error[E0308]: mismatched types --> $DIR/dst-bad-assign.rs:35:14 | LL | f5.ptr = Bar1 {f: 36}; | ------ ^^^^^^^^^^^^ expected trait object `dyn ToBar`, found struct `Bar1` | | | expected due to the type of this binding | = note: expected trait object `dyn ToBar` found struct `Bar1` error[E0277]: the size for values of type `dyn ToBar` cannot be known at compilation time --> $DIR/dst-bad-assign.rs:35:5 | LL | f5.ptr = Bar1 {f: 36}; | ^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `dyn ToBar` = note: the left-hand-side of an assignment must have a statically known size error: aborting due to 2 previous errors Some errors have detailed explanations: E0277, E0308. For more information about an error, try `rustc --explain E0277`.