Simplest way to throw an error/exception with a custom message in Swift 2?

Question

I want to do something in Swift 2 that I\'m used to doing in multiple other languages: throw a runtime exception with a custom message. For example (in Java):

Answer 1

I like @Alexander-Borisenko's answer, but the localized description was not returned when caught as an Error. It seems that you need to use LocalizedError instead:

struct RuntimeError: LocalizedError
{
    let message: String

    init(_ message: String)
    {
        self.message = message
    }

    public var errorDescription: String?
    {
        return message
    }
}

See this answer for more details.