libstdc++
experimental/array
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1 // <experimental/array> -*- C++ -*-
2 
3 // Copyright (C) 2015-2017 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 <experimental/type_traits>
40 
41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43 namespace experimental
44 {
45 inline namespace fundamentals_v2
46 {
47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
48 
49 #define __cpp_lib_experimental_make_array 201505
50  /**
51  * @defgroup make_array Array creation functions
52  * @ingroup experimental
53  *
54  * Array creation functions as described in N4529,
55  * Working Draft, C++ Extensions for Library Fundamentals, Version 2
56  *
57  * @{
58  */
59 
60 template<typename _Dest, typename... _Types>
61  struct __make_array_elem
62  {
63  using type = _Dest;
64  };
65 
66 template<typename... _Types>
67  struct __make_array_elem<void, _Types...>
68  : common_type<_Types...>
69  {
70  template <typename>
71  struct __is_reference_wrapper : false_type
72  {};
73 
74  template <typename _Up>
75  struct __is_reference_wrapper<reference_wrapper<_Up>> : true_type
76  {};
77 
78  static_assert(!__or_<__is_reference_wrapper<decay_t<_Types>>...>::value,
79  "make_array must be used with an explicit target type when"
80  "any of the arguments is a reference_wrapper");
81  };
82 
83 template <typename _Dest = void, typename... _Types>
84  constexpr
85  array<typename __make_array_elem<_Dest, _Types...>::type, sizeof...(_Types)>
86  make_array(_Types&&... __t)
87  {
88  return {{ std::forward<_Types>(__t)... }};
89  }
90 
91 template <typename _Tp, size_t _Nm, size_t... _Idx>
92  constexpr array<remove_cv_t<_Tp>, _Nm>
93  __to_array(_Tp (&__a)[_Nm], index_sequence<_Idx...>)
94  {
95  return {{__a[_Idx]...}};
96  }
97 
98 template <typename _Tp, size_t _Nm>
99  constexpr array<remove_cv_t<_Tp>, _Nm>
100  to_array(_Tp (&__a)[_Nm])
101  noexcept(is_nothrow_constructible<remove_cv_t<_Tp>, _Tp&>::value)
102  {
103  return __to_array(__a, make_index_sequence<_Nm>{});
104  }
105 
106  // @} group make_array
107  _GLIBCXX_END_NAMESPACE_VERSION
108 } // namespace fundamentals_v2
109 } // namespace experimental
110 
111 } // namespace std
112 
113 #endif // C++14
114 
115 #endif // _GLIBCXX_EXPERIMENTAL_ARRAY