Open Radar

 
It’s annoying that we cannot add type information for the type of errors we want to throw. This leads to needing to mark functions as throws or needing to have a catch-all at the end.

Adding “throws MyCustomError” as a constraint would improve the code snippet below.

func base() throws MyCustomError {
    throw MyCustomError.Dance
}

- code snippet -

enum MyCustomError: ErrorType {
    case Happy
    case Dance
}

func base() throws {
    throw MyCustomError.Dance
}

func handle() {
    do {
        try base()
        print("valid value")
    }
    catch MyCustomError.Happy {
        print("Happy error")
    }
    catch MyCustomError.Dance {
        print("Dance error")
    }
    catch {  /* this is really not required */
        print("catch all, because no types")
    }
}