Deep Copy

copy1.swift

protocol DeepCopyable {
  init(deeplyCopying: Self)
}

extension Array: DeepCopyable where Element: DeepCopyable {
  init(deeplyCopying: [Element]) {
    self = deeplyCopying.map(Element.init(deeplyCopying:))
  }
}

extension Dictionary: DeepCopyable where Value: DeepCopyable {
  init(deeplyCopying: [Key: Value]) {
    self = deeplyCopying.mapValues(Value.init(deeplyCopying:))
  }
}

class TestClass: DeepCopyable {
  var x: Int

  init(x: Int) {
    self.x = x
  }

  required init(deeplyCopying: TestClass) {
    self.x = deeplyCopying.x
  }
}

struct TestStruct: DeepCopyable {
  var c: TestClass

  init(c: TestClass) {
    self.c = c
  }

  init(deeplyCopying: TestStruct) {
    self.c = TestClass(deeplyCopying: deeplyCopying.c)
  }
}

let a = TestClass(x: 20)
let b = TestStruct(c: a)

print(b.c.x)

a.x = 10

print(b.c.x)

let c = TestStruct(deeplyCopying: b)

print(c.c.x)

a.x = 30

print(c.c.x)