/*============================================================================= | |
Copyright (c) 2007 Tobias Schwinger | |
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_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED) | |
#define BOOST_FUSION_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED | |
#include <boost/fusion/iterator/next.hpp> | |
#include <boost/fusion/iterator/equal_to.hpp> | |
namespace boost { namespace fusion | |
{ | |
struct repetitive_view_iterator_tag; | |
template <typename Sequence, typename Pos> | |
struct repetitive_view_iterator; | |
namespace extension | |
{ | |
template <typename Tag> | |
struct next_impl; | |
template <> | |
struct next_impl<repetitive_view_iterator_tag> | |
{ | |
template<typename Iterator, | |
bool Last = result_of::equal_to<typename Iterator::end_type, | |
typename result_of::next< | |
typename Iterator::pos_type | |
>::type>::value > | |
struct apply_nonempty // <Iterator,false> | |
{ | |
// advanvce to next position | |
typedef repetitive_view_iterator< | |
typename Iterator::sequence_type, | |
typename result_of::next<typename Iterator::pos_type>::type | |
> | |
type; | |
static type call(Iterator const& i) | |
{ | |
return type(i.seq, next(i.pos)); | |
} | |
}; | |
template <typename Iterator> | |
struct apply_nonempty<Iterator,true> | |
{ | |
// reset to beginning | |
typedef repetitive_view_iterator< | |
typename Iterator::sequence_type, | |
typename Iterator::first_type | |
> | |
type; | |
static type call(Iterator const& i) | |
{ | |
return type(i.seq); | |
} | |
}; | |
template <typename Iterator, | |
bool Empty = result_of::equal_to<typename Iterator::end_type, | |
typename Iterator::pos_type>::value > | |
struct apply // <Iterator,false> | |
: apply_nonempty<Iterator> | |
{ }; | |
template <typename Iterator> | |
struct apply<Iterator,true> | |
{ | |
// eps^n = eps | |
typedef Iterator type; | |
static type call(Iterator const& i) | |
{ | |
return type(i); | |
} | |
}; | |
}; | |
} | |
}} | |
#endif | |