Function FromJSONObjectOptionalField

libs/cppjansson/cppjansson.hpp:201–210

template <typename T>
void FromJSONObjectOptionalField(json_t const * root, std::string const & field, T & result)
{
  auto * json = base::GetJSONOptionalField(root, field);
  if (!json)
  {
    result = T{};
    return;
  }
  FromJSON(json, result);
}

template <typename T, typename std::enable_if<std::is_integral<T>::value, void>::type * = nullptr>
inline base::JSONPtr ToJSON(T value)