[Boost-commit] svn:boost r54067 - in trunk: boost/proto boost/proto/transform libs/proto/doc/reference/concepts libs/proto/doc/reference/transform

Subject: [Boost-commit] svn:boost r54067 - in trunk: boost/proto boost/proto/transform libs/proto/doc/reference/concepts libs/proto/doc/reference/transform
From: eric_at_[hidden]
Date: 2009-06-18 17:39:10

Author: eric_niebler
Date: 2009-06-18 17:39:09 EDT (Thu, 18 Jun 2009)
New Revision: 54067
URL: http://svn.boost.org/trac/boost/changeset/54067

Log:
add a sensible default for proto::_default's template parameter
Text files modified: 
   trunk/boost/proto/proto_fwd.hpp                                     |     5 +++++                                   
   trunk/boost/proto/transform/default.hpp                             |    11 ++++++++++-                             
   trunk/libs/proto/doc/reference/concepts/BasicPrimitiveTransform.xml |     2 +-                                      
   trunk/libs/proto/doc/reference/transform/default.xml                |     9 ++++++++-                               
   4 files changed, 24 insertions(+), 3 deletions(-)

Modified: trunk/boost/proto/proto_fwd.hpp
==============================================================================
--- trunk/boost/proto/proto_fwd.hpp	(original)
+++ trunk/boost/proto/proto_fwd.hpp	2009-06-18 17:39:09 EDT (Thu, 18 Jun 2009)
@@ -188,6 +188,8 @@
         ///
         #define BOOST_PROTO_UNCVREF(X)                                                              \
             typename boost::remove_const<typename boost::remove_reference<X>::type>::type
+
+        struct _default;
     }
 
     typedef detail::ignore const ignore;
@@ -744,6 +746,9 @@
     template<typename Grammar>
     struct pass_through;
 
+    template<typename Grammar = detail::_default>
+    struct _default;
+
     struct _expr;
     struct _state;
     struct _data;

Modified: trunk/boost/proto/transform/default.hpp
==============================================================================
--- trunk/boost/proto/transform/default.hpp	(original)
+++ trunk/boost/proto/transform/default.hpp	2009-06-18 17:39:09 EDT (Thu, 18 Jun 2009)
@@ -31,7 +31,7 @@
 
     namespace boost { namespace proto
     {
-        template<typename Grammar>
+        template<typename Grammar BOOST_PROTO_WHEN_BUILDING_DOCS(= detail::_default)>
         struct _default
           : transform<_default<Grammar> >
         {
@@ -463,6 +463,15 @@
           : mpl::true_
         {};
 
+        namespace detail
+        {
+            // Loopy indirection that allows proto::_default<> to be
+            // used without specifying a Grammar argument.
+            struct _default
+              : proto::_default<>
+            {};
+        }
+
     }}
 
     #endif

Modified: trunk/libs/proto/doc/reference/concepts/BasicPrimitiveTransform.xml
==============================================================================
--- trunk/libs/proto/doc/reference/concepts/BasicPrimitiveTransform.xml	(original)
+++ trunk/libs/proto/doc/reference/concepts/BasicPrimitiveTransform.xml	2009-06-18 17:39:09 EDT (Thu, 18 Jun 2009)
@@ -18,7 +18,7 @@
 
   <description>
     <para>
-      A PrimitiveTransform is class type that
+      A BasicPrimitiveTransform is class type that
       has a nested class template called impl that takes
       three template parameters representing an expression
       type, a state type and a data type. Specializations

Modified: trunk/libs/proto/doc/reference/transform/default.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/default.xml	(original)
+++ trunk/libs/proto/doc/reference/transform/default.xml	2009-06-18 17:39:09 EDT (Thu, 18 Jun 2009)
@@ -4,7 +4,9 @@
     <namespace name="proto">
       <struct name="_default">
         <template>
-          <template-type-parameter name="Grammar"/>
+          <template-type-parameter name="Grammar">
+            <default><replaceable>unspecified</replaceable></default>
+          </template-type-parameter>
         </template>
         <inherit><classname>proto::transform</classname>&lt; _default&lt;Grammar&gt; &gt;</inherit>
         <purpose>A <conceptname>PrimitiveTransform</conceptname> that gives expressions their
@@ -16,6 +18,11 @@
               <classname>proto::_default::impl&lt;&gt;</classname>
             </computeroutput> class template.
           </para>
+          <para>
+            When used without specifying a <computeroutput>Grammar</computeroutput> parameter,
+            <computeroutput>proto::_default</computeroutput> behaves as if the parameter were
+            <computeroutput>proto::_default&lt;&gt;</computeroutput>.
+          </para>
         </description>
         <struct name="impl">
           <template>