1 
2 #ifndef BOOST_MPL_AUX_ORDER_IMPL_HPP_INCLUDED
3 #define BOOST_MPL_AUX_ORDER_IMPL_HPP_INCLUDED
4 
5 // Copyright Aleksey Gurtovoy 2003-2004
6 // Copyright David Abrahams 2003-2004
7 //
8 // Distributed under the Boost Software License, Version 1.0.
9 // (See accompanying file LICENSE_1_0.txt or copy at
10 // http://www.boost.org/LICENSE_1_0.txt)
11 //
12 // See http://www.boost.org/libs/mpl for documentation.
13 
14 // $Id$
15 // $Date$
16 // $Revision$
17 
18 #include <boost/mpl/order_fwd.hpp>
19 #include <boost/mpl/if.hpp>
20 #include <boost/mpl/long.hpp>
21 #include <boost/mpl/has_key.hpp>
22 #include <boost/mpl/aux_/overload_names.hpp>
23 #include <boost/mpl/aux_/static_cast.hpp>
24 #include <boost/mpl/aux_/type_wrapper.hpp>
25 #include <boost/mpl/aux_/traits_lambda_spec.hpp>
26 #include <boost/mpl/aux_/config/msvc.hpp>
27 #include <boost/mpl/aux_/config/static_constant.hpp>
28 #include <boost/mpl/aux_/config/workaround.hpp>
29 
30 namespace boost { namespace mpl {
31 
32 // default implementation; requires 'Seq' to provide corresponding overloads
33 // of BOOST_MPL_AUX_OVERLOAD_ORDER_BY_KEY
34 
35 template< typename Seq, typename Key > struct x_order_impl
36 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) \
37     || BOOST_WORKAROUND(__EDG_VERSION__, <= 245)
38 {
39     BOOST_STATIC_CONSTANT(long, value =
40           sizeof( BOOST_MPL_AUX_OVERLOAD_CALL_ORDER_BY_KEY(
41               Seq
42             , BOOST_MPL_AUX_STATIC_CAST(aux::type_wrapper<Key>*, 0)
43             ) )
44         );
45 
46     typedef long_<value> type;
47 
48 #else // ISO98 C++
49     : long_<
50           sizeof( BOOST_MPL_AUX_OVERLOAD_CALL_ORDER_BY_KEY(
51               Seq
52             , BOOST_MPL_AUX_STATIC_CAST(aux::type_wrapper<Key>*, 0)
53             ) )
54         >
55 {
56 #endif
57 };
58 
59 template< typename Tag >
60 struct order_impl
61 {
62     template< typename Seq, typename Key > struct apply
63         : if_<
64               typename has_key_impl<Tag>::template apply<Seq,Key>
65             , x_order_impl<Seq,Key>
66             , void_
67             >::type
68     {
69     };
70 };
71 
72 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(2,order_impl)
73 
74 }}
75 
76 #endif // BOOST_MPL_AUX_ORDER_IMPL_HPP_INCLUDED
77