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3 years ago
/*=============================================================================
Copyright (c) 2006 Eric Niebler
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(BOOST_FUSION_SEGMENTS_04052005_1141)
#define BOOST_FUSION_SEGMENTS_04052005_1141
#include <boost/fusion/support/config.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/fusion/sequence/intrinsic_fwd.hpp>
#include <boost/fusion/support/tag_of.hpp>
namespace boost { namespace fusion
{
// Special tags:
struct sequence_facade_tag;
struct iterator_range_tag;
// segments: returns a sequence of sequences
namespace extension
{
template <typename Tag>
struct segments_impl
{
template <typename Sequence>
struct apply {};
};
template <>
struct segments_impl<sequence_facade_tag>
{
template <typename Sequence>
struct apply : Sequence::template segments<Sequence> {};
};
template <>
struct segments_impl<iterator_range_tag>;
}
namespace result_of
{
template <typename Sequence>
struct segments
{
typedef typename traits::tag_of<Sequence>::type tag_type;
typedef typename
extension::segments_impl<tag_type>::template apply<Sequence>::type
type;
};
}
template <typename Sequence>
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
inline typename
lazy_disable_if<
is_const<Sequence>
, result_of::segments<Sequence>
>::type
segments(Sequence& seq)
{
typedef typename traits::tag_of<Sequence>::type tag_type;
return extension::segments_impl<tag_type>::template apply<Sequence>::call(seq);
}
template <typename Sequence>
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
inline typename result_of::segments<Sequence const>::type
segments(Sequence const& seq)
{
typedef typename traits::tag_of<Sequence const>::type tag_type;
return extension::segments_impl<tag_type>::template apply<Sequence const>::call(seq);
}
}}
#endif