blob: 75b9cf2e331621788ace7a5a987afeb66ebd9e7b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
|
$ cargo run
Compiling error-handling v0.1.0 (file:///projects/error-handling)
error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
--> src/main.rs:4:48
|
3 | fn main() {
| --------- this function should return `Result` or `Option` to accept `?`
4 | let greeting_file = File::open("hello.txt")?;
| ^ cannot use the `?` operator in a function that returns `()`
|
= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
For more information about this error, try `rustc --explain E0277`.
error: could not compile `error-handling` due to previous error
|
