Multiple Type Constraints in Swift

Question

Let\'s say I have these protocols:

protocol SomeProtocol {

}

protocol SomeOtherProtocol {

}

Now, if I want a function that takes a gener

Answer 1

Swift 3 offers up to 3 different ways to declare your function.

protocol SomeProtocol {
    /* ... */
}

protocol SomeOtherProtocol {
    /* ... */        
}

1. Using & operator

func someFunc(arg: T) {
    /* ... */
}

2. Using where clause

func someFunc(arg: T) where T: SomeProtocol, T: SomeOtherProtocol {
    /* ... */
}

3. Using where clause and & operator

func someFunc(arg: T) where T: SomeProtocol & SomeOtherProtocol {
    /* ... */        
}

---

Also note that you can use typealias in order to shorten your function declaration.

typealias RequiredProtocols = SomeProtocol & SomeOtherProtocol

func someFunc(arg: T) {
    /* ... */   
}