Float-initialized UIColors

Discovered on the Swift-User list that UIColor in the most recent May 3rd toolchain supports initializers for both Float and CGFloat. Which is odd:

Screen Shot 2016-05-11 at 8.33.08 AM

You can see both initializers at the bottom of the screen shot.

Bit of a problem because Xcode complains about an “Ambiguous use of init(red:green:blue:alpha:)”. No kidding. So right now, you can start casting everything, e.g.

let color = UIColor(red: CGFloat(0.5), green: CGFloat(0.5), blue: CGFloat(0.5),  alpha: CGFloat(1.0))

Or you can do something really stupid like this:

extension Double {
    var cg: CGFloat { return CGFloat(self) }

class ViewController: UIViewController {
    override func viewDidLoad() {
        let c = UIColor(red: 0.5.cg, green: 0.5, blue: 0.5, alpha: 0.5)

It works but ew.

So here’s my question: who ever uses Float with UIColor to begin with and why did this pop up in the latest build? Is it part of the Cocoa auto-migration thing? And do you think I should just go ahead and file a bug?

Update: Bug filed. SR-1479 Resolved as dupe. 🙂


  • Yes and yes

  • Definitely seems like a migration thing. and definitely seems like a bug 🙂 I would expect those types to eventually be interchangeable, but who knows…

  • Since when you’re working on an application you probably use a certain palette of colors what I do is this

    import UIKit

    /** A simple representation of color. */
    public struct ColorStyleUtils {
    let uiColor: UIColor

    /** Constructs a color from RGB and alpha values. Arguments range from 0.0 to 1.0. */
    public init(red: Double, green: Double, blue: Double, alpha: Double = 1.0) {
    uiColor = UIColor(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: CGFloat(alpha))

    public static var someColor: ColorStyleUtils { return ColorStyleUtils(red: 125.0/255.0, green: 125.0/255.0, blue: 125.0/255.0, alpha: 1.0) }

    Then on my others objects I just call the predefined color.

    someButton.backgroundColor = ColorStyleUtils.someColor