error[E0378]: the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, ZST fields with 1 byte alignment, and nothing else --> $DIR/invalid_dispatch_from_dyn_impls.rs:10:1 | LL | impl DispatchFromDyn> for WrapperWithExtraField | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: extra field `1` of type `i32` is not allowed error[E0378]: implementing the `DispatchFromDyn` trait requires multiple coercions --> $DIR/invalid_dispatch_from_dyn_impls.rs:21:1 | LL | impl DispatchFromDyn> for MultiplePointers | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the trait `DispatchFromDyn` may only be implemented for a coercion between structures with a single field being coerced = note: currently, 2 fields need coercions: `ptr1` (`*const T` to `*const U`), `ptr2` (`*const T` to `*const U`) error[E0378]: the trait `DispatchFromDyn` may only be implemented for a coercion between structures with a single field being coerced, none found --> $DIR/invalid_dispatch_from_dyn_impls.rs:31:1 | LL | impl DispatchFromDyn> for NothingToCoerce {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error[E0378]: structs implementing `DispatchFromDyn` may not have `#[repr(packed)]` or `#[repr(C)]` --> $DIR/invalid_dispatch_from_dyn_impls.rs:37:1 | LL | impl DispatchFromDyn> for HasReprC | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error[E0378]: the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, ZST fields with 1 byte alignment, and nothing else --> $DIR/invalid_dispatch_from_dyn_impls.rs:46:1 | LL | impl DispatchFromDyn> for OverAligned | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: extra field `1` of type `OverAlignedZst` is not allowed error: aborting due to 5 previous errors For more information about this error, try `rustc --explain E0378`.