optional2.swift

protocol Emptyable {
    var isEmpty: Bool { get }
}
 
extension Optional where Wrapped: Emptyable {
    func orWhenNilOrEmpty(_ defaultValue: Wrapped) -> Wrapped {
        switch(self) {
        case .none:
            return defaultValue
        case .some(let value) where value.isEmpty:
            return defaultValue
        case .some(let value):
            return value
        }
    }
}
 
extension String: Emptyable {}
 
extension Array: Emptyable {}