Swift 2.2中协议“ Equatable”的“泛型”冗余一致性

Question

I am Having an error in Equatable while compilation. I wanted to add find or contains method in the list to check the value. My Code Below

class Generic: NSObject, Equatable, NSCoding //Am Having an error -  Redundant conformance of 'Generic' to protocol 'Equatable'

{

  var genericCode: String?
  var genericName : String?
  var genericType : String?
  var genericImageUrl : String?
  var genericPhone: String?
  var orgName : String?

override init()
{

    self.genericCode = String("")
    self.genericName = String("")
    self.genericType = String("")
    self.genericImageUrl = String("")
    self.genericPhone = String("")
    self.orgName = String("")

}

//Parameterzed Constructor for the Generic
init(genericCode: String , genericName: String , genericPhone: String, genericType: String, genericImageUrl : String)
{
    self.genericCode = genericCode
    self.genericName = genericName
    self.genericType = genericType
    self.genericImageUrl = genericImageUrl
    self.genericPhone = genericPhone

}

required init(coder aDecoder: NSCoder) {
    genericCode = aDecoder.decodeObjectForKey("genericCode") as? String
    genericName = aDecoder.decodeObjectForKey("genericName") as? String
    genericType = aDecoder.decodeObjectForKey("genericType") as? String
    genericPhone = aDecoder.decodeObjectForKey("genericPhone") as? String
}

func encodeWithCoder(aCoder: NSCoder) {
    aCoder.encodeObject(genericCode, forKey: "genericCode")
    aCoder.encodeObject(genericName, forKey: "genericName")
    aCoder.encodeObject(genericType, forKey: "genericType")
    aCoder.encodeObject(genericPhone, forKey: "genericPhone")
}

}

func ==(lhs: Generic, rhs: Generic) -> Bool
{
  return lhs.genericCode == rhs.genericCode
}

Error has occured , Is it because i am using NSCoding and NSobject?

Answer 1

A class inheriting NSObject already conforms to Equatable . So declaring Object: Equatable is redundant.

However, the conformance does not mean that it has been implemented properly ( NSObject just checks whether the pointers are the same). If you wish to properly implement Equatable for NSObject , just exclude the protocol conformance statement ( : Equatable ), but still implement the comparison method:

static func ==(lhs: Object, rhs: Object) -> Bool {
   return lhs.text == rhs.text
}

Answer 2

According to the docs , NSObject conforms to Equatable :

Conforms To
CVarArgType
CustomDebugStringConvertible
CustomStringConvertible
Equatable
Hashable
NSObjectProtocol

... therefore, like your error says, conformance to Equatable is redundant...