// Imagine these sheet classes and the bed struct in a separate module somewhere

class Sheet {
    func pullOver() {
        print("sleep time")
    }
}

class ComfySheet : Sheet {
    public static let veryComfy: ComfySheet = {
        return ComfySheet()
    }()

    func comfort() {
        print("comfortable")
    }
}

class BouncySheet : Sheet {
    public static let veryBouncy: BouncySheet = {
        return BouncySheet()
    }()

    func bounce() {
        print("bounce")
    }
}

class AwfulSheet : Sheet {
    override func pullOver() {
        print("ew")
    }
}

struct Bed<SheetType> where SheetType : Sheet {
    public let size: Double
    public let sheets: SheetType
}

// This protocol and the corresponding extensions are editable

protocol EnjoymentMeasurable where Self : Sheet {
    func enjoy()
}

extension ComfySheet : EnjoymentMeasurable {
    func enjoy() {
        print("8/10")
    }
}

extension BouncySheet : EnjoymentMeasurable {
    func enjoy() {
        print("11/10")
    }
}

func doSomething() {
    let bed: Bed<EnjoymentMeasurable> // error here: "'Bed' requires that 'EnjoymentMeasurable' inherit from 'Sheet'"
    bed = Bed(size: 4.0, sheets: ComfySheet.veryComfy)
    bed.sheets.enjoy()
}