Incomplete work for using Boost.Polygon to compute medial axis

xs/src/boost/mpl/protect.hpp

@@ -0,0 +1,55 @@
+
+#ifndef BOOST_MPL_PROTECT_HPP_INCLUDED
+#define BOOST_MPL_PROTECT_HPP_INCLUDED
+
+// Copyright Peter Dimov 2001
+// Copyright Aleksey Gurtovoy 2002-2004
+//
+// 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)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+
+// $Id: protect.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
+// $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
+// $Revision: 49267 $
+
+#include <boost/mpl/aux_/arity.hpp>
+#include <boost/mpl/aux_/config/dtp.hpp>
+#include <boost/mpl/aux_/nttp_decl.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+
+namespace boost { namespace mpl {
+
+template<
+      typename BOOST_MPL_AUX_NA_PARAM(T)
+    , int not_le_ = 0
+    >
+struct protect : T
+{
+#if BOOST_WORKAROUND(__EDG_VERSION__, == 238)
+    typedef mpl::protect type;
+#else
+    typedef protect type;
+#endif
+};
+
+#if defined(BOOST_MPL_CFG_BROKEN_DEFAULT_PARAMETERS_IN_NESTED_TEMPLATES)
+namespace aux { 
+template< BOOST_MPL_AUX_NTTP_DECL(int, N), typename T >
+struct arity< protect<T>, N > 
+    : arity<T,N>
+{ 
+};
+} // namespace aux
+#endif
+
+BOOST_MPL_AUX_NA_SPEC_MAIN(1, protect)
+#if !defined(BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT)
+BOOST_MPL_AUX_NA_SPEC_TEMPLATE_ARITY(1, 1, protect)
+#endif
+
+}}
+
+#endif // BOOST_MPL_PROTECT_HPP_INCLUDED