From 3adf4d2869b80d4227be6cf872b4a0486181fbe1 Mon Sep 17 00:00:00 2001
From: Neil Groves <neil@grovescomputing.com>
Date: Thu, 23 Dec 2010 00:56:04 +0000
Subject: [PATCH] [boost][range] - Resolution of Trac item 4905 -
 Implementation of boost::range::map_keys should use boost::range_reference

[SVN r67423]
---
 include/boost/range/adaptor/map.hpp | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/include/boost/range/adaptor/map.hpp b/include/boost/range/adaptor/map.hpp
index 8c39eca..ff8b97e 100755
--- a/include/boost/range/adaptor/map.hpp
+++ b/include/boost/range/adaptor/map.hpp
@@ -14,6 +14,7 @@
 #include <boost/range/adaptor/transformed.hpp>
 #include <boost/range/iterator_range.hpp>
 #include <boost/range/value_type.hpp>
+#include <boost/range/reference.hpp>
 
 namespace boost
 {
@@ -25,11 +26,10 @@ namespace boost
         template< class Map >
         struct select_first
         {
-            typedef BOOST_DEDUCED_TYPENAME range_value<Map>::type pair_t;
-            typedef const BOOST_DEDUCED_TYPENAME pair_t::first_type&
-                result_type;
+            typedef BOOST_DEDUCED_TYPENAME range_reference<const Map>::type argument_type;
+            typedef const BOOST_DEDUCED_TYPENAME range_value<const Map>::type::first_type& result_type;
 
-            result_type operator()( const pair_t& r ) const
+            result_type operator()( argument_type r ) const
             {
                 return r.first;
             }
@@ -38,10 +38,10 @@ namespace boost
         template< class Map >
         struct select_second_mutable
         {
-            typedef BOOST_DEDUCED_TYPENAME range_value<Map>::type pair_t;
-            typedef BOOST_DEDUCED_TYPENAME pair_t::second_type& result_type;
+            typedef BOOST_DEDUCED_TYPENAME range_reference<Map>::type argument_type;
+            typedef BOOST_DEDUCED_TYPENAME range_value<Map>::type::second_type& result_type;
 
-            result_type operator()( pair_t& r ) const
+            result_type operator()( argument_type r ) const
             {
                 return r.second;
             }
@@ -50,11 +50,10 @@ namespace boost
         template< class Map >
         struct select_second_const
         {
-            typedef BOOST_DEDUCED_TYPENAME range_value<Map>::type pair_t;
-            typedef const BOOST_DEDUCED_TYPENAME pair_t::second_type&
-                result_type;
+            typedef BOOST_DEDUCED_TYPENAME range_reference<const Map>::type argument_type;
+            typedef const BOOST_DEDUCED_TYPENAME range_value<const Map>::type::second_type& result_type;
 
-            result_type operator()( const pair_t& r ) const
+            result_type operator()( argument_type r ) const
             {
                 return r.second;
             }