From ac31f6d1cb8e3c1b5c12036c63393ce36a94918b Mon Sep 17 00:00:00 2001
From: Joel de Guzman <djowel@gmail.com>
Date: Mon, 25 Sep 2006 13:56:22 +0000
Subject: [PATCH] migrated std_pair_iterator and mpl_iterator to
 iterator_facade

[SVN r35321]
---
 .../sequence/adapted/array/array_iterator.hpp |  60 +++------
 .../adapted/mpl/detail/advance_impl.hpp       |  45 -------
 .../adapted/mpl/detail/deref_impl.hpp         |  44 ------
 .../adapted/mpl/detail/distance_impl.hpp      |  48 -------
 .../adapted/mpl/detail/equal_to_impl.hpp      |  41 ------
 .../sequence/adapted/mpl/detail/next_impl.hpp |  47 -------
 .../adapted/mpl/detail/prior_impl.hpp         |  47 -------
 .../adapted/mpl/detail/value_of_impl.hpp      |  38 ------
 .../sequence/adapted/mpl/mpl_iterator.hpp     | 104 +++++++++++---
 .../std_pair/Attic/std_pair_iterator.hpp      | 127 +++++++++++++++---
 .../adapted/std_pair/detail/Attic/at_impl.hpp |   1 +
 .../adapted/std_pair/detail/advance_impl.hpp  |  47 -------
 .../adapted/std_pair/detail/at_impl.hpp       |   1 +
 .../adapted/std_pair/detail/deref_impl.hpp    |  74 ----------
 .../adapted/std_pair/detail/distance_impl.hpp |  42 ------
 .../adapted/std_pair/detail/equal_to_impl.hpp |  40 ------
 .../adapted/std_pair/detail/next_impl.hpp     |  46 -------
 .../adapted/std_pair/detail/prior_impl.hpp    |  46 -------
 .../adapted/std_pair/detail/value_of_impl.hpp |  46 -------
 .../adapted/std_pair/std_pair_iterator.hpp    | 127 +++++++++++++++---
 20 files changed, 328 insertions(+), 743 deletions(-)
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/advance_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/deref_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/distance_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/equal_to_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/next_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/prior_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/mpl/detail/value_of_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp
 delete mode 100644 include/boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp

diff --git a/include/boost/fusion/sequence/adapted/array/array_iterator.hpp b/include/boost/fusion/sequence/adapted/array/array_iterator.hpp
index 71a9921c..a0eef60f 100644
--- a/include/boost/fusion/sequence/adapted/array/array_iterator.hpp
+++ b/include/boost/fusion/sequence/adapted/array/array_iterator.hpp
@@ -11,7 +11,7 @@
 
 #include <cstddef>
 #include <boost/config.hpp>
-#include <boost/mpl/size_t.hpp>
+#include <boost/mpl/int.hpp>
 #include <boost/mpl/assert.hpp>
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/minus.hpp>
@@ -22,14 +22,14 @@ namespace boost { namespace fusion
 {
     struct random_access_traversal_tag;
 
-    template<typename Array, std::size_t Pos>
+    template <typename Array, int Pos>
     struct array_iterator
         : iterator_facade<array_iterator<Array, Pos>, random_access_traversal_tag>
     {
-        BOOST_MPL_ASSERT_RELATION(Pos,>=,0);
-        BOOST_MPL_ASSERT_RELATION(Pos,<=,std::size_t(Array::static_size));
+        BOOST_MPL_ASSERT_RELATION(Pos, >=, 0);
+        BOOST_MPL_ASSERT_RELATION(Pos, <=, Array::static_size);
 
-        typedef mpl::size_t<Pos> index;
+        typedef mpl::int_<Pos> index;
         typedef Array array_type;
 
         array_iterator(Array& a)
@@ -63,36 +63,6 @@ namespace boost { namespace fusion
             }
         };
 
-        template <typename Iterator>
-        struct next
-        {
-            typedef typename Iterator::array_type array_type;
-            typedef typename Iterator::index index;
-            static int const index_val = index::value;
-            typedef array_iterator<array_type, index_val + 1> type;
-
-            static type
-            call(Iterator const& i)
-            {
-                return type(i.array);
-            }
-        };
-
-        template <typename Iterator>
-        struct prior
-        {
-            typedef typename Iterator::array_type array_type;
-            typedef typename Iterator::index index;
-            static int const index_val = index::value;
-            typedef array_iterator<array_type, index_val - 1> type;
-
-            static type
-            call(Iterator const& i)
-            {
-                return type(i.array);
-            }
-        };
-
         template <typename Iterator, typename N>
         struct advance
         {
@@ -107,15 +77,23 @@ namespace boost { namespace fusion
             }
         };
 
-        template <typename First, typename Last>
-        struct distance : mpl::minus<typename Last::index, typename First::index>
+        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 Last::index, typename First::index>::type 
+            typedef typename
+                mpl::minus<
+                    typename I2::index, typename I1::index
+                >::type 
             type;
 
             static type
-            call(First const&, Last const&)
+            call(I1 const&, I2 const&)
             {
                 return type();
             }
@@ -123,7 +101,7 @@ namespace boost { namespace fusion
 
     private:
 
-        array_iterator<Array, Pos> operator=(const array_iterator<Array, Pos>&);
+        array_iterator<Array, Pos>& operator=(array_iterator<Array, Pos> const&);
     };
 }}
 
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/advance_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/advance_impl.hpp
deleted file mode 100644
index 9603a737..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/advance_impl.hpp
+++ /dev/null
@@ -1,45 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_ADVANCE_IMPL_09232005_2324)
-#define FUSION_ADVANCE_IMPL_09232005_2324
-
-#include <boost/mpl/advance.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    template <typename Iterator>
-    struct mpl_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct advance_impl;
-    
-        template <>
-        struct advance_impl<mpl_iterator_tag>
-        {
-            template <typename Iterator, typename N>
-            struct apply
-            {
-                typedef mpl_iterator<
-                    typename mpl::advance<typename Iterator::iterator_type, N>::type> 
-                type;
-    
-                static type
-                call(Iterator const& i)
-                {
-                    return type();
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/deref_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/deref_impl.hpp
deleted file mode 100644
index e692c93b..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/deref_impl.hpp
+++ /dev/null
@@ -1,44 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_DEREF_IMPL_05052005_0733)
-#define FUSION_DEREF_IMPL_05052005_0733
-
-#include <boost/mpl/deref.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct deref_impl;
-
-        template <>
-        struct deref_impl<mpl_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply
-            {
-                typedef typename mpl::deref<
-                    typename Iterator::iterator_type>::type
-                type;
-    
-                static type
-                call(Iterator)
-                {
-                    return type();
-                }
-            };
-        };
-    }
-}}
-
-#endif
-
-
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/distance_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/distance_impl.hpp
deleted file mode 100644
index 893c3112..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/distance_impl.hpp
+++ /dev/null
@@ -1,48 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_DISTANCE_IMPL_09232005_2303)
-#define FUSION_DISTANCE_IMPL_09232005_2303
-
-#include <boost/mpl/minus.hpp>
-#include <boost/mpl/distance.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct distance_impl;
-
-        template <>
-        struct distance_impl<mpl_iterator_tag>
-        {
-            template <typename First, typename Last>
-            struct apply 
-                : mpl::distance<
-                    typename First::iterator_type
-                  , typename Last::iterator_type>
-            {    
-                static typename mpl::distance<
-                    typename First::iterator_type
-                  , typename Last::iterator_type>::type
-                call(First const&, Last const&)
-                {
-                    typedef typename mpl::distance<
-                        typename First::iterator_type
-                      , typename Last::iterator_type>::type
-                    result;
-                    return result();
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/equal_to_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/equal_to_impl.hpp
deleted file mode 100644
index 25a3e886..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/equal_to_impl.hpp
+++ /dev/null
@@ -1,41 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_EQUAL_TO_IMPL_05232005_0621)
-#define FUSION_EQUAL_TO_IMPL_05232005_0621
-
-#include <boost/type_traits/is_same.hpp>
-#include <boost/type_traits/remove_const.hpp>
-#include <boost/mpl/equal_to.hpp>
-#include <boost/mpl/and.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct equal_to_impl;
-
-        template <>
-        struct equal_to_impl<mpl_iterator_tag>
-        {
-            template <typename I1, typename I2>
-            struct apply             
-                : is_same<
-                    typename remove_const<typename I1::iterator_type>::type
-                  , typename remove_const<typename I2::iterator_type>::type
-                >
-            {
-            };
-        };
-    }
-}}
-
-#endif
-
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/next_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/next_impl.hpp
deleted file mode 100644
index 6427e283..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/next_impl.hpp
+++ /dev/null
@@ -1,47 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_NEXT_IMPL_05052005_0733)
-#define FUSION_NEXT_IMPL_05052005_0733
-
-#include <boost/mpl/next.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    template <typename Iterator>
-    struct mpl_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct next_impl;
-
-        template <>
-        struct next_impl<mpl_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef mpl_iterator<
-                    typename mpl::next<typename Iterator::iterator_type>::type
-                > type;
-    
-                static type
-                call(Iterator)
-                {
-                    return type();
-                }
-            };
-        };
-    }
-}}
-
-#endif
-
-
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/prior_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/prior_impl.hpp
deleted file mode 100644
index e2ae56be..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/prior_impl.hpp
+++ /dev/null
@@ -1,47 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_PRIOR_IMPL_05202005_0930)
-#define FUSION_PRIOR_IMPL_05202005_0930
-
-#include <boost/mpl/next.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    template <typename Iterator>
-    struct mpl_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct prior_impl;
-
-        template <>
-        struct prior_impl<mpl_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef mpl_iterator<
-                    typename mpl::prior<typename Iterator::iterator_type>::type
-                > type;
-    
-                static type
-                call(Iterator)
-                {
-                    return type();
-                }
-            };
-        };
-    }
-}}
-
-#endif
-
-
diff --git a/include/boost/fusion/sequence/adapted/mpl/detail/value_of_impl.hpp b/include/boost/fusion/sequence/adapted/mpl/detail/value_of_impl.hpp
deleted file mode 100644
index 3d7c9fff..00000000
--- a/include/boost/fusion/sequence/adapted/mpl/detail/value_of_impl.hpp
+++ /dev/null
@@ -1,38 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_VALUE_OF_TRAITS_05052005_0734)
-#define FUSION_VALUE_OF_TRAITS_05052005_0734
-
-#include <boost/mpl/deref.hpp>
-
-namespace boost { namespace fusion
-{
-    struct mpl_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct value_of_impl;
-
-        template <>
-        struct value_of_impl<mpl_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply
-            {
-                typedef typename mpl::deref<
-                    typename Iterator::iterator_type>::type
-                type;
-            };
-        };
-    }
-}}
-
-#endif
-
-
diff --git a/include/boost/fusion/sequence/adapted/mpl/mpl_iterator.hpp b/include/boost/fusion/sequence/adapted/mpl/mpl_iterator.hpp
index 68612a44..baf85db4 100644
--- a/include/boost/fusion/sequence/adapted/mpl/mpl_iterator.hpp
+++ b/include/boost/fusion/sequence/adapted/mpl/mpl_iterator.hpp
@@ -8,30 +8,104 @@
 #if !defined(FUSION_MPL_ITERATOR_05052005_0731)
 #define FUSION_MPL_ITERATOR_05052005_0731
 
-#include <boost/fusion/support/iterator_base.hpp>
 #include <boost/fusion/support/detail/mpl_iterator_category.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/deref_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/next_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/prior_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/value_of_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/equal_to_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/distance_impl.hpp>
-#include <boost/fusion/sequence/adapted/mpl/detail/advance_impl.hpp>
+#include <boost/fusion/iterator/iterator_facade.hpp>
 #include <boost/type_traits/remove_const.hpp>
+#include <boost/mpl/deref.hpp>
+#include <boost/mpl/next.hpp>
+#include <boost/mpl/prior.hpp>
+#include <boost/mpl/advance.hpp>
+#include <boost/mpl/distance.hpp>
 
 namespace boost { namespace fusion
 {
-    struct mpl_iterator_tag;
-
     template <typename Iterator>
     struct mpl_iterator
-        : iterator_base<mpl_iterator<Iterator> >
+        : iterator_facade<
+            mpl_iterator<Iterator>
+          , typename detail::mpl_iterator_category<typename Iterator::category>::type
+        >
     {
-        typedef mpl_iterator_tag fusion_tag;
-        typedef typename detail::mpl_iterator_category<
-            typename Iterator::category>::type 
-        category;
         typedef typename remove_const<Iterator>::type iterator_type;
+
+        template <typename Iterator>
+        struct value_of : mpl::deref<typename Iterator::iterator_type> {};
+
+        template <typename Iterator>
+        struct deref
+        {
+            typedef typename mpl::deref<
+                typename Iterator::iterator_type>::type
+            type;
+
+            static type
+            call(Iterator)
+            {
+                return type();
+            }
+        };
+
+        template <typename Iterator>
+        struct next
+        {
+            typedef mpl_iterator<
+                typename mpl::next<typename Iterator::iterator_type>::type> 
+            type;
+
+            static type
+            call(Iterator)
+            {
+                return type();
+            }
+        };
+
+        template <typename Iterator>
+        struct prior
+        {
+            typedef mpl_iterator<
+                typename mpl::prior<typename Iterator::iterator_type>::type> 
+            type;
+
+            static type
+            call(Iterator)
+            {
+                return type();
+            }
+        };
+
+        template <typename Iterator, typename N>
+        struct advance
+        {
+            typedef mpl_iterator<
+                typename mpl::advance<typename Iterator::iterator_type, N>::type>
+            type;
+
+            static type
+            call(Iterator const& i)
+            {
+                return type();
+            }
+        };
+
+        template <typename I1, typename I2>
+        struct distance : 
+            mpl::distance<
+                typename I1::iterator_type
+              , typename I2::iterator_type>
+        {
+            typedef typename 
+                mpl::distance<
+                    typename I1::iterator_type
+                  , typename I2::iterator_type
+                >::type
+            type;
+            
+            static type
+            call(I1 const&, I2 const&)
+            {
+                return type();
+            }
+        };
     };
 }}
 
diff --git a/include/boost/fusion/sequence/adapted/std_pair/Attic/std_pair_iterator.hpp b/include/boost/fusion/sequence/adapted/std_pair/Attic/std_pair_iterator.hpp
index 1121e315..a2cb7f52 100644
--- a/include/boost/fusion/sequence/adapted/std_pair/Attic/std_pair_iterator.hpp
+++ b/include/boost/fusion/sequence/adapted/std_pair/Attic/std_pair_iterator.hpp
@@ -8,39 +8,130 @@
 #if !defined(FUSION_STD_PAIR_ITERATOR_09262005_0934)
 #define FUSION_STD_PAIR_ITERATOR_09262005_0934
 
-#include <boost/fusion/support/iterator_base.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp>
-#include <boost/type_traits/add_const.hpp>
+//~ #include <boost/fusion/support/iterator_base.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp>
+//~ #include <boost/type_traits/add_const.hpp>
+
+
+
+#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 <utility>
 
 namespace boost { namespace fusion
 {
-    struct std_pair_iterator_tag;
     struct random_access_traversal_tag;
 
-    template <typename Pair, int N>
-    struct std_pair_iterator_identity;
-
     template <typename Pair, int N>
     struct std_pair_iterator
-        : iterator_base<std_pair_iterator<Pair, N> >
+        : 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 std_pair_iterator_tag fusion_tag;
-        typedef random_access_traversal_tag category;
-        typedef std_pair_iterator_identity<
-            typename add_const<Pair>::type, N> identity;
         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();
+            }
+        };
     };
 }}
 
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/Attic/at_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/Attic/at_impl.hpp
index dce5f86c..b257089d 100644
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/Attic/at_impl.hpp
+++ b/include/boost/fusion/sequence/adapted/std_pair/detail/Attic/at_impl.hpp
@@ -12,6 +12,7 @@
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/int.hpp>
 #include <boost/static_assert.hpp>
+#include <boost/fusion/support/detail/access.hpp>
 
 namespace boost { namespace fusion {
 
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp
deleted file mode 100644
index 6a883994..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp
+++ /dev/null
@@ -1,47 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_ADVANCE_IMPL_09302005_1847)
-#define FUSION_ADVANCE_IMPL_09302005_1847
-
-#include <boost/static_assert.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-
-    template <typename Vector, int N>
-    struct std_pair_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct advance_impl;
-    
-        template <>
-        struct advance_impl<std_pair_iterator_tag>
-        {
-            template <typename Iterator, typename N>
-            struct apply
-            {
-                typedef typename Iterator::index index;
-                typedef typename Iterator::pair_type pair_type;
-                typedef std_pair_iterator<pair_type, index::value+N::value> type;
-                BOOST_STATIC_ASSERT(
-                    (index::value+N::value) >= 0 &&(index::value+N::value) < 2);
-    
-                static type
-                call(Iterator const& i)
-                {
-                    return type(i.vec);
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/at_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/at_impl.hpp
index dce5f86c..b257089d 100644
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/at_impl.hpp
+++ b/include/boost/fusion/sequence/adapted/std_pair/detail/at_impl.hpp
@@ -12,6 +12,7 @@
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/int.hpp>
 #include <boost/static_assert.hpp>
+#include <boost/fusion/support/detail/access.hpp>
 
 namespace boost { namespace fusion {
 
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp
deleted file mode 100644
index 371cf2ce..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp
+++ /dev/null
@@ -1,74 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_DEREF_IMPL_09302005_1846)
-#define FUSION_DEREF_IMPL_09302005_1846
-
-#include <boost/fusion/support/detail/access.hpp>
-#include <boost/type_traits/is_const.hpp>
-#include <boost/static_assert.hpp>
-#include <boost/mpl/if.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct deref_impl;
-
-        template <>
-        struct deref_impl<std_pair_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef typename Iterator::pair_type pair_type;
-                typedef typename Iterator::index index;
-                static int const index_val = index::value;
-
-                BOOST_STATIC_ASSERT(index_val >= 0 && index_val <= 2);
-                typedef typename
-                    mpl::if_c<
-                        (index::value == 0)
-                      , typename pair_type::first_type
-                      , typename pair_type::second_type
-                    >
-                element;
-                
-                typedef typename
-                    mpl::eval_if<
-                        is_const<pair_type>
-                      , fusion::detail::cref_result<element>
-                      , fusion::detail::ref_result<element>
-                    >::type
-                type;
-
-                template <typename RT>
-                static RT get(pair_type& p, mpl::int_<0>)
-                {
-                    return  p.first;
-                }
-
-                template <typename RT>
-                static RT get(pair_type& p, mpl::int_<1>)
-                {
-                    return  p.second;
-                }
-
-                static type
-                call(Iterator const& iter)
-                {
-                    return get<type>(iter.pair, index());
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp
deleted file mode 100644
index ad1761b7..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp
+++ /dev/null
@@ -1,42 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_DISTANCE_IMPL_09302005_1846)
-#define FUSION_DISTANCE_IMPL_09302005_1846
-
-#include <boost/mpl/minus.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct distance_impl;
-
-        template <>
-        struct distance_impl<std_pair_iterator_tag>
-        {
-            template <typename First, typename Last>
-            struct apply : mpl::minus<typename Last::index, typename First::index>
-            {    
-                static typename mpl::minus<
-                    typename Last::index, typename First::index>::type
-                call(First const&, Last const&)
-                {
-                    typedef typename mpl::minus<
-                        typename Last::index, typename First::index>::type 
-                    result;
-                    return result();
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp
deleted file mode 100644
index 85088280..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp
+++ /dev/null
@@ -1,40 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_EQUAL_TO_IMPL_09302005_1847)
-#define FUSION_EQUAL_TO_IMPL_09302005_1847
-
-#include <boost/type_traits/is_same.hpp>
-#include <boost/mpl/equal_to.hpp>
-#include <boost/mpl/and.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct equal_to_impl;
-
-        template <>
-        struct equal_to_impl<std_pair_iterator_tag>
-        {
-            template <typename I1, typename I2>
-            struct apply             
-                : is_same<
-                    typename I1::identity
-                  , typename I2::identity
-                >
-            {
-            };
-        };
-    }
-}}
-
-#endif
-
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp
deleted file mode 100644
index dc320903..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_NEXT_IMPL_09302005_1847)
-#define FUSION_NEXT_IMPL_09302005_1847
-
-#include <boost/static_assert.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-    template <typename Vector, int N>
-    struct std_pair_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct next_impl;
-
-        template <>
-        struct next_impl<std_pair_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef typename Iterator::pair_type pair_type;
-                typedef typename Iterator::index index;
-                static int const index_val = index::value;
-                typedef std_pair_iterator<pair_type, index_val+1> type;
-                BOOST_STATIC_ASSERT((index_val+1) >= 0 &&(index_val+1) <= 2);
-
-                static type
-                call(Iterator const& i)
-                {
-                    return type(i.pair);
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp
deleted file mode 100644
index fe243185..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_PRIOR_IMPL_09302005_1847)
-#define FUSION_PRIOR_IMPL_09302005_1847
-
-#include <boost/static_assert.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-    template <typename Vector, int N>
-    struct std_pair_iterator;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct prior_impl;
-
-        template <>
-        struct prior_impl<std_pair_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef typename Iterator::pair_type pair_type;
-                typedef typename Iterator::index index;
-                static int const index_val = index::value;
-                typedef std_pair_iterator<pair_type, index_val-1> type;
-                BOOST_STATIC_ASSERT((index_val-1) >= 0 &&(index_val-1) <= 2);
-
-                static type
-                call(Iterator const& i)
-                {
-                    return type(i.pair);
-                }
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp b/include/boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp
deleted file mode 100644
index 240b56e9..00000000
--- a/include/boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
-
-    Use, modification and distribution is subject to 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_VALUE_OF_IMPL_09302005_1847)
-#define FUSION_VALUE_OF_IMPL_09302005_1847
-
-#include <boost/static_assert.hpp>
-#include <boost/mpl/if.hpp>
-
-namespace boost { namespace fusion
-{
-    struct std_pair_iterator_tag;
-
-    namespace extension
-    {
-        template <typename Tag>
-        struct value_of_impl;
-
-        template <>
-        struct value_of_impl<std_pair_iterator_tag>
-        {
-            template <typename Iterator>
-            struct apply 
-            {
-                typedef typename Iterator::pair_type pair_type;
-                typedef typename Iterator::index index;
-                static int const index_value = index::value;
-
-                BOOST_STATIC_ASSERT(index_value >= 0 && index_value <= 2);
-                typedef typename
-                    mpl::if_c<
-                        (index_value == 0)
-                      , typename pair_type::first_type
-                      , typename pair_type::second_type
-                    >::type
-                type;
-            };
-        };
-    }
-}}
-
-#endif
diff --git a/include/boost/fusion/sequence/adapted/std_pair/std_pair_iterator.hpp b/include/boost/fusion/sequence/adapted/std_pair/std_pair_iterator.hpp
index 1121e315..a2cb7f52 100644
--- a/include/boost/fusion/sequence/adapted/std_pair/std_pair_iterator.hpp
+++ b/include/boost/fusion/sequence/adapted/std_pair/std_pair_iterator.hpp
@@ -8,39 +8,130 @@
 #if !defined(FUSION_STD_PAIR_ITERATOR_09262005_0934)
 #define FUSION_STD_PAIR_ITERATOR_09262005_0934
 
-#include <boost/fusion/support/iterator_base.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp>
-#include <boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp>
-#include <boost/type_traits/add_const.hpp>
+//~ #include <boost/fusion/support/iterator_base.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/advance_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/deref_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/distance_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/equal_to_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/next_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/prior_impl.hpp>
+//~ #include <boost/fusion/sequence/adapted/std_pair/detail/value_of_impl.hpp>
+//~ #include <boost/type_traits/add_const.hpp>
+
+
+
+#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 <utility>
 
 namespace boost { namespace fusion
 {
-    struct std_pair_iterator_tag;
     struct random_access_traversal_tag;
 
-    template <typename Pair, int N>
-    struct std_pair_iterator_identity;
-
     template <typename Pair, int N>
     struct std_pair_iterator
-        : iterator_base<std_pair_iterator<Pair, N> >
+        : 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 std_pair_iterator_tag fusion_tag;
-        typedef random_access_traversal_tag category;
-        typedef std_pair_iterator_identity<
-            typename add_const<Pair>::type, N> identity;
         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();
+            }
+        };
     };
 }}