How to express Result<Value, Error: Errortype> in a method signature

I've been trying to make an Alamofire upgrade from 2.0 to 3.0. One of the methods contains this signature:

func standardResponse(request: NSURLRequest?, response: NSHTTPURLResponse?, result: Result<AnyObject>, success: (object: AnyObject?) -> Void, failure: (error: ServerError) -> Void)

There's an error pointing at Result<AnyObject>, stating that generic type 'Result' specialized with too few type parameters (got 1, but expected 2)

Alright, so I put in 2. According to the Alamofire 3.0 migration guide, Result has changed to accommodate an extra Error: ErrorType parameter. I tried this next:

Result<AnyObject, Error>

This time the error was that Error does not conform to protocol ErrorType.

So maybe this?

Result<AnyObject, Error: ErrorType>

No cigar. Please help me understand.

Solution

It looks like the second parameter has to be an object conforming to ErrorType.

So you could for example create your own error type with an enum like this:

enum MyErrorType: ErrorType { 
    case SomeError 
    case SomeOtherError 
}

Then use it the way the compiler asks:

Result<AnyObject, MyErrorType>