error[E0038]: the trait `Trait` is not dyn compatible --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:16:33 | LL | let t_box: Box = Box::new(S); | ^^^^^^^^^^^ `Trait` is not dyn compatible | note: for a trait to be dyn compatible it needs to allow building a vtable for more information, visit --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:6:14 | LL | trait Trait: Sized {} | ----- ^^^^^ ...because it requires `Self: Sized` | | | this trait is not dyn compatible... = help: only type `S` implements `Trait`; consider using it directly instead. = note: required for the cast from `Box` to `Box` error[E0038]: the trait `Trait` is not dyn compatible --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:17:15 | LL | takes_box(Box::new(S)); | ^^^^^^^^^^^ `Trait` is not dyn compatible | note: for a trait to be dyn compatible it needs to allow building a vtable for more information, visit --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:6:14 | LL | trait Trait: Sized {} | ----- ^^^^^ ...because it requires `Self: Sized` | | | this trait is not dyn compatible... = help: only type `S` implements `Trait`; consider using it directly instead. = note: required for the cast from `Box` to `Box<(dyn Trait + 'static)>` error[E0038]: the trait `Trait` is not dyn compatible --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:15:5 | LL | Box::new(S) as Box; | ^^^^^^^^^^^ `Trait` is not dyn compatible | note: for a trait to be dyn compatible it needs to allow building a vtable for more information, visit --> $DIR/wf-convert-dyn-incompat-trait-obj-box.rs:6:14 | LL | trait Trait: Sized {} | ----- ^^^^^ ...because it requires `Self: Sized` | | | this trait is not dyn compatible... = help: only type `S` implements `Trait`; consider using it directly instead. = note: required for the cast from `Box` to `Box` error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0038`.