| error[E0038]: the trait `NotObjectSafe` cannot be made into an object |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:21:13 |
| | |
| LL | fn car() -> dyn NotObjectSafe { |
| | ^^^^^^^^^^^^^^^^^ `NotObjectSafe` 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 <https://doc.rust-lang.org/reference/items/traits.html#object-safety> |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:3:8 |
| | |
| LL | trait NotObjectSafe { |
| | ------------- this trait cannot be made into an object... |
| LL | fn foo() -> Self; |
| | ^^^ ...because associated function `foo` has no `self` parameter |
| = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead: |
| A |
| B |
| help: consider turning `foo` into a method by giving it a `&self` argument |
| | |
| LL | fn foo(&self) -> Self; |
| | +++++ |
| help: alternatively, consider constraining `foo` so it does not apply to trait objects |
| | |
| LL | fn foo() -> Self where Self: Sized; |
| | +++++++++++++++++ |
| |
| error[E0038]: the trait `NotObjectSafe` cannot be made into an object |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:29:17 |
| | |
| LL | fn cat() -> Box<dyn NotObjectSafe> { |
| | ^^^^^^^^^^^^^^^^^ `NotObjectSafe` 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 <https://doc.rust-lang.org/reference/items/traits.html#object-safety> |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:3:8 |
| | |
| LL | trait NotObjectSafe { |
| | ------------- this trait cannot be made into an object... |
| LL | fn foo() -> Self; |
| | ^^^ ...because associated function `foo` has no `self` parameter |
| = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead: |
| A |
| B |
| help: consider turning `foo` into a method by giving it a `&self` argument |
| | |
| LL | fn foo(&self) -> Self; |
| | +++++ |
| help: alternatively, consider constraining `foo` so it does not apply to trait objects |
| | |
| LL | fn foo() -> Self where Self: Sized; |
| | +++++++++++++++++ |
| |
| error[E0746]: return type cannot have an unboxed trait object |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:21:13 |
| | |
| LL | fn car() -> dyn NotObjectSafe { |
| | ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time |
| | |
| = help: if there were a single returned type, you could use `impl Trait` instead |
| help: box the return type, and wrap all of the returned values in `Box::new` |
| | |
| LL ~ fn car() -> Box<dyn NotObjectSafe> { |
| LL | |
| LL | if true { |
| LL ~ return Box::new(A); |
| LL | } |
| LL ~ Box::new(B) |
| | |
| |
| error[E0038]: the trait `NotObjectSafe` cannot be made into an object |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:31:16 |
| | |
| LL | return Box::new(A); |
| | ^^^^^^^^^^^ `NotObjectSafe` 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 <https://doc.rust-lang.org/reference/items/traits.html#object-safety> |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:3:8 |
| | |
| LL | trait NotObjectSafe { |
| | ------------- this trait cannot be made into an object... |
| LL | fn foo() -> Self; |
| | ^^^ ...because associated function `foo` has no `self` parameter |
| = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead: |
| A |
| B |
| = note: required for the cast from `Box<A>` to `Box<(dyn NotObjectSafe + 'static)>` |
| help: consider turning `foo` into a method by giving it a `&self` argument |
| | |
| LL | fn foo(&self) -> Self; |
| | +++++ |
| help: alternatively, consider constraining `foo` so it does not apply to trait objects |
| | |
| LL | fn foo() -> Self where Self: Sized; |
| | +++++++++++++++++ |
| |
| error[E0038]: the trait `NotObjectSafe` cannot be made into an object |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:33:5 |
| | |
| LL | Box::new(B) |
| | ^^^^^^^^^^^ `NotObjectSafe` 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 <https://doc.rust-lang.org/reference/items/traits.html#object-safety> |
| --> $DIR/object-unsafe-trait-in-return-position-dyn-trait.rs:3:8 |
| | |
| LL | trait NotObjectSafe { |
| | ------------- this trait cannot be made into an object... |
| LL | fn foo() -> Self; |
| | ^^^ ...because associated function `foo` has no `self` parameter |
| = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead: |
| A |
| B |
| = note: required for the cast from `Box<B>` to `Box<(dyn NotObjectSafe + 'static)>` |
| help: consider turning `foo` into a method by giving it a `&self` argument |
| | |
| LL | fn foo(&self) -> Self; |
| | +++++ |
| help: alternatively, consider constraining `foo` so it does not apply to trait objects |
| | |
| LL | fn foo() -> Self where Self: Sized; |
| | +++++++++++++++++ |
| |
| error: aborting due to 5 previous errors |
| |
| Some errors have detailed explanations: E0038, E0746. |
| For more information about an error, try `rustc --explain E0038`. |