check packet size by static_assert (#2830)

Author: salix5

gframe/duelclient.h

@@ -55,8 +55,7 @@ class DuelClient {
 	template<typename ST>
 	static void SendPacketToServer(unsigned char proto, const ST& st) {
 		auto p = duel_client_write;
-		if (sizeof(ST) > MAX_DATA_SIZE)
-			return;
+		static_assert(sizeof(ST) <= MAX_DATA_SIZE, "Packet size is too large.");
 		buffer_write<uint16_t>(p, (uint16_t)(1 + sizeof(ST)));
 		buffer_write<uint8_t>(p, proto);
 		std::memcpy(p, &st, sizeof(ST));

gframe/netserver.h

@@ -43,8 +43,7 @@ class NetServer {
 	template<typename ST>
 	static void SendPacketToPlayer(DuelPlayer* dp, unsigned char proto, const ST& st) {
 		auto p = net_server_write;
-		if (sizeof(ST) > MAX_DATA_SIZE)
-			return;
+		static_assert(sizeof(ST) <= MAX_DATA_SIZE, "Packet size is too large.");
 		buffer_write<uint16_t>(p, (uint16_t)(1 + sizeof(ST)));
 		buffer_write<uint8_t>(p, proto);
 		std::memcpy(p, &st, sizeof(ST));