libstdc++
experimental/array
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1 // <experimental/array> -*- C++ -*-
2 
3 // Copyright (C) 2015-2016 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 <= 201103L
35 # include <bits/c++14_warning.h>
36 #else
37 
38 #include <array>
39 #include <functional>
40 #include <experimental/type_traits>
41 
42 namespace std _GLIBCXX_VISIBILITY(default)
43 {
44 namespace experimental
45 {
46 inline namespace fundamentals_v2
47 {
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 
50 #define __cpp_lib_experimental_make_array 201505
51  /**
52  * @defgroup make_array Array creation functions
53  * @ingroup experimental
54  *
55  * Array creation functions as described in N4529,
56  * Working Draft, C++ Extensions for Library Fundamentals, Version 2
57  *
58  * @{
59  */
60 
61 template <typename _Up>
62  struct __is_reference_wrapper : false_type
63  {};
64 
65 template <typename _Up>
66  struct __is_reference_wrapper<reference_wrapper<_Up>> : true_type
67  {};
68 
69 template <typename _Dest = void, typename... _Types>
70  constexpr auto
71  make_array(_Types&&... __t)
72  -> array<conditional_t<is_void_v<_Dest>,
73  common_type_t<_Types...>,
74  _Dest>,
75  sizeof...(_Types)>
76  {
77  static_assert(__or_<
78  __not_<is_void<_Dest>>,
79  __and_<__not_<__is_reference_wrapper<decay_t<_Types>>>...>>
80  ::value,
81  "make_array cannot be used without an explicit target type "
82  "if any of the types given is a reference_wrapper");
83  return {{forward<_Types>(__t)...}};
84  }
85 
86 template <typename _Tp, size_t _Nm, size_t... _Idx>
87  constexpr array<remove_cv_t<_Tp>, _Nm>
88  __to_array(_Tp (&__a)[_Nm],
89  index_sequence<_Idx...>)
90  {
91  return {{__a[_Idx]...}};
92  }
93 
94 template <typename _Tp, size_t _Nm>
95  constexpr array<remove_cv_t<_Tp>, _Nm>
96  to_array(_Tp (&__a)[_Nm])
97  {
98  return __to_array(__a, make_index_sequence<_Nm>{});
99  }
100 
101  // @} group make_array
102  _GLIBCXX_END_NAMESPACE_VERSION
103 } // namespace fundamentals_v2
104 } // namespace experimental
105 
106 } // namespace std
107 
108 #endif // C++14
109 
110 #endif // _GLIBCXX_EXPERIMENTAL_ARRAY