Fixing non-reference base_t::reference case for replaced_if adaptor

Author: m-karcz

include/boost/range/adaptor/replaced_if.hpp

@@ -16,49 +16,61 @@
 #include <boost/range/iterator_range.hpp>
 #include <boost/range/begin.hpp>
 #include <boost/range/end.hpp>
-#include <boost/range/value_type.hpp>
+#include <boost/range/reference.hpp>
 #include <boost/range/concepts.hpp>
 #include <boost/iterator/iterator_adaptor.hpp>
 #include <boost/iterator/transform_iterator.hpp>
 #include <boost/optional/optional.hpp>
+#include <boost/move/utility_core.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/type_traits/is_reference.hpp>
+#include <boost/type_traits/conditional.hpp>
 
 namespace boost
 {
     namespace range_detail
     {
-        template< class Pred, class Value >
+        template< class Pred, class Reference >
         class replace_value_if
         {
         public:
-            typedef const Value& result_type;
-            typedef const Value& first_argument_type;
+            typedef BOOST_DEDUCED_TYPENAME boost::conditional<boost::is_reference<Reference>::value,
+                                                              const BOOST_DEDUCED_TYPENAME boost::remove_reference<Reference>::type&,
+                                                              Reference>::type result_type;
+            typedef Reference first_argument_type;
 
             // Rationale:
             // required to allow the iterator to be default constructible.
             replace_value_if()
             {
             }
 
-            replace_value_if(const Pred& pred, const Value& to)
+            replace_value_if(const Pred& pred, const BOOST_DEDUCED_TYPENAME boost::remove_reference<Reference>::type& to)
                 : m_impl(data(pred, to))
             {
             }
 
-            const Value& operator()(const Value& x) const
+            result_type operator()(Reference x) const
             {
+            #if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) 
                 return m_impl->m_pred(x) ? m_impl->m_to : x;
+            #else
+                return m_impl->m_pred(x) ? m_impl->m_to : boost::forward<Reference>(x);
+            #endif
             }
 
         private:
+            
+
             struct data
             {
-                data(const Pred& p, const Value& t)
+                data(const Pred& p, const BOOST_DEDUCED_TYPENAME boost::remove_reference<Reference>::type& t)
                     : m_pred(p), m_to(t)
                 {
                 }
 
                 Pred  m_pred;
-                Value m_to;
+                BOOST_DEDUCED_TYPENAME boost::remove_reference<Reference>::type m_to;
             };
             boost::optional<data> m_impl;
         };
@@ -67,21 +79,21 @@ namespace boost
         class replaced_if_range :
             public boost::iterator_range<
                 boost::transform_iterator<
-                    replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >,
+                    replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_reference<R>::type >,
                     BOOST_DEDUCED_TYPENAME range_iterator<R>::type > >
         {
         private:
-            typedef replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn;
+            typedef replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_reference<R>::type > Fn;
 
             typedef boost::iterator_range<
                 boost::transform_iterator<
-                    replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >,
+                    replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_reference<R>::type >,
                     BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t;
 
         public:
-            typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type;
+            typedef BOOST_DEDUCED_TYPENAME range_reference<R>::type reference_type;
 
-            replaced_if_range( R& r, const Pred& pred, value_type to )
+            replaced_if_range( R& r, const Pred& pred, const BOOST_DEDUCED_TYPENAME boost::remove_reference<reference_type>::type& to )
                 : base_t( make_transform_iterator( boost::begin(r), Fn(pred, to) ),
                           make_transform_iterator( boost::end(r), Fn(pred, to) ) )
             { }

test/adaptor_test/replaced_if.cpp

@@ -9,6 +9,8 @@
 // For more information, see http://www.boost.org/libs/range/
 //
 #include <boost/range/adaptor/replaced_if.hpp>
+#include <boost/range/adaptor/transformed.hpp>
+#include <boost/range/iterator_range.hpp>
 
 #include <boost/test/test_tools.hpp>
 #include <boost/test/unit_test.hpp>
@@ -30,6 +32,13 @@ namespace boost
             bool operator()(int x) const { return x == 1; }
         };
 
+        struct minus_one
+        {
+            typedef int result_type;
+            typedef int argument_type;
+            int operator()(int x) const {return x - 1; }
+        };
+
         template< class Container >
         void replaced_if_test_impl( Container& c )
         {
@@ -81,6 +90,33 @@ namespace boost
             replaced_if_test_impl< std::set< int > >();
             replaced_if_test_impl< std::multiset< int > >();
         }
+
+        void replaced_if_combined_with_transformed_test()
+        {
+            using namespace boost::adaptors;
+            using namespace boost::assign;
+
+            minus_one unary_fn;
+            if_value_is_one pred;
+
+            std::vector<int> input;
+
+            input += 4,3,2,1;
+
+            const int replacement_value = 7;
+
+            std::vector<int> reference;
+
+            std::vector<int> temp;
+            boost::push_back(temp, input | transformed(unary_fn));
+            boost::push_back(reference, temp | replaced_if(pred, replacement_value));
+
+            std::vector<int> test_result = boost::copy_range< std::vector<int> >(input | transformed(unary_fn)
+                                                                                     | replaced_if(pred, replacement_value));
+
+            BOOST_CHECK_EQUAL_COLLECTIONS( reference.begin(), reference.end(),
+                                           test_result.begin(), test_result.end() );
+        }
     }
 }
 
@@ -91,6 +127,7 @@ init_unit_test_suite(int argc, char* argv[])
         = BOOST_TEST_SUITE( "RangeTestSuite.adaptor.replaced_if" );
 
     test->add( BOOST_TEST_CASE( &boost::replaced_if_test ) );
+    test->add( BOOST_TEST_CASE( &boost::replaced_if_combined_with_transformed_test ) );
 
     return test;
 }