| // We used to allow erroneous `DispatchFromDyn` impls whose RHS type contained |
| // fields that weren't ZSTs. I don't believe this was possible to abuse, but |
| // it's at least nice to give users better errors. |
| |
| #![feature(arbitrary_self_types)] |
| #![feature(unsize)] |
| #![feature(dispatch_from_dyn)] |
| |
| use std::marker::Unsize; |
| use std::ops::DispatchFromDyn; |
| |
| struct Dispatchable<T: ?Sized, Z> { |
| _ptr: Box<T>, |
| z: Z, |
| } |
| |
| impl<T, U> DispatchFromDyn<Dispatchable<U, i32>> for Dispatchable<T, ()> |
| //~^ ERROR implementing `DispatchFromDyn` does not allow multiple fields to be coerced |
| where |
| T: Unsize<U> + ?Sized, |
| U: ?Sized, |
| { |
| } |
| |
| fn main() {} |
