From cdaba1bebbb7cf4afa12c476f892933ca78492fd Mon Sep 17 00:00:00 2001
From: Bruno Lalande <bruno.lalande@gmail.com>
Date: Tue, 13 Dec 2011 23:24:52 +0000
Subject: [PATCH] Improved not_implemented.

[SVN r75935]
---
 .../tools/support_status/support_status.cpp   |  6 +-
 include/boost/geometry/algorithms/convert.hpp |  4 +-
 .../boost/geometry/algorithms/distance.hpp    |  5 +-
 .../geometry/algorithms/not_implemented.hpp   | 81 ++++++++++++++++++-
 4 files changed, 86 insertions(+), 10 deletions(-)

diff --git a/doc/src/docutils/tools/support_status/support_status.cpp b/doc/src/docutils/tools/support_status/support_status.cpp
index 5bd3f0640..df14199fa 100644
--- a/doc/src/docutils/tools/support_status/support_status.cpp
+++ b/doc/src/docutils/tools/support_status/support_status.cpp
@@ -66,8 +66,8 @@ struct distance_tester
         typedef typename boost::geometry::tag<T1>::type tag1;
         typedef typename boost::geometry::tag<T2>::type tag2;
 
-        if (boost::is_base_of<boost::geometry::not_implemented<T1, T2>, check_distance<tag1, tag2, T1, T2> >::type::value
-         && boost::is_base_of<boost::geometry::not_implemented<T2, T1>, check_distance<tag2, tag1, T2, T1> >::type::value)
+        if (boost::is_base_of<boost::geometry::not_implemented_base, check_distance<tag1, tag2, T1, T2> >::type::value
+         && boost::is_base_of<boost::geometry::not_implemented_base, check_distance<tag2, tag1, T2, T1> >::type::value)
         {
             std::cout << "-\t";
         }
@@ -96,7 +96,7 @@ struct convert_tester
     template <typename T2>
     void operator()(T2)
     {
-        if (boost::is_base_of<boost::geometry::not_implemented<T1, T2>, check_convert<T1, T2> >::type::value)
+        if (boost::is_base_of<boost::geometry::not_implemented_base, check_convert<T1, T2> >::type::value)
         {
             std::cout << "-\t";
         }
diff --git a/include/boost/geometry/algorithms/convert.hpp b/include/boost/geometry/algorithms/convert.hpp
index fe58064d2..526dc9c9f 100644
--- a/include/boost/geometry/algorithms/convert.hpp
+++ b/include/boost/geometry/algorithms/convert.hpp
@@ -220,7 +220,9 @@ template
     bool UseAssignment = boost::is_same<Geometry1, Geometry2>::value
                          && !boost::is_array<Geometry1>::value
 >
-struct convert: boost::geometry::not_implemented<Geometry1, Geometry2>
+struct convert: boost::geometry::not_implemented<for_geometry<Tag1>,
+                                                 and_geometry<Tag2>,
+                                                 in_dimension<DimensionCount> >
 {};
 
 
diff --git a/include/boost/geometry/algorithms/distance.hpp b/include/boost/geometry/algorithms/distance.hpp
index de8c9e85d..09340b6b5 100644
--- a/include/boost/geometry/algorithms/distance.hpp
+++ b/include/boost/geometry/algorithms/distance.hpp
@@ -247,11 +247,12 @@ using strategy::distance::services::return_type;
 
 template
 <
-    typename GeometryTag1, typename GeometryTag2,
+    typename Tag1, typename Tag2,
     typename Geometry1, typename Geometry2,
     typename StrategyTag, typename Strategy
 >
-struct distance: not_implemented<Geometry1, Geometry2>
+struct distance: not_implemented<for_geometry<Tag1>,
+                                 and_geometry<Tag2> >
 {};
 
 
diff --git a/include/boost/geometry/algorithms/not_implemented.hpp b/include/boost/geometry/algorithms/not_implemented.hpp
index b21643b74..3699cd305 100644
--- a/include/boost/geometry/algorithms/not_implemented.hpp
+++ b/include/boost/geometry/algorithms/not_implemented.hpp
@@ -17,25 +17,98 @@
 
 
 #include <boost/mpl/assert.hpp>
+#include <boost/mpl/fold.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/mpl/remove.hpp>
+#include <boost/mpl/apply_wrap.hpp>
 
 
 namespace boost { namespace geometry
 {
 
 
+// Class containing the elements of the actual user-facing error message
+
+template <class>
+struct FOR_GEOMETRY_TYPE
+{
+    template <class>
+    struct AND_GEOMETRY_TYPE
+    {
+        template <size_t>
+        struct IN_DIMENSION
+        {};
+    };
+
+    template <size_t>
+    struct IN_DIMENSION
+    {};
+};
+
+
+// Unary metafunction class templates which return their corresponding error
+// message element nested in the previous one.
+
+template <class G>
+struct for_geometry
+{
+    template <class>
+    struct apply
+    {
+        typedef FOR_GEOMETRY_TYPE<G> type;
+    };
+};
+
+template <class G>
+struct and_geometry
+{
+    template <class Prev>
+    struct apply
+    {
+        typedef typename Prev::template AND_GEOMETRY_TYPE<G> type;
+    };
+};
+
+template <size_t D>
+struct in_dimension
+{
+    template <class Prev>
+    struct apply
+    {
+        typedef typename Prev::template IN_DIMENSION<D> type;
+    };
+};
+
+
 #ifndef BOOST_GEOMETRY_IMPLEMENTATION_STATUS_BUILD
 # define BOOST_GEOMETRY_IMPLEMENTATION_STATUS_BUILD false
 #endif
 
 
-template <typename Geometry1, typename Geometry2>
-struct not_implemented
+struct not_implemented_base {};
+
+
+template <
+    typename Word1 = void,
+    typename Word2 = void,
+    typename Word3 = void
+>
+struct not_implemented: not_implemented_base
 {
     BOOST_MPL_ASSERT_MSG
         (
             BOOST_GEOMETRY_IMPLEMENTATION_STATUS_BUILD,
-            NOT_OR_NOT_YET_IMPLEMENTED_FOR_THIS_GEOMETRY_TYPE
-            , (types<Geometry1, Geometry2>)
+            THIS_OPERATION_IS_NOT_OR_NOT_YET_IMPLEMENTED,
+            (
+                typename boost::mpl::fold<
+                    typename boost::mpl::remove<
+                        boost::mpl::vector<Word1, Word2, Word3>,
+                        void
+                    >::type,
+                    void,
+                    boost::mpl::apply_wrap1<boost::mpl::_2, boost::mpl::_1>
+                >::type
+            )
         );
 };