[Boost-commit] svn:boost r55090 - trunk/boost/spirit/home/support

Subject: [Boost-commit] svn:boost r55090 - trunk/boost/spirit/home/support
From: joel_at_[hidden]
Date: 2009-07-22 16:14:12

Author: djowel
Date: 2009-07-22 16:14:12 EDT (Wed, 22 Jul 2009)
New Revision: 55090
URL: http://svn.boost.org/trac/boost/changeset/55090

Log:
fix missing include
Text files modified: 
   trunk/boost/spirit/home/support/attributes.hpp |    46 +++++++++++++++++++++++++++++---------- 
   1 files changed, 34 insertions(+), 12 deletions(-)

Modified: trunk/boost/spirit/home/support/attributes.hpp
==============================================================================
--- trunk/boost/spirit/home/support/attributes.hpp	(original)
+++ trunk/boost/spirit/home/support/attributes.hpp	2009-07-22 16:14:12 EDT (Wed, 22 Jul 2009)
@@ -19,6 +19,7 @@
 #include <boost/fusion/include/as_vector.hpp>
 #include <boost/fusion/include/push_front.hpp>
 #include <boost/fusion/include/is_sequence.hpp>
+#include <boost/fusion/include/for_each.hpp>
 #include <boost/utility/value_init.hpp>
 #include <boost/type_traits/is_same.hpp>
 #include <boost/mpl/eval_if.hpp>
@@ -426,52 +427,73 @@
     ///////////////////////////////////////////////////////////////////////////
     // clear
     //
-    // Clear data efficiently ()
+    // Clear data efficiently
     ///////////////////////////////////////////////////////////////////////////
     template <typename T>
     struct is_container;
 
     namespace detail
     {
+        // this is used by the variant and fusion sequence dispatch
+        struct clear_visitor : static_visitor<>
+        {
+            template <typename T>
+            void operator()(T& val) const
+            {
+                clear(val);
+            }
+        };
+
+        // default
         template <typename T>
-        void clear_impl(T& val, mpl::false_)
+        void clear_impl2(T& val, mpl::false_)
         {
             val = T();
         }
 
+        // for fusion sequences
+        template <typename T>
+        void clear_impl2(T& val, mpl::true_) 
+        {
+            fusion::for_each(val, clear_visitor());
+        }
+
+        // dispatch default or fusion sequence
+        template <typename T>
+        void clear_impl(T& val, mpl::false_) 
+        {
+            clear_impl2(val, fusion::traits::is_sequence<T>());
+        }
+
+        // STL containers
         template <typename T>
         void clear_impl(T& val, mpl::true_)
         {
             val.clear();
         }
-        
-        struct clear_visitor : static_visitor<>
-        {
-            template <typename T>
-            void operator()(T& val) const
-            {
-                clear(val);
-            }
-        };
     }
 
+    // main dispatch
     template <typename T>
     void clear(T& val)
     {
         detail::clear_impl(val, typename is_container<T>::type());
     }
 
+    // for unused
     inline void clear(unused_type)
     {
     }
 
+    // optionals
     template <typename T>
     void clear(optional<T>& val)
     {
         if (val)
             clear(*val);
     }
-
+    
+    // variants
     template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
     void clear(variant<BOOST_VARIANT_ENUM_PARAMS(T)>& var)
     {