1 // <experimental/tuple> -*- C++ -*-
3 // Copyright (C) 2014-2025 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file experimental/tuple
26 * This is a TS C++ Library header.
30 #ifndef _GLIBCXX_EXPERIMENTAL_TUPLE
31 #define _GLIBCXX_EXPERIMENTAL_TUPLE 1
33 #ifdef _GLIBCXX_SYSHDR
34 #pragma GCC system_header
37 #include <bits/requires_hosted.h> // experimental is currently omitted
39 #if __cplusplus >= 201402L
42 #include <bits/invoke.h>
43 #include <experimental/bits/lfts_config.h>
45 namespace std _GLIBCXX_VISIBILITY(default)
47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 namespace experimental
51 inline namespace fundamentals_v1
53 // See C++14 20.4.2.5, tuple helper classes
54 template <typename _Tp>
55 constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
57 #define __cpp_lib_experimental_tuple 201402
59 template <typename _Fn, typename _Tuple, std::size_t... _Idx>
60 constexpr decltype(auto)
61 __apply_impl(_Fn&& __f, _Tuple&& __t, std::index_sequence<_Idx...>)
63 return std::__invoke(std::forward<_Fn>(__f),
64 std::get<_Idx>(std::forward<_Tuple>(__t))...);
67 template <typename _Fn, typename _Tuple>
68 constexpr decltype(auto)
69 apply(_Fn&& __f, _Tuple&& __t)
72 std::make_index_sequence<tuple_size_v<std::decay_t<_Tuple>>>;
73 return experimental::__apply_impl(std::forward<_Fn>(__f),
74 std::forward<_Tuple>(__t),
77 } // namespace fundamentals_v1
78 } // namespace experimental
80 _GLIBCXX_END_NAMESPACE_VERSION
85 #endif // _GLIBCXX_EXPERIMENTAL_TUPLE