Open Radar

 
First: thanks for Swift! I like it a lot.

In the process of migrating to Swift 2, I found a bug.

When a protocol has a Self requirement, I can't implement it inside a function or a method. See the attached source code. My use case is implementing a protocol in a test function: https://github.com/macoscope/SwiftyStateMachine/blob/350f9a0f5cdd5f3a11bcc6b6a6f03460b20716b8/StateMachineTests/StateMachineSpec.swift#L243-L253


Xcode 7.0 beta (7A120f)
OS X 10.10.3 (14D136)


attached test.swift:

// > xcrun swift --version
// Apple Swift version 2.0 (swiftlang-700.0.38.1 clang-700.0.53)
// Target: x86_64-apple-darwin14.3.0


protocol MyEnumProtocol {
    static var allCases: [Self] { get }
}


// works on the top level
enum MyEnum: MyEnumProtocol {
    case A
    static var allCases: [MyEnum] { return [.A] }
}


class WorksInsideAClass {
    enum MyOtherEnum: MyEnumProtocol {
        case A
        static var allCases: [MyOtherEnum] { return [.A] }
    }
}


func doesntWorkInsideFunctions() {
    // error: protocol 'MyEnumProtocol' can only be used as a generic
    // constraint because it has Self or associated type requirements
    enum MyYetAnotherEnum: MyEnumProtocol {
        case A
        static var allCases: [MyYetAnotherEnum] { return [.A] }
    }
}