1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
error[E0782]: expected a type, found a trait
--> $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]: expected a type, found a trait
--> $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]: expected a type, found a trait
--> $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`.
|
