#![deny(unused_variables)] struct Point { x: i32, y: i32, } fn main() { let points = vec!(Point { x: 1, y: 2 }, Point { x: 3, y: 4 }); let _: i32 = points.iter() .map(|Point { x, y }| y) //~^ ERROR unused variable .sum(); let _: i32 = points.iter() .map(|x| 4) //~^ ERROR unused variable .sum(); }