1 : // Pair implementation -*- C++ -*-
2 :
3 : // Copyright (C) 2001, 2004 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 2, 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 : // You should have received a copy of the GNU General Public License along
17 : // with this library; see the file COPYING. If not, write to the Free
18 : // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19 : // USA.
20 :
21 : // As a special exception, you may use this file as part of a free software
22 : // library without restriction. Specifically, if other files instantiate
23 : // templates or use macros or inline functions from this file, or you compile
24 : // this file and link it with other files to produce an executable, this
25 : // file does not by itself cause the resulting executable to be covered by
26 : // the GNU General Public License. This exception does not however
27 : // invalidate any other reasons why the executable file might be covered by
28 : // the GNU General Public License.
29 :
30 : /*
31 : *
32 : * Copyright (c) 1994
33 : * Hewlett-Packard Company
34 : *
35 : * Permission to use, copy, modify, distribute and sell this software
36 : * and its documentation for any purpose is hereby granted without fee,
37 : * provided that the above copyright notice appear in all copies and
38 : * that both that copyright notice and this permission notice appear
39 : * in supporting documentation. Hewlett-Packard Company makes no
40 : * representations about the suitability of this software for any
41 : * purpose. It is provided "as is" without express or implied warranty.
42 : *
43 : *
44 : * Copyright (c) 1996,1997
45 : * Silicon Graphics Computer Systems, Inc.
46 : *
47 : * Permission to use, copy, modify, distribute and sell this software
48 : * and its documentation for any purpose is hereby granted without fee,
49 : * provided that the above copyright notice appear in all copies and
50 : * that both that copyright notice and this permission notice appear
51 : * in supporting documentation. Silicon Graphics makes no
52 : * representations about the suitability of this software for any
53 : * purpose. It is provided "as is" without express or implied warranty.
54 : */
55 :
56 : /** @file stl_pair.h
57 : * This is an internal header file, included by other library headers.
58 : * You should not attempt to use it directly.
59 : */
60 :
61 : #ifndef _PAIR_H
62 : #define _PAIR_H 1
63 :
64 : namespace std
65 : {
66 : /// pair holds two objects of arbitrary type.
67 : template<class _T1, class _T2>
68 : struct pair
69 7878159 : {
70 : typedef _T1 first_type; ///< @c first_type is the first bound type
71 : typedef _T2 second_type; ///< @c second_type is the second bound type
72 :
73 : _T1 first; ///< @c first is a copy of the first object
74 : _T2 second; ///< @c second is a copy of the second object
75 :
76 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
77 : // 265. std::pair::pair() effects overly restrictive
78 : /** The default constructor creates @c first and @c second using their
79 : * respective default constructors. */
80 0 : pair()
81 0 : : first(), second() { }
82 :
83 : /** Two objects may be passed to a @c pair constructor to be copied. */
84 17070596 : pair(const _T1& __a, const _T2& __b)
85 17070596 : : first(__a), second(__b) { }
86 :
87 : /** There is also a templated copy ctor for the @c pair class itself. */
88 : template<class _U1, class _U2>
89 1055859 : pair(const pair<_U1, _U2>& __p)
90 1055859 : : first(__p.first), second(__p.second) { }
91 : };
92 :
93 : /// Two pairs of the same type are equal iff their members are equal.
94 : template<class _T1, class _T2>
95 : inline bool
96 : operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
97 : { return __x.first == __y.first && __x.second == __y.second; }
98 :
99 : /// <http://gcc.gnu.org/onlinedocs/libstdc++/20_util/howto.html#pairlt>
100 : template<class _T1, class _T2>
101 : inline bool
102 557 : operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
103 : { return __x.first < __y.first
104 557 : || (!(__y.first < __x.first) && __x.second < __y.second); }
105 :
106 : /// Uses @c operator== to find the result.
107 : template<class _T1, class _T2>
108 : inline bool
109 : operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
110 : { return !(__x == __y); }
111 :
112 : /// Uses @c operator< to find the result.
113 : template<class _T1, class _T2>
114 : inline bool
115 : operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
116 : { return __y < __x; }
117 :
118 : /// Uses @c operator< to find the result.
119 : template<class _T1, class _T2>
120 : inline bool
121 : operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
122 : { return !(__y < __x); }
123 :
124 : /// Uses @c operator< to find the result.
125 : template<class _T1, class _T2>
126 : inline bool
127 : operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
128 : { return !(__x < __y); }
129 :
130 : /**
131 : * @brief A convenience wrapper for creating a pair from two objects.
132 : * @param x The first object.
133 : * @param y The second object.
134 : * @return A newly-constructed pair<> object of the appropriate type.
135 : *
136 : * The standard requires that the objects be passed by reference-to-const,
137 : * but LWG issue #181 says they should be passed by const value. We follow
138 : * the LWG by default.
139 : */
140 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
141 : // 181. make_pair() unintended behavior
142 : template<class _T1, class _T2>
143 : inline pair<_T1, _T2>
144 1675104 : make_pair(_T1 __x, _T2 __y)
145 1675104 : { return pair<_T1, _T2>(__x, __y); }
146 : } // namespace std
147 :
148 : #endif /* _PAIR_H */
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