diff --git a/include/ndnboost/iostreams/detail/codecvt_helper.hpp b/include/ndnboost/iostreams/detail/codecvt_helper.hpp
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+++ b/include/ndnboost/iostreams/detail/codecvt_helper.hpp
@@ -0,0 +1,237 @@
+// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
+// (C) Copyright 2003-2007 Jonathan Turkanis
+// 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/iostreams for documentation.
+
+// Contains the definition of the template codecvt_helper, useful for
+// defining specializations of std::codecvt where state_type != mbstate_t.
+// Compensates for the fact that some standard library implementations 
+// do not derive the primiary codecvt template from locale::facet or 
+// provide the correct member types and functions.
+
+// Usage: 
+//
+// // In global namespace:
+// NDNBOOST_IOSTREAMS_CODECVT_SPEC(mystate)
+//
+// // In user namespace:
+// template<typename Intern, typename Extern>
+// struct mycodecvt : codecvt_helper<Intern, Extern, State> { ... };
+//
+// // Or:
+// struct mycodecvt : codecvt_helper<wchar_t, char, State> { ... };
+// 
+// Etc.
+
+#ifndef NDNBOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED
+#define NDNBOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include <ndnboost/config.hpp>  // Put size_t in std, NDNBOOST_MSVC, Dinkum.
+#include <ndnboost/detail/workaround.hpp>
+#include <algorithm>         // min.
+#include <cstddef>           // size_t.
+#include <locale>            // locale, codecvt_base, codecvt.
+#include <ndnboost/iostreams/detail/config/codecvt.hpp>
+
+//------------------Definition of traits--------------------------------------//
+
+namespace ndnboost { namespace iostreams { namespace detail {
+
+#if !NDNBOOST_WORKAROUND(NDNBOOST_DINKUMWARE_STDLIB, == 1) //-----------------------//
+
+template<typename T>
+struct codecvt_intern { typedef typename T::intern_type type; };
+
+template<typename T>
+struct codecvt_extern { typedef typename T::extern_type type; };
+
+#else // #if !NDNBOOST_WORKAROUND(NDNBOOST_DINKUMWARE_STDLIB, == 1) //--------------//
+
+template<typename T>
+struct codecvt_intern { typedef typename T::from_type type; };
+
+template<typename T>
+struct codecvt_extern { typedef typename T::to_type type; };
+
+#endif // #if !NDNBOOST_WORKAROUND(NDNBOOST_DINKUMWARE_STDLIB, == 1) //-------------//
+
+template<typename T>
+struct codecvt_state { typedef typename T::state_type type; };
+
+} } } // End namespaces detail, iostreams, boost.
+
+//------------------Definition of codecvt_impl--------------------------------//
+
+#if defined(NDNBOOST_IOSTREAMS_NO_PRIMARY_CODECVT_DEFINITION) || \
+    defined(NDNBOOST_IOSTREAMS_EMPTY_PRIMARY_CODECVT_DEFINITION) || \
+    defined(NDNBOOST_IOSTREAMS_NO_LOCALE) \
+    /**/
+
+namespace ndnboost { namespace iostreams { namespace detail {
+
+template<typename Intern, typename Extern, typename State>
+struct codecvt_impl : std::locale::facet, std::codecvt_base {
+public:
+    typedef Intern  intern_type;
+    typedef Extern  extern_type;
+    typedef State   state_type;
+
+    codecvt_impl(std::size_t refs = 0) : std::locale::facet(refs) { } 
+
+    std::codecvt_base::result
+    in( State& state, const Extern* first1, const Extern* last1,
+        const Extern*& next1, Intern* first2, Intern* last2,
+        Intern*& next2 ) const
+    {
+        return do_in(state, first1, last1, next1, first2, last2, next2);
+    }
+
+    std::codecvt_base::result
+    out( State& state, const Intern* first1, const Intern* last1,
+         const Intern*& next1, Extern* first2, Extern* last2,
+         Extern*& next2 ) const
+    {
+        return do_out(state, first1, last1, next1, first2, last2, next2);
+    }
+
+    std::codecvt_base::result
+    unshift(State& state, Extern* first2, Extern* last2, Extern*& next2) const
+    {
+        return do_unshift(state, first2, last2, next2);
+    }
+
+    bool always_noconv() const throw() { return do_always_noconv(); }
+
+    int max_length() const throw() { return do_max_length(); }
+
+    int encoding() const throw() { return do_encoding(); }
+
+    int length( NDNBOOST_IOSTREAMS_CODECVT_CV_QUALIFIER State& state, 
+                const Extern* first1, const Extern* last1,
+                std::size_t len2 ) const throw()
+    {
+        return do_length(state, first1, last1, len2);
+    }
+protected:
+    std::codecvt_base::result
+    virtual do_in( State&, const Extern*, const Extern*, const Extern*&, 
+                   Intern*, Intern*, Intern*& ) const
+    {
+        return std::codecvt_base::noconv;
+    }
+
+    std::codecvt_base::result
+    virtual do_out( State&, const Intern*, const Intern*, const Intern*&, 
+                    Extern*, Extern*, Extern*& ) const
+    {
+        return std::codecvt_base::noconv;
+    }
+
+    std::codecvt_base::result
+    virtual do_unshift(State&, Extern*, Extern*, Extern*&) const
+    {
+        return std::codecvt_base::ok;
+    }
+
+    virtual bool do_always_noconv() const throw() { return true; }
+
+    virtual int do_max_length() const throw() { return 1; }
+
+    virtual int do_encoding() const throw() { return 1; }
+
+    virtual int do_length( NDNBOOST_IOSTREAMS_CODECVT_CV_QUALIFIER State&, 
+                           const Extern* first1, const Extern* last1,
+                           std::size_t len2 ) const throw()
+    {
+        return (std::min)(static_cast<std::size_t>(last1 - first1), len2);
+    }
+};
+
+} } } // End namespaces detail, iostreams, boost.
+
+#endif // no primary codecvt definition, empty definition.
+
+//------------------Definition of NDNBOOST_IOSTREAMS_CODECVT_SPEC----------------//
+
+#if defined(NDNBOOST_IOSTREAMS_NO_PRIMARY_CODECVT_DEFINITION) || \
+    defined(NDNBOOST_IOSTREAMS_EMPTY_PRIMARY_CODECVT_DEFINITION) \
+    /**/
+# ifndef NDNBOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
+#  define NDNBOOST_IOSTREAMS_CODECVT_SPEC(state) \
+    namespace std { \
+        template<typename Intern, typename Extern> \
+        class codecvt<Intern, Extern, state> \
+            : public ::ndnboost::iostreams::detail::codecvt_impl< \
+                         Intern, Extern, state \
+                     > \
+        { \
+        public: \
+            codecvt(std::size_t refs = 0) \
+                : ::ndnboost::iostreams::detail::codecvt_impl< \
+                      Intern, Extern, state \
+                  >(refs) \
+                { } \
+            static std::locale::id id; \
+        }; \
+        template<typename Intern, typename Extern> \
+        std::locale::id codecvt<Intern, Extern, state>::id; \
+    } \
+    /**/
+# else
+#  define NDNBOOST_IOSTREAMS_CODECVT_SPEC(state) \
+    namespace std { \
+        template<> \
+        class codecvt<wchar_t, char, state> \
+            : public ::ndnboost::iostreams::detail::codecvt_impl< \
+                         wchar_t, char, state \
+                     > \
+        { \
+        public: \
+            codecvt(std::size_t refs = 0) \
+                : ::ndnboost::iostreams::detail::codecvt_impl< \
+                      wchar_t, char, state \
+                  >(refs) \
+                { } \
+            static std::locale::id id; \
+        }; \
+        template<> \
+        std::locale::id codecvt<wchar_t, char, state>::id; \
+    } \
+    /**/
+# endif
+#else
+# define NDNBOOST_IOSTREAMS_CODECVT_SPEC(state)
+#endif // no primary codecvt definition, or empty definition.
+
+namespace ndnboost { namespace iostreams { namespace detail {
+                    
+//------------------Definition of codecvt_helper------------------------------//
+
+template<typename Intern, typename Extern, typename State>
+struct codecvt_helper : std::codecvt<Intern, Extern, State> { 
+    typedef Intern  intern_type;
+    typedef Extern  extern_type;
+    typedef State   state_type;
+    codecvt_helper(std::size_t refs = 0) 
+    #if !defined(NDNBOOST_IOSTREAMS_NO_CODECVT_CTOR_FROM_SIZE_T)
+        : std::codecvt<Intern, Extern, State>(refs)
+    #else
+        : std::codecvt<Intern, Extern, State>()
+    #endif
+        { }
+#ifdef NDNBOOST_IOSTREAMS_NO_CODECVT_MAX_LENGTH
+    int max_length() const throw() { return do_max_length(); }
+protected:
+    virtual int do_max_length() const throw() { return 1; }
+#endif
+};
+
+} } } // End namespaces detail, iostreams, boost.
+
+#endif // #ifndef NDNBOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED