87 lines
3.4 KiB
Plaintext
87 lines
3.4 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 function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/return-from-residual-sugg-issue-125997.rs:31:44
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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 4 previous errors
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For more information about this error, try `rustc --explain E0277`.
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