/*============================================================================= | |
Copyright (c) 2001-2006 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) | |
==============================================================================*/ | |
#ifndef FUSION_MULTIPLE_VIEW_05052005_0335 | |
#define FUSION_MULTIPLE_VIEW_05052005_0335 | |
#include <boost/mpl/int.hpp> | |
#include <boost/mpl/bool.hpp> | |
#include <boost/mpl/next.hpp> | |
#include <boost/fusion/support/detail/access.hpp> | |
#include <boost/fusion/support/sequence_base.hpp> | |
#include <boost/fusion/support/iterator_base.hpp> | |
#include <boost/fusion/support/detail/as_fusion_element.hpp> | |
namespace boost { namespace fusion | |
{ | |
struct multiple_view_tag; | |
struct forward_traversal_tag; | |
struct fusion_sequence_tag; | |
template<typename Size, typename T> | |
struct multiple_view | |
: sequence_base<multiple_view<Size, T> > | |
{ | |
typedef multiple_view_tag fusion_tag; | |
typedef fusion_sequence_tag tag; // this gets picked up by MPL | |
typedef forward_traversal_tag category; | |
typedef mpl::true_ is_view; | |
typedef mpl::int_<Size::value> size; | |
typedef T value_type; | |
multiple_view() | |
: val() | |
{} | |
explicit multiple_view(typename detail::call_param<T>::type val) | |
: val(val) | |
{} | |
value_type val; | |
}; | |
template<typename Size, typename T> | |
inline multiple_view<Size, typename detail::as_fusion_element<T>::type> | |
make_multiple_view(T const& v) | |
{ | |
return multiple_view<Size, typename detail::as_fusion_element<T>::type>(v); | |
} | |
struct multiple_view_iterator_tag; | |
struct forward_traversal_tag; | |
template<typename Index, typename MultipleView> | |
struct multiple_view_iterator | |
: iterator_base<multiple_view_iterator<Index, MultipleView> > | |
{ | |
typedef multiple_view_iterator_tag fusion_tag; | |
typedef forward_traversal_tag category; | |
typedef typename MultipleView::value_type value_type; | |
typedef MultipleView multiple_view_type; | |
typedef Index index; | |
explicit multiple_view_iterator(multiple_view_type const &view_) | |
: view(view_) | |
{} | |
multiple_view_type view; | |
}; | |
namespace extension | |
{ | |
template <typename Tag> | |
struct next_impl; | |
template <> | |
struct next_impl<multiple_view_iterator_tag> | |
{ | |
template <typename Iterator> | |
struct apply | |
{ | |
typedef multiple_view_iterator< | |
typename mpl::next<typename Iterator::index>::type | |
, typename Iterator::multiple_view_type | |
> type; | |
static type | |
call(Iterator const &where) | |
{ | |
return type(where.view); | |
} | |
}; | |
}; | |
template <typename Tag> | |
struct end_impl; | |
template <> | |
struct end_impl<multiple_view_tag> | |
{ | |
template <typename Sequence> | |
struct apply | |
{ | |
typedef multiple_view_iterator< | |
typename Sequence::size | |
, Sequence | |
> type; | |
static type | |
call(Sequence &seq) | |
{ | |
return type(seq); | |
} | |
}; | |
}; | |
template <typename Tag> | |
struct deref_impl; | |
template <> | |
struct deref_impl<multiple_view_iterator_tag> | |
{ | |
template <typename Iterator> | |
struct apply | |
{ | |
typedef typename Iterator::value_type type; | |
static type | |
call(Iterator const& i) | |
{ | |
return i.view.val; | |
} | |
}; | |
}; | |
template <typename Tag> | |
struct begin_impl; | |
template <> | |
struct begin_impl<multiple_view_tag> | |
{ | |
template <typename Sequence> | |
struct apply | |
{ | |
typedef multiple_view_iterator< | |
mpl::int_<0> | |
, Sequence | |
> type; | |
static type | |
call(Sequence &seq) | |
{ | |
return type(seq); | |
} | |
}; | |
}; | |
template <typename Tag> | |
struct value_of_impl; | |
template <> | |
struct value_of_impl<multiple_view_iterator_tag> | |
{ | |
template <typename Iterator> | |
struct apply | |
{ | |
typedef typename Iterator::multiple_view_type multiple_view_type; | |
typedef typename multiple_view_type::value_type type; | |
}; | |
}; | |
} | |
}} | |
#endif | |