1 | |
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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 | |
22 | namespace 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 | |
28 | template< typename Tag > |
29 | struct 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 | |
39 | BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1, back_impl) |
40 | |
41 | }} |
42 | |
43 | #endif // BOOST_MPL_AUX_BACK_IMPL_HPP_INCLUDED |
44 |