[Boost-commit] svn:boost r55054 - trunk/boost/spirit/home/support

Subject: [Boost-commit] svn:boost r55054 - trunk/boost/spirit/home/support
From: joel_at_[hidden]
Date: 2009-07-21 03:10:26

Author: djowel
Date: 2009-07-21 03:10:25 EDT (Tue, 21 Jul 2009)
New Revision: 55054
URL: http://svn.boost.org/trac/boost/changeset/55054

Log:
fix/optimize traits::clear
Text files modified: 
   trunk/boost/spirit/home/support/attributes.hpp |    33 +++++++++++++++++++++------------       
   1 files changed, 21 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	2009-07-21 03:10:25 EDT (Tue, 21 Jul 2009)
@@ -444,19 +444,15 @@
         {
             val.clear();
         }
-
-        template <typename T>
-        void clear_impl(optional<T>& val, mpl::true_)
-        {
-            val = T();
-        }
-
-        template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
-        void clear_impl(variant<BOOST_VARIANT_ENUM_PARAMS(T)>& val
-          , mpl::true_)
+        
+        struct clear_visitor : static_visitor<>
         {
-            val = variant<BOOST_VARIANT_ENUM_PARAMS(T)>();
-        }
+            template <typename T>
+            void operator()(T& val) const
+            {
+                clear(val);
+            }
+        };
     }
 
     template <typename T>
@@ -469,6 +465,19 @@
     {
     }
 
+    template <typename T>
+    void clear(optional<T>& val)
+    {
+        if (val)
+            clear(*val);
+    }
+
+    template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
+    void clear(variant<BOOST_VARIANT_ENUM_PARAMS(T)>& var)
+    {
+        apply_visitor(detail::clear_visitor(), var);
+    }
+
 }}}
 
 #endif