1 | /*============================================================================= |
2 | Copyright (c) 2011 Eric Niebler |
3 | |
4 | Distributed under the Boost Software License, Version 1.0. (See accompanying |
5 | file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
6 | ==============================================================================*/ |
7 | |
8 | #if !defined(BOOST_FUSION_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM) |
9 | #define BOOST_FUSION_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM |
10 | |
11 | #include <boost/fusion/support/config.hpp> |
12 | #include <boost/mpl/minus.hpp> |
13 | |
14 | namespace boost { namespace fusion |
15 | { |
16 | struct single_view_iterator_tag; |
17 | |
18 | namespace extension |
19 | { |
20 | template<typename Tag> |
21 | struct distance_impl; |
22 | |
23 | template<> |
24 | struct distance_impl<single_view_iterator_tag> |
25 | { |
26 | template<typename First, typename Last> |
27 | struct apply |
28 | : mpl::minus<typename Last::position, typename First::position> |
29 | { |
30 | typedef typename mpl::minus<typename Last::position, |
31 | typename First::position>::type type; |
32 | |
33 | BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
34 | static type |
35 | call(First const& /*first*/, Last const& /*last*/) |
36 | { |
37 | return type(); |
38 | } |
39 | }; |
40 | }; |
41 | } |
42 | |
43 | }} |
44 | |
45 | #endif |
46 | |