draconisplusplus/include/rfl/internal/move_and_flatten_field_tuple.hpp

#ifndef RFL_INTERNAL_MOVE_AND_FLATTEN_FIELD_TUPLE_HPP_
#define RFL_INTERNAL_MOVE_AND_FLATTEN_FIELD_TUPLE_HPP_

#include <tuple>

#include "is_flatten_field.hpp"
#include "move_to_field_tuple.hpp"

namespace rfl {
  namespace internal {

    template <class FieldTuple, class... Args>
    auto move_and_flatten_field_tuple(FieldTuple&& _t, Args&&... _args) {
      constexpr auto i = sizeof...(Args);
      if constexpr (i == std::tuple_size_v<std::remove_cvref_t<FieldTuple>>) {
        return std::tuple_cat(std::move(_args)...);
      } else {
        using T = std::tuple_element_t<i, std::remove_cvref_t<FieldTuple>>;
        if constexpr (is_flatten_field<T>::value) {
          return move_and_flatten_field_tuple(
              std::move(_t), std::move(_args)...,
              move_and_flatten_field_tuple(
                  move_to_field_tuple(std::move(std::get<i>(_t).value_))));
        } else {
          return move_and_flatten_field_tuple(
              std::move(_t), std::move(_args)...,
              std::make_tuple(std::move(std::get<i>(_t))));
        }
      }
    }

  } // namespace internal
} // namespace rfl

#endif