You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
61 lines
1.7 KiB
61 lines
1.7 KiB
/*============================================================================= |
|
Copyright (c) 2001-2011 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_EMPTY_09162005_0335) |
|
#define FUSION_EMPTY_09162005_0335 |
|
|
|
#include <boost/fusion/sequence/intrinsic_fwd.hpp> |
|
#include <boost/fusion/sequence/intrinsic/size.hpp> |
|
#include <boost/mpl/bool.hpp> |
|
#include <boost/fusion/support/tag_of.hpp> |
|
|
|
namespace boost { namespace fusion |
|
{ |
|
// Special tags: |
|
struct sequence_facade_tag; |
|
struct mpl_sequence_tag; // mpl sequence tag |
|
|
|
namespace extension |
|
{ |
|
template <typename Tag> |
|
struct empty_impl |
|
{ |
|
template <typename Sequence> |
|
struct apply |
|
: mpl::bool_<(result_of::size<Sequence>::value == 0)> |
|
{}; |
|
}; |
|
|
|
template <> |
|
struct empty_impl<sequence_facade_tag> |
|
{ |
|
template <typename Sequence> |
|
struct apply : Sequence::template empty<Sequence> {}; |
|
}; |
|
|
|
template <> |
|
struct empty_impl<mpl_sequence_tag>; |
|
} |
|
|
|
namespace result_of |
|
{ |
|
template <typename Sequence> |
|
struct empty |
|
: extension::empty_impl<typename detail::tag_of<Sequence>::type>:: |
|
template apply<Sequence> |
|
{}; |
|
} |
|
|
|
template <typename Sequence> |
|
inline typename result_of::empty<Sequence>::type |
|
empty(Sequence const&) |
|
{ |
|
typedef typename result_of::empty<Sequence>::type result; |
|
return result(); |
|
} |
|
}} |
|
|
|
#endif
|
|
|