1// TR1 utility -*- C++ -*-
2
3// Copyright (C) 2004, 2005 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 
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{
41namespace 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    struct tuple_element<0, std::pair<_Tp1, _Tp2> >
53    { typedef _Tp1 type; };
54 
55  template<class _Tp1, class _Tp2>
56    struct tuple_element<1, std::pair<_Tp1, _Tp2> >
57    { typedef _Tp2 type; };
58 
59
60  template<int _Int> struct __pair_get;
61
62  template<>
63    struct __pair_get<0>
64    {
65      template<typename _Tp1, typename _Tp2>
66      static _Tp1& __get(std::pair<_Tp1, _Tp2>& __pair)
67      { return __pair.first; }
68
69      template<typename _Tp1, typename _Tp2>
70      static const _Tp1& __const_get(const std::pair<_Tp1, _Tp2>& __pair)
71      { return __pair.first; }
72    };
73
74  template<>
75    struct __pair_get<1>
76    {
77      template<typename _Tp1, typename _Tp2>
78      static _Tp2& __get(std::pair<_Tp1, _Tp2>& __pair)
79      { return __pair.second; }
80
81      template<typename _Tp1, typename _Tp2>
82      static const _Tp2& __const_get(const std::pair<_Tp1, _Tp2>& __pair)
83      { return __pair.second; }
84    };
85
86   template<int _Int, class _Tp1, class _Tp2>
87     typename tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&
88     get(pair<_Tp1, _Tp2>& __in)
89     { return __pair_get<_Int>::__get(__in); }
90 
91   template<int _Int, class _Tp1, class _Tp2>
92     const typename tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&
93     get(const pair<_Tp1, _Tp2>& __in)
94     { return __pair_get<_Int>::__const_get(__in); }
95}
96} 
97
98#endif
99