Example of how easily we can build a "virtual proxy" in Swift 3.0

virtualproxy.swift

/*
 All it takes is the "lazy" keyword in front of the var definition and the object is instantiated when it is first used.  Brilliant.
*/

class MoralFibre {
    init() {
        print("***Creating MoralFibre***")
    }
    func actSociallyResponsibly() -> Int {
        print("supporting local soup kitchen")
        return 100_000
    }
    func empowerEmployees() -> Int {
        print("giving shares to our beloved employees")
        return 300_000
    }
    func cleanupEnvironment() -> Int {
        print("sending money to SANCCOB")
        return 1_500_000
    }
}

class Company : CustomStringConvertible {
    lazy var moralFibre = MoralFibre() // virtual proxy pattern
  
    var cash : Int
    let name : String
    
    init(name : String, cash : Int = 0) {
        print("***Creating Company***")
        self.name = name
        self.cash = cash
    }
    
    func makeMoney() {
        cash += 1_000_000
        print("Making tons of cash \(self)")
    }
    
    func destroyEnvironment() {
        cash += 2_000_000
        print("Sacrificing baby seals for profit \(self)")
    }
    
    func becomeFocusOfMediaAttention() {
        cash -= moralFibre.actSociallyResponsibly()
        cash -= moralFibre.empowerEmployees()
        cash -= moralFibre.cleanupEnvironment()
        print("Poor \(self)")
    }
    
    var description: String {
        return "Company \(name) has $\(cash)"
    }
}

let cretesoft = Company(name:"Cretesoft Limited", cash:10_000_000)
cretesoft.makeMoney()
cretesoft.makeMoney()
cretesoft.makeMoney()
cretesoft.destroyEnvironment()
cretesoft.makeMoney()
cretesoft.becomeFocusOfMediaAttention()

/*
Output is:
***Creating Company***
Making tons of cash Company Cretesoft Limited has $11000000
Making tons of cash Company Cretesoft Limited has $12000000
Making tons of cash Company Cretesoft Limited has $13000000
Sacrificing baby seals for profit Company Cretesoft Limited has $15000000
Making tons of cash Company Cretesoft Limited has $16000000
***Creating MoralFibre***
supporting local soup kitchen
giving shares to our beloved employees
sending money to SANCCOB
Poor Company Cretesoft Limited has $14100000
*/

/*
If we take away the "lazy" keyword, then we will have output:
***Creating MoralFibre***
***Creating Company***
Making tons of cash Company Cretesoft Limited has $11000000
Making tons of cash Company Cretesoft Limited has $12000000
Making tons of cash Company Cretesoft Limited has $13000000
Sacrificing baby seals for profit Company Cretesoft Limited has $15000000
Making tons of cash Company Cretesoft Limited has $16000000
supporting local soup kitchen
giving shares to our beloved employees
sending money to SANCCOB
Poor Company Cretesoft Limited has $14100000
*/