IBDesignable Build Failed : <p>I have Created <code>IBDesignable</code> and <code>IBInspectable</code> custom class to give shadow and corner radius for view</p>

<p>But When I assign <code>Designable</code> class to <code>view</code>, I get Designable Build Failed</p>

<p>This is my code </p>

<pre><code>import Foundation

import UIKit

@IBDesignable
class DesignableView: UIView {
}

@IBDesignable
class DesignableButton: UIButton {
}

@IBDesignable
class DesignableLabel: UILabel {
}

@IBDesignable
class DesignableTableView: UITableView {

}

extension UIView {

    @IBInspectable
    var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
        }
    }

    @IBInspectable
    var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable
    var borderColor: UIColor? {
        get {
            if let color = layer.borderColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.borderColor = color.cgColor
            } else {
                layer.borderColor = nil
            }
        }
    }

    @IBInspectable
    var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.shadowRadius = newValue
        }
    }

    @IBInspectable
    var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.shadowOpacity = newValue
        }
    }

    @IBInspectable
    var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            layer.shadowOffset = newValue
        }
    }

    @IBInspectable
    var shadowColor: UIColor? {
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.shadowColor = color.cgColor
            } else {
                layer.shadowColor = nil
            }
        }
    }
}
</code></pre>

<p>This is what I got </p>

<p><a href="https://i.stack.imgur.com/LeXPP.png" rel="noreferrer"><img src="https://i.stack.imgur.com/LeXPP.png" alt="error"></a></p>
