#![feature(let_else)] #![deny(unused_variables)] fn main() { let Some(_): Option = ({ let x = 1; //~ ERROR unused variable: `x` Some(1) }) else { return; }; #[allow(unused_variables)] let Some(_): Option = ({ let x = 1; Some(1) }) else { return; }; let Some(_): Option = ({ #[allow(unused_variables)] let x = 1; Some(1) }) else { return; }; let x = 1; //~ ERROR unused variable: `x` }