warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes --> $DIR/upcast.rs:3:12 | LL | #![feature(dyn_star, trait_upcasting)] | ^^^^^^^^ | = note: see issue #102425 for more information = note: `#[warn(incomplete_features)]` on by default error[E0277]: `dyn* Foo` needs to have the same alignment and size as a pointer --> $DIR/upcast.rs:30:23 | LL | let w: dyn* Bar = w; | ^ `dyn* Foo` needs to be a pointer-like type | = help: the trait `PointerLike` is not implemented for `dyn* Foo` error: aborting due to previous error; 1 warning emitted For more information about this error, try `rustc --explain E0277`.