How to access a Swift enum associated value outside of a switch statement

Question

Consider:

enum Line {
    case    Horizontal(CGFloat)
    case    Vertical(CGFloat)
}

let leftEdge             =  Line.Horizontal(0.0)
let leftMaskRightEdge    =  Line.Horizontal(0.05)

How can I access, say, lefEdge's associated value, directly, without using a switch statement?

let noIdeaHowTo          = leftEdge.associatedValue + 0.5

This doesn't even compile!

I had a look at these SO questions but none of the answers seem to address this issue.

The noIdeaHowTo non compiling line above should really be that one-liner, but because the associated value can be any type, I fail to even see how user code could write even a "generic" get or associatedValue method in le enum itself.

I ended up with this, but it is gross, and needs me to revisit the code each time I add/modify a case ...

enum Line {
    case    Horizontal(CGFloat)
    case    Vertical(CGFloat)

    var associatedValue: CGFloat {
        get {
            switch self {
                case    .Horizontal(let value): return value
                case    .Vertical(let value): return value
            }
        }
    }
}

Any pointer anyone?

question from:https://stackoverflow.com/questions/66063041/i-cant-get-enum-value

Answer 1

As others have pointed out, this is now kind of possible in Swift 2:

import CoreGraphics

enum Line {
    case    Horizontal(CGFloat)
    case    Vertical(CGFloat)
}

let min = Line.Horizontal(0.0)
let mid = Line.Horizontal(0.5)
let max = Line.Horizontal(1.0)

func doToLine(line: Line) -> CGFloat? {
    if case .Horizontal(let value) = line {
        return value
    }
    return .None
}

doToLine(min) // prints 0
doToLine(mid) // prints 0.5
doToLine(max) // prints 1