CGRect Codable implementation

CGRect+Codable.swift

// known-good: Swift 4, in Xcode Version 9.0 beta 2 (9M137d)
// will be unnecessary once the language can auto-synthesize for this case, or
// when Apple's ships a Codable implementation for CoreGraphics struct types.

extension CGSize : Codable {
  enum CodingKeys: String, CodingKey {
    case width
    case height
  }

  public func encode(to encoder: Encoder) throws {
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(width,forKey:.width)
    try container.encode(height,forKey:.height)
  }

  public init(from decoder:Decoder) throws {
    let values =  try decoder.container(keyedBy: CodingKeys.self)
    width = try values.decode(CGFloat.self, forKey: .width)
    height = try values.decode(CGFloat.self, forKey: .height)
  }
}

extension CGPoint : Codable {
  enum CodingKeys: String, CodingKey {
    case x
    case y
  }

  public func encode(to encoder: Encoder) throws {
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(x,forKey:.x)
    try container.encode(y,forKey:.y)
  }

  public init(from decoder:Decoder) throws {
    let values =  try decoder.container(keyedBy: CodingKeys.self)
    x = try values.decode(CGFloat.self, forKey: .x)
    y = try values.decode(CGFloat.self, forKey: .y)
  }
}

extension CGRect : Codable {
  enum CodingKeys: String, CodingKey {
    case origin
    case size
  }
  public func encode(to encoder: Encoder) throws {
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(origin,forKey:.origin)
    try container.encode(size,forKey:.size)
  }
  public init(from decoder:Decoder) throws {
    let values =  try decoder.container(keyedBy: CodingKeys.self)
    origin = try values.decode(CGPoint.self, forKey: .origin)
    size = try values.decode(CGSize.self, forKey: .size)
  }
}

Warning. Currently it seems to me that:

• Apple did ship a default Codable implementation for CGPoint, on iOS
• Apple did ship a default Codable implementation for CGPoint, but not on macOS (?!)
• it uses a different scheme than the one above