HashableExample.swift

class User: Hashable {
  let name: String
  let age: Int

  init(name: String, age: Int) {
    self.name = name
    self.age = age
  }

  func hash(into hasher: inout Hasher) {
    hasher.combine(self.name)
    hasher.combine(self.age)
  }

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

let user1 = User(name: "전수열", age: 25)
let user2 = User(name: "전수열", age: 25)
print(user1 == user2)