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_AT_IMPL_JUL_07_2011_1348PM) |
9 | #define BOOST_FUSION_SINGLE_VIEW_AT_IMPL_JUL_07_2011_1348PM |
10 | |
11 | #include <boost/fusion/support/config.hpp> |
12 | #include <boost/mpl/int.hpp> |
13 | #include <boost/mpl/assert.hpp> |
14 | #include <boost/mpl/equal_to.hpp> |
15 | |
16 | namespace boost { namespace fusion |
17 | { |
18 | struct single_view_tag; |
19 | |
20 | namespace extension |
21 | { |
22 | template<typename Tag> |
23 | struct at_impl; |
24 | |
25 | template<> |
26 | struct at_impl<single_view_tag> |
27 | { |
28 | template<typename Sequence, typename N> |
29 | struct apply |
30 | { |
31 | BOOST_MPL_ASSERT((mpl::equal_to<N, mpl::int_<0> >)); |
32 | typedef typename Sequence::value_type type; |
33 | |
34 | BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
35 | static type |
36 | call(Sequence& seq) |
37 | { |
38 | return seq.val; |
39 | } |
40 | }; |
41 | }; |
42 | } |
43 | |
44 | }} |
45 | |
46 | #endif |
47 |