tuple 2.4 KB

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  1. // <experimental/tuple> -*- C++ -*-
  2. // Copyright (C) 2014-2018 Free Software Foundation, Inc.
  3. //
  4. // This file is part of the GNU ISO C++ Library. This library is free
  5. // software; you can redistribute it and/or modify it under the
  6. // terms of the GNU General Public License as published by the
  7. // Free Software Foundation; either version 3, or (at your option)
  8. // any later version.
  9. // This library is distributed in the hope that it will be useful,
  10. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12. // GNU General Public License for more details.
  13. // Under Section 7 of GPL version 3, you are granted additional
  14. // permissions described in the GCC Runtime Library Exception, version
  15. // 3.1, as published by the Free Software Foundation.
  16. // You should have received a copy of the GNU General Public License and
  17. // a copy of the GCC Runtime Library Exception along with this program;
  18. // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
  19. // <http://www.gnu.org/licenses/>.
  20. /** @file experimental/tuple
  21. * This is a TS C++ Library header.
  22. */
  23. #ifndef _GLIBCXX_EXPERIMENTAL_TUPLE
  24. #define _GLIBCXX_EXPERIMENTAL_TUPLE 1
  25. #pragma GCC system_header
  26. #if __cplusplus >= 201402L
  27. #include <tuple>
  28. #include <bits/invoke.h>
  29. #include <experimental/bits/lfts_config.h>
  30. namespace std _GLIBCXX_VISIBILITY(default)
  31. {
  32. _GLIBCXX_BEGIN_NAMESPACE_VERSION
  33. namespace experimental
  34. {
  35. inline namespace fundamentals_v1
  36. {
  37. // See C++14 §20.4.2.5, tuple helper classes
  38. template <typename _Tp>
  39. constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
  40. #define __cpp_lib_experimental_tuple 201402
  41. template <typename _Fn, typename _Tuple, std::size_t... _Idx>
  42. constexpr decltype(auto)
  43. __apply_impl(_Fn&& __f, _Tuple&& __t, std::index_sequence<_Idx...>)
  44. {
  45. return std::__invoke(std::forward<_Fn>(__f),
  46. std::get<_Idx>(std::forward<_Tuple>(__t))...);
  47. }
  48. template <typename _Fn, typename _Tuple>
  49. constexpr decltype(auto)
  50. apply(_Fn&& __f, _Tuple&& __t)
  51. {
  52. using _Indices =
  53. std::make_index_sequence<tuple_size_v<std::decay_t<_Tuple>>>;
  54. return experimental::__apply_impl(std::forward<_Fn>(__f),
  55. std::forward<_Tuple>(__t),
  56. _Indices{});
  57. }
  58. } // namespace fundamentals_v1
  59. } // namespace experimental
  60. _GLIBCXX_END_NAMESPACE_VERSION
  61. } // namespace std
  62. #endif // C++14
  63. #endif // _GLIBCXX_EXPERIMENTAL_TUPLE