mingw/lib/gcc/mingw32/4.4.0/include/c++/bits/stl_pair.h

   1 // Pair implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 /*
  27  *
  28  * Copyright (c) 1994
  29  * Hewlett-Packard Company
  30  *
  31  * Permission to use, copy, modify, distribute and sell this software
  32  * and its documentation for any purpose is hereby granted without fee,
  33  * provided that the above copyright notice appear in all copies and
  34  * that both that copyright notice and this permission notice appear
  35  * in supporting documentation.  Hewlett-Packard Company makes no
  36  * representations about the suitability of this software for any
  37  * purpose.  It is provided "as is" without express or implied warranty.
  38  *
  39  *
  40  * Copyright (c) 1996,1997
  41  * Silicon Graphics Computer Systems, Inc.
  42  *
  43  * Permission to use, copy, modify, distribute and sell this software
  44  * and its documentation for any purpose is hereby granted without fee,
  45  * provided that the above copyright notice appear in all copies and
  46  * that both that copyright notice and this permission notice appear
  47  * in supporting documentation.  Silicon Graphics makes no
  48  * representations about the suitability of this software for any
  49  * purpose.  It is provided "as is" without express or implied warranty.
  50  */
  51
  52 /** @file stl_pair.h
  53  *  This is an internal header file, included by other library headers.
  54  *  You should not attempt to use it directly.
  55  */
  56
  57 #ifndef _STL_PAIR_H
  58 #define _STL_PAIR_H 1
  59
  60 #include <bits/move.h> // for std::move / std::forward, std::decay, and
  61                        // std::swap
  62
  63 _GLIBCXX_BEGIN_NAMESPACE(std)
  64
  65   /// pair holds two objects of arbitrary type.
  66   template<class _T1, class _T2>
  67     struct pair
  68     {
  69       typedef _T1 first_type;    ///<  @c first_type is the first bound type
  70       typedef _T2 second_type;   ///<  @c second_type is the second bound type
  71
  72       _T1 first;                 ///< @c first is a copy of the first object
  73       _T2 second;                ///< @c second is a copy of the second object
  74
  75       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  76       // 265.  std::pair::pair() effects overly restrictive
  77       /** The default constructor creates @c first and @c second using their
  78        *  respective default constructors.  */
  79       pair()
  80       : first(), second() { }
  81
  82       /** Two objects may be passed to a @c pair constructor to be copied.  */
  83       pair(const _T1& __a, const _T2& __b)
  84       : first(__a), second(__b) { }
  85
  86 #ifdef __GXX_EXPERIMENTAL_CXX0X__
  87       template<class _U1, class _U2>
  88         pair(_U1&& __x, _U2&& __y)
  89         : first(std::forward<_U1>(__x)),
  90           second(std::forward<_U2>(__y)) { }
  91
  92       pair(pair&& __p)
  93       : first(std::move(__p.first)),
  94         second(std::move(__p.second)) { }
  95 #endif
  96
  97       /** There is also a templated copy ctor for the @c pair class itself.  */
  98       template<class _U1, class _U2>
  99         pair(const pair<_U1, _U2>& __p)
 100         : first(__p.first),
 101           second(__p.second) { }
 102
 103 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 104       template<class _U1, class _U2>
 105         pair(pair<_U1, _U2>&& __p)
 106         : first(std::move(__p.first)),
 107           second(std::move(__p.second)) { }
 108
 109       // http://gcc.gnu.org/ml/libstdc++/2007-08/msg00052.html
 110       template<class _U1, class _Arg0, class... _Args>
 111         pair(_U1&& __x, _Arg0&& __arg0, _Args&&... __args)
 112         : first(std::forward<_U1>(__x)),
 113           second(std::forward<_Arg0>(__arg0),
 114                  std::forward<_Args>(__args)...) { }
 115
 116       pair&
 117       operator=(pair&& __p)
 118       {
 119         first = std::move(__p.first);
 120         second = std::move(__p.second);
 121         return *this;
 122       }
 123
 124       template<class _U1, class _U2>
 125         pair&
 126         operator=(pair<_U1, _U2>&& __p)
 127         {
 128           first = std::move(__p.first);
 129           second = std::move(__p.second);
 130           return *this;
 131         }
 132
 133       void
 134       swap(pair&& __p)
 135       {
 136         using std::swap;
 137         swap(first, __p.first);
 138         swap(second, __p.second);
 139       }
 140 #endif
 141     };
 142
 143   /// Two pairs of the same type are equal iff their members are equal.
 144   template<class _T1, class _T2>
 145     inline bool
 146     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 147     { return __x.first == __y.first && __x.second == __y.second; }
 148
 149   /// <http://gcc.gnu.org/onlinedocs/libstdc++/manual/utilities.html>
 150   template<class _T1, class _T2>
 151     inline bool
 152     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 153     { return __x.first < __y.first
 154              || (!(__y.first < __x.first) && __x.second < __y.second); }
 155
 156   /// Uses @c operator== to find the result.
 157   template<class _T1, class _T2>
 158     inline bool
 159     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 160     { return !(__x == __y); }
 161
 162   /// Uses @c operator< to find the result.
 163   template<class _T1, class _T2>
 164     inline bool
 165     operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 166     { return __y < __x; }
 167
 168   /// Uses @c operator< to find the result.
 169   template<class _T1, class _T2>
 170     inline bool
 171     operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 172     { return !(__y < __x); }
 173
 174   /// Uses @c operator< to find the result.
 175   template<class _T1, class _T2>
 176     inline bool
 177     operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
 178     { return !(__x < __y); }
 179
 180 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 181   /// See std::pair::swap().
 182   // Note:  no std::swap overloads in C++03 mode, this has performance
 183   //        implications, see, eg, libstdc++/38466.
 184   template<class _T1, class _T2>
 185     inline void
 186     swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
 187     { __x.swap(__y); }
 188
 189   template<class _T1, class _T2>
 190     inline void
 191     swap(pair<_T1, _T2>&& __x, pair<_T1, _T2>& __y)
 192     { __x.swap(__y); }
 193
 194   template<class _T1, class _T2>
 195     inline void
 196     swap(pair<_T1, _T2>& __x, pair<_T1, _T2>&& __y)
 197     { __x.swap(__y); }
 198 #endif
 199
 200   /**
 201    *  @brief A convenience wrapper for creating a pair from two objects.
 202    *  @param  x  The first object.
 203    *  @param  y  The second object.
 204    *  @return   A newly-constructed pair<> object of the appropriate type.
 205    *
 206    *  The standard requires that the objects be passed by reference-to-const,
 207    *  but LWG issue #181 says they should be passed by const value.  We follow
 208    *  the LWG by default.
 209    */
 210   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 211   // 181.  make_pair() unintended behavior
 212 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 213   template<class _T1, class _T2>
 214     inline pair<_T1, _T2>
 215     make_pair(_T1 __x, _T2 __y)
 216     { return pair<_T1, _T2>(__x, __y); }
 217 #else
 218   template<typename _Tp>
 219     class reference_wrapper;
 220
 221   // Helper which adds a reference to a type when given a reference_wrapper
 222   template<typename _Tp>
 223     struct __strip_reference_wrapper
 224     {
 225       typedef _Tp __type;
 226     };
 227
 228   template<typename _Tp>
 229     struct __strip_reference_wrapper<reference_wrapper<_Tp> >
 230     {
 231       typedef _Tp& __type;
 232     };
 233
 234   template<typename _Tp>
 235     struct __strip_reference_wrapper<const reference_wrapper<_Tp> >
 236     {
 237       typedef _Tp& __type;
 238     };
 239
 240   template<typename _Tp>
 241     struct __decay_and_strip
 242     {
 243       typedef typename __strip_reference_wrapper<
 244         typename decay<_Tp>::type>::__type __type;
 245     };
 246
 247   // NB: DR 706.
 248   template<class _T1, class _T2>
 249     inline pair<typename __decay_and_strip<_T1>::__type,
 250                 typename __decay_and_strip<_T2>::__type>
 251     make_pair(_T1&& __x, _T2&& __y)
 252     {
 253       return pair<typename __decay_and_strip<_T1>::__type,
 254                   typename __decay_and_strip<_T2>::__type>
 255         (std::forward<_T1>(__x), std::forward<_T2>(__y));
 256     }
 257 #endif
 258
 259 _GLIBCXX_END_NAMESPACE
 260
 261 #endif /* _STL_PAIR_H */