From 8e13ad0c3cf9802931250d1aa57c68eb394add14 Mon Sep 17 00:00:00 2001
From: "Timur A. Fatkhullin" <timur@sao.ru>
Date: Fri, 1 Nov 2024 17:26:52 +0300
Subject: [PATCH] ...

---
 device/adc_device.h               |  26 ++--
 device/adc_device_attribute.h     | 222 +++++++++++++-----------------
 device/adc_device_concepts.h      |  12 +-
 net/adc_device_netserver.h        |   4 +-
 tests/adc_asio_netserver_test.cpp |  18 ++-
 5 files changed, 128 insertions(+), 154 deletions(-)

diff --git a/device/adc_device.h b/device/adc_device.h
index 7aac2f2..c48da6d 100644
--- a/device/adc_device.h
+++ b/device/adc_device.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <algorithm>
+#include <memory>
 #include <ranges>
 #include <system_error>
 #include <unordered_map>
@@ -100,7 +101,8 @@ public:
         auto it = _deviceCommands.find(cmd_ident);
 
         if (it != _deviceCommands.end()) {
-            it->second();
+            // it->second();
+            it->second->operator()();
         } else {
             throw std::system_error(AdcGenericDeviceErrorCode::ERROR_COMMAND_IDENT);
         }
@@ -113,7 +115,8 @@ public:
     {
         auto it = _deviceAttributes.find(attr_ident);
         if (it != _deviceAttributes.end()) {
-            return it->second;
+            // return it->second;
+            return *(it->second);
         }
 
         throw std::system_error(AdcGenericDeviceErrorCode::ERROR_ATTR_IDENT);
@@ -122,7 +125,8 @@ public:
 
     AdcGenericDevice& addCommand(CommandT&& cmd)
     {
-        _deviceCommands.insert({cmd.ident(), std::move(cmd)});
+        // _deviceCommands.insert({cmd.ident(), std::move(cmd)});
+        _deviceCommands.insert({cmd.ident(), std::make_unique<CommandT>(std::move(cmd))});
 
         return *this;
     }
@@ -131,10 +135,7 @@ public:
     template <typename... CtorArgTs>
     AdcGenericDevice& addCommand(CtorArgTs&&... ctor_args)
     {
-        // _deviceCommands.emplace(std::forward<CtorArgTs>(ctor_args)...);
         return addCommand({std::forward<CtorArgTs>(ctor_args)...});
-
-        // return *this;
     }
 
     AdcGenericDevice& delCommand(const cmd_ident_t& cmd_ident)
@@ -147,7 +148,8 @@ public:
 
     AdcGenericDevice& addAttribute(AttributeT&& attr)
     {
-        _deviceAttributes.insert({attr.ident(), std::move(attr)});
+        // _deviceAttributes.insert({attr.ident(), std::move(attr)});
+        _deviceAttributes.insert({attr.ident(), std::make_unique<AttributeT>(std::move(attr))});
 
         return *this;
     }
@@ -155,11 +157,7 @@ public:
     template <typename... CtorArgTs>
     AdcGenericDevice& addAttribute(CtorArgTs&&... ctor_args)
     {
-        // _deviceAttributes.emplace(std::forward<CtorArgTs>(ctor_args)...);
-
         return addAttribute({std::forward<CtorArgTs>(ctor_args)...});
-
-        // return *this;
     }
 
 
@@ -190,8 +188,10 @@ public:
 protected:
     IdentT _ident;
 
-    std::unordered_map<attr_ident_t, AttributeT> _deviceAttributes;
-    std::unordered_map<cmd_ident_t, CommandT> _deviceCommands;
+    // std::unordered_map<attr_ident_t, AttributeT> _deviceAttributes;
+    // std::unordered_map<cmd_ident_t, CommandT> _deviceCommands;
+    std::unordered_map<attr_ident_t, std::unique_ptr<AttributeT>> _deviceAttributes;
+    std::unordered_map<cmd_ident_t, std::unique_ptr<CommandT>> _deviceCommands;
 };
 
 }  // namespace adc
diff --git a/device/adc_device_attribute.h b/device/adc_device_attribute.h
index 393dc1a..c16422b 100644
--- a/device/adc_device_attribute.h
+++ b/device/adc_device_attribute.h
@@ -187,9 +187,11 @@ inline std::error_code make_error_code(AdcDeviceAttributeErrorCode ec)
 
 
 
-template <typename IdentT>
+template <typename IdentT = std::string, typename SerializedT = std::vector<char>>
 class AdcDeviceAttribute
 {
+    static_assert(!std::is_null_pointer_v<SerializedT>, "Deduced serialized type must not be std::nullptr_t!!!");
+
 protected:
     template <typename T>
     using ret_value_t = std::decay_t<traits::adc_retval_t<T>>;
@@ -200,12 +202,9 @@ protected:
     template <typename VT>
     inline static std::unordered_map<const AdcDeviceAttribute*, std::function<void(const VT&)>> _setterFunc{};
 
-    template <typename SerializedT>
-    inline static std::unordered_map<const AdcDeviceAttribute*, std::function<SerializedT()>> _serializerFunc{};
+    std::function<SerializedT()> _serializerFunc;
 
-    template <typename SerializedT>
-    inline static std::unordered_map<const AdcDeviceAttribute*, std::function<void(const SerializedT&)>>
-        _deserializerFunc{};
+    std::function<void(const SerializedT&)> _deserializerFunc;
 
     std::function<void()> _clearFunc;
 
@@ -213,10 +212,18 @@ protected:
     std::function<void(AdcDeviceAttribute*)> _moveFunc;
 
 
+    template <typename VT>
+    struct ValueHolder {
+        std::function<VT()> _getterFunc;
+        std::function<void(const VT&)> _setterFunc;
+
+        // std::unordered_map<const AdcDeviceAttribute*>
+    };
+
 public:
     typedef IdentT ident_t;
 
-    typedef std::string default_serialized_t;
+    typedef SerializedT serialized_t;
 
     enum AccessType { ReadOnly, WriteOnly, ReadWrite };
 
@@ -227,21 +234,18 @@ public:
               traits::adc_attr_setter_c ST,
               typename ValueT = traits::attr_value_t<GT, ST>,
               traits::adc_serializer_c<ValueT> SRT =
-                  decltype(utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>),
+                  decltype(utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>),
               traits::adc_deserializer_c<ValueT> DSRT =
-                  decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>)>
-    AdcDeviceAttribute(
-        const IdentT& ident,
-        GT&& getter,
-        ST&& setter,
-        SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>,
-        DSRT&& deserializer = utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>)
+                  decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)>
+    AdcDeviceAttribute(const IdentT& ident,
+                       GT&& getter,
+                       ST&& setter,
+                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>,
+                       DSRT&& deserializer = utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)
         : _ident(ident), _accessType(AdcDeviceAttribute::ReadWrite)
     {
         static_assert(!std::is_null_pointer_v<ValueT>, "Getter and Setter can not be nullptr simultaneously!!!");
 
-        using SerializedT = traits::adc_attr_serialized_t<SRT, DSRT>;
-        static_assert(!std::is_null_pointer_v<SerializedT>, "Deduced serialized type must not be std::nullptr_t!!!");
 
         _getterFunc<ValueT>.emplace(this, std::forward<GT>(getter));
         _setterFunc<ValueT>.emplace(this, std::forward<ST>(setter));
@@ -255,8 +259,7 @@ public:
         }
 
         if constexpr (!std::is_null_pointer_v<GT> && !std::is_null_pointer_v<SRT>) {
-            _serializerFunc<SerializedT>[this] = [wrapper = traits::adc_pf_wrapper(std::forward<SRT>(serializer)),
-                                                  this]() {
+            _serializerFunc = [wrapper = traits::adc_pf_wrapper(std::forward<SRT>(serializer)), this]() {
                 auto& serializer = std::get<0>(wrapper);
 
 
@@ -268,8 +271,8 @@ public:
 
 
         if constexpr (!std::is_null_pointer_v<ST> && !std::is_null_pointer_v<DSRT>) {
-            _deserializerFunc<SerializedT>[this] = [wrapper = traits::adc_pf_wrapper(std::forward<DSRT>(deserializer)),
-                                                    this](const SerializedT& sval) {
+            _deserializerFunc = [wrapper = traits::adc_pf_wrapper(std::forward<DSRT>(deserializer)),
+                                 this](const SerializedT& sval) {
                 auto& deserializer = std::get<0>(wrapper);
 
                 ValueT val = deserializer(sval);
@@ -281,9 +284,6 @@ public:
         _clearFunc = [this]() {
             _getterFunc<ValueT>.erase(this);
             _setterFunc<ValueT>.erase(this);
-
-            _serializerFunc<SerializedT>.erase(this);
-            _deserializerFunc<SerializedT>.erase(this);
         };
 
 
@@ -292,16 +292,10 @@ public:
             _getterFunc<ValueT>.emplace(other, _getterFunc<ValueT>[this]);
             _setterFunc<ValueT>.emplace(other, _setterFunc<ValueT>[this]);
 
-            _serializerFunc<SerializedT>.emplace(other, _serializerFunc<SerializedT>[this]);
-            _deserializerFunc<SerializedT>.emplace(other, _deserializerFunc<SerializedT>[this]);
-
             // define copy-function for newly constructed object
             other->_copyFunc = [other](AdcDeviceAttribute* o_next) {
                 _getterFunc<ValueT>.emplace(o_next, _getterFunc<ValueT>[other]);
                 _setterFunc<ValueT>.emplace(o_next, _setterFunc<ValueT>[other]);
-
-                _serializerFunc<SerializedT>.emplace(o_next, _serializerFunc<SerializedT>[other]);
-                _deserializerFunc<SerializedT>.emplace(o_next, _deserializerFunc<SerializedT>[other]);
             };
         };
 
@@ -311,16 +305,10 @@ public:
             _getterFunc<ValueT>.emplace(other, std::move(_getterFunc<ValueT>[this]));
             _setterFunc<ValueT>.emplace(other, std::move(_setterFunc<ValueT>[this]));
 
-            _serializerFunc<SerializedT>.emplace(other, std::move(_serializerFunc<SerializedT>[this]));
-            _deserializerFunc<SerializedT>.emplace(other, std::move(_deserializerFunc<SerializedT>[this]));
-
             // define move-function for newly constructed object
             other->_moveFunc = [other](AdcDeviceAttribute* o_next) {
                 _getterFunc<ValueT>.emplace(o_next, std::move(_getterFunc<ValueT>[other]));
                 _setterFunc<ValueT>.emplace(o_next, std::move(_setterFunc<ValueT>[other]));
-
-                _serializerFunc<SerializedT>.emplace(o_next, std::move(_serializerFunc<SerializedT>[other]));
-                _deserializerFunc<SerializedT>.emplace(o_next, std::move(_deserializerFunc<SerializedT>[other]));
             };
         };
     }
@@ -331,16 +319,15 @@ public:
               traits::adc_attr_setter_c ST,
               typename ValueT = traits::attr_value_t<GT, ST>,
               traits::adc_serializer_c<ValueT> SRT =
-                  decltype(utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>),
+                  decltype(utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>),
               traits::adc_deserializer_c<ValueT> DSRT =
-                  decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>)>
-    AdcDeviceAttribute(
-        const IdentT& ident,
-        TupleT&&,
-        GT&& getter,
-        ST&& setter,
-        SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>,
-        DSRT&& deserializer = utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>)
+                  decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)>
+    AdcDeviceAttribute(const IdentT& ident,
+                       TupleT&&,
+                       GT&& getter,
+                       ST&& setter,
+                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>,
+                       DSRT&& deserializer = utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)
         : AdcDeviceAttribute(ident,
                              std::forward<GT>(getter),
                              std::forward<ST>(setter),
@@ -357,11 +344,10 @@ public:
     template <std::invocable GT,
               typename ValueT = ret_value_t<GT>,
               traits::adc_serializer_c<ValueT> SRT =
-                  decltype(utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>),
-              typename SerializedT = ret_value_t<SRT>>
+                  decltype(utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>)>
     AdcDeviceAttribute(const IdentT& ident,
                        GT&& getter,
-                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>)
+                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>)
         : AdcDeviceAttribute(ident, std::forward<GT>(getter), nullptr, std::forward<SRT>(serializer), nullptr)
     {
     }
@@ -371,12 +357,11 @@ public:
               std::invocable GT,
               typename ValueT = ret_value_t<GT>,
               traits::adc_serializer_c<ValueT> SRT =
-                  decltype(utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>),
-              typename SerializedT = ret_value_t<SRT>>
+                  decltype(utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>)>
     AdcDeviceAttribute(const IdentT& ident,
                        TupleT&&,
                        GT&& getter,
-                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<default_serialized_t, ValueT>)
+                       SRT&& serializer = utils::AdcDefaultValueConverter<>::serialize<serialized_t, ValueT>)
         : AdcDeviceAttribute(ident, TupleT{}, std::forward<GT>(getter), nullptr, std::forward<SRT>(serializer), nullptr)
     {
     }
@@ -385,8 +370,7 @@ public:
     // write-only attribute constructor
     template <traits::adc_attr_setter_c ST,
               typename ValueT = std::decay_t<traits::adc_func_arg1_t<ST>>,
-              typename DSRT = decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>),
-              typename SerializedT = std::decay_t<traits::adc_func_arg1_t<DSRT>>>
+              typename DSRT = decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)>
     AdcDeviceAttribute(const IdentT& ident,
                        ST&& setter,
                        DSRT&& deserializer = utils::AdcDefaultValueConverter<>::deserialize<ValueT, SerializedT>)
@@ -398,8 +382,7 @@ public:
     template <traits::adc_tuple_like TupleT,
               traits::adc_attr_setter_c ST,
               typename ValueT = std::decay_t<traits::adc_func_arg1_t<ST>>,
-              typename DSRT = decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, default_serialized_t>),
-              typename SerializedT = std::decay_t<traits::adc_func_arg1_t<DSRT>>>
+              typename DSRT = decltype(utils::AdcDefaultValueConverter<>::deserialize<ValueT, serialized_t>)>
     AdcDeviceAttribute(const IdentT& ident,
                        TupleT&&,
                        ST&& setter,
@@ -416,28 +399,22 @@ public:
 
     AdcDeviceAttribute(const AdcDeviceAttribute& other)
     {
-        // _clearFunc();
-
         if (&other != this) {
             other._copyFunc(this);
-        }
 
-        // _clearFunc = other._clearFunc;
-        // _copyFunc = other._copyFunc;
-        // _moveFunc = other._moveFunc;
+            _serializerFunc = other._serializerFunc;
+            _deserializerFunc = other._deserializerFunc;
+        }
     }
 
     AdcDeviceAttribute(AdcDeviceAttribute&& other)
     {
         if (&other != this) {
             other._moveFunc(this);
+
+            _serializerFunc = std::move(other._serializerFunc);
+            _deserializerFunc = std::move(other._deserializerFunc);
         }
-
-        // other._clearFunc();
-
-        // _clearFunc = std::move(other._clearFunc);
-        // _copyFunc = std::move(other._copyFunc);
-        // _moveFunc = std::move(other._moveFunc);
     }
 
 
@@ -516,6 +493,15 @@ public:
 
             _getterFunc<user_t>.emplace(other, _getterFunc<user_t>[this]);
             _setterFunc<user_t>.emplace(other, _setterFunc<user_t>[this]);
+
+            // redefine copy-function for newly constructed instance
+            // other._copyFunc was defined in the 'prev_copy(other)' call above
+            other->_moveFunc = [other, copy_f = other->_copyFunc](AdcDeviceAttribute* o_next) {
+                copy_f(o_next);
+
+                _getterFunc<user_t>.emplace(o_next, _getterFunc<user_t>[other]);
+                _setterFunc<user_t>.emplace(o_next, _setterFunc<user_t>[other]);
+            };
         };
 
         // move TO other
@@ -524,6 +510,15 @@ public:
 
             _getterFunc<user_t>.emplace(other, std::move(_getterFunc<user_t>[this]));
             _setterFunc<user_t>.emplace(other, std::move(_setterFunc<user_t>[this]));
+
+            // redefine move-function for newly constructed instance
+            // other._moveFunc was defined in the 'prev_move(other)' call above
+            other->_moveFunc = [other, move_f = other->_moveFunc](AdcDeviceAttribute* o_next) {
+                move_f(o_next);
+
+                _getterFunc<user_t>.emplace(o_next, std::move(_getterFunc<user_t>[other]));
+                _setterFunc<user_t>.emplace(o_next, std::move(_setterFunc<user_t>[other]));
+            };
         };
 
         return *this;
@@ -543,13 +538,6 @@ public:
         } catch (const std::out_of_range&) {
             throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_CONV_FUNC);
         }
-
-        // auto& getter = _getterFunc<val_t>[this];
-        // if (getter) {
-        //     return getter();
-        // }
-
-        // throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_CONV_FUNC);
     }
 
     template <typename UT>
@@ -567,13 +555,6 @@ public:
             throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_CONV_FUNC);
         }
 
-        // auto& setter = _setterFunc<val_t>[this];
-        // if (setter) {
-        //     setter(std::forward<UT>(val));
-        // } else {
-        //     throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_CONV_FUNC);
-        // }
-
         return *this;
     }
 
@@ -581,13 +562,10 @@ public:
     AdcDeviceAttribute& operator=(const AdcDeviceAttribute& other)
     {
         if (&other != this) {
-            // _clearFunc();
-
             other._copyFunc(this);
 
-            // _clearFunc = other._clearFunc;
-            // _copyFunc = other._copyFunc;
-            // _moveFunc = other._moveFunc;
+            _serializerFunc = other._serializerFunc;
+            _deserializerFunc = other._deserializerFunc;
         }
 
         return *this;
@@ -597,73 +575,61 @@ public:
     AdcDeviceAttribute& operator=(AdcDeviceAttribute&& other)
     {
         if (&other != this) {
-            // _clearFunc();
-
             other._moveFunc(this);
 
-            // _clearFunc = std::move(other._clearFunc);
-            // _copyFunc = std::move(other._copyFunc);
-            // _moveFunc = std::move(other._moveFunc);
+            _serializerFunc = std::move(other._serializerFunc);
+            _deserializerFunc = std::move(other._deserializerFunc);
         }
 
         return *this;
     }
 
-    template <typename SerializedT>
-    SerializedT serialize()
+    serialized_t serialize()
     {
         if (_accessType == AdcDeviceAttribute::WriteOnly) {
             throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_WRITE_ONLY);
         }
 
-        using s_t = std::decay_t<SerializedT>;
-
-        try {
-            _serializerFunc<s_t>.at(this)();
-        } catch (const std::out_of_range&) {
-            throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_INVALID_SERIALIZED_TYPE);
-        } catch (const std::bad_function_call&) {  // serializer was not defined in ctor!
-            throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_SERIALIZER);
-        }
-
-        // auto& serializer = _serializerFunc<s_t>[this];
-
-        // if (serializer) {
-        //     return serializer();
-        // }
-
-        // throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_INVALID_SERIALIZED_TYPE);
+        return _serializerFunc();
     }
 
-    default_serialized_t serialize()
+    template <typename ST>
+        requires(!std::convertible_to<serialized_t, std::decay_t<ST>>)
+    ST serialize()
     {
-        return serialize<default_serialized_t>();
+        using s_t = std::decay_t<ST>;
+
+        if constexpr (traits::adc_output_char_range<s_t> && traits::adc_output_char_range<serialized_t>) {
+            s_t res;
+            std::ranges::copy(serialize(), std::back_inserter(res));
+        } else {
+            static_assert(false, "INVALID USER SERIALIZATION TYPE!");
+        }
     }
 
-    template <typename SerializedT>
-    AdcDeviceAttribute& deserialize(const SerializedT& sval)
+    AdcDeviceAttribute& deserialize(const serialized_t& sval)
     {
         if (_accessType == AdcDeviceAttribute::ReadOnly) {
             throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_READ_ONLY);
         }
 
-        using s_t = std::decay_t<SerializedT>;
+        _deserializerFunc(sval);
 
-        try {
-            _deserializerFunc<s_t>.at(this)(sval);
-        } catch (const std::out_of_range&) {
-            throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_INVALID_SERIALIZED_TYPE);
-        } catch (const std::bad_function_call&) {  // deserializer was not defined in ctor!
-            throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_NO_DESERIALIZER);
+        return *this;
+    }
+
+    template <typename ST>
+        requires(!std::convertible_to<std::decay_t<ST>, serialized_t>)
+    AdcDeviceAttribute& deserialize(const ST& sval)
+    {
+        using s_t = std::decay_t<ST>;
+
+        if constexpr (traits::adc_input_char_range<s_t> && traits::adc_input_char_range<serialized_t>) {
+            _deserializerFunc(serialized_t(sval.begin(), sval.end()));
+        } else {
+            static_assert(false, "INVALID USER SERIALIZATION TYPE!");
         }
 
-        // auto& deserializer = _deserializerFunc<s_t>[this];
-        // if (deserializer) {
-        //     deserializer(sval);
-        // } else {
-        //     throw std::system_error(AdcDeviceAttributeErrorCode::ERROR_INVALID_SERIALIZED_TYPE);
-        // }
-
         return *this;
     }
 
diff --git a/device/adc_device_concepts.h b/device/adc_device_concepts.h
index 02743e6..34716f4 100644
--- a/device/adc_device_concepts.h
+++ b/device/adc_device_concepts.h
@@ -7,21 +7,21 @@ namespace adc::interfaces
 
 // ADC device attribute concept
 template <typename T>
-concept adc_device_attr_c = requires(T t, const T const_t) {
+concept adc_device_attr_c = std::movable<T> && requires(T t, const T const_t) {
     typename T::ident_t;
-    typename T::default_serialized_t;
+    typename T::serialized_t;
 
     { const_t.ident() } -> std::same_as<typename T::ident_t>;
 
-    // serializer and desiarializer must return/accept at least a value of type T::default_serialized_t
-    { t.serialize() } -> std::convertible_to<typename T::default_serialized_t>;
-    t.deserialize(std::declval<typename T::default_serialized_t>());
+    // serializer and deserializer must return/accept at least a value of type T::serialized_t
+    { t.serialize() } -> std::convertible_to<typename T::serialized_t>;
+    t.deserialize(std::declval<typename T::serialized_t>());
 };
 
 
 // ADC device command concept
 template <typename T>
-concept adc_device_cmd_c = requires(T t, const T const_t) {
+concept adc_device_cmd_c = std::movable<T> && requires(T t, const T const_t) {
     typename T::ident_t;
 
     { const_t.ident() } -> std::same_as<typename T::ident_t>;
diff --git a/net/adc_device_netserver.h b/net/adc_device_netserver.h
index 761ee29..d9f8613 100644
--- a/net/adc_device_netserver.h
+++ b/net/adc_device_netserver.h
@@ -159,6 +159,8 @@ protected:
             _get_attr = [dev_ptr, wrapper = traits::adc_pf_wrapper(std::forward<AttrIdDeserialT>(attr_id_deser_func))](
                             const auto& attr_name) mutable {
                 auto attr_id = std::get<0>(wrapper)(attr_name);
+                // auto attr = (*dev_ptr)[attr_id];
+                // auto val = attr.serialize();
                 auto val = (*dev_ptr)[attr_id].serialize();
                 using val_t = std::remove_cvref_t<decltype(val)>;
 
@@ -316,7 +318,7 @@ public:
                             }
                         }
                         if (found) {
-                            msg.ack();
+                            msg.ack(attrs);
                         } else {
                             msg.err(std::make_error_code(AdcDeviceNetServerSessionError::ERROR_UNKNOWN_DEVICE_ID));
                         }
diff --git a/tests/adc_asio_netserver_test.cpp b/tests/adc_asio_netserver_test.cpp
index e3761ea..6ac6070 100644
--- a/tests/adc_asio_netserver_test.cpp
+++ b/tests/adc_asio_netserver_test.cpp
@@ -8,12 +8,16 @@
 #include "../net/adc_netproto.h"
 #include "../net/asio/adc_device_netserver_asio.h"
 
+typedef adc::impl::AdcDeviceNetServerASIO server_t;
+
 
 class Device1 : public adc::AdcGenericDevice<std::string,
-                                             adc::AdcDeviceAttribute<std::string>,
+                                             adc::AdcDeviceAttribute<std::string, server_t::serialized_t>,
                                              adc::AdcDeviceCommand<std::string>>
 {
-    typedef adc::AdcGenericDevice<std::string, adc::AdcDeviceAttribute<std::string>, adc::AdcDeviceCommand<std::string>>
+    typedef adc::AdcGenericDevice<std::string,
+                                  adc::AdcDeviceAttribute<std::string, server_t::serialized_t>,
+                                  adc::AdcDeviceCommand<std::string>>
         base_t;
 
 public:
@@ -23,10 +27,13 @@ public:
     }
 };
 
-class Device2
-    : public adc::AdcGenericDevice<std::string, adc::AdcDeviceAttribute<size_t>, adc::AdcDeviceCommand<std::string>>
+class Device2 : public adc::AdcGenericDevice<std::string,
+                                             adc::AdcDeviceAttribute<size_t, server_t::serialized_t>,
+                                             adc::AdcDeviceCommand<std::string>>
 {
-    typedef adc::AdcGenericDevice<std::string, adc::AdcDeviceAttribute<size_t>, adc::AdcDeviceCommand<std::string>>
+    typedef adc::AdcGenericDevice<std::string,
+                                  adc::AdcDeviceAttribute<size_t, server_t::serialized_t>,
+                                  adc::AdcDeviceCommand<std::string>>
         base_t;
 
 public:
@@ -106,7 +113,6 @@ int main(int argc, char* argv[])
         asio::signal_set signals(io_ctx, SIGINT, SIGTERM);
         signals.async_wait([&](std::error_code, int) { io_ctx.stop(); });
 
-        using server_t = adc::impl::AdcDeviceNetServerASIO;
         adc::impl::AdcDeviceNetServerASIO server("TEST SRV", io_ctx);
         server.setupSignals();