| //! Test that non-coercion casts aren't allowed to drop the principal, |
| //! because they cannot modify the pointer metadata. |
| //! |
| //! We test this in a const context to guard against UB if this is allowed |
| //! in the future. |
| |
| trait Trait {} |
| impl Trait for () {} |
| |
| struct Wrapper<T: ?Sized>(T); |
| |
| const OBJECT: *const (dyn Trait + Send) = &(); |
| |
| // coercions are allowed |
| const _: *const dyn Send = OBJECT as _; |
| |
| // casts are **not** allowed |
| const _: *const Wrapper<dyn Send> = OBJECT as _; |
| //~^ ERROR casting `*const (dyn Trait + Send + 'static)` as `*const Wrapper<dyn Send>` is invalid |
| |
| fn main() {} |
