// Check that we do not allow casts or coercions // to dyn-incompatible trait objects inside a Box #![feature(dyn_compatible_for_dispatch)] trait Trait: Sized {} struct S; impl Trait for S {} fn takes_box(t: Box) {} fn main() { Box::new(S) as Box; //~ ERROR E0038 let t_box: Box = Box::new(S); //~ ERROR E0038 takes_box(Box::new(S)); //~ ERROR E0038 }