diff --git a/ndnboost/numeric/conversion/detail/sign_mixture.hpp b/ndnboost/numeric/conversion/detail/sign_mixture.hpp
new file mode 100644
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+++ b/ndnboost/numeric/conversion/detail/sign_mixture.hpp
@@ -0,0 +1,72 @@
+//  (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
+//  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)
+
+//  See library home page at http://www.boost.org/libs/numeric/conversion
+//
+// Contact the author at: fernando_cacciola@hotmail.com
+// 
+#ifndef BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP
+#define BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP
+
+#include "ndnboost/config.hpp"
+#include "ndnboost/limits.hpp"
+
+#include "ndnboost/numeric/conversion/sign_mixture_enum.hpp"
+#include "ndnboost/numeric/conversion/detail/meta.hpp"
+
+#include "ndnboost/mpl/integral_c.hpp"
+
+namespace ndnboost { namespace numeric { namespace convdetail
+{
+  // Integral Constants for 'SignMixture'
+  typedef mpl::integral_c<sign_mixture_enum, unsigned_to_unsigned> unsig2unsig_c ;
+  typedef mpl::integral_c<sign_mixture_enum, signed_to_signed>     sig2sig_c ;
+  typedef mpl::integral_c<sign_mixture_enum, signed_to_unsigned>   sig2unsig_c ;
+  typedef mpl::integral_c<sign_mixture_enum, unsigned_to_signed>   unsig2sig_c ;
+
+  // Metafunction:
+  //
+  //   get_sign_mixture<T,S>::type
+  //
+  // Selects the appropriate SignMixture Integral Constant for the combination T,S.
+  //
+  template<class T,class S>
+  struct get_sign_mixture
+  {
+    typedef mpl::bool_< ::std::numeric_limits<S>::is_signed > S_signed ;
+    typedef mpl::bool_< ::std::numeric_limits<T>::is_signed > T_signed ;
+
+    typedef typename
+      for_both<S_signed, T_signed, sig2sig_c, sig2unsig_c, unsig2sig_c, unsig2unsig_c>::type
+        type ;
+  } ;
+
+  // Metafunction:
+  //
+  //   for_sign_mixture<SignMixture,Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig>::type
+  //
+  // {SignMixture} is one of the Integral Constants for SignMixture, declared above.
+  // {Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig} are aribtrary types. (not metafunctions)
+  //
+  // According to the value of 'SignMixture', selects the corresponding type.
+  //
+  template<class SignMixture, class Sig2Sig, class Sig2Unsig, class Unsig2Sig, class Unsig2Unsig>
+  struct for_sign_mixture
+  {
+    typedef typename
+      ct_switch4<SignMixture
+                 , sig2sig_c, sig2unsig_c, unsig2sig_c  // default
+                 , Sig2Sig  , Sig2Unsig  , Unsig2Sig  , Unsig2Unsig
+                >::type
+        type ;
+  } ;
+
+} } } // namespace ndnboost::numeric::convdetail
+
+#endif
+//
+///////////////////////////////////////////////////////////////////////////////////////////////
+
+