1// <experimental/array> -*- C++ -*-
2
3// Copyright (C) 2015-2019 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/array
26 *  This is a TS C++ Library header.
27 */
28
29#ifndef _GLIBCXX_EXPERIMENTAL_ARRAY
30#define _GLIBCXX_EXPERIMENTAL_ARRAY 1
31
32#pragma GCC system_header
33
34#if __cplusplus >= 201402L
35
36#include <array>
37#include <experimental/type_traits>
38
39namespace std _GLIBCXX_VISIBILITY(default)
40{
41_GLIBCXX_BEGIN_NAMESPACE_VERSION
42
43namespace experimental
44{
45inline namespace fundamentals_v2
46{
47#define __cpp_lib_experimental_make_array 201505
48  /**
49   * @defgroup make_array Array creation functions
50   * @ingroup experimental
51   *
52   * Array creation functions as described in N4529,
53   * Working Draft, C++ Extensions for Library Fundamentals, Version 2
54   *
55   * @{
56   */
57
58template<typename _Dest, typename... _Types>
59  struct __make_array_elem
60  {
61    using type = _Dest;
62  };
63
64template<typename... _Types>
65  struct __make_array_elem<void, _Types...>
66  : common_type<_Types...>
67  {
68    template <typename>
69      struct __is_reference_wrapper : false_type
70      {};
71
72    template <typename _Up>
73      struct __is_reference_wrapper<reference_wrapper<_Up>> : true_type
74      {};
75
76    static_assert(!__or_<__is_reference_wrapper<decay_t<_Types>>...>::value,
77                  "make_array must be used with an explicit target type when"
78                  "any of the arguments is a reference_wrapper");
79  };
80
81template <typename _Dest = void, typename... _Types>
82  constexpr
83  array<typename __make_array_elem<_Dest, _Types...>::type, sizeof...(_Types)>
84  make_array(_Types&&... __t)
85  {
86    return {{ std::forward<_Types>(__t)... }};
87  }
88
89template <typename _Tp, size_t _Nm, size_t... _Idx>
90  constexpr array<remove_cv_t<_Tp>, _Nm>
91  __to_array(_Tp (&__a)[_Nm], index_sequence<_Idx...>)
92  {
93    return {{__a[_Idx]...}};
94  }
95
96template <typename _Tp, size_t _Nm>
97  constexpr array<remove_cv_t<_Tp>, _Nm>
98  to_array(_Tp (&__a)[_Nm])
99  noexcept(is_nothrow_constructible<remove_cv_t<_Tp>, _Tp&>::value)
100  {
101    return __to_array(__a, make_index_sequence<_Nm>{});
102  }
103
104  /// @} group make_array
105} // namespace fundamentals_v2
106} // namespace experimental
107
108_GLIBCXX_END_NAMESPACE_VERSION
109} // namespace std
110
111#endif // C++14
112
113#endif // _GLIBCXX_EXPERIMENTAL_ARRAY
114