The Flyweight Pattern is a structural design pattern that minimizes memory usage and processing. The flyweight pattern provides a shared instance that allows other instances to be created too. Every reference to the class refers to the same underlying instance.

FlyweightPattern.swift

import UIKit

let red = UIColor.red
let red2 = UIColor.red
print(red === red2) // proves this is a flyweight

let color = UIColor(red: 1, green: 0, blue: 0, alpha: 1)
let color2 = UIColor(red: 1, green: 0, blue: 0, alpha: 1)
print(color === color2) // proves this is NOT a flyweight

extension UIColor {

    public static var colorStore: [String: UIColor] = [:]

    public class func rgba(_ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat) -> UIColor {

        let key = "\(red)\(green)\(blue)\(alpha)"
//    print("Your key is  \(key)")
        if let color = colorStore[key] {
            return color
        }

        let color = UIColor(red: red,
                            green: green,
                            blue: blue,
                            alpha: alpha)
        colorStore[key] = color
        return color
    }
}

let flyColor = UIColor.rgba(1, 0, 0, 1)
let flyColor2 = UIColor.rgba(1, 45, 6, 1)
print(flyColor === flyColor2) // proves this is a flyweight class method