How to Create Enum with Raw Type of Cgpoint

Enum variables in Swift?

For Swift enum, you can only use (String|Integer|Float)LiteralConvertible types as the raw value. If you want to use existing type(e.g. CGPoint) for the raw value, you should follow @Alex answer.

I will provide 2 alternatives in this answer

Very simple solution

enum Test: String {
    case A = "foo:1"
    case B = "bar:2"

    var var1: String {
        return split(self.rawValue, { $0 == ":" })[0]
    }
    var var2: Int {
        return split(self.rawValue, { $0 == ":" })[1].toInt()!
    }
}

let test = Test.A
println(test.var1) // -> "foo"

You don't like this? go to next one :)

Behavior emulation using struct and static constants

struct Test {
    let var1: String
    let var2: Int
    private init(_ var1:String, _ var2:Int) {
        self.var1 = var1
        self.var2 = var2
    }
}

extension Test {
    static let A = Test("foo", 1)
    static let B = Test("bar", 2)
    static let allValues = [A, B]
}

let test = Test.A
println(test.var1) // -> "foo"

But of course, struct lacks some features from enum. You have to manually implement it.

Swift enum implicitly conforms Hashable protocol.

extension Test: Hashable {
    var hashValue:Int {
        return find(Test.allValues, self)!
    }
}

func ==(lhs:Test, rhs:Test) -> Bool {
    return lhs.var1 == rhs.var1 && lhs.var2 == rhs.var2
}

Test.A.hashValue // -> 0
Test.B.hashValue // -> 1
Test.A == Test.B // -> false

In the first code, we already have allValues that is corresponding to values() in Java. valueOf(...) in Java is equivalent to init?(rawValue:) in RawRepresentable protocol in Swift:

extension Test: RawRepresentable {

    typealias RawValue = (String, Int)

    init?(rawValue: RawValue) {
        self.init(rawValue)
        if find(Test.allValues, self) == nil{
            return nil
        }
    }

    var rawValue: RawValue {
        return (var1, var2)
    }
}

Test(rawValue: ("bar", 2)) == Test.B
Test(rawValue: ("bar", 4)) == nil

And so on...

I know this is not "in a generic way". And one thing we never can emulate is "Matching Enumeration Values with a Switch Statement" feature in Swift. you always need default case:

var test = Test.A
switch test {
case Test.A: println("is A")
case Test.B: println("is B")
default: fatalError("cannot be here!")
}

How to declare a typedef enum of structs in Objective-C if possible

You can declare enum only of integral type, so struct or any other composite type is not allowed here. In your case const CGPoint is probably the best option:

const CGPoint kFeedbackPositionMiddle = {20.f,80.f};
...

I want my custom Error type has name Error

The name of the module is Swift, with a capital "S".

enum Error: Swift.Error {
    
}

@IBInspectable with enum?

That's not possible (for now). You can only use those types that you see in User Defined Runtime Attributes section.

From Apple's doc:

You can attach the IBInspectable attribute to any property in a class declaration, class extension, or category for any type that’s supported by the Interface Builder defined runtime attributes: boolean, integer or floating point number, string, localized string, rectangle, point, size, color, range, and nil.

---

Related Topics