枚举 – Swift如何指定类型约束为枚举？

我想指定类型约束，类型应该是一个原始值枚举：

enum SomeEnum: Int {
  case One,Two,Three
}

class SomeProtocol<E: enum<Int>> { // <- won't compile
    func doSomething(e: E) {
        compute(e.toRaw())
    }
}

我怎么能在斯威夫特呢？ (我用F#语法为例)

enum SomeEnum: Int {
    case One,Three
}

class SomeClass<E: RawRepresentable where E.RawValue == Int>{
    func doSomething(e: E) {
        print(e.rawValue)
    }
}

class SomeEnumClass : SomeClass<SomeEnum> {

}

或直接

class SomeOtherClass{
    func doSomething<E: RawRepresentable where E.RawValue == Int>(e: E) {
        print(e.rawValue)
    }
}

swift3的更新：

enum SomeEnum: Int {
    case One,Three
}

class SomeClass<E: RawRepresentable> where E.RawValue == Int {
    func doSomething(e: E) {
        print(e.rawValue)
    }
}

class SomeEnumClass : SomeClass<SomeEnum> {

}

RESP。

class SomeOtherClass{
    func doSomething<E: RawRepresentable>(e: E) where E.RawValue == Int {
        print(e.rawValue)
    }
}