| /*============================================================================= |
| Copyright (c) 2001-2006 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_STD_PAIR_ITERATOR_09262005_0934) |
| #define FUSION_STD_PAIR_ITERATOR_09262005_0934 |
| |
| #include <boost/fusion/iterator/iterator_facade.hpp> |
| #include <boost/type_traits/is_const.hpp> |
| #include <boost/mpl/assert.hpp> |
| #include <boost/mpl/identity.hpp> |
| #include <boost/mpl/if.hpp> |
| #include <boost/mpl/int.hpp> |
| #include <boost/mpl/minus.hpp> |
| #include <boost/config/no_tr1/utility.hpp> |
| |
| namespace boost { namespace fusion |
| { |
| struct random_access_traversal_tag; |
| |
| template <typename Pair_, int N_> |
| struct std_pair_iterator |
| : iterator_facade<std_pair_iterator<Pair_, N_>, random_access_traversal_tag> |
| { |
| BOOST_MPL_ASSERT_RELATION(N_, >=, 0); |
| BOOST_MPL_ASSERT_RELATION(N_, <=, 2); |
| |
| typedef mpl::int_<N_> index; |
| typedef Pair_ pair_type; |
| |
| std_pair_iterator(Pair_& pair) |
| : pair(pair) {} |
| Pair_& pair; |
| |
| template <typename Iterator> |
| struct value_of; |
| |
| template <typename Pair> |
| struct value_of<std_pair_iterator<Pair, 0> > |
| : mpl::identity<typename Pair::first_type> {}; |
| |
| template <typename Pair> |
| struct value_of<std_pair_iterator<Pair, 1> > |
| : mpl::identity<typename Pair::second_type> {}; |
| |
| template <typename Iterator> |
| struct deref; |
| |
| template <typename Pair> |
| struct deref<std_pair_iterator<Pair, 0> > |
| { |
| typedef typename |
| mpl::if_< |
| is_const<Pair> |
| , typename Pair::first_type const& |
| , typename Pair::first_type& |
| >::type |
| type; |
| |
| static type |
| call(std_pair_iterator<Pair, 0> const& iter) |
| { |
| return iter.pair.first; |
| } |
| }; |
| |
| template <typename Pair> |
| struct deref<std_pair_iterator<Pair, 1> > |
| { |
| typedef typename |
| mpl::if_< |
| is_const<Pair> |
| , typename Pair::second_type const& |
| , typename Pair::second_type& |
| >::type |
| type; |
| |
| static type |
| call(std_pair_iterator<Pair, 1> const& iter) |
| { |
| return iter.pair.second; |
| } |
| }; |
| |
| template <typename Iterator, typename N> |
| struct advance |
| { |
| typedef typename Iterator::index index; |
| typedef typename Iterator::pair_type pair_type; |
| typedef std_pair_iterator<pair_type, index::value + N::value> type; |
| |
| static type |
| call(Iterator const& iter) |
| { |
| return type(iter.pair); |
| } |
| }; |
| |
| template <typename Iterator> |
| struct next : advance<Iterator, mpl::int_<1> > {}; |
| |
| template <typename Iterator> |
| struct prior : advance<Iterator, mpl::int_<-1> > {}; |
| |
| template <typename I1, typename I2> |
| struct distance : mpl::minus<typename I2::index, typename I1::index> |
| { |
| typedef typename |
| mpl::minus< |
| typename I2::index, typename I1::index |
| >::type |
| type; |
| |
| static type |
| call(I1 const&, I2 const&) |
| { |
| return type(); |
| } |
| }; |
| }; |
| }} |
| |
| #endif |
| |
| |