| //@ compile-flags: --crate-type=lib | |
| pub trait Tr {} | |
| impl Tr for u32 {} | |
| pub fn foo() -> Box<impl Tr + ?Sized> { | |
| if true { | |
| let x = foo(); | |
| let y: Box<dyn Tr> = x; | |
| //~^ ERROR: the size for values of type `impl Tr + ?Sized` cannot be known | |
| } | |
| Box::new(1u32) | |
| } |