#![feature(dyn_trait)] fn main() { // checks rustfmt doesn't remove dyn trait MyTrait { fn method(&self) -> u64; } fn f1(a: Box) {} // checks if line wrap works correctly trait Very_______________________Long__________________Name_______________________________Trait { fn method(&self) -> u64; } fn f2( a: Box< dyn Very_______________________Long__________________Name____________________Trait + 'static, >, ) { } }