/*=============================================================================
    Copyright (c) 2001-2011 Joel de Guzman
    Copyright (c) 2005 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(FUSION_CONS_ITERATOR_07172005_0849)
#define FUSION_CONS_ITERATOR_07172005_0849

#include <boost/fusion/support/config.hpp>
#include <boost/type_traits/add_const.hpp>
#include <boost/fusion/support/iterator_base.hpp>
#include <boost/fusion/container/list/detail/deref_impl.hpp>
#include <boost/fusion/container/list/detail/next_impl.hpp>
#include <boost/fusion/container/list/detail/value_of_impl.hpp>
#include <boost/fusion/container/list/detail/equal_to_impl.hpp>
#include <boost/fusion/container/list/list_fwd.hpp>

namespace boost {
namespace fusion {
struct nil_;
struct cons_iterator_tag;
struct forward_traversal_tag;

template <typename Cons>
struct cons_iterator_identity;

#ifdef _MSC_VER
#  pragma warning(push)
#  pragma warning(disable: 4512) // assignment operator could not be generated.
#endif
template <typename Cons = nil_>
struct cons_iterator : iterator_base<cons_iterator<Cons> >
{
    typedef cons_iterator_tag fusion_tag;
    typedef forward_traversal_tag category;
    typedef Cons cons_type;
    typedef cons_iterator_identity<
    typename add_const<Cons>::type>
    identity;

    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    cons_iterator(cons_type& in_cons) BOOST_NOEXCEPT
        :
    cons(in_cons) {}

    cons_type& cons;
};
#ifdef _MSC_VER
#  pragma warning(pop)
#endif

struct nil_iterator : iterator_base<nil_iterator>
{
    typedef forward_traversal_tag category;
    typedef cons_iterator_tag fusion_tag;
    typedef nil_ cons_type;
    typedef cons_iterator_identity<
    add_const<nil_>::type>
    identity;

    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    nil_iterator() BOOST_NOEXCEPT {}
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    nil_iterator(nil_ const&) BOOST_NOEXCEPT {}
};

template <>
struct cons_iterator<nil_> : nil_iterator
{
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    cons_iterator() BOOST_NOEXCEPT {}
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
};

template <>
struct cons_iterator<nil_ const> : nil_iterator
{
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    cons_iterator() BOOST_NOEXCEPT {}
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
};

template <>
struct cons_iterator<list<> > : nil_iterator
{
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    cons_iterator() BOOST_NOEXCEPT {}
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
};

template <>
struct cons_iterator<list<> const> : nil_iterator
{
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    cons_iterator() BOOST_NOEXCEPT {}
    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
    explicit
    cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
};
}
}

#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
namespace std {
template <typename Cons>
struct iterator_traits< ::boost::fusion::cons_iterator<Cons> >
{ };
}
#endif

#endif
