receive_policy must provide an invalid_msg_do_what method

chat_networking.hpp

@@ -171,6 +171,8 @@ namespace chat
                                  receive_policy::logout_do_what
                                          (chat_message(message::LOGOUT, content));
                                  break;
+                             default:
+                                 receive_policy::invalid_msg_do_what(msg);
                          }
 
                          for (auto& fun : _subscriptions)               // notify subscribers

check_policy.hpp

@@ -10,7 +10,8 @@
  *      - static void handshake_do_what(chat_message)
  *      - static void serverdirection_do_what(chat_message)
  *      - static void login_do_what(chat_message)
- *      - static void logout_do_what(chat_message)                                   */
+ *      - static void logout_do_what(chat_message)
+ *      - static void invalid_msg_do_what(chat_message)                               */
 template <class PolicyCandidate, typename = void>
 struct is_valid_receive_policy : std::false_type {};
 
@@ -48,6 +49,12 @@ struct is_valid_receive_policy<
                                  ::logout_do_what(std::declval<chat::chat_message>())),
                         void
                 >::value
+                &&
+                std::is_same<
+                        decltype(PolicyCandidate
+                                 ::invalid_msg_do_what(std::declval<chat::chat_message>())),
+                        void
+                >::value
         >::type>
 : std::true_type {};
 

commandline_chat.cpp

@@ -1,5 +1,6 @@
 #include <iostream>
 #include <thread>
+#include <stdexcept>
 #include "chat_networking.hpp"
 
 
@@ -20,6 +21,9 @@ struct receive_policy_stdout
 
     static void logout_do_what(const chat::chat_message& msg)
     { std::cout << msg.get_content() << " kilépett.\n"; }
+
+    static void invalid_msg_do_what(const chat::chat_message& msg)
+    { throw std::runtime_error("Invalid message received!"); }
 };
 
 struct send_policy_stdout
@@ -45,7 +49,6 @@ int main()
     chat::client_network_manager<receive_policy_stdout, send_policy_stdout> cnm(ios, epit, "BATMAN");
     std::thread t([&ios]{ ios.run(); });
 
-
     std::string input;
     while (true)
     {