From e9d0fe0ec6ff446b18a1736b34bf8bb9cfdadb39 Mon Sep 17 00:00:00 2001
From: Adam Wulkiewicz <adam.wulkiewicz@gmail.com>
Date: Sun, 7 Jun 2015 12:20:41 +0200
Subject: [PATCH] [algorithms][detail] Improve single_geometry() and
 sub_range().

Support single geometries which are returned by non-true-reference.
Make the interface of sub_range() complete (Geometry const)
---
 .../boost/geometry/algorithms/detail/single_geometry.hpp   | 7 +------
 include/boost/geometry/algorithms/detail/sub_range.hpp     | 7 +++++++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/single_geometry.hpp b/include/boost/geometry/algorithms/detail/single_geometry.hpp
index c9da80e16..d0646323e 100644
--- a/include/boost/geometry/algorithms/detail/single_geometry.hpp
+++ b/include/boost/geometry/algorithms/detail/single_geometry.hpp
@@ -46,12 +46,7 @@ struct single_geometry
 template <typename Geometry>
 struct single_geometry<Geometry, true>
 {
-    typedef typename boost::mpl::if_c
-        <
-            boost::is_const<Geometry>::value,
-            typename boost::range_value<Geometry>::type const&,
-            typename boost::range_value<Geometry>::type
-        >::type return_type;
+    typedef typename boost::range_reference<Geometry>::type return_type;
 
     template <typename Id>
     static inline return_type apply(Geometry & g, Id const& id)
diff --git a/include/boost/geometry/algorithms/detail/sub_range.hpp b/include/boost/geometry/algorithms/detail/sub_range.hpp
index be499048f..6fc44c564 100644
--- a/include/boost/geometry/algorithms/detail/sub_range.hpp
+++ b/include/boost/geometry/algorithms/detail/sub_range.hpp
@@ -113,6 +113,13 @@ sub_range(Geometry & geometry, Id const& id)
     return detail_dispatch::sub_range<Geometry>::apply(geometry, id);
 }
 
+template <typename Geometry, typename Id> inline
+typename sub_range_return_type<Geometry const>::type
+sub_range(Geometry const& geometry, Id const& id)
+{
+    return detail_dispatch::sub_range<Geometry const>::apply(geometry, id);
+}
+
 } // namespace detail
 #endif // DOXYGEN_NO_DETAIL