File Coverage

/usr/include/c++/5/bits/stl_pair.h
Criterion Covered Total %
statement 2 2 100.0
branch n/a
condition n/a
subroutine n/a
pod n/a
total 2 2 100.0


line stmt bran cond sub pod time code
1             // Pair implementation -*- C++ -*-
2              
3             // Copyright (C) 2001-2015 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             // .
24              
25             /*
26             *
27             * Copyright (c) 1994
28             * Hewlett-Packard Company
29             *
30             * Permission to use, copy, modify, distribute and sell this software
31             * and its documentation for any purpose is hereby granted without fee,
32             * provided that the above copyright notice appear in all copies and
33             * that both that copyright notice and this permission notice appear
34             * in supporting documentation. Hewlett-Packard Company makes no
35             * representations about the suitability of this software for any
36             * purpose. It is provided "as is" without express or implied warranty.
37             *
38             *
39             * Copyright (c) 1996,1997
40             * Silicon Graphics Computer Systems, Inc.
41             *
42             * Permission to use, copy, modify, distribute and sell this software
43             * and its documentation for any purpose is hereby granted without fee,
44             * provided that the above copyright notice appear in all copies and
45             * that both that copyright notice and this permission notice appear
46             * in supporting documentation. Silicon Graphics makes no
47             * representations about the suitability of this software for any
48             * purpose. It is provided "as is" without express or implied warranty.
49             */
50              
51             /** @file bits/stl_pair.h
52             * This is an internal header file, included by other library headers.
53             * Do not attempt to use it directly. @headername{utility}
54             */
55              
56             #ifndef _STL_PAIR_H
57             #define _STL_PAIR_H 1
58              
59             #include // for std::move / std::forward, and std::swap
60              
61             #if __cplusplus >= 201103L
62             #include // for std::__decay_and_strip too
63             #endif
64              
65             namespace std _GLIBCXX_VISIBILITY(default)
66             {
67             _GLIBCXX_BEGIN_NAMESPACE_VERSION
68              
69             /**
70             * @addtogroup utilities
71             * @{
72             */
73              
74             #if __cplusplus >= 201103L
75             /// piecewise_construct_t
76             struct piecewise_construct_t { };
77              
78             /// piecewise_construct
79             constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
80              
81             // Forward declarations.
82             template
83             class tuple;
84              
85             template
86             struct _Index_tuple;
87             #endif
88              
89             /**
90             * @brief Struct holding two objects of arbitrary type.
91             *
92             * @tparam _T1 Type of first object.
93             * @tparam _T2 Type of second object.
94             */
95             template
96             struct pair
97             {
98             typedef _T1 first_type; /// @c first_type is the first bound type
99             typedef _T2 second_type; /// @c second_type is the second bound type
100              
101             _T1 first; /// @c first is a copy of the first object
102             _T2 second; /// @c second is a copy of the second object
103              
104             // _GLIBCXX_RESOLVE_LIB_DEFECTS
105             // 265. std::pair::pair() effects overly restrictive
106             /** The default constructor creates @c first and @c second using their
107             * respective default constructors. */
108             _GLIBCXX_CONSTEXPR pair()
109             : first(), second() { }
110              
111             /** Two objects may be passed to a @c pair constructor to be copied. */
112 456           _GLIBCXX_CONSTEXPR pair(const _T1& __a, const _T2& __b)
113 456           : first(__a), second(__b) { }
114              
115             /** There is also a templated copy ctor for the @c pair class itself. */
116             #if __cplusplus < 201103L
117             template
118             pair(const pair<_U1, _U2>& __p)
119             : first(__p.first), second(__p.second) { }
120             #else
121             template
122             enable_if<__and_,
123             is_convertible>::value>::type>
124             constexpr pair(const pair<_U1, _U2>& __p)
125             : first(__p.first), second(__p.second) { }
126              
127             constexpr pair(const pair&) = default;
128             constexpr pair(pair&&) = default;
129              
130             // DR 811.
131             template
132             enable_if::value>::type>
133             constexpr pair(_U1&& __x, const _T2& __y)
134             : first(std::forward<_U1>(__x)), second(__y) { }
135              
136             template
137             enable_if::value>::type>
138             constexpr pair(const _T1& __x, _U2&& __y)
139             : first(__x), second(std::forward<_U2>(__y)) { }
140              
141             template
142             enable_if<__and_,
143             is_convertible<_U2, _T2>>::value>::type>
144             constexpr pair(_U1&& __x, _U2&& __y)
145             : first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y)) { }
146              
147             template
148             enable_if<__and_,
149             is_convertible<_U2, _T2>>::value>::type>
150             constexpr pair(pair<_U1, _U2>&& __p)
151             : first(std::forward<_U1>(__p.first)),
152             second(std::forward<_U2>(__p.second)) { }
153              
154             template
155             pair(piecewise_construct_t, tuple<_Args1...>, tuple<_Args2...>);
156              
157             pair&
158             operator=(const pair& __p)
159             {
160             first = __p.first;
161             second = __p.second;
162             return *this;
163             }
164              
165             pair&
166             operator=(pair&& __p)
167             noexcept(__and_,
168             is_nothrow_move_assignable<_T2>>::value)
169             {
170             first = std::forward(__p.first);
171             second = std::forward(__p.second);
172             return *this;
173             }
174              
175             template
176             pair&
177             operator=(const pair<_U1, _U2>& __p)
178             {
179             first = __p.first;
180             second = __p.second;
181             return *this;
182             }
183              
184             template
185             pair&
186             operator=(pair<_U1, _U2>&& __p)
187             {
188             first = std::forward<_U1>(__p.first);
189             second = std::forward<_U2>(__p.second);
190             return *this;
191             }
192              
193             void
194             swap(pair& __p)
195             noexcept(noexcept(swap(first, __p.first))
196             && noexcept(swap(second, __p.second)))
197             {
198             using std::swap;
199             swap(first, __p.first);
200             swap(second, __p.second);
201             }
202              
203             private:
204             template
205             typename... _Args2, std::size_t... _Indexes2>
206             pair(tuple<_Args1...>&, tuple<_Args2...>&,
207             _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
208             #endif
209             };
210              
211             /// Two pairs of the same type are equal iff their members are equal.
212             template
213             inline _GLIBCXX_CONSTEXPR bool
214             operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
215             { return __x.first == __y.first && __x.second == __y.second; }
216              
217             ///
218             template
219             inline _GLIBCXX_CONSTEXPR bool
220             operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
221             { return __x.first < __y.first
222             || (!(__y.first < __x.first) && __x.second < __y.second); }
223              
224             /// Uses @c operator== to find the result.
225             template
226             inline _GLIBCXX_CONSTEXPR bool
227             operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
228             { return !(__x == __y); }
229              
230             /// Uses @c operator< to find the result.
231             template
232             inline _GLIBCXX_CONSTEXPR bool
233             operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
234             { return __y < __x; }
235              
236             /// Uses @c operator< to find the result.
237             template
238             inline _GLIBCXX_CONSTEXPR bool
239             operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
240             { return !(__y < __x); }
241              
242             /// Uses @c operator< to find the result.
243             template
244             inline _GLIBCXX_CONSTEXPR bool
245             operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
246             { return !(__x < __y); }
247              
248             #if __cplusplus >= 201103L
249             /// See std::pair::swap().
250             // Note: no std::swap overloads in C++03 mode, this has performance
251             // implications, see, eg, libstdc++/38466.
252             template
253             inline void
254             swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
255             noexcept(noexcept(__x.swap(__y)))
256             { __x.swap(__y); }
257             #endif
258              
259             /**
260             * @brief A convenience wrapper for creating a pair from two objects.
261             * @param __x The first object.
262             * @param __y The second object.
263             * @return A newly-constructed pair<> object of the appropriate type.
264             *
265             * The standard requires that the objects be passed by reference-to-const,
266             * but LWG issue #181 says they should be passed by const value. We follow
267             * the LWG by default.
268             */
269             // _GLIBCXX_RESOLVE_LIB_DEFECTS
270             // 181. make_pair() unintended behavior
271             #if __cplusplus >= 201103L
272             // NB: DR 706.
273             template
274             constexpr pair::__type,
275             typename __decay_and_strip<_T2>::__type>
276             make_pair(_T1&& __x, _T2&& __y)
277             {
278             typedef typename __decay_and_strip<_T1>::__type __ds_type1;
279             typedef typename __decay_and_strip<_T2>::__type __ds_type2;
280             typedef pair<__ds_type1, __ds_type2> __pair_type;
281             return __pair_type(std::forward<_T1>(__x), std::forward<_T2>(__y));
282             }
283             #else
284             template
285             inline pair<_T1, _T2>
286             make_pair(_T1 __x, _T2 __y)
287             { return pair<_T1, _T2>(__x, __y); }
288             #endif
289              
290             /// @}
291              
292             _GLIBCXX_END_NAMESPACE_VERSION
293             } // namespace std
294              
295             #endif /* _STL_PAIR_H */