1// TR1 utility -*- C++ -*-
2
3// Copyright (C) 2004, 2005, 2006, 2007 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/** @file tr1/utility
31 *  This is a TR1 C++ Library header. 
32 */
33
34#ifndef _TR1_UTILITY
35#define _TR1_UTILITY 1
36
37#include "../utility"
38
39namespace std
40{
41_GLIBCXX_BEGIN_NAMESPACE(tr1)
42
43  template<class _Tp> class tuple_size;
44  template<int _Int, class _Tp> class tuple_element;
45
46   // Various functions which give std::pair a tuple-like interface.
47  template<class _Tp1, class _Tp2>
48    struct tuple_size<std::pair<_Tp1, _Tp2> >
49    { static const int value = 2; };
50
51  template<class _Tp1, class _Tp2>
52    const int tuple_size<std::pair<_Tp1, _Tp2> >::value;
53
54  template<class _Tp1, class _Tp2>
55    struct tuple_element<0, std::pair<_Tp1, _Tp2> >
56    { typedef _Tp1 type; };
57 
58  template<class _Tp1, class _Tp2>
59    struct tuple_element<1, std::pair<_Tp1, _Tp2> >
60    { typedef _Tp2 type; };
61 
62
63  template<int _Int> struct __pair_get;
64
65  template<>
66    struct __pair_get<0>
67    {
68      template<typename _Tp1, typename _Tp2>
69      static _Tp1& __get(std::pair<_Tp1, _Tp2>& __pair)
70      { return __pair.first; }
71
72      template<typename _Tp1, typename _Tp2>
73      static const _Tp1& __const_get(const std::pair<_Tp1, _Tp2>& __pair)
74      { return __pair.first; }
75    };
76
77  template<>
78    struct __pair_get<1>
79    {
80      template<typename _Tp1, typename _Tp2>
81      static _Tp2& __get(std::pair<_Tp1, _Tp2>& __pair)
82      { return __pair.second; }
83
84      template<typename _Tp1, typename _Tp2>
85      static const _Tp2& __const_get(const std::pair<_Tp1, _Tp2>& __pair)
86      { return __pair.second; }
87    };
88
89   template<int _Int, class _Tp1, class _Tp2>
90     inline typename tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&
91     get(std::pair<_Tp1, _Tp2>& __in)
92     { return __pair_get<_Int>::__get(__in); }
93 
94   template<int _Int, class _Tp1, class _Tp2>
95     inline const typename tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&
96     get(const std::pair<_Tp1, _Tp2>& __in)
97     { return __pair_get<_Int>::__const_get(__in); }
98
99_GLIBCXX_END_NAMESPACE
100} 
101
102#endif
103