From b6df98e86c08c30342afc3d59bd963bbfd686d49 Mon Sep 17 00:00:00 2001
From: Joel de Guzman <djowel@gmail.com>
Date: Mon, 10 Oct 2011 09:55:41 +0000
Subject: [PATCH] Made map random access. Thanks to Brandon Kohn!

[SVN r74881]
---
 .../fusion/container/map/detail/at_impl.hpp   | 57 +++++++++++++++++++
 .../map/detail/preprocessed/map10.hpp         |  2 +-
 .../map/detail/preprocessed/map20.hpp         |  2 +-
 .../map/detail/preprocessed/map30.hpp         |  2 +-
 .../map/detail/preprocessed/map40.hpp         |  2 +-
 .../map/detail/preprocessed/map50.hpp         |  2 +-
 .../container/map/detail/value_at_impl.hpp    | 34 +++++++++++
 include/boost/fusion/container/map/map.hpp    |  4 +-
 8 files changed, 99 insertions(+), 6 deletions(-)
 create mode 100644 include/boost/fusion/container/map/detail/at_impl.hpp
 create mode 100644 include/boost/fusion/container/map/detail/value_at_impl.hpp

diff --git a/include/boost/fusion/container/map/detail/at_impl.hpp b/include/boost/fusion/container/map/detail/at_impl.hpp
new file mode 100644
index 00000000..f871bee0
--- /dev/null
+++ b/include/boost/fusion/container/map/detail/at_impl.hpp
@@ -0,0 +1,57 @@
+/*=============================================================================
+    Copyright (c) 2001-2011 Joel de Guzman
+    Copyright (c) 2011 Brandon Kohn
+
+    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_MAP_DETAIL_AT_IMPL_HPP)
+#define BOOST_FUSION_MAP_DETAIL_AT_IMPL_HPP
+
+#include <boost/fusion/support/detail/access.hpp>
+#include <boost/type_traits/is_const.hpp>
+#include <boost/mpl/at.hpp>
+#include <boost/mpl/int.hpp>
+
+namespace boost { namespace fusion
+{
+    struct map_tag;
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct at_impl;
+
+        template <>
+        struct at_impl<map_tag>
+        {
+            template <typename Sequence, typename N>
+            struct apply 
+            {
+                typedef mpl::at<typename Sequence::storage_type::types, N> element;
+                typedef typename detail::ref_result<element>::type type;
+    
+                static type
+                call(Sequence& m)
+                {
+                    return m.get_data().at_impl(N());
+                }
+            };
+
+            template <typename Sequence, typename N>
+            struct apply <Sequence const, N>
+            {
+                typedef mpl::at<typename Sequence::storage_type::types, N> element;
+                typedef typename detail::cref_result<element>::type type;
+    
+                static type
+                call(Sequence const& m)
+                {
+                    return m.get_data().at_impl(N());
+                }
+            };
+        };
+    }
+}}
+
+#endif //BOOST_FUSION_MAP_DETAIL_AT_IMPL_HPP
diff --git a/include/boost/fusion/container/map/detail/preprocessed/map10.hpp b/include/boost/fusion/container/map/detail/preprocessed/map10.hpp
index cae643d8..fdf28eb2 100644
--- a/include/boost/fusion/container/map/detail/preprocessed/map10.hpp
+++ b/include/boost/fusion/container/map/detail/preprocessed/map10.hpp
@@ -13,7 +13,7 @@ namespace boost { namespace fusion
     template <typename T0 , typename T1 , typename T2 , typename T3 , typename T4 , typename T5 , typename T6 , typename T7 , typename T8 , typename T9>
     struct map : sequence_base<map<T0 , T1 , T2 , T3 , T4 , T5 , T6 , T7 , T8 , T9> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; 
         typedef mpl::false_ is_view;
diff --git a/include/boost/fusion/container/map/detail/preprocessed/map20.hpp b/include/boost/fusion/container/map/detail/preprocessed/map20.hpp
index 01105265..33cd2e59 100644
--- a/include/boost/fusion/container/map/detail/preprocessed/map20.hpp
+++ b/include/boost/fusion/container/map/detail/preprocessed/map20.hpp
@@ -13,7 +13,7 @@ namespace boost { namespace fusion
     template <typename T0 , typename T1 , typename T2 , typename T3 , typename T4 , typename T5 , typename T6 , typename T7 , typename T8 , typename T9 , typename T10 , typename T11 , typename T12 , typename T13 , typename T14 , typename T15 , typename T16 , typename T17 , typename T18 , typename T19>
     struct map : sequence_base<map<T0 , T1 , T2 , T3 , T4 , T5 , T6 , T7 , T8 , T9 , T10 , T11 , T12 , T13 , T14 , T15 , T16 , T17 , T18 , T19> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; 
         typedef mpl::false_ is_view;
diff --git a/include/boost/fusion/container/map/detail/preprocessed/map30.hpp b/include/boost/fusion/container/map/detail/preprocessed/map30.hpp
index ede29720..54f492d0 100644
--- a/include/boost/fusion/container/map/detail/preprocessed/map30.hpp
+++ b/include/boost/fusion/container/map/detail/preprocessed/map30.hpp
@@ -13,7 +13,7 @@ namespace boost { namespace fusion
     template <typename T0 , typename T1 , typename T2 , typename T3 , typename T4 , typename T5 , typename T6 , typename T7 , typename T8 , typename T9 , typename T10 , typename T11 , typename T12 , typename T13 , typename T14 , typename T15 , typename T16 , typename T17 , typename T18 , typename T19 , typename T20 , typename T21 , typename T22 , typename T23 , typename T24 , typename T25 , typename T26 , typename T27 , typename T28 , typename T29>
     struct map : sequence_base<map<T0 , T1 , T2 , T3 , T4 , T5 , T6 , T7 , T8 , T9 , T10 , T11 , T12 , T13 , T14 , T15 , T16 , T17 , T18 , T19 , T20 , T21 , T22 , T23 , T24 , T25 , T26 , T27 , T28 , T29> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; 
         typedef mpl::false_ is_view;
diff --git a/include/boost/fusion/container/map/detail/preprocessed/map40.hpp b/include/boost/fusion/container/map/detail/preprocessed/map40.hpp
index 6a75d2c6..7060a670 100644
--- a/include/boost/fusion/container/map/detail/preprocessed/map40.hpp
+++ b/include/boost/fusion/container/map/detail/preprocessed/map40.hpp
@@ -13,7 +13,7 @@ namespace boost { namespace fusion
     template <typename T0 , typename T1 , typename T2 , typename T3 , typename T4 , typename T5 , typename T6 , typename T7 , typename T8 , typename T9 , typename T10 , typename T11 , typename T12 , typename T13 , typename T14 , typename T15 , typename T16 , typename T17 , typename T18 , typename T19 , typename T20 , typename T21 , typename T22 , typename T23 , typename T24 , typename T25 , typename T26 , typename T27 , typename T28 , typename T29 , typename T30 , typename T31 , typename T32 , typename T33 , typename T34 , typename T35 , typename T36 , typename T37 , typename T38 , typename T39>
     struct map : sequence_base<map<T0 , T1 , T2 , T3 , T4 , T5 , T6 , T7 , T8 , T9 , T10 , T11 , T12 , T13 , T14 , T15 , T16 , T17 , T18 , T19 , T20 , T21 , T22 , T23 , T24 , T25 , T26 , T27 , T28 , T29 , T30 , T31 , T32 , T33 , T34 , T35 , T36 , T37 , T38 , T39> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; 
         typedef mpl::false_ is_view;
diff --git a/include/boost/fusion/container/map/detail/preprocessed/map50.hpp b/include/boost/fusion/container/map/detail/preprocessed/map50.hpp
index f9c36302..1da73641 100644
--- a/include/boost/fusion/container/map/detail/preprocessed/map50.hpp
+++ b/include/boost/fusion/container/map/detail/preprocessed/map50.hpp
@@ -13,7 +13,7 @@ namespace boost { namespace fusion
     template <typename T0 , typename T1 , typename T2 , typename T3 , typename T4 , typename T5 , typename T6 , typename T7 , typename T8 , typename T9 , typename T10 , typename T11 , typename T12 , typename T13 , typename T14 , typename T15 , typename T16 , typename T17 , typename T18 , typename T19 , typename T20 , typename T21 , typename T22 , typename T23 , typename T24 , typename T25 , typename T26 , typename T27 , typename T28 , typename T29 , typename T30 , typename T31 , typename T32 , typename T33 , typename T34 , typename T35 , typename T36 , typename T37 , typename T38 , typename T39 , typename T40 , typename T41 , typename T42 , typename T43 , typename T44 , typename T45 , typename T46 , typename T47 , typename T48 , typename T49>
     struct map : sequence_base<map<T0 , T1 , T2 , T3 , T4 , T5 , T6 , T7 , T8 , T9 , T10 , T11 , T12 , T13 , T14 , T15 , T16 , T17 , T18 , T19 , T20 , T21 , T22 , T23 , T24 , T25 , T26 , T27 , T28 , T29 , T30 , T31 , T32 , T33 , T34 , T35 , T36 , T37 , T38 , T39 , T40 , T41 , T42 , T43 , T44 , T45 , T46 , T47 , T48 , T49> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; 
         typedef mpl::false_ is_view;
diff --git a/include/boost/fusion/container/map/detail/value_at_impl.hpp b/include/boost/fusion/container/map/detail/value_at_impl.hpp
new file mode 100644
index 00000000..31d9b383
--- /dev/null
+++ b/include/boost/fusion/container/map/detail/value_at_impl.hpp
@@ -0,0 +1,34 @@
+/*=============================================================================
+    Copyright (c) 2001-2011 Joel de Guzman
+    Copyright (c) 2011 Brandon Kohn
+
+    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_MAP_DETAIL_VALUE_AT_IMPL_HPP)
+#define BOOST_FUSION_MAP_DETAIL_VALUE_AT_IMPL_HPP
+
+#include <boost/mpl/at.hpp>
+
+namespace boost { namespace fusion
+{
+    struct map_tag;
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct value_at_impl;
+
+        template <>
+        struct value_at_impl<map_tag>
+        {
+            template <typename Sequence, typename N>
+            struct apply 
+            {
+                typedef typename mpl::at<typename Sequence::storage_type::types, N>::type type;
+            };
+        };
+    }
+}}
+
+#endif //BOOST_FUSION_MAP_DETAIL_VALUE_AT_IMPL_HPP
diff --git a/include/boost/fusion/container/map/map.hpp b/include/boost/fusion/container/map/map.hpp
index d61df914..5152e6e1 100644
--- a/include/boost/fusion/container/map/map.hpp
+++ b/include/boost/fusion/container/map/map.hpp
@@ -11,6 +11,8 @@
 #include <boost/fusion/support/category_of.hpp>
 #include <boost/fusion/support/detail/access.hpp>
 #include <boost/fusion/container/map/map_fwd.hpp>
+#include <boost/fusion/container/map/detail/at_impl.hpp>
+#include <boost/fusion/container/map/detail/value_at_impl.hpp>
 #include <boost/fusion/container/map/detail/begin_impl.hpp>
 #include <boost/fusion/container/map/detail/end_impl.hpp>
 #include <boost/fusion/container/map/detail/value_of_impl.hpp>
@@ -50,7 +52,7 @@ namespace boost { namespace fusion
     template <BOOST_PP_ENUM_PARAMS(FUSION_MAX_MAP_SIZE, typename T)>
     struct map : sequence_base<map<BOOST_PP_ENUM_PARAMS(FUSION_MAX_MAP_SIZE, T)> >
     {
-        struct category : forward_traversal_tag, associative_tag {};
+        struct category : random_access_traversal_tag, associative_tag {};
 
         typedef map_tag fusion_tag;
         typedef fusion_sequence_tag tag; // this gets picked up by MPL