Raw type 'Bool' is not expressible by any literal

my solution on swift 3

enum DataType: RawRepresentable {
    case given
    case received

    typealias RawValue = Bool
    var rawValue: RawValue {
        return self == .given ? true : false
    }
    init?(rawValue: RawValue) {
        self = rawValue == true ? .given : .received
    }
}

Swift 3 natively defines those nine literal representations:

• ExpressibleByNilLiteral (nil)
• ExpressibleByBooleanLiteral (false)
• ExpressibleByArrayLiteral ([])
• ExpressibleByDictionaryLiteral ([:])
• ExpressibleByIntegerLiteral (0)
• ExpressibleByFloatLiteral (0.0)
• ExpressibleByUnicodeScalarLiteral ("\u{0}")
• ExpressibleByExtendedGraphemeClusterLiteral ("\u{0}")
• ExpressibleByStringLiteral ("")

But enum raw representation will apparently only accept natively the subset of those representions that start with a digit (0-9), a sign (-, +) or a quote ("): the last five protocols of above list.

In my opinion, the error message should have been more specific. Maybe something explicit like that would have been nice:

Raw type 'Bool' is not expressible by any numeric or quoted-string literal

Extending Bool to conform to one of those protocols is still possible, for example:

extension Bool: ExpressibleByIntegerLiteral {
    public init(integerLiteral value: Int) {
        self = value != 0
    }
}

And after doing so, this code now builds fine:

enum TopBarStyle: Bool {
    case darkOnLight
    case lightOnDark
}

@IBInspectable var style = TopBarStyle(rawValue: false)!

Simplify your life:

enum TopBarStyle {
    case darkOnLight
    case lightOnDark

    var bool: Bool {
        switch self {
        case .darkOnLight:
            return true
        default:
            return false
        }
    }
}

Use as usual:

    var current = TopBarStyle.darkOnLight

    if current.bool {
        // do this
    } else {
        // do that
    }

You can extend cases to more but they are not reversible since its an N : 2 matrix