From 553b9713ac9d92cf53f3df4686f1e2088c154e98 Mon Sep 17 00:00:00 2001
From: morinmorin <mimomorin@gmail.com>
Date: Wed, 6 Sep 2017 23:12:18 +0900
Subject: [PATCH] Remove dead class template (i.e.
 function_reference_input_iterator).

Both make_function_input_iterator(function) and make...(&function)
do not depend on function_reference_input_iterator. Actually, passing a
function reference as a template argument to function_input_iterator is
not supported. Doing so results in compiler errors.
---
 .../iterator/function_input_iterator.hpp      | 23 ++-----------------
 1 file changed, 2 insertions(+), 21 deletions(-)

diff --git a/include/boost/iterator/function_input_iterator.hpp b/include/boost/iterator/function_input_iterator.hpp
index f4035e6..a82b0c0 100644
--- a/include/boost/iterator/function_input_iterator.hpp
+++ b/include/boost/iterator/function_input_iterator.hpp
@@ -14,7 +14,6 @@
 #include <boost/core/addressof.hpp>
 #include <boost/mpl/if.hpp>
 #include <boost/function_types/is_function_pointer.hpp>
-#include <boost/function_types/is_function_reference.hpp>
 #include <boost/function_types/result_type.hpp>
 #include <boost/iterator/iterator_facade.hpp>
 #include <boost/none.hpp>
@@ -101,16 +100,6 @@ namespace iterators {
             mutable optional<typename function_types::result_type<Function>::type> value;
         };
 
-        template <class Function, class Input>
-        class function_reference_input_iterator
-            : public function_pointer_input_iterator<Function*,Input>
-        {
-        public:
-            function_reference_input_iterator(Function & f_, Input state_ = Input())
-                : function_pointer_input_iterator<Function*,Input>(&f_, state_)
-            {}
-        };
-
     } // namespace impl
 
     template <class Function, class Input>
@@ -118,21 +107,13 @@ namespace iterators {
         : public mpl::if_<
             function_types::is_function_pointer<Function>,
             impl::function_pointer_input_iterator<Function,Input>,
-            typename mpl::if_<
-                function_types::is_function_reference<Function>,
-                impl::function_reference_input_iterator<Function,Input>,
-                impl::function_input_iterator<Function,Input>
-            >::type
+            impl::function_input_iterator<Function,Input>
         >::type
     {
         typedef typename mpl::if_<
             function_types::is_function_pointer<Function>,
             impl::function_pointer_input_iterator<Function,Input>,
-            typename mpl::if_<
-                function_types::is_function_reference<Function>,
-                impl::function_reference_input_iterator<Function,Input>,
-                impl::function_input_iterator<Function,Input>
-            >::type
+            impl::function_input_iterator<Function,Input>
         >::type base_type;
     public:
         function_input_iterator(Function & f, Input i)