|  | //@ check-pass | 
|  |  | 
|  | #![warn(unused_must_use)] | 
|  | #![feature(never_type)] | 
|  |  | 
|  | use std::ops::Add; | 
|  | use std::ops::Sub; | 
|  | use std::ops::Mul; | 
|  | use std::ops::Div; | 
|  | use std::ops::Rem; | 
|  |  | 
|  | fn main() { | 
|  | let x = 2_u32; | 
|  | (x.add(4), x.sub(4), x.mul(4), x.div(4), x.rem(4)); | 
|  |  | 
|  | x.add(4); //~ WARN unused return value of `add` that must be used | 
|  |  | 
|  | x.sub(4); //~ WARN unused return value of `sub` that must be used | 
|  |  | 
|  | x.mul(4); //~ WARN unused return value of `mul` that must be used | 
|  |  | 
|  | x.div(4); //~ WARN unused return value of `div` that must be used | 
|  |  | 
|  | x.rem(4); //~ WARN unused return value of `rem` that must be used | 
|  |  | 
|  | println!("{}", x); | 
|  | } |