[Boost-commit] svn:boost r55010 - trunk/boost/spirit/home/support

Subject: [Boost-commit] svn:boost r55010 - trunk/boost/spirit/home/support
From: hartmut.kaiser_at_[hidden]
Date: 2009-07-17 23:39:04

Author: hkaiser
Date: 2009-07-17 23:39:03 EDT (Fri, 17 Jul 2009)
New Revision: 55010
URL: http://svn.boost.org/trac/boost/changeset/55010

Log:
Spirit: fixing inconsistency in list parser behavior for optional/variant based attributes 
Text files modified: 
   trunk/boost/spirit/home/support/attributes.hpp |    19 ++++++++++++--                          
   trunk/boost/spirit/home/support/container.hpp  |    51 +++++++++++++++++++++++++++++++++++++-- 
   2 files changed, 64 insertions(+), 6 deletions(-)

Modified: trunk/boost/spirit/home/support/attributes.hpp
==============================================================================
--- trunk/boost/spirit/home/support/attributes.hpp	(original)
+++ trunk/boost/spirit/home/support/attributes.hpp	2009-07-17 23:39:03 EDT (Fri, 17 Jul 2009)
@@ -430,7 +430,7 @@
     ///////////////////////////////////////////////////////////////////////////
     template <typename T>
     struct is_container;
-        
+
     namespace detail
     {
         template <typename T>
@@ -438,14 +438,27 @@
         {
             val = T();
         }
-        
+
         template <typename T>
         void clear_impl(T& val, mpl::true_)
         {
             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(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& val
+          , mpl::true_)
+        {
+            val = T0();
+        }
     }
-    
+
     template <typename T>
     void clear(T& val)
     {

Modified: trunk/boost/spirit/home/support/container.hpp
==============================================================================
--- trunk/boost/spirit/home/support/container.hpp	(original)
+++ trunk/boost/spirit/home/support/container.hpp	2009-07-17 23:39:03 EDT (Fri, 17 Jul 2009)
@@ -57,7 +57,7 @@
    /***/
 
    template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
-   struct is_container<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> > 
+   struct is_container<variant<BOOST_VARIANT_ENUM_PARAMS(T)> > 
      : mpl::bool_<BOOST_PP_REPEAT(BOOST_VARIANT_LIMIT_TYPES
          , BOOST_SPIRIT_IS_CONTAINER, _) false> {};
 
@@ -79,10 +79,10 @@
 
         // this will be instantiated if the variant holds a container
         template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
-        struct value<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
+        struct value<variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
         {
             typedef typename 
-                boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types 
+                variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types 
             types;
             typedef typename 
                 mpl::find_if<types, is_container<mpl::_1> >::type 
@@ -166,6 +166,51 @@
         c.push_back(val);
     }
 
+    template <typename Container, typename T>
+    inline void push_back(optional<Container>& c, T const& val)
+    {
+        if (!c)
+            c = Container();
+        push_back(boost::get<Container>(c), val);
+    }
+
+    namespace detail
+    {
+        template <typename T>
+        struct push_back_visitor : public static_visitor<>
+        {
+            push_back_visitor(T const& t) : t_(t) {}
+
+            template <typename Container>
+            void push_back_impl(Container& c, mpl::true_) const
+            {
+                push_back(c, t_);
+            }
+
+            template <typename T_>
+            void push_back_impl(T_&, mpl::false_) const
+            {
+                // this variant doesn't hold a container
+                BOOST_ASSERT(false);
+            }
+
+            template <typename T_>
+            void operator()(T_& c) const
+            {
+                push_back_impl(c, typename is_container<T_>::type());
+            }
+
+            T const& t_;
+        };
+    }
+
+    template <BOOST_VARIANT_ENUM_PARAMS(typename T_), typename T>
+    inline void push_back(variant<BOOST_VARIANT_ENUM_PARAMS(T_)>& c
+      , T const& val)
+    {
+        apply_visitor(detail::push_back_visitor<T>(val), c);
+    }
+
     template <typename Container>
     inline void push_back(Container&, unused_type)
     {