Hacker News new | comments | show | ask | jobs | submit login

`-> 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.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact