src/test/ui/invalid_dispatch_from_dyn_impls.stderr

   1 error[E0378]: the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, `PhantomData` fields, and nothing else
   2   --> $DIR/invalid_dispatch_from_dyn_impls.rs:10:1
   3    |
   4 LL | / impl<T, U> DispatchFromDyn<WrapperWithExtraField<U>> for WrapperWithExtraField<T>
   5 LL | | where
   6 LL | |     T: DispatchFromDyn<U>,
   7 LL | | {} //~^^^ ERROR [E0378]
   8    | |__^
   9    |
  10    = note: extra field `1` of type `i32` is not allowed
  11
  12 error[E0378]: implementing the `DispatchFromDyn` trait requires multiple coercions
  13   --> $DIR/invalid_dispatch_from_dyn_impls.rs:21:1
  14    |
  15 LL | / impl<T: ?Sized, U: ?Sized> DispatchFromDyn<MultiplePointers<U>> for MultiplePointers<T>
  16 LL | | where
  17 LL | |     T: Unsize<U>,
  18 LL | | {} //~^^^ ERROR [E0378]
  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
  24 error[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    |
  27 LL | impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NothingToCoerce<T>> for NothingToCoerce<U> {}
  28    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  29
  30 error[E0378]: structs implementing `DispatchFromDyn` may not have `#[repr(packed)]` or `#[repr(C)]`
  31   --> $DIR/invalid_dispatch_from_dyn_impls.rs:37:1
  32    |
  33 LL | / impl<T: ?Sized, U: ?Sized> DispatchFromDyn<HasReprC<U>> for HasReprC<T>
  34 LL | | where
  35 LL | |     T: Unsize<U>,
  36 LL | | {} //~^^^ ERROR [E0378]
  37    | |__^
  38
  39 error: aborting due to 4 previous errors
  40
  41 For more information about this error, try `rustc --explain E0378`.