1 | /*============================================================================= |
2 | Copyright (c) 2001-2011 Joel de Guzman |
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 | #if !defined(FUSION_CONVERT_ITERATOR_05062005_1218) |
8 | #define FUSION_CONVERT_ITERATOR_05062005_1218 |
9 | |
10 | #include <boost/fusion/support/config.hpp> |
11 | #include <boost/fusion/support/is_iterator.hpp> |
12 | #include <boost/mpl/if.hpp> |
13 | #include <boost/mpl/bool.hpp> |
14 | |
15 | namespace boost { namespace fusion |
16 | { |
17 | template <typename Iterator> |
18 | struct mpl_iterator; // forward declaration |
19 | |
20 | // Test T. If it is a fusion iterator, return a reference to it. |
21 | // else, assume it is an mpl iterator. |
22 | |
23 | template <typename T> |
24 | struct convert_iterator |
25 | { |
26 | typedef typename |
27 | mpl::if_< |
28 | is_fusion_iterator<T> |
29 | , T |
30 | , mpl_iterator<T> |
31 | >::type |
32 | type; |
33 | |
34 | BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
35 | static T const& |
36 | call(T const& x, mpl::true_) |
37 | { |
38 | return x; |
39 | } |
40 | |
41 | BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
42 | static mpl_iterator<T> |
43 | call(T const& /*x*/, mpl::false_) |
44 | { |
45 | return mpl_iterator<T>(); |
46 | } |
47 | |
48 | BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED |
49 | static typename |
50 | mpl::if_< |
51 | is_fusion_iterator<T> |
52 | , T const& |
53 | , mpl_iterator<T> |
54 | >::type |
55 | call(T const& x) |
56 | { |
57 | return call(x, is_fusion_iterator<T>()); |
58 | } |
59 | }; |
60 | }} |
61 | |
62 | #endif |
63 | |