|  | #![feature(box_into_boxed_slice)] | 
|  |  | 
|  | use std::boxed::Box; | 
|  | use std::fmt::Debug; | 
|  | fn main() { | 
|  | let boxed_slice = Box::new([1,2,3]) as Box<[u8]>; | 
|  | let _ = Box::into_boxed_slice(boxed_slice); | 
|  | //~^ ERROR the size for values of type `[u8]` cannot be known at compilation time | 
|  | //~^^ ERROR the size for values of type `[u8]` cannot be known at compilation time | 
|  | let boxed_trait: Box<dyn Debug> = Box::new(5u8); | 
|  | let _ = Box::into_boxed_slice(boxed_trait); | 
|  | //~^ ERROR the size for values of type `dyn Debug` cannot be known at compilation time | 
|  | //~^^ ERROR the size for values of type `dyn Debug` cannot be known at compilation time | 
|  | } |