| 1 | /*============================================================================= |
|---|---|
| 2 | Copyright (c) 2007 Tobias Schwinger |
| 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(BOOST_FUSION_SEQUENCE_EMPTY_IMPL_HPP_INCLUDED) |
| 8 | #define BOOST_FUSION_SEQUENCE_EMPTY_IMPL_HPP_INCLUDED |
| 9 | |
| 10 | #include <boost/fusion/support/config.hpp> |
| 11 | #include <boost/type_traits/is_convertible.hpp> |
| 12 | #include <boost/fusion/container/list/nil.hpp> |
| 13 | |
| 14 | namespace boost { namespace fusion |
| 15 | { |
| 16 | struct cons_tag; |
| 17 | |
| 18 | struct nil_; |
| 19 | |
| 20 | template <typename Car, typename Cdr> |
| 21 | struct cons; |
| 22 | |
| 23 | namespace extension |
| 24 | { |
| 25 | template <typename Tag> |
| 26 | struct empty_impl; |
| 27 | |
| 28 | template <> |
| 29 | struct empty_impl<cons_tag> |
| 30 | { |
| 31 | template <typename Sequence> |
| 32 | struct apply |
| 33 | : boost::is_convertible<Sequence, nil_> |
| 34 | {}; |
| 35 | }; |
| 36 | } |
| 37 | }} |
| 38 | |
| 39 | #endif |
| 40 |