boost/mpl/at.hpp

0001
0002 #ifndef BOOST_MPL_AT_HPP_INCLUDED
0003 #define BOOST_MPL_AT_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2000-2004
0006 //
0007 // Distributed under the Boost Software License, Version 1.0.
0008 // (See accompanying file LICENSE_1_0.txt or copy at
0009 // http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // See http://www.boost.org/libs/mpl for documentation.
0012
0013 // $Id$
0014 // $Date$
0015 // $Revision$
0016
0017 #include <boost/mpl/at_fwd.hpp>
0018 #include <boost/mpl/aux_/at_impl.hpp>
0019 #include <boost/mpl/long.hpp>
0020 #include <boost/mpl/sequence_tag.hpp>
0021 #include <boost/mpl/aux_/na_spec.hpp>
0022 #include <boost/mpl/aux_/lambda_support.hpp>
0023 #include <boost/mpl/aux_/nttp_decl.hpp>
0024
0025 namespace boost { namespace mpl {
0026
0027 template<
0028       typename BOOST_MPL_AUX_NA_PARAM(Sequence)
0029     , typename BOOST_MPL_AUX_NA_PARAM(N)
0030     >
0031 struct at
0032     : at_impl< typename sequence_tag<Sequence>::type >
0033         ::template apply< Sequence,N >
0034 {
0035     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,at,(Sequence,N))
0036 };
0037
0038 template<
0039       typename Sequence
0040     , BOOST_MPL_AUX_NTTP_DECL(long, N)
0041     >
0042 struct at_c
0043     : at_impl< typename sequence_tag<Sequence>::type >
0044         ::template apply< Sequence,mpl::long_<N> >
0045 {
0046 };
0047
0048 BOOST_MPL_AUX_NA_SPEC(2, at)
0049
0050 }}
0051
0052 #endif // BOOST_MPL_AT_HPP_INCLUDED