takaishota
10/29/2017 - 5:20 AM

String?.isNullOrEmpty

String?.isNullOrEmpty

protocol StringOptionalProtocol {}
extension String: StringOptionalProtocol {}

extension Optional where Wrapped: StringOptionalProtocol {
    var isNullOrEmpty: Bool {
        if let str = self as? String {
            return str.isEmpty
        }
        return true
    }
}