[Boost-commit] svn:boost r56742 - in trunk/boost/spirit/home: qi/nonterminal support

Subject: [Boost-commit] svn:boost r56742 - in trunk/boost/spirit/home: qi/nonterminal support
From: hartmut.kaiser_at_[hidden]
Date: 2009-10-12 12:33:34

Author: hkaiser
Date: 2009-10-12 12:33:33 EDT (Mon, 12 Oct 2009)
New Revision: 56742
URL: http://svn.boost.org/trac/boost/changeset/56742

Log:
Spirit: added missing specialization to transform_attribute.
Text files modified: 
   trunk/boost/spirit/home/qi/nonterminal/rule.hpp |     8 ++++----                                
   trunk/boost/spirit/home/support/attributes.hpp  |    10 +++++++++-                              
   2 files changed, 13 insertions(+), 5 deletions(-)

Modified: trunk/boost/spirit/home/qi/nonterminal/rule.hpp
==============================================================================
--- trunk/boost/spirit/home/qi/nonterminal/rule.hpp	(original)
+++ trunk/boost/spirit/home/qi/nonterminal/rule.hpp	2009-10-12 12:33:33 EDT (Mon, 12 Oct 2009)
@@ -221,8 +221,8 @@
                 typedef traits::transform_attribute<
                     typename make_attribute::type, attr_type> transform;
 
-                typename transform::type attr_ = 
-                    transform::pre(make_attribute::call(attr));
+                typename make_attribute::type made_attr = make_attribute::call(attr);
+                typename transform::type attr_ = transform::pre(made_attr);
 
                 // If you are seeing a compilation error here, you are probably
                 // trying to use a rule or a grammar which has inherited
@@ -261,8 +261,8 @@
                 typedef traits::transform_attribute<
                     typename make_attribute::type, attr_type> transform;
 
-                typename transform::type attr_ = 
-                    transform::pre(make_attribute::call(attr));
+                typename make_attribute::type made_attr = make_attribute::call(attr);
+                typename transform::type attr_ = transform::pre(made_attr);
 
                 // If you are seeing a compilation error here, you are probably
                 // trying to use a rule or a grammar which has inherited

Modified: trunk/boost/spirit/home/support/attributes.hpp
==============================================================================
--- trunk/boost/spirit/home/support/attributes.hpp	(original)
+++ trunk/boost/spirit/home/support/attributes.hpp	2009-10-12 12:33:33 EDT (Mon, 12 Oct 2009)
@@ -325,7 +325,6 @@
         typedef Transformed type;
 
         static Transformed pre(Exposed& val) { return Transformed(val); }
-        static Transformed pre(Exposed const& val) { return Transformed(val); }
 
         // By default do post transformation only if types are convertible, 
         // otherwise we assume no post transform is required (i.e. the user 
@@ -352,6 +351,15 @@
         // Karma only, no post() required
     };
 
+    // handle case where no transformation is required as the types are the same
+    template <typename Attribute>
+    struct transform_attribute<Attribute, Attribute>
+    {
+        typedef Attribute& type;
+        static Attribute& pre(Attribute& val) { return val; }
+        static void post(Attribute& val, Attribute const& attr) {}
+    };
+
     template <typename Attribute>
     struct transform_attribute<Attribute const, Attribute>
     {