Factoring out of adapt_struct.hpp all the FILLER_* macros details.

As of BOOST_FUSION_ADAPT_STRUCT without type deduction, there were only
simple attributes filler. Now this need more complex logic to handle both
API: the backward compatible one with type specificiation, the one without
type specification and the non-variadic one which enables omitting the type
specification by providing BOOST_FUSION_ADAPT_AUTO instead of the type.

That's why I extracted the FILLER_* macros details in a separate source
file.

include/boost/fusion/adapted/struct/adapt_struct.hpp

@@ -12,10 +12,6 @@
 
 #include <boost/fusion/support/config.hpp>
 #include <boost/preprocessor/config/config.hpp>
-#include <boost/preprocessor/variadic.hpp>
-#include <boost/preprocessor/variadic/to_seq.hpp>
-#include <boost/preprocessor/seq/for_each.hpp>
-#include <boost/preprocessor/seq/push_front.hpp>
 #include <boost/preprocessor/cat.hpp>
 #include <boost/preprocessor/empty.hpp>
 #include <boost/preprocessor/comparison/equal.hpp>
@@ -37,8 +33,6 @@
 #include <boost/fusion/adapted/struct/detail/value_of_impl.hpp>
 #include <boost/fusion/adapted/struct/detail/deref_impl.hpp>
 
-#define BOOST_FUSION_ADAPT_AUTO BOOST_PP_EMPTY()
-
 #define BOOST_FUSION_ADAPT_STRUCT_C(TEMPLATE_PARAMS_SEQ, NAME_SEQ, I, ATTRIBUTE)\
     BOOST_FUSION_ADAPT_STRUCT_C_BASE(                                           \
         TEMPLATE_PARAMS_SEQ,                                                    \
@@ -59,6 +53,8 @@
         BOOST_FUSION_ADAPT_STRUCT_C)
 
 
+#define BOOST_FUSION_ADAPT_AUTO BOOST_PP_EMPTY()
+
 #if BOOST_PP_VARIADICS
 
 #   define BOOST_FUSION_ADAPT_STRUCT(NAME, ...)                                 \

include/boost/fusion/adapted/struct/detail/adapt_base.hpp

@@ -14,7 +14,7 @@
 #include <boost/fusion/support/config.hpp>
 #include <boost/config.hpp>
 #include <boost/fusion/support/tag_of_fwd.hpp>
-#include <boost/fusion/adapted/struct/detail/preprocessor/is_seq.hpp>
+#include <boost/fusion/adapted/struct/detail/adapt_base_attr_filler.hpp>
 
 #include <boost/preprocessor/empty.hpp>
 #include <boost/preprocessor/stringize.hpp>
@@ -27,7 +27,6 @@
 #include <boost/preprocessor/tuple/eat.hpp>
 #include <boost/preprocessor/tuple/elem.hpp>
 #include <boost/preprocessor/arithmetic/dec.hpp>
-#include <boost/preprocessor/facilities/is_empty.hpp>
 #include <boost/mpl/bool.hpp>
 #include <boost/mpl/tag.hpp>
 #include <boost/mpl/eval_if.hpp>
@@ -189,43 +188,6 @@
         }                                                                       \
     };
 
-#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0(X, Y)                                \
-    BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X,Y)                             \
-    BOOST_FUSION_ADAPT_STRUCT_FILLER_1
-
-#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1(X, Y)                                \
-    BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X,Y)                             \
-    BOOST_FUSION_ADAPT_STRUCT_FILLER_0
-
-#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0_END
-#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1_END
-
-#define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X, Y)                        \
-    BOOST_PP_IF(BOOST_PP_IS_EMPTY(X),                                           \
-      ((1, (Y))),                                                               \
-      ((2, (X,Y)))                                                              \
-    )
-
-#if BOOST_PP_VARIADICS
-
-#   define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER_OP(r, data, elem)        \
-        BOOST_PP_IF(BOOST_FUSION_PP_IS_SEQ(elem),                               \
-            BOOST_PP_CAT( BOOST_FUSION_ADAPT_STRUCT_FILLER_0 elem ,_END),       \
-            BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(BOOST_FUSION_ADAPT_AUTO, \
-                elem)                                                           \
-        )
-
-#   define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER(...)                     \
-        BOOST_PP_SEQ_PUSH_FRONT(                                                \
-            BOOST_PP_SEQ_FOR_EACH(                                              \
-                BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER_OP,                 \
-                unused, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__)),                 \
-                (0,0)                                                           \
-        )
-
-#endif // BOOST_PP_VARIADICS
-
-
 #define BOOST_FUSION_ADAPT_STRUCT_BASE(                                         \
     TEMPLATE_PARAMS_SEQ,                                                        \
     NAME_SEQ,                                                                   \

include/boost/fusion/adapted/struct/detail/adapt_base_attr_filler.hpp

@@ -0,0 +1,56 @@
+/*=============================================================================
+    Copyright (c) 2013-2014 Damien Buhl
+
+    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)
+==============================================================================*/
+
+#ifndef BOOST_FUSION_ADAPTED_STRUCT_DETAIL_ADAPT_BASE_ATTR_FILLER_HPP
+#define BOOST_FUSION_ADAPTED_STRUCT_DETAIL_ADAPT_BASE_ATTR_FILLER_HPP
+
+#include <boost/config.hpp>
+#include <boost/fusion/adapted/struct/detail/preprocessor/is_seq.hpp>
+
+#include <boost/preprocessor/empty.hpp>
+#include <boost/preprocessor/facilities/is_empty.hpp>
+#include <boost/preprocessor/variadic/to_seq.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+#include <boost/preprocessor/seq/push_front.hpp>
+
+#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0(X, Y)                                \
+    BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X,Y)                             \
+    BOOST_FUSION_ADAPT_STRUCT_FILLER_1
+
+#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1(X, Y)                                \
+    BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X,Y)                             \
+    BOOST_FUSION_ADAPT_STRUCT_FILLER_0
+
+#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0_END
+#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1_END
+
+#define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(X, Y)                        \
+    BOOST_PP_IF(BOOST_PP_IS_EMPTY(X),                                           \
+      ((1, (Y))),                                                               \
+      ((2, (X,Y)))                                                              \
+    )
+
+#if BOOST_PP_VARIADICS
+
+#   define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER_OP(r, data, elem)        \
+        BOOST_PP_IF(BOOST_FUSION_PP_IS_SEQ(elem),                               \
+            BOOST_PP_CAT( BOOST_FUSION_ADAPT_STRUCT_FILLER_0 elem ,_END),       \
+            BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTE_FILLER(BOOST_FUSION_ADAPT_AUTO, \
+                elem)                                                           \
+        )
+
+#   define BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER(...)                     \
+        BOOST_PP_SEQ_PUSH_FRONT(                                                \
+            BOOST_PP_SEQ_FOR_EACH(                                              \
+                BOOST_FUSION_ADAPT_STRUCT_ATTRIBUTES_FILLER_OP,                 \
+                unused, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__)),                 \
+                (0,0)                                                           \
+        )
+
+#endif // BOOST_PP_VARIADICS
+
+#endif