Swift's OptionSet

Elements
1

Is this something that Silver will support eventually? I know I can produce similar behavior using a Set right now but OptionSet offers extra convenience.

2

can you elaborate?

3

OptionSet behaves like a set but defines its own set elements. It is designed for bitsets and is quite handy.

Link to official Swift documentation: https://developer.apple.com/documentation/swift/optionset

4

Ah, I see. you feel like contributing it to https://github.com/remobjects/SwiftBaseLibrary, based on Set?

5

That’s a possibility. I’ll see what I can do, when I have some free time.

6

Cool.

Probably easiest to either copy Set and adjust it or (less per-platform work) but on top of the exiting Set, either by descending or wrapping it (depending on API needs)

7

I’ve been experimenting a bit. This is how I’ve set things up so far (this doesn’t do anything - just trying to incrementally get it to compile). This is in a shared project (“SharedProject” in the attached test case):

public protocol OptionSet: RawRepresentable {
    associatedtype Element = Self
}

This is in an iOS application project:

public struct Flags: OptionSet {

    typealias RawValue = UInt

    let rawValue: UInt

    init(rawValue: UInt) {
        self.rawValue = rawValue
    }

    public static let flag1 = Flags(rawValue: 1 << 0)
    public static let flag2 = Flags(rawValue: 1 << 1)
    public static let flag3 = Flags(rawValue: 1 << 2)
    public static let flag4 = Flags(rawValue: 1 << 3)
    public static let flag5 = Flags(rawValue: 1 << 4)
    public static let flag6 = Flags(rawValue: 1 << 5)
}

The second snippet is identical to what I had in my Xcode/Swift app’s source code (plus the typealias line, since it wasn’t required).

Here’s what I’m getting when compiling:

39
Capture d’écran, le 2019-01-21 à 15.22.39.png2366×566 81.7 KB

I have attached this minimalist test case below:

TestOptionSet.zip (157.5 KB)

8

Hmm, this seems like a bug, but I think its getting confused because RawRepresentable seems to be generic, but you’re declaring to implement RawRepresentable, not RawRepresentable. I’m not sure.

protocol IRawRepresentable<id!>! { 
    init(`init` rawValue: RawValue)
    let rawValue: id { get }
}

        let rawValue: UInt

        init(rawValue: UInt) {
            self.rawValue = rawValue
        }

these should match up, for for some reason they don’t…

9

Thanks, logged as bugs://81777