Enum to represent exit code
- We can also define Failure variant of the ExitCode type to have an number - a small number holding a value between 0-255.
- We can use a match statement to extract the actual number from the Failure.
examples/enums/exit-code/src/main.rs
#[derive(Debug)] enum ExitCode { Success, Failure(u8), } fn main() { let args = std::env::args().collect::<Vec<_>>(); let exit = if args.len() == 2 { ExitCode::Success } else if args.len() < 2 { ExitCode::Failure(1) } else { ExitCode::Failure(2) }; println!("{exit:?}"); let code = match exit { ExitCode::Success => { println!("success"); 0 } ExitCode::Failure(err) => { println!("Error: {err}"); err } }; println!("{:?}", code); }
- Apparently the standard library of Rust uses a struct to represent an ExitCode.