From f8bb69dc9a54e18bfc66fd445e84b139bf189964 Mon Sep 17 00:00:00 2001
From: Dan Marsden <danmarsden@yahoo.co.uk>
Date: Tue, 8 May 2007 22:14:58 +0000
Subject: [PATCH] adding struct associative adaptor

[SVN r37638]
---
 .../adapted/struct/adapt_assoc_struct.hpp     | 94 +++++++++++++++++++
 .../adapted/struct/detail/at_key_impl.hpp     | 54 +++++++++++
 .../adapted/struct/detail/has_key_impl.hpp    | 40 ++++++++
 .../struct/detail/value_at_key_impl.hpp       | 39 ++++++++
 .../sequence/adapted/struct/extension.hpp     | 24 +++++
 5 files changed, 251 insertions(+)
 create mode 100644 include/boost/fusion/sequence/adapted/struct/adapt_assoc_struct.hpp
 create mode 100644 include/boost/fusion/sequence/adapted/struct/detail/at_key_impl.hpp
 create mode 100644 include/boost/fusion/sequence/adapted/struct/detail/has_key_impl.hpp
 create mode 100644 include/boost/fusion/sequence/adapted/struct/detail/value_at_key_impl.hpp

diff --git a/include/boost/fusion/sequence/adapted/struct/adapt_assoc_struct.hpp b/include/boost/fusion/sequence/adapted/struct/adapt_assoc_struct.hpp
new file mode 100644
index 00000000..44357c00
--- /dev/null
+++ b/include/boost/fusion/sequence/adapted/struct/adapt_assoc_struct.hpp
@@ -0,0 +1,94 @@
+/*=============================================================================
+    Copyright (c) 2001-2007 Joel de Guzman
+    Copyright (c) 2007 Dan Marsden
+
+    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_ADAPT_ASSOC_STRUCT_20070508_2207)
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_20070508_2207
+
+#include <boost/fusion/support/tag_of_fwd.hpp>
+#include <boost/fusion/sequence/adapted/struct/extension.hpp>
+#include <boost/fusion/sequence/adapted/struct/struct_iterator.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/is_view_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/is_sequence_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/category_of_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/begin_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/end_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/size_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/at_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/value_at_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/has_key_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/at_key_impl.hpp>
+#include <boost/fusion/sequence/adapted/struct/detail/value_at_key_impl.hpp>
+
+#include <boost/preprocessor/cat.hpp>
+#include <boost/preprocessor/punctuation/comma_if.hpp>
+#include <boost/preprocessor/seq/for_each_i.hpp>
+#include <boost/preprocessor/tuple/elem.hpp>
+#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/preprocessor/cat.hpp>
+#include <boost/mpl/int.hpp>
+#include <utility>
+
+namespace boost { namespace fusion { namespace extension {
+    template<typename Struct, typename Key>
+    struct struct_assoc_member;
+}}}
+
+
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT(name, bseq)                                   \
+    BOOST_FUSION_ADAPT_ASSOC_STRUCT_I(                                                \
+        name, BOOST_PP_CAT(BOOST_FUSION_ADAPT_ASSOC_STRUCT_X bseq, 0))                \
+    /***/
+
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_X(x, y, z) ((x, y, z)) BOOST_FUSION_ADAPT_ASSOC_STRUCT_Y
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_Y(x, y, z) ((x, y, z)) BOOST_FUSION_ADAPT_ASSOC_STRUCT_X
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_X0
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_Y0
+
+// BOOST_FUSION_ADAPT_ASSOC_STRUCT_I generates the overarching structure and uses
+// SEQ_FOR_EACH_I to generate the "linear" substructures.
+// Thanks to Paul Mensonides for the PP macro help
+
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_I(name, seq)                                  \
+    namespace boost { namespace fusion { namespace traits                       \
+    {                                                                           \
+        template <>                                                             \
+        struct tag_of<name>                                                     \
+        {                                                                       \
+            typedef struct_tag type;                                            \
+        };                                                                      \
+    }}}                                                                         \
+    namespace boost { namespace fusion { namespace extension                    \
+    {                                                                           \
+        template <>                                                             \
+        struct struct_size<name> : mpl::int_<BOOST_PP_SEQ_SIZE(seq)> {};        \
+        BOOST_PP_SEQ_FOR_EACH_I(BOOST_FUSION_ADAPT_ASSOC_STRUCT_C, name, seq)         \
+    }}}                                                                         \
+    /***/
+
+#define BOOST_FUSION_ADAPT_ASSOC_STRUCT_C(r, name, i, xy)                             \
+    template <>                                                                 \
+    struct struct_member<name, i>                                               \
+    {                                                                           \
+        typedef BOOST_PP_TUPLE_ELEM(3, 0, xy) type;                             \
+        static type& call(name& struct_)                                        \
+        {                                                                       \
+            return struct_.BOOST_PP_TUPLE_ELEM(3, 1, xy);                       \
+        };                                                                      \
+    };                                                                          \
+    template<>                                                                  \
+    struct struct_assoc_member<name, BOOST_PP_TUPLE_ELEM(3, 2, xy)>             \
+    {                                                                           \
+        typedef BOOST_PP_TUPLE_ELEM(3, 0, xy) type;                             \
+        static type& call(name& struct_)                                        \
+        {                                                                       \
+            return struct_.BOOST_PP_TUPLE_ELEM(3, 1, xy);                       \
+        };                                                                      \
+    };
+    /***/
+
+#endif
diff --git a/include/boost/fusion/sequence/adapted/struct/detail/at_key_impl.hpp b/include/boost/fusion/sequence/adapted/struct/detail/at_key_impl.hpp
new file mode 100644
index 00000000..4ce0fce9
--- /dev/null
+++ b/include/boost/fusion/sequence/adapted/struct/detail/at_key_impl.hpp
@@ -0,0 +1,54 @@
+/*=============================================================================
+    Copyright (c) 2001-2007 Joel de Guzman
+    Copyright (c) 2005-2007 Dan Marsden
+
+    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_AT_KEY_IMPL_20070508_2248)
+#define BOOST_FUSION_AT_KEY_IMPL_20070508_2248
+
+#include <boost/fusion/support/detail/access.hpp>
+
+namespace boost { namespace fusion
+{
+    struct struct_tag;
+
+    namespace extension
+    {
+        template<typename T>
+        struct at_key_impl;
+
+        template <typename Struct, typename Key>
+        struct struct_assoc_member;
+
+        template <>
+        struct at_key_impl<struct_tag>
+        {
+            template <typename Sequence, typename Key>
+            struct apply
+            {
+                typedef typename
+                extension::struct_assoc_member<Sequence, Key>
+                element;
+
+                typedef typename
+                    mpl::eval_if<
+                        is_const<Sequence>
+                      , detail::cref_result<element>
+                      , detail::ref_result<element>
+                    >::type
+                type;
+
+                static type
+                call(Sequence& seq)
+                {
+                    return extension::
+                        struct_assoc_member<Sequence, Key>::call(seq);
+                }
+            };
+        };
+    }
+}}
+
+#endif
diff --git a/include/boost/fusion/sequence/adapted/struct/detail/has_key_impl.hpp b/include/boost/fusion/sequence/adapted/struct/detail/has_key_impl.hpp
new file mode 100644
index 00000000..8972f5df
--- /dev/null
+++ b/include/boost/fusion/sequence/adapted/struct/detail/has_key_impl.hpp
@@ -0,0 +1,40 @@
+/*=============================================================================
+    Copyright (c) 2001-2007 Joel de Guzman
+    Copyright (c) 2005-2007 Dan Marsden
+
+    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_HAS_KEY_IMPL_20070508_2231)
+#define BOOST_FUSION_HAS_KEY_IMPL_20070508_2231
+
+#include <boost/type_traits/is_same.hpp>
+#include <boost/mpl/not.hpp>
+
+namespace boost { namespace fusion {
+
+    struct struct_tag;
+
+    namespace extension
+    {
+        struct no_such_member;
+
+        template<typename T>
+        struct has_key_impl;
+
+        template<typename Struct, typename Key>
+        struct struct_assoc_member;
+
+        template<>
+        struct has_key_impl<struct_tag>
+        {
+            template<typename Sequence, typename Key>
+            struct apply
+                : mpl::not_<is_same<no_such_member, typename struct_assoc_member<Sequence, Key>::type> >
+            {
+            };
+        };
+    }
+}}
+
+#endif
diff --git a/include/boost/fusion/sequence/adapted/struct/detail/value_at_key_impl.hpp b/include/boost/fusion/sequence/adapted/struct/detail/value_at_key_impl.hpp
new file mode 100644
index 00000000..b1b3dcfb
--- /dev/null
+++ b/include/boost/fusion/sequence/adapted/struct/detail/value_at_key_impl.hpp
@@ -0,0 +1,39 @@
+/*=============================================================================
+    Copyright (c) 2001-2007 Joel de Guzman
+    Copyright (c) 2005-2007 Dan Marsden
+
+    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_VALUE_AT_KEY_IMPL_20070508_2300)
+#define BOOST_FUSION_VALUE_AT_KEY_IMPL_20070508_2300
+
+#include <boost/mpl/if.hpp>
+
+namespace boost { namespace fusion
+{
+    struct struct_tag;
+
+    namespace extension
+    {
+        template<typename T>
+        struct value_at_key_impl;
+
+        template <typename Struct, typename Key>
+        struct struct_assoc_member;
+
+        template <>
+        struct value_at_key_impl<struct_tag>
+        {
+            template <typename Sequence, typename Key>
+            struct apply
+            {
+                typedef typename
+                    extension::struct_assoc_member<Sequence, Key>::type
+                type;
+            };
+        };
+    }
+}}
+
+#endif
diff --git a/include/boost/fusion/sequence/adapted/struct/extension.hpp b/include/boost/fusion/sequence/adapted/struct/extension.hpp
index f0af1baa..c5516ae5 100644
--- a/include/boost/fusion/sequence/adapted/struct/extension.hpp
+++ b/include/boost/fusion/sequence/adapted/struct/extension.hpp
@@ -37,6 +37,30 @@ namespace boost { namespace fusion { namespace extension
     struct struct_size<Struct const>
         : struct_size<Struct>
     {};
+
+    struct no_such_member;
+
+    template<typename Struct, typename Key>
+    struct struct_assoc_member
+    {
+        typedef no_such_member type;
+    };
+
+    template<typename Struct, typename Key>
+    struct struct_assoc_member<Struct const, Key>
+    {
+        typedef typename
+        add_const<typename struct_assoc_member<Struct, Key>::type>::type
+        type;
+
+        static type&
+        call(Struct const& struct_)
+        {
+            return struct_member<Struct, Key>::call(
+                const_cast<Struct&>(struct_));
+        }
+    };
+
 }}}
 
 #endif