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diff --git a/boost/type_erasure/relaxed.hpp b/boost/type_erasure/relaxed.hpp
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+// Boost.TypeErasure library
+//
+// Copyright 2011 Steven Watanabe
+//
+// 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)
+//
+// $Id$
+
+#ifndef BOOST_TYPE_ERASURE_RELAXED_HPP_INCLUDED
+#define BOOST_TYPE_ERASURE_RELAXED_HPP_INCLUDED
+
+#include <boost/mpl/vector.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/is_sequence.hpp>
+#include <boost/mpl/find_if.hpp>
+#include <boost/mpl/not.hpp>
+#include <boost/mpl/end.hpp>
+#include <boost/type_traits/is_same.hpp>
+
+namespace boost {
+namespace type_erasure {
+
+template<class T>
+struct is_relaxed;
+
+namespace detail {
+
+template<class T>
+struct is_relaxed_impl :
+    ::boost::mpl::not_<
+        typename ::boost::is_same<
+            typename ::boost::mpl::find_if<
+                T,
+                ::boost::type_erasure::is_relaxed< ::boost::mpl::_1>
+            >::type,
+            typename ::boost::mpl::end<T>::type
+        >::type
+    >::type
+{};
+
+}
+
+/**
+ * This special concept enables various useful default behavior that
+ * makes @ref any act like an ordinary object.  By default @ref any
+ * forwards all operations to the underlying type, and provides only
+ * the operations that are specified in its @c Concept.
+ *
+ * In detail, @ref relaxed enables the following:
+ * - A raw value can be assigned to an @ref any.  This will replace
+ *   the value stored by the @ref any.  (But note that if @ref assignable
+ *   is present, it takes priority.)
+ * - copy assignment of @ref any uses the copy constructor if it can't
+ *   use @ref assignable (either because @ref assignable is missing,
+ *   or because the stored types do not match).
+ * - default construction of @ref any is allowed and creates a null any.
+ * - @ref equality_comparable "equality_comparable": If the types do not
+ *   match, it will return false.
+ * - @ref less_than_comparable "less_than_comparable": If the types do not
+ *   match, the ordering will be according to
+ *   @c std::type_info::before.
+ * - if the arguments to any other function do not match, it will throw
+ *   a @ref bad_function_call exception instead of having undefined
+ *   behavior.
+ */
+struct relaxed : ::boost::mpl::vector0<> {};
+
+/**
+ * A metafunction indicating whether @c Concept
+ * includes @ref relaxed.
+ */
+template<class Concept>
+struct is_relaxed :
+    ::boost::mpl::eval_if< ::boost::mpl::is_sequence<Concept>,
+        ::boost::type_erasure::detail::is_relaxed_impl<Concept>,
+        ::boost::mpl::false_
+    >::type
+{};
+
+/** INTERNAL ONLY */
+template<>
+struct is_relaxed< ::boost::type_erasure::relaxed> :
+    ::boost::mpl::true_
+{};
+
+}
+}
+
+#endif