glz::reflectable<T> fails when glz::meta<T> is explicitly declared, is it the expected behaviour?

[StormLord07]

Declaring glz::meta explicitly seems to break glz::reflectable — despite the struct being obviously reflectable. Surprisingly, removing the glz::meta specialization makes it pass all reflect and reflectable checks.

Compiler Explorer

i'm not sure if it's the same with #721 but defining glz::make_reflectable c-tor doesn't help.

The problem occured when i tried to make from python dict function like that, just to check out if I can make python work with glaze, just for fun.

// Map py::dict to Payload using field reflection
template <typename T> T from_dict(const py::dict &dict) {
  T obj{};
  std::size_t idx = 0;
  glz::for_each_field(obj, [&](auto &field) {
    using FieldType = std::remove_cvref_t<decltype(field)>;
    const auto &key = glz::reflect<T>::keys[idx++];
    std::cout << "Processing key: " << key
              << ", Type: " << typeid(FieldType).name()
              << ", is reflectable: " << glz::reflectable<FieldType>;
    if (dict.contains(key.data())) {
      if constexpr (glz::reflectable<FieldType>) {
        std::cout << " reflectable" << std::endl;
        field = from_dict<FieldType>(dict[key.data()]);
      } else {
        std::cout << " usual" << std::endl;
        field = py::cast<std::decay_t<decltype(field)>>(dict[key.data()]);
      }
    }
  });
  return obj;
}

which just failed because i cant cast field to (struct Nested) because FieldType isn't considered reflectable, which can be checked with static assert

[StormLord07]

Might I ask for help please?

[stephenberry]

Sorry for overlooking this. glz::reflectable<T> indicates that the type should use pure reflection. When a glz::meta is defined this can be checked via glz::glaze_object_t<T>. So, Glaze code for JSON objects tends to use: glaze_object_t<T> || reflectable<T>. You probably want to use these two concepts together.

[StormLord07]

Thanks a lot, was thinking i'm getting insane