I'm doing something similar in C++ for vertex attributes, integration with Lua et.al. First I define the struct:

  INTROSPECTION_DEFINE_STRUCT(S,
    (int, anInt),
    (bool, aBool),
    (float, aFloat),
    (double, aDouble),
    (std::string, aString)
  );

Then I create an instance of it:

  S s{ 23, true, 37.5f, 42.25, "String" };

And finally I can e.g. iterate over all fields and output their value using a generic lambda:

  forEachField(s, [](auto v) {
    std::cout << v;
  });

There are also definitions for the field's type, offset, name etc. generated by the macro, so it's easy to create a binding for vertex attributes, map the struct to a table in Lua, serialize/deserialize it and so on.

I'm really hoping C++ gets introspection soon. There are some proposals like https://isocpp.org/files/papers/n3996.pdf and a working group at https://groups.google.com/a/isocpp.org/forum/#!forum/reflect... but I'm not holding my breath for 2017.