'[(UIView)]' is not identical to 'UInt8' when using += in Xcode 6 beta 5. Use append method instead?

Question

I was using += to an a UIView to an array and that no longer seems to work. The line

dropsFound += hitView

Gives an error \'[(UIView)]\' is

Answer 1

The solution appears to be that you need to use the append method for the array rather than +=. I don't know the reason for this, so another answer might be more appropriate.

Instead of

dropsFound += hitView

use

dropsFound.append(hitView!)

Again, note that the UIView returned from hitTest is an optional as of Xcode 6 beta 5.

I verified that this is a general problem with arrays with the following playground sample. A bug report has been posted to Apple.

var s: [String] = []
// s += "hello"  // error: '[String]' is not identical to 'UInt8'
s.append("hello")
s

There is an additional complexity if you are trying to append a tuple, and perhaps other types.

// line below no longer works in Xcode 6 beta 5
// and you will also get an error trying to append the tuple directly
// which is probably a bug
// possibleFlipsArray += (x, y)
// possibleFlipsArray.append((x, y))
let tempTuple = (x, y)
possibleFlipsArray.append(tempTuple)

This probably deserves its own question, though I think it is just another bug, so again I've posted it to Apple.

Answer 2

That changed in the last release. From the beta 5 release notes:

The += operator on arrays only concatenates arrays, it does not append an element. This resolves ambiguity working with Any, AnyObject and related types.

So if the left side of += is an array, the right now must be as well.

so:

dropsFound.append(hitView)

Or if you really wanted to use += you could probably do:

dropsFound += [hitView]

But that would be a little silly. Use append like the error message suggests.

Answer 3

adding object in array dropsFound += hitView,in this way, is removed in last release. You can add element in array by using this syntax dropsFound += [hitView] or dropsFound.append(hitView)