1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP___TUPLE
12#define _LIBCPP___TUPLE
13
14#include <__config>
15#include <cstddef>
16#include <type_traits>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#pragma GCC system_header
20#endif
21
22
23_LIBCPP_BEGIN_NAMESPACE_STD
24
25template <class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_size;
26
27template <class _Tp>
28class _LIBCPP_TYPE_VIS_ONLY tuple_size<const _Tp>
29    : public tuple_size<_Tp> {};
30
31template <class _Tp>
32class _LIBCPP_TYPE_VIS_ONLY tuple_size<volatile _Tp>
33    : public tuple_size<_Tp> {};
34
35template <class _Tp>
36class _LIBCPP_TYPE_VIS_ONLY tuple_size<const volatile _Tp>
37    : public tuple_size<_Tp> {};
38
39template <size_t _Ip, class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_element;
40
41template <size_t _Ip, class _Tp>
42class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const _Tp>
43{
44public:
45    typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
46};
47
48template <size_t _Ip, class _Tp>
49class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, volatile _Tp>
50{
51public:
52    typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
53};
54
55template <size_t _Ip, class _Tp>
56class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const volatile _Tp>
57{
58public:
59    typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
60};
61
62template <class _Tp> struct __tuple_like : false_type {};
63
64template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {};
65template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {};
66template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {};
67
68// tuple specializations
69
70#if !defined(_LIBCPP_HAS_NO_VARIADICS)
71template <class ..._Tp> class _LIBCPP_TYPE_VIS_ONLY tuple;
72
73template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};
74
75template <size_t _Ip, class ..._Tp>
76_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
77typename tuple_element<_Ip, tuple<_Tp...> >::type&
78get(tuple<_Tp...>&) _NOEXCEPT;
79
80template <size_t _Ip, class ..._Tp>
81_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
82const typename tuple_element<_Ip, tuple<_Tp...> >::type&
83get(const tuple<_Tp...>&) _NOEXCEPT;
84
85template <size_t _Ip, class ..._Tp>
86_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
87typename tuple_element<_Ip, tuple<_Tp...> >::type&&
88get(tuple<_Tp...>&&) _NOEXCEPT;
89#endif
90
91// pair specializations
92
93template <class _T1, class _T2> struct _LIBCPP_TYPE_VIS_ONLY pair;
94
95template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};
96
97template <size_t _Ip, class _T1, class _T2>
98_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
99typename tuple_element<_Ip, pair<_T1, _T2> >::type&
100get(pair<_T1, _T2>&) _NOEXCEPT;
101
102template <size_t _Ip, class _T1, class _T2>
103_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
104const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
105get(const pair<_T1, _T2>&) _NOEXCEPT;
106
107#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
108template <size_t _Ip, class _T1, class _T2>
109_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
110typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
111get(pair<_T1, _T2>&&) _NOEXCEPT;
112#endif
113
114// array specializations
115
116template <class _Tp, size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY array;
117
118template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};
119
120template <size_t _Ip, class _Tp, size_t _Size>
121_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
122_Tp&
123get(array<_Tp, _Size>&) _NOEXCEPT;
124
125template <size_t _Ip, class _Tp, size_t _Size>
126_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
127const _Tp&
128get(const array<_Tp, _Size>&) _NOEXCEPT;
129
130#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
131template <size_t _Ip, class _Tp, size_t _Size>
132_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
133_Tp&&
134get(array<_Tp, _Size>&&) _NOEXCEPT;
135#endif
136
137#if !defined(_LIBCPP_HAS_NO_VARIADICS)
138
139// __make_tuple_indices
140
141template <size_t...> struct __tuple_indices {};
142
143template <size_t _Sp, class _IntTuple, size_t _Ep>
144struct __make_indices_imp;
145
146template <size_t _Sp, size_t ..._Indices, size_t _Ep>
147struct __make_indices_imp<_Sp, __tuple_indices<_Indices...>, _Ep>
148{
149    typedef typename __make_indices_imp<_Sp+1, __tuple_indices<_Indices..., _Sp>, _Ep>::type type;
150};
151
152template <size_t _Ep, size_t ..._Indices>
153struct __make_indices_imp<_Ep, __tuple_indices<_Indices...>, _Ep>
154{
155    typedef __tuple_indices<_Indices...> type;
156};
157
158template <size_t _Ep, size_t _Sp = 0>
159struct __make_tuple_indices
160{
161    static_assert(_Sp <= _Ep, "__make_tuple_indices input error");
162    typedef typename __make_indices_imp<_Sp, __tuple_indices<>, _Ep>::type type;
163};
164
165// __tuple_types
166
167template <class ..._Tp> struct __tuple_types {};
168
169template <size_t _Ip>
170class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<> >
171{
172public:
173    static_assert(_Ip == 0, "tuple_element index out of range");
174    static_assert(_Ip != 0, "tuple_element index out of range");
175};
176
177template <class _Hp, class ..._Tp>
178class _LIBCPP_TYPE_VIS_ONLY tuple_element<0, __tuple_types<_Hp, _Tp...> >
179{
180public:
181    typedef _Hp type;
182};
183
184template <size_t _Ip, class _Hp, class ..._Tp>
185class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<_Hp, _Tp...> >
186{
187public:
188    typedef typename tuple_element<_Ip-1, __tuple_types<_Tp...> >::type type;
189};
190
191template <class ..._Tp>
192class _LIBCPP_TYPE_VIS_ONLY tuple_size<__tuple_types<_Tp...> >
193    : public integral_constant<size_t, sizeof...(_Tp)>
194{
195};
196
197template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {};
198
199// __make_tuple_types
200
201// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a
202// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep).
203// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>.  If _Tuple is a
204// lvalue_reference type, then __tuple_types<_Types&...> is the result.
205
206template <class _TupleTypes, class _Tp, size_t _Sp, size_t _Ep>
207struct __make_tuple_types_imp;
208
209template <class ..._Types, class _Tp, size_t _Sp, size_t _Ep>
210struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Sp, _Ep>
211{
212    typedef typename remove_reference<_Tp>::type _Tpr;
213    typedef typename __make_tuple_types_imp<__tuple_types<_Types...,
214                                            typename conditional<is_lvalue_reference<_Tp>::value,
215                                                typename tuple_element<_Sp, _Tpr>::type&,
216                                                typename tuple_element<_Sp, _Tpr>::type>::type>,
217                                            _Tp, _Sp+1, _Ep>::type type;
218};
219
220template <class ..._Types, class _Tp, size_t _Ep>
221struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Ep, _Ep>
222{
223    typedef __tuple_types<_Types...> type;
224};
225
226template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value, size_t _Sp = 0>
227struct __make_tuple_types
228{
229    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
230    typedef typename __make_tuple_types_imp<__tuple_types<>, _Tp, _Sp, _Ep>::type type;
231};
232
233// __tuple_convertible
234
235template <class, class>
236struct __tuple_convertible_imp : public false_type {};
237
238template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
239struct __tuple_convertible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
240    : public integral_constant<bool,
241                               is_convertible<_Tp0, _Up0>::value &&
242                               __tuple_convertible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
243
244template <>
245struct __tuple_convertible_imp<__tuple_types<>, __tuple_types<> >
246    : public true_type {};
247
248template <bool, class, class>
249struct __tuple_convertible_apply : public false_type {};
250
251template <class _Tp, class _Up>
252struct __tuple_convertible_apply<true, _Tp, _Up>
253  : public __tuple_convertible_imp<
254      typename __make_tuple_types<_Tp>::type
255    , typename __make_tuple_types<_Up>::type
256    >
257{};
258
259template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
260                                bool = __tuple_like<_Up>::value>
261struct __tuple_convertible
262    : public false_type {};
263
264template <class _Tp, class _Up>
265struct __tuple_convertible<_Tp, _Up, true, true>
266    : public __tuple_convertible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
267                                     tuple_size<_Up>::value, _Tp, _Up>
268{};
269
270// __tuple_constructible
271
272template <class, class>
273struct __tuple_constructible_imp : public false_type {};
274
275template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
276struct __tuple_constructible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
277    : public integral_constant<bool,
278                               is_constructible<_Up0, _Tp0>::value &&
279                               __tuple_constructible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
280
281template <>
282struct __tuple_constructible_imp<__tuple_types<>, __tuple_types<> >
283    : public true_type {};
284
285template <bool _SameSize, class, class>
286struct __tuple_constructible_apply : public false_type {};
287
288template <class _Tp, class _Up>
289struct __tuple_constructible_apply<true, _Tp, _Up>
290  : public __tuple_constructible_imp<
291      typename __make_tuple_types<_Tp>::type
292    , typename __make_tuple_types<_Up>::type
293    >
294{};
295
296template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
297                                bool = __tuple_like<_Up>::value>
298struct __tuple_constructible
299    : public false_type {};
300
301template <class _Tp, class _Up>
302struct __tuple_constructible<_Tp, _Up, true, true>
303    : public __tuple_constructible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
304                                     tuple_size<_Up>::value, _Tp, _Up>
305{};
306
307// __tuple_assignable
308
309template <class, class>
310struct __tuple_assignable_imp : public false_type {};
311
312template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
313struct __tuple_assignable_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
314    : public integral_constant<bool,
315                               is_assignable<_Up0&, _Tp0>::value &&
316                               __tuple_assignable_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
317
318template <>
319struct __tuple_assignable_imp<__tuple_types<>, __tuple_types<> >
320    : public true_type {};
321
322template <bool, class, class>
323struct __tuple_assignable_apply : public false_type {};
324
325template <class _Tp, class _Up>
326struct __tuple_assignable_apply<true, _Tp, _Up>
327  : __tuple_assignable_imp<
328      typename __make_tuple_types<_Tp>::type
329    , typename __make_tuple_types<_Up>::type
330    >
331{};
332
333template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
334                                bool = __tuple_like<_Up>::value>
335struct __tuple_assignable
336    : public false_type {};
337
338template <class _Tp, class _Up>
339struct __tuple_assignable<_Tp, _Up, true, true>
340    : public __tuple_assignable_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
341                                    tuple_size<_Up>::value, _Tp, _Up>
342{};
343
344#endif  // _LIBCPP_HAS_NO_VARIADICS
345
346_LIBCPP_END_NAMESPACE_STD
347
348#endif  // _LIBCPP___TUPLE
349