anycall.cpp

anycall.cpp

		template <typename Handler, typename Request, typename Reply>
		class type_erasure_handler
		{
		public:
			type_erasure_handler(Handler&& handler)
				: handler_(std::forward<Handler>(handler))
			{}
			~type_erasure_handler()
			{}

			static void true_func_call(std::any handler,
				const ::google::protobuf::Message& req, ::google::protobuf::Message& ret)
			{
				auto this_object = std::any_cast<type_erasure_handler<Handler, Request, Reply>>(handler);
				this_object.handler_(
					static_cast<const Request&>(req), static_cast<Reply&>(ret));
			}

			Handler handler_;
		};

		typedef void(*type_erasure_call_function)(std::any handler,
			const ::google::protobuf::Message& req, ::google::protobuf::Message& ret);
      
    type_erasure_call_function func_call_;
		std::any handler_;
    
    handler_ = type_erasure_handler<Handler, Request, Reply>(std::forward<Handler>(handler));
		func_call_ = type_erasure_handler<Handler, Request, Reply>::true_func_call;
    
    func_call_(handler_, *msg, *ret);