480c4a18d5
Remove confusing 'while checking' note from opaque future type mismatches
Maybe I'm just misinterpreting the wording of the note. The only value I can see in this note is that it points out where the async's opaque future is coming from, but the way it's doing it is misleading IMO.
For example:
```rust
note: while checking the return type of the `async fn`
--> $DIR/dont-suggest-missing-await.rs:7:24
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LL | async fn make_u32() -> u32 {
| ^^^ checked the `Output` of this `async fn`, found opaque type
```
We point at the type `u32` in the HIR, but then say "found opaque type". We also say "while checking"... but we're typechecking a totally different function when we get this type mismatch!
r? ``@estebank`` but feel free to reassign and/or take your time reviewing this. I'd be inclined to also discuss reworking the presentation of this type mismatch to restore some of these labels in a way that makes it more clear what it's trying to point out.
37 lines
1.2 KiB
Plaintext
37 lines
1.2 KiB
Plaintext
error[E0308]: mismatched types
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--> $DIR/issue-102605.rs:13:20
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LL | convert_result(foo())
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| -------------- ^^^^^ expected `Result<(), _>`, found opaque type
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| arguments to this function are incorrect
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= note: expected enum `Result<(), _>`
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found opaque type `impl Future<Output = Result<(), String>>`
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note: function defined here
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--> $DIR/issue-102605.rs:7:4
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LL | fn convert_result<T, E>(r: Result<T, E>) -> Option<T> {
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| ^^^^^^^^^^^^^^ ---------------
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help: consider `await`ing on the `Future`
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LL | convert_result(foo().await)
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| ++++++
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help: try wrapping the expression in `Err`
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LL | convert_result(Err(foo()))
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| ++++ +
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error[E0277]: `main` has invalid return type `Option<()>`
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--> $DIR/issue-102605.rs:11:14
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LL | fn main() -> Option<()> {
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| ^^^^^^^^^^ `main` can only return types that implement `Termination`
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= help: consider using `()`, or a `Result`
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error: aborting due to 2 previous errors
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Some errors have detailed explanations: E0277, E0308.
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For more information about an error, try `rustc --explain E0277`.
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