error[E0308]: mismatched types --> $DIR/dst-bad-assign.rs:45:14 | LL | f5.ptr = Bar1 {f: 36}; | ^^^^^^^^^^^^ expected trait ToBar, found struct `Bar1` | = note: expected type `dyn ToBar` found type `Bar1` error[E0277]: the size for values of type `dyn ToBar` cannot be known at compilation time --> $DIR/dst-bad-assign.rs:45:5 | LL | f5.ptr = Bar1 {f: 36}; | ^^^^^^ doesn't have a size known at compile-time | = help: the trait `std::marker::Sized` is not implemented for `dyn ToBar` = note: to learn more, visit = note: the left-hand-side of an assignment must have a statically known size error: aborting due to 2 previous errors Some errors occurred: E0277, E0308. For more information about an error, try `rustc --explain E0277`.