rust/tests/ui/traits/bound/not-on-bare-trait-2021.stderr
Esteban Küber 0487500776 Provide better suggestions when encountering a bare trait as a type
Add the following suggestions:

```
error[E0782]: trait objects must include the `dyn` keyword
  --> $DIR/not-on-bare-trait-2021.rs:11:11
   |
LL | fn bar(x: Foo) -> Foo {
   |           ^^^
   |
help: use a generic type parameter, constrained by the trait `Foo`
   |
LL | fn bar<T: Foo>(x: T) -> Foo {
   |       ++++++++    ~
help: you can also use `impl Foo`, but users won't be able to specify the type paramer when calling the `fn`, having to rely exclusively on type inference
   |
LL | fn bar(x: impl Foo) -> Foo {
   |           ++++
help: alternatively, use a trait object to accept any type that implements `Foo`, accessing its methods at runtime using dynamic dispatch
   |
LL | fn bar(x: &dyn Foo) -> Foo {
   |           ++++

error[E0782]: trait objects must include the `dyn` keyword
  --> $DIR/not-on-bare-trait-2021.rs:11:19
   |
LL | fn bar(x: Foo) -> Foo {
   |                   ^^^
   |
help: use `impl Foo` to return an opaque type, as long as you return a single underlying type
   |
LL | fn bar(x: Foo) -> impl Foo {
   |                   ++++
help: alternatively, you can return an owned trait object
   |
LL | fn bar(x: Foo) -> Box<dyn Foo> {
   |                   +++++++    +
```
2024-01-03 18:59:42 +00:00

57 lines
2.0 KiB
Plaintext

error[E0782]: trait objects must include the `dyn` keyword
--> $DIR/not-on-bare-trait-2021.rs:8:12
|
LL | fn foo(_x: Foo + Send) {
| ^^^^^^^^^^
|
help: use a new generic type parameter, constrained by `Foo + Send`
|
LL | fn foo<T: Foo + Send>(_x: T) {
| +++++++++++++++ ~
help: you can also use an opaque type, but users won't be able to specify the type parameter when calling the `fn`, having to rely exclusively on type inference
|
LL | fn foo(_x: impl Foo + Send) {
| ++++
help: alternatively, use a trait object to accept any type that implements `Foo + Send`, accessing its methods at runtime using dynamic dispatch
|
LL | fn foo(_x: &(dyn Foo + Send)) {
| +++++ +
error[E0782]: trait objects must include the `dyn` keyword
--> $DIR/not-on-bare-trait-2021.rs:11:11
|
LL | fn bar(x: Foo) -> Foo {
| ^^^
|
help: use a new generic type parameter, constrained by `Foo`
|
LL | fn bar<T: Foo>(x: T) -> Foo {
| ++++++++ ~
help: you can also use an opaque type, but users won't be able to specify the type parameter when calling the `fn`, having to rely exclusively on type inference
|
LL | fn bar(x: impl Foo) -> Foo {
| ++++
help: alternatively, use a trait object to accept any type that implements `Foo`, accessing its methods at runtime using dynamic dispatch
|
LL | fn bar(x: &dyn Foo) -> Foo {
| ++++
error[E0782]: trait objects must include the `dyn` keyword
--> $DIR/not-on-bare-trait-2021.rs:11:19
|
LL | fn bar(x: Foo) -> Foo {
| ^^^
|
help: use `impl Foo` to return an opaque type, as long as you return a single underlying type
|
LL | fn bar(x: Foo) -> impl Foo {
| ++++
help: alternatively, you can return an owned trait object
|
LL | fn bar(x: Foo) -> Box<dyn Foo> {
| +++++++ +
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0782`.