...

net/adc_net_concepts.h

@@ -47,6 +47,20 @@ using adc_common_duration_t = adc_duration_common_type_t<std::chrono::nanosecond
                                                          std::chrono::months,
                                                          std::chrono::years>;
 
+// concepts for asynchronous opereration callback callable first argument type (asynchronous operation error)
+//      1) the type must be convertible to boolean and
+//         a) true - asynchronous operation completed without errors
+//         b) false - an error occured
+template <typename ERRT>
+concept adc_async_callback_err_t = std::convertible_to<std::remove_cvref_t<ERRT>, bool>;
+
+// concepts for asynchronous opereration callback callable
+//      1) the type must be a callable with at least 1 input argument
+//      2) the first argument type must satisfy the concept adc_async_callback_err_t
+template <typename T>
+concept adc_async_callback_t = traits::adc_is_callable<T> && traits::adc_func_traits<T>::arity &&
+                               adc_async_callback_err_t<traits::adc_func_arg1_t<T>>;
+
 /*
     struct NetService {
         typedef ImplementationDependentT netservice_ident_t;