1 
2 #ifndef BOOST_MPL_AT_HPP_INCLUDED
3 #define BOOST_MPL_AT_HPP_INCLUDED
4 
5 // Copyright Aleksey Gurtovoy 2000-2004
6 //
7 // Distributed under the Boost Software License, Version 1.0.
8 // (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 //
11 // See http://www.boost.org/libs/mpl for documentation.
12 
13 // $Id$
14 // $Date$
15 // $Revision$
16 
17 #include <boost/mpl/at_fwd.hpp>
18 #include <boost/mpl/aux_/at_impl.hpp>
19 #include <boost/mpl/long.hpp>
20 #include <boost/mpl/sequence_tag.hpp>
21 #include <boost/mpl/aux_/na_spec.hpp>
22 #include <boost/mpl/aux_/lambda_support.hpp>
23 #include <boost/mpl/aux_/nttp_decl.hpp>
24 
25 namespace boost { namespace mpl {
26 
27 template<
28       typename BOOST_MPL_AUX_NA_PARAM(Sequence)
29     , typename BOOST_MPL_AUX_NA_PARAM(N)
30     >
31 struct at
32     : at_impl< typename sequence_tag<Sequence>::type >
33         ::template apply< Sequence,N >
34 {
35     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,at,(Sequence,N))
36 };
37 
38 template<
39       typename Sequence
40     , BOOST_MPL_AUX_NTTP_DECL(long, N)
41     >
42 struct at_c
43     : at_impl< typename sequence_tag<Sequence>::type >
44         ::template apply< Sequence,mpl::long_<N> >
45 {
46 };
47 
48 BOOST_MPL_AUX_NA_SPEC(2, at)
49 
50 }}
51 
52 #endif // BOOST_MPL_AT_HPP_INCLUDED
53