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
15namespace 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

source code of include/boost/fusion/iterator/mpl/convert_iterator.hpp