6efddac288
Expand the primary span of E0277 when the immediate unmet bound is not what the user wrote:
```
error[E0277]: the trait bound `i32: Bar` is not satisfied
--> f100.rs:6:6
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6 | <i32 as Foo>::foo();
| ^^^ the trait `Bar` is not implemented for `i32`, which is required by `i32: Foo`
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help: this trait has no implementations, consider adding one
--> f100.rs:2:1
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2 | trait Bar {}
| ^^^^^^^^^
note: required for `i32` to implement `Foo`
--> f100.rs:3:14
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3 | impl<T: Bar> Foo for T {}
| --- ^^^ ^
| |
| unsatisfied trait bound introduced here
```
Fix #40120.
63 lines
3.0 KiB
Plaintext
63 lines
3.0 KiB
Plaintext
error[E0277]: `?` couldn't convert the error to `String`
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--> $DIR/question-mark-result-err-mismatch.rs:14:22
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LL | fn foo() -> Result<String, String> {
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| ---------------------- expected `String` because of this
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...
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LL | .map_err(|e| {
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| __________-
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LL | | e;
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| | - help: remove this semicolon
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LL | | })
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| |__________- this can't be annotated with `?` because it has type `Result<_, ()>`
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LL | .map(|()| "")?;
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| ^ the trait `From<()>` is not implemented for `String`, which is required by `Result<String, String>: FromResidual<Result<Infallible, ()>>`
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= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
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= note: required for `Result<String, String>` to implement `FromResidual<Result<Infallible, ()>>`
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error[E0277]: `?` couldn't convert the error to `String`
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--> $DIR/question-mark-result-err-mismatch.rs:28:25
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LL | fn bar() -> Result<(), String> {
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| ------------------ expected `String` because of this
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LL | let x = foo();
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| ----- this has type `Result<_, String>`
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...
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LL | .map_err(|_| ())?;
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| ---------------^ the trait `From<()>` is not implemented for `String`, which is required by `Result<(), String>: FromResidual<Result<Infallible, ()>>`
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| this can't be annotated with `?` because it has type `Result<_, ()>`
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= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
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= help: the following other types implement trait `From<T>`:
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<String as From<char>>
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<String as From<Box<str>>>
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<String as From<Cow<'a, str>>>
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<String as From<&str>>
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<String as From<&mut str>>
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<String as From<&String>>
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= note: required for `Result<(), String>` to implement `FromResidual<Result<Infallible, ()>>`
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error[E0277]: `?` couldn't convert the error to `String`
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--> $DIR/question-mark-result-err-mismatch.rs:48:11
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LL | fn baz() -> Result<String, String> {
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| ---------------------- expected `String` because of this
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...
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LL | .ok_or_else(|| {
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| __________-
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LL | | "Couldn't split the test string";
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| | - help: remove this semicolon
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LL | | })?;
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| | -^ the trait `From<()>` is not implemented for `String`, which is required by `Result<String, String>: FromResidual<Result<Infallible, ()>>`
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| |__________|
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| this can't be annotated with `?` because it has type `Result<_, ()>`
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= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
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= note: required for `Result<String, String>` to implement `FromResidual<Result<Infallible, ()>>`
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error: aborting due to 3 previous errors
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For more information about this error, try `rustc --explain E0277`.
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