From db23bb2e832ae6f460d5fc14a4395b7a887f47bf Mon Sep 17 00:00:00 2001
From: Bruno Lalande <bruno.lalande@gmail.com>
Date: Tue, 9 Oct 2012 23:19:54 +0000
Subject: [PATCH] Made dispatch::for_each able to retrieve the tag by itself.

[SVN r80922]
---
 .../boost/geometry/algorithms/for_each.hpp    | 36 ++++++++-----------
 .../geometry/multi/algorithms/for_each.hpp    | 12 ++-----
 2 files changed, 16 insertions(+), 32 deletions(-)

diff --git a/include/boost/geometry/algorithms/for_each.hpp b/include/boost/geometry/algorithms/for_each.hpp
index a13348b4a..0156c6371 100644
--- a/include/boost/geometry/algorithms/for_each.hpp
+++ b/include/boost/geometry/algorithms/for_each.hpp
@@ -148,63 +148,63 @@ namespace dispatch
 
 template
 <
-    typename Tag,
-    typename Geometry
+    typename Geometry,
+    typename Tag = typename tag_cast<typename tag<Geometry>::type, multi_tag>::type
 >
 struct for_each_point {};
 
 
 template <typename Point>
-struct for_each_point<point_tag, Point>
+struct for_each_point<Point, point_tag>
     : detail::for_each::fe_point_per_point
 {};
 
 
 template <typename Linestring>
-struct for_each_point<linestring_tag, Linestring>
+struct for_each_point<Linestring, linestring_tag>
     : detail::for_each::fe_range_per_point
 {};
 
 
 template <typename Ring>
-struct for_each_point<ring_tag, Ring>
+struct for_each_point<Ring, ring_tag>
     : detail::for_each::fe_range_per_point
 {};
 
 
 template <typename Polygon>
-struct for_each_point<polygon_tag, Polygon>
+struct for_each_point<Polygon, polygon_tag>
     : detail::for_each::fe_polygon_per_point
 {};
 
 
 template
 <
-    typename Tag,
-    typename Geometry
+    typename Geometry,
+    typename Tag = typename tag_cast<typename tag<Geometry>::type, multi_tag>::type
 >
 struct for_each_segment {};
 
 template <typename Point>
-struct for_each_segment<point_tag, Point>
+struct for_each_segment<Point, point_tag>
     : detail::for_each::fe_point_per_segment
 {};
 
 
 template <typename Linestring>
-struct for_each_segment<linestring_tag, Linestring>
+struct for_each_segment<Linestring, linestring_tag>
     : detail::for_each::fe_range_per_segment
 {};
 
 
 template <typename Ring>
-struct for_each_segment<ring_tag, Ring>
+struct for_each_segment<Ring, ring_tag>
     : detail::for_each::fe_range_per_segment
 {};
 
 
 template <typename Polygon>
-struct for_each_segment<polygon_tag, Polygon>
+struct for_each_segment<Polygon, polygon_tag>
     : detail::for_each::fe_polygon_per_segment
 {};
 
@@ -232,11 +232,7 @@ inline Functor for_each_point(Geometry& geometry, Functor f)
 {
     concept::check<Geometry>();
 
-    return dispatch::for_each_point
-        <
-            typename tag_cast<typename tag<Geometry>::type, multi_tag>::type,
-            Geometry
-        >::apply(geometry, f);
+    return dispatch::for_each_point<Geometry>::apply(geometry, f);
 }
 
 
@@ -258,11 +254,7 @@ inline Functor for_each_segment(Geometry& geometry, Functor f)
 {
     concept::check<Geometry>();
 
-    return dispatch::for_each_segment
-        <
-            typename tag_cast<typename tag<Geometry>::type, multi_tag>::type,
-            Geometry
-        >::apply(geometry, f);
+    return dispatch::for_each_segment<Geometry>::apply(geometry, f);
 }
 
 
diff --git a/include/boost/geometry/multi/algorithms/for_each.hpp b/include/boost/geometry/multi/algorithms/for_each.hpp
index cd542ffdf..8a1521039 100644
--- a/include/boost/geometry/multi/algorithms/for_each.hpp
+++ b/include/boost/geometry/multi/algorithms/for_each.hpp
@@ -60,16 +60,12 @@ namespace dispatch
 {
 
 template <typename MultiGeometry>
-struct for_each_point<multi_tag, MultiGeometry>
+struct for_each_point<MultiGeometry, multi_tag>
     : detail::for_each::for_each_multi
         <
             // Specify the dispatch of the single-version as policy
             for_each_point
                 <
-                    typename single_tag_of
-                        <
-                            typename tag<MultiGeometry>::type
-                        >::type,
                     typename add_const_if_c
                         <
                             is_const<MultiGeometry>::value,
@@ -81,16 +77,12 @@ struct for_each_point<multi_tag, MultiGeometry>
 
 
 template <typename MultiGeometry>
-struct for_each_segment<multi_tag, MultiGeometry>
+struct for_each_segment<MultiGeometry, multi_tag>
     : detail::for_each::for_each_multi
         <
             // Specify the dispatch of the single-version as policy
             for_each_segment
                 <
-                    typename single_tag_of
-                        <
-                            typename tag<MultiGeometry>::type
-                        >::type,
                     typename add_const_if_c
                         <
                             is_const<MultiGeometry>::value,