Array sorting by predefined sorting ids list

Array+Sort.swift

extension Array {
  
  func sortByArray<T, Z: Hashable>(of ids:[Z],
                   keyType: Z.Type,
                   idClosure: (_ obj: T) -> (Z)) -> [T] {
    var dict = [Z: T]()
    
    guard let arr = self as? [T] else {
      return []
    }
    
    for o: T in arr {
      let key = idClosure(o)
      dict[key] = o
    }
    
    var output = [T]()
    for itemID in ids {
      if let obj = dict[itemID] {
        output.append(obj)
      }
    }
    
    return output
  }
  
}