符合协议的结构类型的Swift数组

Question

I have a series of several struct s conforming to MyProtocol . I need an array of these structs' types (because they have a static method declared in MyProtocol that I need to be able to access). I have tried all kinds of things but I can't make Xcode like it.

Also, before this is marked as dupe – I tried this , but all I got was:

//Foo and Bar are structs conforming to MyProtocol

let MyStructArray: Array<MyProtocol.self> = [Foo.self, Bar.self]
//Protocol 'MyProtocol' can only be used as a generic constant because it has Self or associated type requirements

Answer 1

How about this?:

protocol MyProtocol {
    static func hello()
}

struct Foo: MyProtocol {
    static func hello() {
        println("I am a Foo")
    }
    var a: Int
}

struct Bar: MyProtocol {
    static func hello() {
        println("I am a Bar")
    }
    var b: Double
}

struct Baz: MyProtocol {
    static func hello() {
        println("I am a Baz")
    }
    var b: Double
}

let mystructarray: Array<MyProtocol.Type> = [Foo.self, Bar.self, Baz.self]

(mystructarray[0] as? Foo.Type)?.hello()  // prints "I am a Foo"

for v in mystructarray {
    switch(v) {
    case let a as Foo.Type:
        a.hello()
    case let a as Bar.Type:
        a.hello()
    default:
        println("I am something else")
    }
}

// The above prints:
I am a Foo
I am a Bar
I am something else

Answer 2

I found the problem. My protocol was inheriting from RawOptionSetType . Not sure why that caused an issue, but commenting that inheritance out made it work. Weird.