[range] Make iterator of 'indexed' adaptor default-constructible (refs #7827).

[SVN r84617]

include/boost/range/adaptor/indexed.hpp

@@ -55,6 +55,9 @@ namespace boost
             index_type m_index;
 
         public:
+            indexed_iterator()
+            : m_index(index_type()) {}
+            
             explicit indexed_iterator( Iter i, index_type index )
             : base(i), m_index(index)
             {

test/adaptor_test/indexed.cpp

@@ -15,11 +15,14 @@
 
 #include <boost/assign.hpp>
 #include <boost/range/algorithm_ext.hpp>
+#include <boost/range/concepts.hpp>
 
 #include <algorithm>
 #include <list>
 #include <vector>
 
+#include "../test_utils.hpp"
+
 namespace boost
 {
     namespace
@@ -83,6 +86,9 @@ namespace boost
         {
             indexed_test_impl< std::vector< int > >();
             indexed_test_impl< std::list< int > >();
+            
+            check_random_access_range_concept(std::vector<int>() | boost::adaptors::indexed(0));
+            check_bidirectional_range_concept(std::list<int>() | boost::adaptors::indexed(0));
         }
     }
 }

test/test_utils.hpp

@@ -0,0 +1,24 @@
+// Boost.Range library
+//
+//  Copyright Akira Takahashi 2013. Use, modification and
+//  distribution is subject to the Boost Software License, Version
+//  1.0. (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//
+//
+// For more information, see http://www.boost.org/libs/range/
+//
+
+#include <boost/range/concepts.hpp>
+
+template <class RandomAccessRng>
+void check_random_access_range_concept(const RandomAccessRng& rng)
+{
+    BOOST_RANGE_CONCEPT_ASSERT(( boost::RandomAccessRangeConcept<RandomAccessRng> ));
+}
+
+template <class BidirectionalRng>
+void check_bidirectional_range_concept(const BidirectionalRng& rng)
+{
+    BOOST_RANGE_CONCEPT_ASSERT(( boost::BidirectionalRangeConcept<BidirectionalRng> ));
+}