flat.hpp 1.2 KB

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  1. /*!
  2. @file
  3. Defines `boost::hana::detail::variadic::reverse_apply_flat`.
  4. @copyright Louis Dionne 2013-2017
  5. Distributed under the Boost Software License, Version 1.0.
  6. (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
  7. */
  8. #ifndef BOOST_HANA_DETAIL_VARIADIC_REVERSE_APPLY_FLAT_HPP
  9. #define BOOST_HANA_DETAIL_VARIADIC_REVERSE_APPLY_FLAT_HPP
  10. #include <boost/hana/config.hpp>
  11. #include <boost/hana/detail/variadic/at.hpp>
  12. #include <utility>
  13. BOOST_HANA_NAMESPACE_BEGIN namespace detail { namespace variadic {
  14. template <int ...i, typename F, typename ...X>
  15. constexpr decltype(auto)
  16. reverse_apply_flat_helper(std::integer_sequence<int, i...>, F&& f, X&& ...x)
  17. {
  18. return static_cast<F&&>(f)(
  19. detail::variadic::at<sizeof...(x) - i - 1>(
  20. static_cast<X&&>(x)...
  21. )...
  22. );
  23. }
  24. template <typename F, typename ...X>
  25. constexpr decltype(auto) reverse_apply_flat(F&& f, X&& ...x) {
  26. return reverse_apply_flat_helper(
  27. std::make_integer_sequence<int, sizeof...(x)>{},
  28. static_cast<F&&>(f),
  29. static_cast<X&&>(x)...
  30. );
  31. }
  32. }} BOOST_HANA_NAMESPACE_END
  33. #endif // !BOOST_HANA_DETAIL_VARIADIC_REVERSE_APPLY_FLAT_HPP