// Solution 1: Usage
let string = matrix.serialized
let newMatrix = matrix_float4x4(string)

// Solution 2: Usage
let string = serialize(matrix)
let newMatrix = deserializeMatrix(string)

// Solution 1: Implementation

extension simd_float4 {
  var serialized: String {
    return [x, y, z, w].map(String.init).joined(separator: ",")
  }

  init(_ string: String) {
    let points = string.split(separator: ",").flatMap(Float.init)
    self.init(points)
  }
}

extension matrix_float4x4 {
  var serialized: String {
    let cs = [columns.0, columns.1, columns.2, columns.3]
    return cs.map { $0.serialized }.joined(separator: "|")
  }

  init(_ string: String) {
    let columns = string.split(separator: "|").map(String.init).map(simd_float4.init)
    self.init(columns)
  }
}

// Solution 2: Implementation

func serialize(_ sf: simd_float4) -> String {
  let points = [sf.x, sf.y, sf.z, sf.w]
  return points.map(String.init).joined(separator: ",")
}

func serialize(_ m: matrix_float4x4) -> String {
  let columns = [m.columns.0, m.columns.1, m.columns.2, m.columns.3]
  return columns.map(serialize).joined(separator: "|")
}

func deserializeFloat4(_ str: String) -> simd_float4 {
  let points = str.split(separator: ",").flatMap(Float.init)
  return simd_float4(points)
}

func deserializeMatrix(_ str: String) -> matrix_float4x4 {
  let columns = str.split(separator: "|").map(String.init).map(deserializeFloat4)
  return matrix_float4x4(columns)
}