Swift extension that provides convenient shorthands for initializing `NSError` objects.

NSError+Shorthand.swift

/**
 Provides convenient shorthands for initializing `NSError` objects.
 */
extension NSError {
    /**
     Same as `init(domain:code:userInfo:)`, but `domain` defaults to the app's
     bundle indentifier.
     */
    convenience init(code: Int, userInfo: [NSObject : AnyObject]?) {
        let bundleIdentifier = NSBundle.mainBundle().bundleIdentifier!
        self.init(domain: bundleIdentifier, code: code, userInfo: userInfo)
    }
    
    /**
     Same as `init(code:userInfo:)`, but `userInfo` defaults to
     `[NSLocalizedDescriptionKey : localizedDescription]`. This is the shortest way
     to initialize an NSError instance.
     
     ###Examples:
         let error1 = NSError(code: -1, localizedDescription: "Something happened!")
         let error2 = NSError(localizedDescription: "Something more happened!")
     */
    convenience init (code: Int = 0, localizedDescription:String) {
        self.init(code: code, userInfo: [NSLocalizedDescriptionKey : localizedDescription])
    }
}

I got tired of having to type NSError(domain: ???, code: ???, userInfo: [NSLocalizedDescriptionKey: "...."]) every time.