4 ms·

Wasn't there an attempt to get a variation of main that returned result at one point(that would presumably print error and set exit code one error)? Back before

• steveklabnik 10y ago
  Yes, and that discussion is still ongoing. The devil, as always, is in the details.
  • JoshTriplett 10y ago
    `-> impl Trait` seems useful in that context, so that main could have a variety of appropriate return value types: `()`, `i32` (for an exit code), or `Result<T, E>` where T implements ReturnValue and E implements Error. `quick_error` uses a trait like that to determine the exit code of `main()`, allowing it to return either () or i32.
• masklinn 10y ago
  FWIW there are third-party libraries which include that feature e.g. error_chain has a `quick_main` macro (working with its `error_chain!`-generated error, but I'm not sure it actually depends on it): quick_main!(|| -> Result<()> { // insert Result-returning code here }); Alternatively it takes a few lines to bootstrap it by hand e.g. ripgrep uses this code to bootstrap: fn main() { match Args::parse().map(Arc::new).and_then(run) { Ok(0) => process::exit(1), Ok(_) => process::exit(0), Err(err) => { eprintln!("{}", err); process::exit(1); } } } https://github.com/BurntSushi/ripgrep/blob/master/src/main.rs#L59 https://github.com/BurntSushi/ripgrep/blob/master/src/main.r...