1 
2 // Copyright Aleksey Gurtovoy 2002-2004
3 //
4 // Distributed under the Boost Software License, Version 1.0.
5 // (See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt)
7 //
8 // See http://www.boost.org/libs/mpl for documentation.
9 
10 // $Id$
11 // $Date$
12 // $Revision$
13 
14 #include <boost/mpl/inherit.hpp>
15 #include <boost/mpl/inherit_linearly.hpp>
16 #include <boost/mpl/list.hpp>
17 
18 #include <iostream>
19 
20 namespace mpl = boost::mpl;
21 using namespace mpl::placeholders;
22 
23 template< typename T >
24 struct tuple_field
25 {
26     typedef tuple_field type; // note the typedef
27     T field_;
28 };
29 
30 template< typename T >
31 inline
field(tuple_field<T> & t)32 T& field(tuple_field<T>& t)
33 {
34     return t.field_;
35 }
36 
37 typedef mpl::inherit_linearly<
38       mpl::list<int,char const*,bool>
39     , mpl::inherit< _1, tuple_field<_2> >
40     >::type my_tuple;
41 
42 
main()43 int main()
44 {
45     my_tuple t;
46 
47     field<int>(t) = -1;
48     field<char const*>(t) = "text";
49     field<bool>(t) = false;
50 
51     std::cout
52         << field<int>(t) << '\n'
53         << field<char const*>(t) << '\n'
54         << field<bool>(t) << '\n'
55         ;
56 
57     return 0;
58 }
59