b4b991e66f
For following:
```rust
struct A;
impl A {
fn test4(&self) {
let mut _file = File::create("foo.txt")?;
//~^ ERROR the `?` operator can only be used in a method
}
```
Suggest:
```rust
impl A {
fn test4(&self) -> Result<(), Box<dyn std::error::Error>> {
let mut _file = File::create("foo.txt")?;
//~^ ERROR the `?` operator can only be used in a method
Ok(())
}
}
```
For #125997
126 lines
5.0 KiB
Plaintext
126 lines
5.0 KiB
Plaintext
error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:10:44
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LL | fn test1() {
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| ---------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a function that returns `()`
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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help: consider adding return type
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LL ~ fn test1() -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL +
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LL + Ok(())
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LL + }
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error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:15:44
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LL | fn test2() {
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| ---------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a function that returns `()`
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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help: consider adding return type
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LL ~ fn test2() -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL | println!();
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LL +
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LL + Ok(())
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LL + }
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error[E0277]: the `?` operator can only be used in a method that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:34:48
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LL | fn test4(&self) {
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| --------------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a method that returns `()`
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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help: consider adding return type
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LL ~ fn test4(&self) -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL ~
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LL + Ok(())
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LL + }
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error[E0277]: the `?` operator can only be used in a method that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:39:48
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LL | fn test5(&self) {
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| --------------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a method that returns `()`
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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help: consider adding return type
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LL ~ fn test5(&self) -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL | println!();
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LL ~
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LL + Ok(())
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LL + }
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error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:46:44
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LL | fn main() {
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| --------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a function that returns `()`
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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help: consider adding return type
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LL ~ fn main() -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL | mac!();
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LL +
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LL + Ok(())
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LL + }
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error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:23:52
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LL | fn test3() {
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| ---------- this function should return `Result` or `Option` to accept `?`
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LL | let mut _file = File::create("foo.txt")?;
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| ^ cannot use the `?` operator in a function that returns `()`
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...
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LL | mac!();
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| ------ in this macro invocation
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= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
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= note: this error originates in the macro `mac` (in Nightly builds, run with -Z macro-backtrace for more info)
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help: consider adding return type
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LL ~ fn test3() -> Result<(), Box<dyn std::error::Error>> {
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LL | let mut _file = File::create("foo.txt")?;
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LL |
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LL | println!();
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LL ~
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LL + Ok(())
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LL + }
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error: aborting due to 6 previous errors
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For more information about this error, try `rustc --explain E0277`.
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