简化头文件结构

Author: cyanray

include/FriendMessage.h

@@ -10,9 +10,6 @@
 #include <functional>
 #include <nlohmann/json.hpp>
 #include "typedef.hpp"
-#include "FriendMessage.h"
-#include "GroupMessage.h"
-#include "message_chain.hpp"
 using std::string;
 using std::runtime_error;
 using std::vector;

include/GroupMessage.h

@@ -14,7 +14,10 @@ namespace Cyan
 		Serializable() {}
 		virtual bool Set(const json& json) = 0;
 		virtual json ToJson() const = 0;
-		virtual string ToString() const = 0;
+		virtual string ToString() const
+		{
+			return ToJson().dump();
+		}
 		virtual ~Serializable() {}
 	};