Question: conditionally group bindings in a trait?

[michael-brade]

Hi, another question: is it possible to conditially group a set of members in a binding trait, and if so, what's the syntax?

a bit stupid example because you could create another struct/class Turnus with its own binding instead:

struct test {
  int		m_id;
  std::string	m_turnusEinheit{}; //'E'=einmalig, 'D'=täglich, 'W'=wöchentlich, 'M'=monatlich
  unsigned int	m_turnusAnzahl{};  // abhängig von der Turnuseinheit auszuwerten, z.B. 2 = alle 2 Wochen/Monate
  unsigned int	m_turnusTag{};	  //'W': 1-7 = Montag-Sonntag; 'M': 1-31 = der 1. des Monats, der 2. des Monats,..., der 31. des Monats
};

template<typename T, typename = void>
struct my_traits
    : public tao::json::traits<T>
{};

template<>
struct my_traits<test>
    : public tao::json::binding::object<
           TAO_JSON_BIND_REQUIRED("id", &test::m_id),
	   // TODO: all three only if (!m_turnusEinheit.empty())
           TAO_JSON_BIND_OPTIONAL("turnusEinheit", &test::m_turnusEinheit),
           TAO_JSON_BIND_OPTIONAL("turnusAnzahl", &test::m_turnusAnzahl),
           TAO_JSON_BIND_OPTIONAL("turnusTag", &test::m_turnusTag)
     >
{};