1// <experimental/tuple> -*- C++ -*-
2
3// Copyright (C) 2014-2020 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file experimental/tuple
26 *  This is a TS C++ Library header.
27 *  @ingroup libfund-ts
28 */
29
30#ifndef _GLIBCXX_EXPERIMENTAL_TUPLE
31#define _GLIBCXX_EXPERIMENTAL_TUPLE 1
32
33#pragma GCC system_header
34
35#if __cplusplus >= 201402L
36
37#include <tuple>
38#include <bits/invoke.h>
39#include <experimental/bits/lfts_config.h>
40
41namespace std _GLIBCXX_VISIBILITY(default)
42{
43_GLIBCXX_BEGIN_NAMESPACE_VERSION
44
45namespace experimental
46{
47inline namespace fundamentals_v1
48{
49  // See C++14 20.4.2.5, tuple helper classes
50  template <typename _Tp>
51    constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
52
53#define __cpp_lib_experimental_tuple 201402
54
55  template <typename _Fn, typename _Tuple, std::size_t... _Idx>
56    constexpr decltype(auto)
57    __apply_impl(_Fn&& __f, _Tuple&& __t, std::index_sequence<_Idx...>)
58    {
59      return std::__invoke(std::forward<_Fn>(__f),
60			   std::get<_Idx>(std::forward<_Tuple>(__t))...);
61    }
62
63  template <typename _Fn, typename _Tuple>
64    constexpr decltype(auto)
65    apply(_Fn&& __f, _Tuple&& __t)
66    {
67      using _Indices =
68	std::make_index_sequence<tuple_size_v<std::decay_t<_Tuple>>>;
69      return experimental::__apply_impl(std::forward<_Fn>(__f),
70					std::forward<_Tuple>(__t),
71					_Indices{});
72    }
73} // namespace fundamentals_v1
74} // namespace experimental
75
76_GLIBCXX_END_NAMESPACE_VERSION
77} // namespace std
78
79#endif // C++14
80
81#endif // _GLIBCXX_EXPERIMENTAL_TUPLE
82