New upstream version 1.56.0~beta.4+dfsg1

[rustc.git] / src / test / ui / impl-trait / object-unsafe-trait-in-return-position-dyn-trait.stderr

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: 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:28:13
   |
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: 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 2 previous errors

For more information about this error, try `rustc --explain E0038`.