(iOS) View rounded corners

UIView+Rounded.swift

import UIKit

extension UIView {

    func roundCorners(corners: UIRectCorner, radius: CGFloat) {
        let path = UIBezierPath(roundedRect: bounds,
                                byRoundingCorners: corners,
                                cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        layer.mask = mask
    }

    func makeCircle() {
        if self.superview == nil {
            print("must call add subview first")
            return
        }

        roundCorners(corners: [.topLeft, .topRight, .bottomLeft, .bottomRight],
                     radius: self.frame.height / 2.0)
    }
}