self, rhs: usize) -> Self::Output {  in mul()  argument