forの部分をきれいに書けない #CodePiece

CodePiece.swift

protocol EnumExtension {}

extension EnumExtension where Self: Hashable {
    static var all: [Self] {
        var result: [Self] = []
        for i in 0..<0xff*MemoryLayout<Self>.size {
            var n = i
            let ptr = withUnsafePointer(to: &n) { UnsafeRawPointer($0) }
                .bindMemory(to: Self.self, capacity: MemoryLayout<Self>.size)
            if ptr.pointee.hashValue != n { break }
            result.append(ptr.pointee)
        }
        return result
    }
}


enum Fruit: EnumExtension {
    case peach
    case apple
    case grape

}

Fruit.all // [peach, apple, grape]