Swift落穂ひろい プトロコル準拠

Swiftで少しわかりにくかった所を整理しておきます。Swift3です。

二つのプロトコル準拠

複数のプロトコル準拠な変数宣言に&を使います。

let animal3:Animal & Helloable = seri

Switch文で特定の型に対して

protocol Animal {
    
}

protocol Helloable {
    func hello()
}


struct Dog : Animal,Helloable {
    let name:String
    let legs:Int
    let age:Int
    
    func hello() {
        print("bow!")
    }
}

struct Cat : Animal, Helloable {
    let name:String
    let legs:Int
    let age:Int
    
    func hello() {
        print("nyao!")
    }
}

struct Fish : Animal {
    let name:String
    let age:Int
}

let seri = Dog(name: "Seri", legs: 4, age:13)
seri.hello()

let tama = Cat(name: "Tama", legs: 4, age:5)
tama.hello()

let kin = Fish(name: "Kin", age:1)

let animal:Animal = seri
let animal2:Helloable = seri
let animal3:Animal & Helloable = seri
let animal4:Any&Helloable = seri

let animals:[Animal] = [seri, tama, kin]

animals.forEach { (p:Animal) in
    switch(p) {
    case let p as Animal & Helloable:
        p.hello()
    default:
        break
    }
}