diff --git a/include/etl/generators/message_packet_generator.h b/include/etl/generators/message_packet_generator.h
index 1524e8f6..a05e51e4 100644
--- a/include/etl/generators/message_packet_generator.h
+++ b/include/etl/generators/message_packet_generator.h
@@ -85,36 +85,74 @@ namespace etl
 
     //********************************************
     message_packet()
-      : valid(false)
+      : data()
+      , valid(false)
     {
     }
 
     //********************************************
     explicit message_packet(const etl::imessage& msg)
-      : valid(true)
+      : data()
     {
-      add_new_message(msg);
+      if (accepts(msg))
+      {
+        add_new_message(msg);
+        valid = true;
+      }
+      else
+      {
+        valid = false;
+      }
+
+      ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
     //********************************************
     explicit message_packet(etl::imessage&& msg)
-      : valid(true)
+      : data()
     {
-      add_new_message(etl::move(msg));
+      if (accepts(msg))
+      {
+        add_new_message(etl::move(msg));
+        valid = true;
+      }
+      else
+      {
+        valid = false;
+      }
+
+      ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
     //********************************************
-    template <typename TMessage, etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
-      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>>, int> = 0>
+    template <typename TMessage, typename = etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                                             !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                             !etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
       explicit message_packet(TMessage&& msg)
-      : valid(true)
+      : data()
+      , valid(true)
+    {
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
+    }
+
+    //********************************************
+    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
+    explicit message_packet(TMessage&& msg)
+      : data()
+      , valid(true)
     {
       add_new_message<TMessage>(etl::forward<TMessage>(msg));
     }
 
     //**********************************************
     message_packet(const message_packet& other)
-      : valid(other.is_valid())
+      : data()
+      , valid(other.is_valid())
     {
       if (valid)
       {
@@ -124,7 +162,8 @@ namespace etl
 
     //**********************************************
     message_packet(message_packet&& other)
-      : valid(other.is_valid())
+      : data()
+      , valid(other.is_valid())
     {
       if (valid)
       {
@@ -204,7 +243,7 @@ namespace etl
     //**********************************************
     template <typename TMessage>
     static ETL_CONSTEXPR
-      typename etl::enable_if<!etl::is_integral<TMessage>::value, bool>::type
+      typename etl::enable_if<etl::is_base_of<etl::imessage, TMessage>::value, bool>::type
       accepts()
     {
       return accepts<TMessage::ID>();
@@ -220,14 +259,14 @@ namespace etl
 
     //**********************************************
     template <etl::message_id_t Id1, etl::message_id_t Id2>
-    static ETL_CONSTEXPR bool accepts_message()
+    static bool accepts_message()
     {
       return Id1 == Id2;
     }
 
     //**********************************************
     template <etl::message_id_t Id1>
-    static ETL_CONSTEXPR bool accepts_message(etl::message_id_t id2)
+    static bool accepts_message(etl::message_id_t id2)
     {
       return Id1 == id2;
     }
@@ -242,10 +281,7 @@ namespace etl
 #if defined(ETL_MESSAGES_ARE_VIRTUAL) || defined(ETL_POLYMORPHIC_MESSAGES)
         pmsg->~imessage();
 #else
-        if (!(delete_current_message_type<TMessageTypes>(pmsg->get_message_id()) || ...))
-        {
-          ETL_ALWAYS_ASSERT(ETL_ERROR(unhandled_message_exception));
-        }
+        (delete_current_message_type<TMessageTypes>(pmsg->get_message_id()) || ...);
 #endif
       }
     }
@@ -253,29 +289,20 @@ namespace etl
     //********************************************
     void add_new_message(const etl::imessage& msg)
     {
-      if (!(add_new_message_type<TMessageTypes>(msg) || ...))
-      {
-        ETL_ALWAYS_ASSERT(ETL_ERROR(unhandled_message_exception));
-      }
+      (add_new_message_type<TMessageTypes>(msg) || ...);
     }
 
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
-      if (!(add_new_message_type<TMessageTypes>(etl::move(msg)) || ...))
-      {
-        ETL_ALWAYS_ASSERT(ETL_ERROR(unhandled_message_exception));
-      }
+      (add_new_message_type<TMessageTypes>(etl::move(msg)) || ...);
     }
 
     //********************************************
-    template <typename TMessage, etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage>, int> = 0>
+    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
     void add_new_message(TMessage&& msg)
     {
-      if (!(add_new_message_type<TMessageTypes, etl::remove_reference_t<TMessage>::ID>(etl::forward<TMessage>(msg)) || ...))
-      {
-        ETL_ALWAYS_ASSERT(ETL_ERROR(unhandled_message_exception));
-      }
+      (add_new_message_type<TMessageTypes, etl::remove_reference_t<TMessage>::ID>(etl::forward<TMessage>(msg)) || ...);
     }
 
     typename etl::aligned_storage<SIZE, ALIGNMENT>::type data;
@@ -367,16 +394,64 @@ namespace etl
 
   /*[[[cog
     import cog
-    def accepts_return(num_id):
+
+    def generate_accepts_return(n):
         cog.out("    return")
-        for i in range(1, num_id + 1):
+        for i in range(1, n + 1):
             cog.out(" T%d::ID == id" % i)
-            if i < num_id:
+            if i < n:
                 cog.out(" ||")
                 if i % 4 == 0:
                     cog.outl("")
                     cog.out("          ")
         cog.outl(";")
+
+    def generate_accepts_return_compile_time(n):
+        cog.out("    return")
+        for i in range(1, n + 1):
+            cog.out(" T%d::ID == Id" % i)
+            if i < n:
+                cog.out(" ||")
+                if i % 4 == 0:
+                    cog.outl("")
+                    cog.out("          ")
+        cog.outl(";")
+
+    def generate_accepts_return_compile_time_TMessage(n):
+        cog.outl("    ETL_CONSTANT etl::message_id_t id = TMessage::ID;")
+        cog.outl("")
+        cog.out("    return")
+        for i in range(1, n + 1):
+            cog.out(" T%d::ID == id" % i)
+            if i < n:
+                cog.out(" ||")
+                if i % 4 == 0:
+                    cog.outl("")
+                    cog.out("          ")
+        cog.outl(";")
+
+    def generate_static_assert_cpp03(n):
+        cog.outl("    // Not etl::message_packet, not etl::imessage and in typelist.")
+        cog.out("    static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<")
+        for i in range(1, n):
+            cog.out("T%d, " % i)
+        cog.outl("T%s> >::value &&" % n)
+        cog.outl("                                 !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&")
+        cog.out("                                 etl::is_one_of<typename etl::remove_reference<TMessage>::type,")
+        for i in range(1, n):
+            cog.out("T%d, " % i)
+        cog.outl("T%s>::value);" % n)      
+        cog.outl("")
+        cog.outl("    ETL_STATIC_ASSERT(Enabled, \"Message not in packet type list\");")   
+
+    def generate_static_assert_cpp11():
+        cog.outl("    // Not etl::message_packet, not etl::imessage and in typelist.")
+        cog.outl("    constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&")
+        cog.outl("                              !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&")
+        cog.outl("                              etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);")
+        cog.outl("")
+        cog.outl("    ETL_STATIC_ASSERT(Enabled, \"Message not in packet type list\");")
+
     ################################################
     # The first definition for all of the messages.
     ################################################
@@ -397,29 +472,81 @@ namespace etl
     cog.outl("")
     cog.outl("  //********************************************")
     cog.outl("  message_packet()")
-    cog.outl("    : valid(false)")
+    cog.outl("    : data()")
+    cog.outl("    , valid(false)")
     cog.outl("  {")
     cog.outl("  }")
     cog.outl("")
     cog.outl("  //********************************************")
     cog.outl("  explicit message_packet(const etl::imessage& msg)")
-    cog.outl("    : valid(true)")
+    cog.outl("    : data()")
     cog.outl("  {")
-    cog.outl("    add_new_message(msg);")
+    cog.outl("    if (accepts(msg))")
+    cog.outl("    {")
+    cog.outl("      add_new_message(msg);")
+    cog.outl("      valid = true;")
+    cog.outl("    }")
+    cog.outl("    else")
+    cog.outl("    {")
+    cog.outl("      valid = false;")
+    cog.outl("    }")
+    cog.outl("")
+    cog.outl("    ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));")
     cog.outl("  }")
     cog.outl("")
-    cog.outl("#if ETL_CPP11_SUPPORTED")
+    cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
     cog.outl("  //********************************************")
     cog.outl("  explicit message_packet(etl::imessage&& msg)")
-    cog.outl("    : valid(true)")
+    cog.outl("    : data()")
     cog.outl("  {")
-    cog.outl("    add_new_message(etl::move(msg));")
+    cog.outl("    if (accepts(msg))")
+    cog.outl("    {")
+    cog.outl("      add_new_message(etl::move(msg));")
+    cog.outl("      valid = true;")
+    cog.outl("    }")
+    cog.outl("    else")
+    cog.outl("    {")
+    cog.outl("      valid = false;")
+    cog.outl("    }")
+    cog.outl("")
+    cog.outl("    ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));")
+    cog.outl("  }")
+    cog.outl("#endif")
+    cog.outl("")
+    cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
+    cog.outl("  //********************************************")
+    cog.outl("  template <typename TMessage, typename = etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&")
+    cog.outl("                                                           !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&")
+    cog.outl("                                                           !etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageHandlers...>>")
+    cog.outl("  explicit message_packet(TMessage&& msg)")
+    cog.outl("    : data()")
+    cog.outl("    , valid(true)")
+    cog.outl("  {")
+    generate_static_assert_cpp11()
+    cog.outl("  }")
+    cog.outl("#else")
+    cog.outl("  //********************************************")
+    cog.outl("  template <typename TMessage>")
+    cog.out("  explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<")
+    for n in range(1, int(Handlers)):
+        cog.out("T%s, " % n)
+    cog.outl("T%s> >::value &&" % int(Handlers))
+    cog.outl("                                                                       !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&")
+    cog.out("                                                                       !etl::is_one_of<typename etl::remove_reference<TMessage>::type, ")
+    for n in range(1, int(Handlers)):
+        cog.out("T%s, " % n)
+    cog.outl("T%s>::value, int>::type = 0)" % int(Handlers))
+    cog.outl("    : data()")
+    cog.outl("    , valid(true)")
+    cog.outl("  {")
+    generate_static_assert_cpp03(int(Handlers))
     cog.outl("  }")
     cog.outl("#endif")
     cog.outl("")
     cog.outl("  //**********************************************")
     cog.outl("  message_packet(const message_packet& other)")
-    cog.outl("    : valid(other.is_valid())")
+    cog.outl("    : data()")
+    cog.outl("    , valid(other.is_valid())")
     cog.outl("  {")
     cog.outl("    if (valid)")
     cog.outl("    {")
@@ -427,10 +554,11 @@ namespace etl
     cog.outl("    }")
     cog.outl("  }")
     cog.outl("")
-    cog.outl("#if ETL_CPP11_SUPPORTED")
+    cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
     cog.outl("  //**********************************************")
     cog.outl("  message_packet(message_packet&& other)")
-    cog.outl("    : valid(other.is_valid())")
+    cog.outl("    : data()")
+    cog.outl("    , valid(other.is_valid())")
     cog.outl("  {")
     cog.outl("    if (valid)")
     cog.outl("    {")
@@ -452,7 +580,7 @@ namespace etl
     cog.outl("    return *this;")
     cog.outl("  }")
     cog.outl("")
-    cog.outl("#if ETL_CPP11_SUPPORTED")
+    cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
     cog.outl("  //**********************************************")
     cog.outl("  message_packet& operator =(message_packet&& rhs)")
     cog.outl("  {")
@@ -494,7 +622,7 @@ namespace etl
     cog.outl("  //**********************************************")
     cog.outl("  static ETL_CONSTEXPR bool accepts(etl::message_id_t id)")
     cog.outl("  {")
-    accepts_return(int(Handlers))
+    generate_accepts_return(int(Handlers))
     cog.outl("  }")
     cog.outl("")
     cog.outl("  //**********************************************")
@@ -507,16 +635,16 @@ namespace etl
     cog.outl("  template <etl::message_id_t Id>")
     cog.outl("  static ETL_CONSTEXPR bool accepts()")
     cog.outl("  {")
-    cog.outl("    return accepts(Id);")
+    generate_accepts_return_compile_time(int(Handlers))
     cog.outl("  }")
     cog.outl("")
     cog.outl("  //**********************************************")
     cog.outl("  template <typename TMessage>")
     cog.outl("  static ETL_CONSTEXPR")
-    cog.outl("  typename etl::enable_if<!etl::is_integral<TMessage>::value, bool>::type")
+    cog.outl("  typename etl::enable_if<etl::is_base_of<etl::imessage, TMessage>::value, bool>::type")
     cog.outl("    accepts()")
     cog.outl("  {")
-    cog.outl("    return accepts(TMessage::ID);")
+    generate_accepts_return_compile_time_TMessage(int(Handlers))
     cog.outl("  }")
     cog.outl("")  
     cog.outl("  enum")
@@ -569,7 +697,7 @@ namespace etl
     cog.outl("    }")
     cog.outl("  }")
     cog.outl("")
-    cog.outl("#if ETL_CPP11_SUPPORTED")
+    cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
     cog.outl("  //********************************************")
     cog.outl("  void add_new_message(etl::imessage&& msg)")
     cog.outl("  {")
@@ -624,29 +752,85 @@ namespace etl
         cog.outl("")
         cog.outl("  //********************************************")
         cog.outl("  message_packet()")
-        cog.outl("    : valid(false)")
+        cog.outl("    : data()")
+        cog.outl("    , valid(false)")
         cog.outl("  {")
         cog.outl("  }")
         cog.outl("")
         cog.outl("  //********************************************")
         cog.outl("  explicit message_packet(const etl::imessage& msg)")
-        cog.outl("    : valid(true)")
+        cog.outl("    : data()")
         cog.outl("  {")
-        cog.outl("    add_new_message(msg);")
+        cog.outl("    if (accepts(msg))")
+        cog.outl("    {")
+        cog.outl("      add_new_message(msg);")
+        cog.outl("      valid = true;")
+        cog.outl("    }")
+        cog.outl("    else")
+        cog.outl("    {")
+        cog.outl("      valid = false;")
+        cog.outl("    }")
+        cog.outl("")
+        cog.outl("    ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));")
         cog.outl("  }")
         cog.outl("")
-        cog.outl("#if ETL_CPP11_SUPPORTED")
+        cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
         cog.outl("  //********************************************")
         cog.outl("  explicit message_packet(etl::imessage&& msg)")
-        cog.outl("    : valid(true)")
+        cog.outl("    : data()")
         cog.outl("  {")
-        cog.outl("    add_new_message(etl::move(msg));")
+        cog.outl("    if (accepts(msg))")
+        cog.outl("    {")
+        cog.outl("      add_new_message(etl::move(msg));")
+        cog.outl("      valid = true;")
+        cog.outl("    }")
+        cog.outl("    else")
+        cog.outl("    {")
+        cog.outl("      valid = false;")
+        cog.outl("    }")
+        cog.outl("")
+        cog.outl("    ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));")
         cog.outl("  }")
         cog.outl("#endif")
         cog.outl("")
+        cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
+        cog.outl("  //********************************************")
+        cog.outl("  template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&")
+        cog.outl("                                                                    !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&")
+        cog.outl("                                                                    !etl::is_one_of_v<etl::remove_reference_t<TMessage>")
+        for t in range(1, n):
+            cog.out("T%s, " % t)
+        cog.outl("T%s>>" % n)
+        cog.outl("  explicit message_packet(TMessage&& msg)")
+        cog.outl("    : data()")
+        cog.outl("    , valid(true)")
+        cog.outl("  {")
+        generate_static_assert_cpp11()
+        cog.outl("  }")
+        cog.outl("#else")
+        cog.outl("  //********************************************")
+        cog.outl("  template <typename TMessage>")
+        cog.out("  explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<")
+        for t in range(1, n):
+            cog.out("T%s, " % t)
+        cog.outl("T%s> >::value &&" % n)
+        cog.outl("                                                                       !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&")
+        cog.out("                                                                       !etl::is_one_of<typename etl::remove_reference<TMessage>::type, ")
+        for t in range(1, n):
+            cog.out("T%s, " % t)
+        cog.outl("T%s>::value, int>::type = 0)" % n)
+        cog.outl("    : data()")
+        cog.outl("    , valid(true)")
+        cog.outl("  {")
+        generate_static_assert_cpp03(n)
+        cog.outl("  }")
+        cog.outl("#endif")
+        cog.outl("")
+        cog.outl("")
         cog.outl("  //**********************************************")
         cog.outl("  message_packet(const message_packet& other)")
-        cog.outl("    : valid(other.is_valid())")
+        cog.outl("    : data()")
+        cog.outl("    , valid(other.is_valid())")
         cog.outl("  {")
         cog.outl("    if (valid)")
         cog.outl("    {")
@@ -654,10 +838,11 @@ namespace etl
         cog.outl("    }")
         cog.outl("  }")
         cog.outl("")
-        cog.outl("#if ETL_CPP11_SUPPORTED")
+        cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
         cog.outl("  //**********************************************")
         cog.outl("  message_packet(message_packet&& other)")
-        cog.outl("    : valid(other.is_valid())")
+        cog.outl("    : data()")
+        cog.outl("    , valid(other.is_valid())")
         cog.outl("  {")
         cog.outl("    if (valid)")
         cog.outl("    {")
@@ -679,7 +864,7 @@ namespace etl
         cog.outl("    return *this;")
         cog.outl("  }")
         cog.outl("")
-        cog.outl("#if ETL_CPP11_SUPPORTED")
+        cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
         cog.outl("  //**********************************************")
         cog.outl("  message_packet& operator =(message_packet&& rhs)")
         cog.outl("  {")
@@ -721,7 +906,7 @@ namespace etl
         cog.outl("  //**********************************************")
         cog.outl("  static ETL_CONSTEXPR bool accepts(etl::message_id_t id)")
         cog.outl("  {")
-        accepts_return(n)
+        generate_accepts_return(n)
         cog.outl("  }")
         cog.outl("")
         cog.outl("  //**********************************************")
@@ -734,16 +919,16 @@ namespace etl
         cog.outl("  template <etl::message_id_t Id>")
         cog.outl("  static ETL_CONSTEXPR bool accepts()")
         cog.outl("  {")
-        cog.outl("    return accepts(Id);")
+        generate_accepts_return_compile_time(n)
         cog.outl("  }")
         cog.outl("")
         cog.outl("  //**********************************************")
         cog.outl("  template <typename TMessage>")
         cog.outl("  static ETL_CONSTEXPR")
-        cog.outl("  typename etl::enable_if<!etl::is_integral<TMessage>::value, bool>::type")
+        cog.outl("  typename etl::enable_if<etl::is_base_of<etl::imessage, TMessage>::value, bool>::type")
         cog.outl("    accepts()")
         cog.outl("  {")
-        cog.outl("    return accepts(TMessage::ID);")
+        generate_accepts_return_compile_time_TMessage(n)
         cog.outl("  }")
         cog.outl("")
         cog.outl("  enum")
@@ -792,11 +977,11 @@ namespace etl
         cog.outl("    {")
         for t in range(1, n + 1):
             cog.outl("      case T%d::ID: ::new (p) T%d(static_cast<const T%d&>(msg)); break;" %(t, t, t))
-        cog.outl("      default: ETL_ASSERT(false, ETL_ERROR(unhandled_message_exception)); break;")
+        cog.outl("      default: break;")
         cog.outl("    }")
         cog.outl("  }")
         cog.outl("")
-        cog.outl("#if ETL_CPP11_SUPPORTED")
+        cog.outl("#if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)")
         cog.outl("  //********************************************")
         cog.outl("  void add_new_message(etl::imessage&& msg)")
         cog.outl("  {")
@@ -807,7 +992,7 @@ namespace etl
         cog.outl("    {")
         for t in range(1, n + 1):
             cog.outl("      case T%d::ID: ::new (p) T%d(static_cast<T%d&&>(msg)); break;" %(t, t, t))
-        cog.outl("      default: ETL_ASSERT(false, ETL_ERROR(unhandled_message_exception)); break;")
+        cog.outl("      default: break;")
         cog.outl("    }")
         cog.outl("  }")
         cog.outl("#endif")
diff --git a/include/etl/message_packet.h b/include/etl/message_packet.h
index d486c215..6d6bc007 100644
--- a/include/etl/message_packet.h
+++ b/include/etl/message_packet.h
@@ -113,20 +113,25 @@ namespace etl
     }
 
     //********************************************
-    template <typename TMessage, etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
-                                                  !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
-                                                  !etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int> = 0>
-    explicit message_packet(TMessage&& msg)
+    template <typename TMessage, typename = etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                                             !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                             !etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
+      explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      ETL_STATIC_ASSERT(false, "Unsupported message type");
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
 
     //********************************************
-    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int> = 0>
+    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
     explicit message_packet(TMessage&& msg)
-      : data() 
+      : data()
       , valid(true)
     {
       add_new_message<TMessage>(etl::forward<TMessage>(msg));
@@ -282,7 +287,7 @@ namespace etl
     }
 
     //********************************************
-    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int> = 0>
+    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>, int>>
     void add_new_message(TMessage&& msg)
     {
       (add_new_message_type<TMessageTypes, etl::remove_reference_t<TMessage>::ID>(etl::forward<TMessage>(msg)) || ...);
@@ -410,7 +415,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -429,46 +434,40 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::value, int>::type = 0>
+    template <typename TMessage, typename = etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                             !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                             !etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageHandlers...>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::value, int>::type Dummy = 0)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::value, int>::type = 0)
       : data()
       , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
-    //********************************************
-    template <typename TMessage, etl::enable_if_t<!etl::is_same<etl::remove_reference_t<TMessage>, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>::value &&
-                                                  !etl::is_same<etl::remove_reference_t<TMessage>, etl::imessage>::value &&
-                                                  !etl::is_one_of<etl::remove_reference_t<TMessage>, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::value, int> = 0>
-      explicit message_packet(const TMessage& msg)
-      : data()
-      , valid(true)
-    {
-      ETL_STATIC_ASSERT(false, "Unsupported message type");
-    }
-
-    //********************************************
-    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>, int> = 0>
-    explicit message_packet(const TMessage& msg)
-      : data()
-      , valid(true)
-    {
-      add_new_message<TMessage>(etl::forward<TMessage>(msg));
-    }
-
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -480,7 +479,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -506,7 +505,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -656,7 +655,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -725,7 +724,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -744,44 +743,41 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
-    //********************************************
-    template <typename TMessage, etl::enable_if_t<!etl::is_same<etl::remove_reference_t<TMessage>, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>>::value &&
-                                                  !etl::is_same<etl::remove_reference_t<TMessage>, etl::imessage>::value &&
-                                                  !etl::is_one_of<etl::remove_reference_t<TMessage>, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>::value, int> = 0>
-      explicit message_packet(const TMessage& msg)
-      : data()
-      , valid(true)
-    {
-      ETL_STATIC_ASSERT(false, "Unsupported message type");
-    }
-
-    //********************************************
-    template <typename TMessage, etl::enable_if_t<etl::is_one_of_v<etl::remove_reference_t<TMessage>, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>, int> = 0>
-    explicit message_packet(const TMessage& msg)
-      : data()
-      , valid(true)
-    {
-      add_new_message<TMessage>(etl::forward<TMessage>(msg));
-    }
 
     //**********************************************
     message_packet(const message_packet& other)
@@ -794,7 +790,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -820,7 +816,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -968,7 +964,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -1036,7 +1032,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -1055,25 +1051,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -1085,7 +1098,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -1111,7 +1124,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -1257,7 +1270,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -1324,7 +1337,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -1343,25 +1356,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -1373,7 +1403,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -1399,7 +1429,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -1543,7 +1573,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -1608,7 +1638,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -1627,25 +1657,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -1657,7 +1704,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -1683,7 +1730,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -1822,7 +1869,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -1886,7 +1933,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -1905,25 +1952,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -1935,7 +1999,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -1961,7 +2025,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -2098,7 +2162,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -2161,7 +2225,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -2180,25 +2244,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -2210,7 +2291,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -2236,7 +2317,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -2371,7 +2452,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -2433,7 +2514,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -2452,25 +2533,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8, T9>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8, T9>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8, T9> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8, T9>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -2482,7 +2580,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -2508,7 +2606,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -2641,7 +2739,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -2701,7 +2799,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -2720,25 +2818,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7, T8>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7, T8>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7, T8> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7, T8>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -2750,7 +2865,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -2776,7 +2891,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -2904,7 +3019,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -2963,7 +3078,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -2982,25 +3097,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6, T7>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6, T7>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6, T7> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6, T7>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -3012,7 +3144,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -3038,7 +3170,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -3164,7 +3296,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -3222,7 +3354,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -3241,25 +3373,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5, T6>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5, T6>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5, T6> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5, T6>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -3271,7 +3420,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -3297,7 +3446,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -3421,7 +3570,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -3478,7 +3627,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -3497,25 +3646,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4, T5>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4, T5>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4, T5> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4, T5>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -3527,7 +3693,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -3553,7 +3719,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -3675,7 +3841,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -3730,7 +3896,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -3749,25 +3915,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3, T4>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3, T4>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3, T4> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3, T4>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -3779,7 +3962,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -3805,7 +3988,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -3922,7 +4105,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -3976,7 +4159,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -3995,25 +4178,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2, T3>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2, T3>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2, T3> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2, T3>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -4025,7 +4225,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -4051,7 +4251,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -4166,7 +4366,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -4219,7 +4419,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -4238,25 +4438,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1, T2>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1, T2>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1, T2> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1, T2>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -4268,7 +4485,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -4294,7 +4511,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -4407,7 +4624,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
@@ -4459,7 +4676,7 @@ namespace etl
       ETL_ASSERT(valid, ETL_ERROR(unhandled_message_exception));
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     explicit message_packet(etl::imessage&& msg)
       : data()
@@ -4478,25 +4695,42 @@ namespace etl
     }
   #endif
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
-    template <typename TMessage, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1>::value, int>::type = 0>
+    template <typename TMessage, typename = typename etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageHandlers...>> &&
+                                                                      !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                                                      !etl::is_one_of_v<etl::remove_reference_t<TMessage>
+  T1>>
     explicit message_packet(TMessage&& msg)
       : data()
       , valid(true)
     {
-      add_new_message(etl::forward<TMessage>(msg));
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      constexpr bool Enabled = (!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>> &&
+                                !etl::is_same_v<etl::remove_reference_t<TMessage>, etl::imessage> &&
+                                etl::is_one_of_v<etl::remove_reference_t<TMessage>, TMessageTypes...>);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #else
     //********************************************
     template <typename TMessage>
-    explicit message_packet(const TMessage& msg, typename etl::enable_if<etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1>::value, int>::type Dummy = 0)
-      : valid(true)
+    explicit message_packet(const TMessage& msg, typename etl::enable_if<!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1> >::value &&
+                                                                         !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                                                         !etl::is_one_of<typename etl::remove_reference<TMessage>::type, T1>::value, int>::type = 0)
+      : data()
+      , valid(true)
     {
-      add_new_message(msg);
+      // Not etl::message_packet, not etl::imessage and in typelist.
+      static const bool Enabled = (!etl::is_same<typename etl::remove_reference<TMessage>::type, etl::message_packet<T1> >::value &&
+                                   !etl::is_same<typename etl::remove_reference<TMessage>::type, etl::imessage>::value &&
+                                   etl::is_one_of<typename etl::remove_reference<TMessage>::type,T1>::value);
+
+      ETL_STATIC_ASSERT(Enabled, "Message not in packet type list");
     }
   #endif
 
+
     //**********************************************
     message_packet(const message_packet& other)
       : data()
@@ -4508,7 +4742,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet(message_packet&& other)
       : data()
@@ -4534,7 +4768,7 @@ namespace etl
       return *this;
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //**********************************************
     message_packet& operator =(message_packet&& rhs)
     {
@@ -4645,7 +4879,7 @@ namespace etl
       }
     }
 
-  #if ETL_CPP11_SUPPORTED
+  #if ETL_CPP11_SUPPORTED && !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //********************************************
     void add_new_message(etl::imessage&& msg)
     {
diff --git a/test/test_message_packet.cpp b/test/test_message_packet.cpp
index 75ac200e..029b4bce 100644
--- a/test/test_message_packet.cpp
+++ b/test/test_message_packet.cpp
@@ -197,6 +197,9 @@ namespace
       Packet packet2(message2);
       Packet packet3(message3);
 
+      // Should causes a static assert.
+      //Packet packet4(message4);
+
       CHECK_EQUAL(MESSAGE1, packet1.get().get_message_id());
       CHECK_EQUAL(MESSAGE2, packet2.get().get_message_id());
       CHECK_EQUAL(MESSAGE3, packet3.get().get_message_id());
@@ -214,6 +217,7 @@ namespace
       CHECK_EQUAL("3", static_cast<Message3&>(packet3.get()).x);
     }
 
+#if !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //*************************************************************************
     TEST(message_packet_move_construction)
     {
@@ -235,6 +239,7 @@ namespace
       CHECK_EQUAL(1, static_cast<Message1&>(packet1.get()).x);
       CHECK_EQUAL(2.2, static_cast<Message2&>(packet2.get()).x);
     }
+#endif
 
     //*************************************************************************
     TEST(message_constant_packet_construction)
@@ -302,6 +307,7 @@ namespace
       CHECK_EQUAL(1, static_cast<Message1&>(packet2.get()).x);
     }
 
+#if !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //*************************************************************************
     TEST(message_packet_move_consructor)
     {
@@ -323,6 +329,7 @@ namespace
       CHECK_EQUAL(1, static_cast<Message1&>(packet1.get()).x);
       CHECK_EQUAL(1, static_cast<Message1&>(packet2.get()).x);
     }
+#endif
 
     //*************************************************************************
     TEST(message_packet_assignment)
@@ -348,6 +355,7 @@ namespace
       CHECK_EQUAL(1, static_cast<Message1&>(packet2.get()).x);
     }
 
+#if !defined(ETL_MESSAGE_PACKET_FORCE_CPP03_IMPLEMENTATION)
     //*************************************************************************
     TEST(message_packet_move_assignment)
     {
@@ -371,6 +379,7 @@ namespace
       CHECK_EQUAL(1, static_cast<Message1&>(packet1.get()).x);
       CHECK_EQUAL(1, static_cast<Message1&>(packet2.get()).x);
     }
+#endif
 
     //*************************************************************************
     TEST(message_packet_accepts)