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diff --git a/boost/accumulators/framework/accumulators/reference_accumulator.hpp b/boost/accumulators/framework/accumulators/reference_accumulator.hpp
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+++ b/boost/accumulators/framework/accumulators/reference_accumulator.hpp
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+///////////////////////////////////////////////////////////////////////////////
+// reference_accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under 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)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_REFERENCE_ACCUMULATOR_HPP_EAN_03_23_2006
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_REFERENCE_ACCUMULATOR_HPP_EAN_03_23_2006
+
+#include <boost/ref.hpp>
+#include <boost/mpl/always.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/accumulators/framework/depends_on.hpp> // for feature_tag
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    //////////////////////////////////////////////////////////////////////////
+    // reference_accumulator_impl
+    //
+    template<typename Referent, typename Tag>
+    struct reference_accumulator_impl
+      : accumulator_base
+    {
+        typedef Referent &result_type;
+
+        template<typename Args>
+        reference_accumulator_impl(Args const &args)
+          : ref(args[parameter::keyword<Tag>::get()])
+        {
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->ref;
+        }
+
+    private:
+        reference_wrapper<Referent> ref;
+    };
+} // namespace impl
+
+namespace tag
+{
+    //////////////////////////////////////////////////////////////////////////
+    // reference_tag
+    template<typename Tag>
+    struct reference_tag
+    {
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // reference
+    template<typename Referent, typename Tag>
+    struct reference
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::reference_accumulator_impl<Referent, Tag> > impl;
+    };
+}
+
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, reference, (typename)(typename))
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, reference_tag, (typename))
+}
+
+using extract::reference;
+using extract::reference_tag;
+
+// Map all reference<V,T> features to reference_tag<T> so
+// that references can be extracted using reference_tag<T>
+// without specifying the referent type.
+template<typename ValueType, typename Tag>
+struct feature_of<tag::reference<ValueType, Tag> >
+  : feature_of<tag::reference_tag<Tag> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif