1
2#ifndef BOOST_MPL_AUX_BACK_IMPL_HPP_INCLUDED
3#define BOOST_MPL_AUX_BACK_IMPL_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/begin_end.hpp>
18#include <boost/mpl/next_prior.hpp>
19#include <boost/mpl/deref.hpp>
20#include <boost/mpl/aux_/traits_lambda_spec.hpp>
21
22namespace boost { namespace mpl {
23
24// default implementation, requires at least bi-directional iterators;
25// conrete sequences might override it by specializing either the
26// 'back_impl' or the primary 'back' template
27
28template< typename Tag >
29struct back_impl
30{
31 template< typename Sequence > struct apply
32 {
33 typedef typename end<Sequence>::type end_;
34 typedef typename prior<end_>::type last_;
35 typedef typename deref<last_>::type type;
36 };
37};
38
39BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1, back_impl)
40
41}}
42
43#endif // BOOST_MPL_AUX_BACK_IMPL_HPP_INCLUDED
44