From 9192996a93b3fc01b1e4a30c899c70b3080b7e70 Mon Sep 17 00:00:00 2001
From: morinmorin <mimomorin@gmail.com>
Date: Sun, 23 Sep 2018 21:45:30 +0900
Subject: [PATCH] Add ADL guard namespace for boost::distance(rng).

---
 include/boost/range/distance.hpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/boost/range/distance.hpp b/include/boost/range/distance.hpp
index 8dcf05b..5b82cf0 100644
--- a/include/boost/range/distance.hpp
+++ b/include/boost/range/distance.hpp
@@ -23,13 +23,18 @@
 namespace boost
 {
 
-    template< class T >
-    inline BOOST_CXX14_CONSTEXPR BOOST_DEDUCED_TYPENAME range_difference<T>::type
-    distance( const T& r )
+    namespace range_distance_adl_barrier
     {
-        return boost::distance( boost::begin( r ), boost::end( r ) );
+        template< class T >
+        inline BOOST_CXX14_CONSTEXPR BOOST_DEDUCED_TYPENAME range_difference<T>::type
+        distance( const T& r )
+        {
+            return boost::iterators::distance( boost::begin( r ), boost::end( r ) );
+        }
     }
 
+    using namespace range_distance_adl_barrier;
+
 } // namespace 'boost'
 
 #endif