Use the Keychain to determine if the device has a passcode set.

Passcode+Keychain.swift

    @available(iOS 8.0, *)
    public func devicePasscodeEnabledUsingKeychain() -> Bool {
        let query: [String:Any] = [
            kSecClass as String : kSecClassGenericPassword,
            kSecAttrAccount as String : UUID().uuidString,
            kSecAttrAccessible as String: kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly,
            kSecValueData as String: "HelloWorld".data(using: String.Encoding.utf8)!,
            kSecReturnAttributes as String : kCFBooleanTrue
        ]
        
        var dataTypeRef: AnyObject?
        var status = withUnsafeMutablePointer(to: &dataTypeRef) { SecItemCopyMatching(query as CFDictionary, UnsafeMutablePointer($0)) }
        
        if status == errSecItemNotFound {
            let createStatus = SecItemAdd(query as CFDictionary, nil)
            guard createStatus == errSecSuccess else { return false }
            status = withUnsafeMutablePointer(to: &dataTypeRef) { SecItemCopyMatching(query as CFDictionary, UnsafeMutablePointer($0)) }
        }
        
        guard status == errSecSuccess else { return false }
        
        return true
    }