rustHow to derive error in Rust

Error handling in Rust is done using the Result type, which is an enum that can either be Ok or Err. To derive an error in Rust, you can use the #[derive(Debug)] attribute on a struct or enum. This will allow you to print out the error message when an error occurs.

Code example:

#[derive(Debug)]
enum Error {
    NotFound,
    PermissionDenied,
    ConnectionError,
}

fn main() {
    let result = Err(Error::NotFound);
    println!("{:?}", result);
}

Output

Err(Error::NotFound)

Explanation:

1. The #[derive(Debug)] attribute is used to enable the Debug trait for the Error enum. This allows us to print out the error message when an error occurs.

2. The Error enum is defined with three variants: NotFound, PermissionDenied, and ConnectionError.

3. The main function creates a Result with an Err variant containing the Error::NotFound variant.

4. The println! macro is used to print out the Result, which will print out the error message.

Helpful links:

1. Rust Error Handling
2. Rust Derive

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