| /*============================================================================= |
| Copyright (c) 2001-2006 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| ==============================================================================*/ |
| #if !defined(FUSION_CONVERT_ITERATOR_05062005_1218) |
| #define FUSION_CONVERT_ITERATOR_05062005_1218 |
| |
| #include <boost/fusion/support/is_iterator.hpp> |
| #include <boost/mpl/if.hpp> |
| #include <boost/mpl/bool.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| template <typename Iterator> |
| struct mpl_iterator; // forward declaration |
| |
| // Test T. If it is a fusion iterator, return a reference to it. |
| // else, assume it is an mpl iterator. |
| |
| template <typename T> |
| struct convert_iterator |
| { |
| typedef typename |
| mpl::if_< |
| is_fusion_iterator<T> |
| , T |
| , mpl_iterator<T> |
| >::type |
| type; |
| |
| static T const& |
| call(T const& x, mpl::true_) |
| { |
| return x; |
| } |
| |
| static mpl_iterator<T> |
| call(T const& /*x*/, mpl::false_) |
| { |
| return mpl_iterator<T>(); |
| } |
| |
| static typename |
| mpl::if_< |
| is_fusion_iterator<T> |
| , T const& |
| , mpl_iterator<T> |
| >::type |
| call(T const& x) |
| { |
| return call(x, is_fusion_iterator<T>()); |
| } |
| }; |
| }} |
| |
| #endif |