error[E0038]: the trait `NonObjectSafe1` cannot be made into an object --> $DIR/feature-gate-object_safe_for_dispatch.rs:18:39 | LL | fn takes_non_object_safe_ref(obj: &dyn NonObjectSafe1) { | ^^^^^^^^^^^^^^^^^^ `NonObjectSafe1` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/feature-gate-object_safe_for_dispatch.rs:4:23 | LL | trait NonObjectSafe1: Sized {} | -------------- ^^^^^ ...because it requires `Self: Sized` | | | this trait cannot be made into an object... error[E0038]: the trait `NonObjectSafe2` cannot be made into an object --> $DIR/feature-gate-object_safe_for_dispatch.rs:22:45 | LL | fn return_non_object_safe_ref() -> &'static dyn NonObjectSafe2 { | ^^^^^^^^^^^^^^^^^^ `NonObjectSafe2` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/feature-gate-object_safe_for_dispatch.rs:7:8 | LL | trait NonObjectSafe2 { | -------------- this trait cannot be made into an object... LL | fn static_fn() {} | ^^^^^^^^^ ...because associated function `static_fn` has no `self` parameter help: consider turning `static_fn` into a method by giving it a `&self` argument | LL | fn static_fn(&self) {} | +++++ help: alternatively, consider constraining `static_fn` so it does not apply to trait objects | LL | fn static_fn() where Self: Sized {} | +++++++++++++++++ error[E0038]: the trait `NonObjectSafe3` cannot be made into an object --> $DIR/feature-gate-object_safe_for_dispatch.rs:27:39 | LL | fn takes_non_object_safe_box(obj: Box) { | ^^^^^^^^^^^^^^^^^^ `NonObjectSafe3` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/feature-gate-object_safe_for_dispatch.rs:11:8 | LL | trait NonObjectSafe3 { | -------------- this trait cannot be made into an object... LL | fn foo(&self); | ^^^ ...because method `foo` has generic type parameters = help: consider moving `foo` to another trait error[E0038]: the trait `NonObjectSafe4` cannot be made into an object --> $DIR/feature-gate-object_safe_for_dispatch.rs:31:47 | LL | fn return_non_object_safe_rc() -> std::rc::Rc { | ^^^^^^^^^^^^^^^^^^ `NonObjectSafe4` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/feature-gate-object_safe_for_dispatch.rs:15:22 | LL | trait NonObjectSafe4 { | -------------- this trait cannot be made into an object... LL | fn foo(&self, s: &Self); | ^^^^^ ...because method `foo` references the `Self` type in this parameter = help: consider moving `foo` to another trait error[E0038]: the trait `NonObjectSafe1` cannot be made into an object --> $DIR/feature-gate-object_safe_for_dispatch.rs:38:16 | LL | impl Trait for dyn NonObjectSafe1 {} | ^^^^^^^^^^^^^^^^^^ `NonObjectSafe1` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/feature-gate-object_safe_for_dispatch.rs:4:23 | LL | trait NonObjectSafe1: Sized {} | -------------- ^^^^^ ...because it requires `Self: Sized` | | | this trait cannot be made into an object... error: aborting due to 5 previous errors For more information about this error, try `rustc --explain E0038`.