Swift UIImage extension to create arbitrarily-colored icons from a black-with-alpha master image

ImageColourMask.swift

//
//  ImageColourMask.swift
//
//  Created by Rob Mathers on 2018-07-13.
//  Swift version of https://gist.github.com/omz/1102091/e03982f00ecc34be6c40aedcb0932ed374992741
//  Original Objective-C version by Marco Arment and Ole Zorn
//
//  Usage example:
//  let maskedImage = UIImage(named: "test")?.maskedImage(color: UIColor.blue)

import UIKit

extension UIImage {
    func maskedImage(color: UIColor) -> UIImage? {
        let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, self.scale)
        let context = UIGraphicsGetCurrentContext()
        self.draw(in: rect)
        context?.setFillColor(color.cgColor)
        context?.setBlendMode(CGBlendMode.sourceAtop)
        context?.fill(rect)
        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return result
    }
}