mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-12 16:45:37 +00:00
48 lines
2.0 KiB
Plaintext
48 lines
2.0 KiB
Plaintext
|
error[E0038]: the trait `A` cannot be made into an object
|
||
|
|
--> $DIR/avoid-ice-on-warning-3.rs:4:19
|
||
|
|
|
|
||
|
|
LL | trait B { fn f(a: A) -> A; }
|
||
|
|
| ^ `A` 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/avoid-ice-on-warning-3.rs:12:14
|
||
|
|
|
|
||
|
|
LL | trait A { fn g(b: B) -> B; }
|
||
|
|
| - ^ ...because associated function `g` has no `self` parameter
|
||
|
|
| |
|
||
|
|
| this trait cannot be made into an object...
|
||
|
|
help: consider turning `g` into a method by giving it a `&self` argument
|
||
|
|
|
|
||
|
|
LL | trait A { fn g(&self, b: B) -> B; }
|
||
|
|
| ++++++
|
||
|
|
help: alternatively, consider constraining `g` so it does not apply to trait objects
|
||
|
|
|
|
||
|
|
LL | trait A { fn g(b: B) -> B where Self: Sized; }
|
||
|
|
| +++++++++++++++++
|
||
|
|
|
||
|
|
error[E0038]: the trait `B` cannot be made into an object
|
||
|
|
--> $DIR/avoid-ice-on-warning-3.rs:12:19
|
||
|
|
|
|
||
|
|
LL | trait A { fn g(b: B) -> B; }
|
||
|
|
| ^ `B` 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/avoid-ice-on-warning-3.rs:4:14
|
||
|
|
|
|
||
|
|
LL | trait B { fn f(a: A) -> A; }
|
||
|
|
| - ^ ...because associated function `f` has no `self` parameter
|
||
|
|
| |
|
||
|
|
| this trait cannot be made into an object...
|
||
|
|
help: consider turning `f` into a method by giving it a `&self` argument
|
||
|
|
|
|
||
|
|
LL | trait B { fn f(&self, a: A) -> A; }
|
||
|
|
| ++++++
|
||
|
|
help: alternatively, consider constraining `f` so it does not apply to trait objects
|
||
|
|
|
|
||
|
|
LL | trait B { fn f(a: A) -> A where Self: Sized; }
|
||
|
|
| +++++++++++++++++
|
||
|
|
|
||
|
|
error: aborting due to 2 previous errors
|
||
|
|
|
||
|
|
For more information about this error, try `rustc --explain E0038`.
|