diff --git a/cxx/mcc_finite_state_machine.h b/cxx/mcc_finite_state_machine.h
index 15df69e..4d9ab7c 100644
--- a/cxx/mcc_finite_state_machine.h
+++ b/cxx/mcc_finite_state_machine.h
@@ -73,8 +73,6 @@ inline std::error_code make_error_code(MccFiniteStateMachineErrorCode ec)
     return std::error_code(static_cast<int>(ec), MccFiniteStateMachineCategory::get());
 }
 
-
-
 namespace traits
 {
 
@@ -82,8 +80,7 @@ namespace traits
     The only requirement to Event-class is public-accepted static constant 'ID'
  */
 template <typename T>
-concept fsm_event_c = std::is_default_constructible_v<T> && std::is_move_constructible_v<T> && std::movable<T> &&
-                      requires { requires std::same_as<const std::string_view, decltype(T::ID)>; };
+concept fsm_event_c = requires { requires std::same_as<const std::string_view, decltype(T::ID)>; };
 
 
 /*
@@ -91,11 +88,10 @@ concept fsm_event_c = std::is_default_constructible_v<T> && std::is_move_constru
     definition of type transition_table_t
  */
 template <typename T>
-concept fsm_state_c =
-    std::is_default_constructible_v<T> && std::is_move_constructible_v<T> && std::movable<T> && requires {
-        requires std::same_as<const std::string_view, decltype(T::ID)>;
-        typename T::transition_t;
-    };
+concept fsm_state_c = std::is_default_constructible_v<T> && requires {
+    requires std::same_as<const std::string_view, decltype(T::ID)>;
+    typename T::transition_t;
+};
 
 
 // concept for std::pair
@@ -282,42 +278,6 @@ protected:
     using variant_from_tuple_t = typename variant_from_tuple<TplT>::variant_t;
 
 
-    // call given function for all event-types in the given std::tuple
-    template <traits::fsm_tuple_of_events_c EvTplT, typename FT, size_t... Is>
-    static void for_each_event(FT&& func, std::index_sequence<Is...>)
-    {
-        (func(std::get<Is>(EvTplT{})), ...);
-    };
-
-    template <traits::fsm_tuple_of_events_c EvTplT, typename FT>
-    static void for_each_event(FT&& func)
-    {
-        for_each_event<EvTplT>(std::forward<FT>(func), std::make_index_sequence<std::tuple_size_v<EvTplT>>());
-    };
-
-
-
-    template <traits::fsm_state_c StT, typename FT>
-    static void for_each_event_in_each_state(FT&& func)
-    {
-        for_each_event<typename StT::transition_t::events_t>(std::forward<FT>(func));
-    }
-
-
-    template <typename StTplT, typename FT, size_t... Is>
-    static void for_each_event_in_each_state(FT&& func, std::index_sequence<Is...>)
-    {
-        (for_each_event_in_each_state<std::tuple_element_t<Is, StTplT>>(std::forward<FT>(func)), ...);
-    }
-
-    template <typename StTplT, typename FT>
-    static void for_each_event_in_each_state(FT&& func)
-    {
-        for_each_event_in_each_state<StTplT>(std::forward<FT>(func),
-                                             std::make_index_sequence<std::tuple_size_v<StTplT>>());
-    }
-
-
     // check if given event-type is in std::tuple of event-types
     template <traits::fsm_event_c EvT, typename EvTplT>
     struct in_tuple;
@@ -344,38 +304,6 @@ protected:
     std::mutex _transitionMutex;
 
 
-    template <traits::fsm_tuple_of_events_c EvTplT, typename FT, size_t... Is>
-    void setupInstanceFuncs(FT&& func, std::index_sequence<Is...>)
-    {
-        (_dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>.emplace(this, func), ...);
-
-        (_moveFunc.emplace_back([](MccFiniteStateMachine* from, MccFiniteStateMachine* to) {
-            _dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>[to] =
-                std::move(_dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>[from]);
-        }),
-         ...);
-
-        (_copyFunc.emplace_back([](const MccFiniteStateMachine* from, MccFiniteStateMachine* to) {
-            _dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>[to] =
-                _dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>[from];
-        }),
-         ...);
-
-        (_destroyFunc.emplace_back([](const MccFiniteStateMachine* inst) {
-            //
-            _dispatchEventFunc<std::tuple_element_t<Is, EvTplT>>.erase(inst);
-        }),
-         ...);
-
-        (_eventID.emplace_back(std::tuple_element_t<Is, EvTplT>::ID), ...);
-    };
-
-    template <traits::fsm_tuple_of_events_c EvTplT, typename FT>
-    void setupInstanceFuncs(FT&& func)
-    {
-        setupInstanceFuncs<EvTplT>(std::forward<FT>(func), std::make_index_sequence<std::tuple_size_v<EvTplT>>());
-    };
-
     static MccFiniteStateMachine& copyInstance(const MccFiniteStateMachine* from, MccFiniteStateMachine* to)
     {
         if (from != to) {
@@ -451,119 +379,6 @@ public:
 
         using all_events_t = deduce_events_t<InitStateT>;
 
-        /*
-        for_each_event<all_events_t>([this]<traits::fsm_event_c EvT>(EvT) { _eventID.emplace_back(EvT::ID); });
-
-        for_each_event<all_events_t>([states, currentState, this]<traits::fsm_event_c EvT>(EvT) mutable {
-            if constexpr (!in_tuple_v<EvT, all_events_t>) {
-                throw std::system_error(MccFiniteStateMachineErrorCode::ERROR_UNREGISTERED_EVENT_TYPE);
-            }
-
-            _dispatchEventFunc<EvT>[this] = [states, currentState, this](EvT& event) mutable {
-                std::lock_guard lock(_transitionMutex);
-
-                std::visit(
-                    [&event, states, currentState, this]<traits::fsm_state_c curr_state_t>(curr_state_t*) {
-                        using to_state_t = curr_state_t::transition_t::template find_state_by_event_t<EvT>;
-                        if constexpr (!std::is_void_v<to_state_t>) {
-                            // exit from current
-                            if constexpr (requires(curr_state_t inst) {
-                                              { inst.exit(std::declval<EvT&>()) };
-                                          }) {
-                                std::get<curr_state_t>(*states).exit(event);
-                            } else if constexpr (requires(curr_state_t inst) {
-                                                     { inst.exit() };
-                                                 }) {
-                                std::get<curr_state_t>(*states).exit();
-                            }
-
-                            // transit ...
-                            if constexpr (requires(EvT inst) {
-                                              { inst.onTransit() };
-                                          }) {
-                                event.onTransit();
-                            }
-
-                            *currentState = &std::get<to_state_t>(*states);
-                            _currentStateID = to_state_t::ID;
-
-                            // enter to new
-                            if constexpr (requires(to_state_t inst) {
-                                              { inst.enter(std::declval<EvT&>()) };
-                                          }) {
-                                std::get<to_state_t>(*states).enter(event);
-                            } else if constexpr (requires(to_state_t inst) {
-                                                     { inst.enter() };
-                                                 }) {
-                                std::get<to_state_t>(*states).enter();
-                            }
-                        } else {
-                            throw std::system_error(MccFiniteStateMachineErrorCode::ERROR_UNHANDLED_TRANSITION);
-                        }
-                    },
-                    *currentState);
-            };
-
-            _moveFunc.emplace_back([](MccFiniteStateMachine* from, MccFiniteStateMachine* to) {
-                _dispatchEventFunc<EvT>[to] = std::move(_dispatchEventFunc<EvT>[from]);
-            });
-            _copyFunc.emplace_back([](const MccFiniteStateMachine* from, MccFiniteStateMachine* to) {
-                _dispatchEventFunc<EvT>[to] = _dispatchEventFunc<EvT>[from];
-            });
-            _destroyFunc.emplace_back([](const MccFiniteStateMachine* inst) {
-                //
-                _dispatchEventFunc<EvT>.erase(inst);
-            });
-        });
-
-
-
-        setupInstanceFuncs<all_events_t>([states, currentState, this]<traits::fsm_event_c EvT>(EvT& event) mutable {
-            std::lock_guard lock(_transitionMutex);
-
-            std::visit(
-                [&event, states, currentState, this]<traits::fsm_state_c curr_state_t>(curr_state_t*) {
-                    using to_state_t = curr_state_t::transition_t::template find_state_by_event_t<EvT>;
-                    if constexpr (!std::is_void_v<to_state_t>) {
-                        // exit from current
-                        if constexpr (requires(curr_state_t inst) {
-                                          { inst.exit(std::declval<EvT&>()) };
-                                      }) {
-                            std::get<curr_state_t>(*states).exit(event);
-                        } else if constexpr (requires(curr_state_t inst) {
-                                                 { inst.exit() };
-                                             }) {
-                            std::get<curr_state_t>(*states).exit();
-                        }
-
-                        // transit ...
-                        if constexpr (requires(EvT inst) {
-                                          { inst.onTransit() };
-                                      }) {
-                            event.onTransit();
-                        }
-
-                        *currentState = &std::get<to_state_t>(*states);
-                        _currentStateID = to_state_t::ID;
-
-                        // enter to new
-                        if constexpr (requires(to_state_t inst) {
-                                          { inst.enter(std::declval<EvT&>()) };
-                                      }) {
-                            std::get<to_state_t>(*states).enter(event);
-                        } else if constexpr (requires(to_state_t inst) {
-                                                 { inst.enter() };
-                                             }) {
-                            std::get<to_state_t>(*states).enter();
-                        }
-                    } else {
-                        throw std::system_error(MccFiniteStateMachineErrorCode::ERROR_UNHANDLED_TRANSITION);
-                    }
-                },
-                *currentState);
-        });
-        */
-
         [states, currentState, this]<size_t... Is>(std::index_sequence<Is...>) {
             ((_dispatchEventFunc<std::tuple_element_t<Is, all_events_t>>[this] =
                   [states, currentState, this]<traits::fsm_event_c EvT>(EvT& event) mutable {
@@ -625,7 +440,6 @@ public:
              ...);
 
             (_destroyFunc.emplace_back([](const MccFiniteStateMachine* inst) {
-                //
                 _dispatchEventFunc<std::tuple_element_t<Is, all_events_t>>.erase(inst);
             }),
              ...);
@@ -675,6 +489,7 @@ public:
 
     template <traits::fsm_event_c EvT>
     auto dispatchEvent()
+        requires std::default_initializable<EvT>
     {
         static EvT event;
         return dispatchEvent(event);