1error[E0378]: the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, ZST fields with 1 byte alignment, and nothing else 2 --> $DIR/invalid_dispatch_from_dyn_impls.rs:10:1 3 | 4LL | / impl<T, U> DispatchFromDyn<WrapperWithExtraField<U>> for WrapperWithExtraField<T> 5LL | | where 6LL | | T: DispatchFromDyn<U>, 7LL | | {} 8 | |__^ 9 | 10 = note: extra field `1` of type `i32` is not allowed 11 12error[E0378]: implementing the `DispatchFromDyn` trait requires multiple coercions 13 --> $DIR/invalid_dispatch_from_dyn_impls.rs:21:1 14 | 15LL | / impl<T: ?Sized, U: ?Sized> DispatchFromDyn<MultiplePointers<U>> for MultiplePointers<T> 16LL | | where 17LL | | T: Unsize<U>, 18LL | | {} 19 | |__^ 20 | 21 = note: the trait `DispatchFromDyn` may only be implemented for a coercion between structures with a single field being coerced 22 = note: currently, 2 fields need coercions: `ptr1` (`*const T` to `*const U`), `ptr2` (`*const T` to `*const U`) 23 24error[E0378]: the trait `DispatchFromDyn` may only be implemented for a coercion between structures with a single field being coerced, none found 25 --> $DIR/invalid_dispatch_from_dyn_impls.rs:31:1 26 | 27LL | impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NothingToCoerce<T>> for NothingToCoerce<U> {} 28 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 29 30error[E0378]: structs implementing `DispatchFromDyn` may not have `#[repr(packed)]` or `#[repr(C)]` 31 --> $DIR/invalid_dispatch_from_dyn_impls.rs:37:1 32 | 33LL | / impl<T: ?Sized, U: ?Sized> DispatchFromDyn<HasReprC<U>> for HasReprC<T> 34LL | | where 35LL | | T: Unsize<U>, 36LL | | {} 37 | |__^ 38 39error[E0378]: the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, ZST fields with 1 byte alignment, and nothing else 40 --> $DIR/invalid_dispatch_from_dyn_impls.rs:46:1 41 | 42LL | / impl<T: ?Sized, U: ?Sized> DispatchFromDyn<OverAligned<U>> for OverAligned<T> 43LL | | where 44LL | | T: Unsize<U>, 45LL | | {} 46 | |__^ 47 | 48 = note: extra field `1` of type `OverAlignedZst` is not allowed 49 50error: aborting due to 5 previous errors 51 52For more information about this error, try `rustc --explain E0378`. 53