Make sub_match a valid range as per https://svn.boost.org/trac/boost/ticket/11036

test/concepts/range_concept_check.cpp

@@ -0,0 +1,41 @@
+/*
+*
+* Copyright (c) 2015
+* John Maddock
+*
+* Use, modification and distribution are 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)
+*
+*/
+
+#include <boost/regex.hpp>
+#include <boost/range/concepts.hpp>
+
+template <class T>
+void use_val(const T&){}
+
+template <class T>
+void check()
+{
+   BOOST_CONCEPT_ASSERT((boost::ForwardRangeConcept<T>));
+   BOOST_CONCEPT_ASSERT((boost_concepts::ReadableIteratorConcept<typename boost::range_iterator<T>::type>));
+   BOOST_CONCEPT_ASSERT((boost_concepts::RandomAccessTraversalConcept<typename boost::range_iterator<T>::type>));
+
+#ifndef BOOST_NO_CXX11_RANGE_BASED_FOR
+   const T val;
+   for(auto item : val)
+   {
+      use_val(item);
+   }
+#endif
+}
+
+int main()
+{
+   check<boost::smatch>();
+   check<boost::cmatch>();
+
+   check <boost::sub_match<const char*> >();
+   return 0;
+}