Code modernization: subfolders (#6283)

* Code modernization: subfolders

Modernize various code on subfolders client, network, script, threading, unittests, util

* empty function
* default constructor/destructor
* for range-based loops
* use emplace_back instead of push_back
* C++ STL header style
* Make connection.cpp readable in a pointed place + typo

src/client/tile.cpp

@@ -484,12 +484,11 @@ u32 TextureSource::getTextureId(const std::string &name)
 	/*
 		Get texture
 	*/
-	if (std::this_thread::get_id() == m_main_thread)
-	{
+	if (std::this_thread::get_id() == m_main_thread) {
 		return generateTexture(name);
 	}
-	else
-	{
+
+
 	infostream<<"getTextureId(): Queued: name=\""<<name<<"\""<<std::endl;
 
 	// We're gonna ask the result to be put into here
@@ -498,11 +497,7 @@ u32 TextureSource::getTextureId(const std::string &name)
 	// Throw a request in
 	m_get_texture_queue.add(name, 0, 0, &result_queue);
 
-		/*infostream<<"Waiting for texture from main thread, name=\""
-				<<name<<"\""<<std::endl;*/
-
-		try
-		{
+	try {
 		while(true) {
 			// Wait result for a second
 			GetResult<std::string, u32, u8, u8>
@@ -512,13 +507,10 @@ u32 TextureSource::getTextureId(const std::string &name)
 				return result.item;
 			}
 		}
-		}
-		catch(ItemNotFoundException &e)
-		{
+	} catch(ItemNotFoundException &e) {
 		errorstream << "Waiting for texture " << name << " timed out." << std::endl;
 		return 0;
 	}
-	}
 
 	infostream << "getTextureId(): Failed" << std::endl;
 
@@ -673,7 +665,7 @@ Palette* TextureSource::getPalette(const std::string &name)
 	// Only the main thread may load images
 	sanity_check(std::this_thread::get_id() == m_main_thread);
 
-	if (name == "")
+	if (name.empty())
 		return NULL;
 
 	auto it = m_palettes.find(name);

src/client/tile.h

@@ -237,6 +237,8 @@ struct TileLayer
 		case TILE_MATERIAL_LIQUID_TRANSPARENT:
 			material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
 			break;
+		default:
+			break;
 		}
 		material.BackfaceCulling = (material_flags & MATERIAL_FLAG_BACKFACE_CULLING) != 0;
 		if (!(material_flags & MATERIAL_FLAG_TILEABLE_HORIZONTAL)) {
@@ -304,8 +306,8 @@ struct TileLayer
 struct TileSpec
 {
 	TileSpec() {
-		for (int layer = 0; layer < MAX_TILE_LAYERS; layer++)
-			layers[layer] = TileLayer();
+		for (auto &layer : layers)
+			layer = TileLayer();
 	}
 
 	/*!

src/network/clientpackethandler.cpp

@@ -221,7 +221,7 @@ void Client::handleCommand_AccessDenied(NetworkPacket* pkt)
 		if (denyCode == SERVER_ACCESSDENIED_SHUTDOWN ||
 				denyCode == SERVER_ACCESSDENIED_CRASH) {
 			*pkt >> m_access_denied_reason;
-			if (m_access_denied_reason == "") {
+			if (m_access_denied_reason.empty()) {
 				m_access_denied_reason = accessDeniedStrings[denyCode];
 			}
 			u8 reconnect;
@@ -237,7 +237,7 @@ void Client::handleCommand_AccessDenied(NetworkPacket* pkt)
 			// Until then (which may be never), this is outside
 			// of the defined protocol.
 			*pkt >> m_access_denied_reason;
-			if (m_access_denied_reason == "") {
+			if (m_access_denied_reason.empty()) {
 				m_access_denied_reason = "Unknown";
 			}
 		}
@@ -683,7 +683,7 @@ void Client::handleCommand_AnnounceMedia(NetworkPacket* pkt)
 		Strfnd sf(str);
 		while(!sf.at_end()) {
 			std::string baseurl = trim(sf.next(","));
-			if (baseurl != "")
+			if (!baseurl.empty())
 				m_media_downloader->addRemoteServer(baseurl);
 		}
 	}
@@ -1213,7 +1213,7 @@ void Client::handleCommand_HudSetParam(NetworkPacket* pkt)
 	}
 	else if (param == HUD_PARAM_HOTBAR_IMAGE) {
 		// If value not empty verify image exists in texture source
-		if (value != "" && !getTextureSource()->isKnownSourceImage(value)) {
+		if (!value.empty() && !getTextureSource()->isKnownSourceImage(value)) {
 			errorstream << "Server sent wrong Hud hotbar image (sent value: '"
 				<< value << "')" << std::endl;
 			return;
@@ -1222,7 +1222,7 @@ void Client::handleCommand_HudSetParam(NetworkPacket* pkt)
 	}
 	else if (param == HUD_PARAM_HOTBAR_SELECTED_IMAGE) {
 		// If value not empty verify image exists in texture source
-		if (value != "" && !getTextureSource()->isKnownSourceImage(value)) {
+		if (!value.empty() && !getTextureSource()->isKnownSourceImage(value)) {
 			errorstream << "Server sent wrong Hud hotbar selected image (sent value: '"
 					<< value << "')" << std::endl;
 			return;

src/network/connection.cpp

@@ -18,7 +18,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 #include <iomanip>
-#include <errno.h>
+#include <cerrno>
 #include "connection.h"
 #include "serialization.h"
 #include "log.h"
@@ -151,11 +151,9 @@ std::list<SharedBuffer<u8> > makeSplitPacket(
 	}
 	while(end != data.getSize() - 1);
 
-	for(std::list<SharedBuffer<u8> >::iterator i = chunks.begin();
-		i != chunks.end(); ++i)
-	{
+	for (SharedBuffer<u8> &chunk : chunks) {
 		// Write chunk_count
-		writeU16(&((*i)[3]), chunk_count);
+		writeU16(&(chunk[3]), chunk_count);
 	}
 
 	return chunks;
@@ -174,15 +172,13 @@ std::list<SharedBuffer<u8> > makeAutoSplitPacket(
 		split_seqnum++;
 		return list;
 	}
-	else
-	{
+
 	list.push_back(makeOriginalPacket(data));
-	}
 	return list;
 }
 
 SharedBuffer<u8> makeReliablePacket(
-		SharedBuffer<u8> data,
+		const SharedBuffer<u8> &data,
 		u16 seqnum)
 {
 	u32 header_size = 3;
@@ -206,11 +202,8 @@ void ReliablePacketBuffer::print()
 	MutexAutoLock listlock(m_list_mutex);
 	LOG(dout_con<<"Dump of ReliablePacketBuffer:" << std::endl);
 	unsigned int index = 0;
-	for(std::list<BufferedPacket>::iterator i = m_list.begin();
-		i != m_list.end();
-		++i)
-	{
-		u16 s = readU16(&(i->data[BASE_HEADER_SIZE+1]));
+	for (BufferedPacket &bufferedPacket : m_list) {
+		u16 s = readU16(&(bufferedPacket.data[BASE_HEADER_SIZE+1]));
 		LOG(dout_con<<index<< ":" << s << std::endl);
 		index++;
 	}
@@ -406,11 +399,9 @@ void ReliablePacketBuffer::insert(BufferedPacket &p,u16 next_expected)
 void ReliablePacketBuffer::incrementTimeouts(float dtime)
 {
 	MutexAutoLock listlock(m_list_mutex);
-	for(std::list<BufferedPacket>::iterator i = m_list.begin();
-		i != m_list.end(); ++i)
-	{
-		i->time += dtime;
-		i->totaltime += dtime;
+	for (BufferedPacket &bufferedPacket : m_list) {
+		bufferedPacket.time += dtime;
+		bufferedPacket.totaltime += dtime;
 	}
 }
 
@@ -419,14 +410,12 @@ std::list<BufferedPacket> ReliablePacketBuffer::getTimedOuts(float timeout,
 {
 	MutexAutoLock listlock(m_list_mutex);
 	std::list<BufferedPacket> timed_outs;
-	for(std::list<BufferedPacket>::iterator i = m_list.begin();
-		i != m_list.end(); ++i)
-	{
-		if (i->time >= timeout) {
-			timed_outs.push_back(*i);
+	for (BufferedPacket &bufferedPacket : m_list) {
+		if (bufferedPacket.time >= timeout) {
+			timed_outs.push_back(bufferedPacket);
 
 			//this packet will be sent right afterwards reset timeout here
-			i->time = 0.0;
+			bufferedPacket.time = 0.0f;
 			if (timed_outs.size() >= max_packets)
 				break;
 		}
@@ -441,10 +430,8 @@ std::list<BufferedPacket> ReliablePacketBuffer::getTimedOuts(float timeout,
 IncomingSplitBuffer::~IncomingSplitBuffer()
 {
 	MutexAutoLock listlock(m_map_mutex);
-	for(std::map<u16, IncomingSplitPacket*>::iterator i = m_buf.begin();
-		i != m_buf.end(); ++i)
-	{
-		delete i->second;
+	for (auto &i : m_buf) {
+		delete i.second;
 	}
 }
 /*
@@ -506,15 +493,13 @@ SharedBuffer<u8> IncomingSplitBuffer::insert(BufferedPacket &p, bool reliable)
 	sp->chunks[chunk_num] = chunkdata;
 
 	// If not all chunks are received, return empty buffer
-	if (sp->allReceived() == false)
+	if (!sp->allReceived())
 		return SharedBuffer<u8>();
 
 	// Calculate total size
 	u32 totalsize = 0;
-	for(std::map<u16, SharedBuffer<u8> >::iterator i = sp->chunks.begin();
-		i != sp->chunks.end(); ++i)
-	{
-		totalsize += i->second.getSize();
+	for (const auto &chunk : sp->chunks) {
+		totalsize += chunk.second.getSize();
 	}
 
 	SharedBuffer<u8> fulldata(totalsize);
@@ -541,25 +526,21 @@ void IncomingSplitBuffer::removeUnreliableTimedOuts(float dtime, float timeout)
 	std::list<u16> remove_queue;
 	{
 		MutexAutoLock listlock(m_map_mutex);
-		for(std::map<u16, IncomingSplitPacket*>::iterator i = m_buf.begin();
-			i != m_buf.end(); ++i)
-		{
-			IncomingSplitPacket *p = i->second;
+		for (auto &i : m_buf) {
+			IncomingSplitPacket *p = i.second;
 			// Reliable ones are not removed by timeout
-			if (p->reliable == true)
+			if (p->reliable)
 				continue;
 			p->time += dtime;
 			if (p->time >= timeout)
-				remove_queue.push_back(i->first);
+				remove_queue.push_back(i.first);
 		}
 	}
-	for(std::list<u16>::iterator j = remove_queue.begin();
-		j != remove_queue.end(); ++j)
-	{
+	for (u16 j : remove_queue) {
 		MutexAutoLock listlock(m_map_mutex);
 		LOG(dout_con<<"NOTE: Removing timed out unreliable split packet"<<std::endl);
-		delete m_buf[*j];
-		m_buf.erase(*j);
+		delete m_buf[j];
+		m_buf.erase(j);
 	}
 }
 
@@ -929,7 +910,7 @@ void Peer::RTTStatistics(float rtt, const std::string &profiler_id,
 			m_rtt.jitter_avg  = m_rtt.jitter_avg * (num_samples/(num_samples-1)) +
 								jitter * (1/num_samples);
 
-		if (profiler_id != "") {
+		if (!profiler_id.empty()) {
 			g_profiler->graphAdd(profiler_id + "_rtt", rtt);
 			g_profiler->graphAdd(profiler_id + "_jitter", jitter);
 		}
@@ -1071,7 +1052,7 @@ bool UDPPeer::processReliableSendCommand(
 
 	if (c.raw)
 	{
-		originals.push_back(c.data);
+		originals.emplace_back(c.data);
 	}
 	else {
 		originals = makeAutoSplitPacket(c.data, chunksize_max,split_sequence_number);
@@ -1083,9 +1064,7 @@ bool UDPPeer::processReliableSendCommand(
 	std::queue<BufferedPacket> toadd;
 	volatile u16 initial_sequence_number = 0;
 
-	for(std::list<SharedBuffer<u8> >::iterator i = originals.begin();
-		i != originals.end(); ++i)
-	{
+	for (SharedBuffer<u8> &original : originals) {
 		u16 seqnum = channels[c.channelnum].getOutgoingSequenceNumber(have_sequence_number);
 
 		/* oops, we don't have enough sequence numbers to send this packet */
@@ -1098,7 +1077,7 @@ bool UDPPeer::processReliableSendCommand(
 			have_initial_sequence_number = true;
 		}
 
-		SharedBuffer<u8> reliable = makeReliablePacket(*i, seqnum);
+		SharedBuffer<u8> reliable = makeReliablePacket(original, seqnum);
 
 		// Add base headers and make a packet
 		BufferedPacket p = con::makePacket(address, reliable,
@@ -1110,7 +1089,7 @@ bool UDPPeer::processReliableSendCommand(
 
 	if (have_sequence_number) {
 		volatile u16 pcount = 0;
-		while(toadd.size() > 0) {
+		while (!toadd.empty()) {
 			BufferedPacket p = toadd.front();
 			toadd.pop();
 //			LOG(dout_con<<connection->getDesc()
@@ -1124,14 +1103,14 @@ bool UDPPeer::processReliableSendCommand(
 		sanity_check(channels[c.channelnum].queued_reliables.size() < 0xFFFF);
 		return true;
 	}
-	else {
+
 	volatile u16 packets_available = toadd.size();
 	/* we didn't get a single sequence number no need to fill queue */
-		if (!have_initial_sequence_number)
-		{
+	if (!have_initial_sequence_number) {
 		return false;
 	}
-		while(toadd.size() > 0) {
+
+	while (!toadd.empty()) {
 		/* remove packet */
 		toadd.pop();
 
@@ -1141,6 +1120,7 @@ bool UDPPeer::processReliableSendCommand(
 
 		FATAL_ERROR_IF(!successfully_put_back_sequence_number, "error");
 	}
+
 	LOG(dout_con<<m_connection->getDesc()
 			<< " Windowsize exceeded on reliable sending "
 			<< c.data.getSize() << " bytes"
@@ -1151,9 +1131,9 @@ bool UDPPeer::processReliableSendCommand(
 			<< std::endl << "\t\tpackets queued         : "
 			<< channels[c.channelnum].outgoing_reliables_sent.size()
 			<< std::endl);
+
 	return false;
 }
-}
 
 void UDPPeer::RunCommandQueues(
 							unsigned int max_packet_size,
@@ -1161,21 +1141,21 @@ void UDPPeer::RunCommandQueues(
 							unsigned int maxtransfer)
 {
 
-	for (unsigned int i = 0; i < CHANNEL_COUNT; i++) {
+	for (Channel &channel : channels) {
 		unsigned int commands_processed = 0;
 
-		if ((channels[i].queued_commands.size() > 0) &&
-				(channels[i].queued_reliables.size() < maxtransfer) &&
+		if ((!channel.queued_commands.empty()) &&
+				(channel.queued_reliables.size() < maxtransfer) &&
 				(commands_processed < maxcommands)) {
 			try {
-				ConnectionCommand c = channels[i].queued_commands.front();
+				ConnectionCommand c = channel.queued_commands.front();
 
 				LOG(dout_con << m_connection->getDesc()
 						<< " processing queued reliable command " << std::endl);
 
 				// Packet is processed, remove it from queue
 				if (processReliableSendCommand(c,max_packet_size)) {
-					channels[i].queued_commands.pop_front();
+					channel.queued_commands.pop_front();
 				} else {
 					LOG(dout_con << m_connection->getDesc()
 							<< " Failed to queue packets for peer_id: " << c.peer_id
@@ -1291,10 +1271,8 @@ bool ConnectionSendThread::packetsQueued()
 	if (!m_outgoing_queue.empty() && !peerIds.empty())
 		return true;
 
-	for(std::list<u16>::iterator j = peerIds.begin();
-			j != peerIds.end(); ++j)
-	{
-		PeerHelper peer = m_connection->getPeerNoEx(*j);
+	for (u16 peerId : peerIds) {
+		PeerHelper peer = m_connection->getPeerNoEx(peerId);
 
 		if (!peer)
 			continue;
@@ -1302,10 +1280,8 @@ bool ConnectionSendThread::packetsQueued()
 		if (dynamic_cast<UDPPeer*>(&peer) == 0)
 			continue;
 
-		for(u16 i=0; i < CHANNEL_COUNT; i++) {
-			Channel *channel = &(dynamic_cast<UDPPeer*>(&peer))->channels[i];
-
-			if (channel->queued_commands.size() > 0) {
+		for (Channel &channel : (dynamic_cast<UDPPeer *>(&peer))->channels) {
+			if (channel.queued_commands.size() > 0) {
 				return true;
 			}
 		}
@@ -1320,10 +1296,8 @@ void ConnectionSendThread::runTimeouts(float dtime)
 	std::list<u16> timeouted_peers;
 	std::list<u16> peerIds = m_connection->getPeerIDs();
 
-	for(std::list<u16>::iterator j = peerIds.begin();
-		j != peerIds.end(); ++j)
-	{
-		PeerHelper peer = m_connection->getPeerNoEx(*j);
+	for (u16 &peerId : peerIds) {
+		PeerHelper peer = m_connection->getPeerNoEx(peerId);
 
 		if (!peer)
 			continue;
@@ -1333,7 +1307,7 @@ void ConnectionSendThread::runTimeouts(float dtime)
 
 		PROFILE(std::stringstream peerIdentifier);
 		PROFILE(peerIdentifier << "runTimeouts[" << m_connection->getDesc()
-				<< ";" << *j << ";RELIABLE]");
+				<< ";" << peerId << ";RELIABLE]");
 		PROFILE(ScopeProfiler peerprofiler(g_profiler, peerIdentifier.str(), SPT_AVG));
 
 		SharedBuffer<u8> data(2); // data for sending ping, required here because of goto
@@ -1356,19 +1330,17 @@ void ConnectionSendThread::runTimeouts(float dtime)
 
 		float resend_timeout = dynamic_cast<UDPPeer*>(&peer)->getResendTimeout();
 		bool retry_count_exceeded = false;
-		for(u16 i=0; i<CHANNEL_COUNT; i++)
-		{
+		for (Channel &channel : (dynamic_cast<UDPPeer *>(&peer))->channels) {
 			std::list<BufferedPacket> timed_outs;
-			Channel *channel = &(dynamic_cast<UDPPeer*>(&peer))->channels[i];
 
 			if (dynamic_cast<UDPPeer*>(&peer)->getLegacyPeer())
-				channel->setWindowSize(g_settings->getU16("workaround_window_size"));
+				channel.setWindowSize(g_settings->getU16("workaround_window_size"));
 
 			// Remove timed out incomplete unreliable split packets
-			channel->incoming_splits.removeUnreliableTimedOuts(dtime, m_timeout);
+			channel.incoming_splits.removeUnreliableTimedOuts(dtime, m_timeout);
 
 			// Increment reliable packet times
-			channel->outgoing_reliables_sent.incrementTimeouts(dtime);
+			channel.outgoing_reliables_sent.incrementTimeouts(dtime);
 
 			unsigned int numpeers = m_connection->m_peers.size();
 
@@ -1376,11 +1348,10 @@ void ConnectionSendThread::runTimeouts(float dtime)
 				return;
 
 			// Re-send timed out outgoing reliables
-			timed_outs = channel->
-					outgoing_reliables_sent.getTimedOuts(resend_timeout,
+			timed_outs = channel.outgoing_reliables_sent.getTimedOuts(resend_timeout,
 					(m_max_data_packets_per_iteration/numpeers));
 
-			channel->UpdatePacketLossCounter(timed_outs.size());
+			channel.UpdatePacketLossCounter(timed_outs.size());
 			g_profiler->graphAdd("packets_lost", timed_outs.size());
 
 			m_iteration_packets_avaialble -= timed_outs.size();
@@ -1392,7 +1363,7 @@ void ConnectionSendThread::runTimeouts(float dtime)
 				u8 channelnum  = readChannel(*(k->data));
 				u16 seqnum  = readU16(&(k->data[BASE_HEADER_SIZE+1]));
 
-				channel->UpdateBytesLost(k->data.getSize());
+				channel.UpdateBytesLost(k->data.getSize());
 				k->resend_count++;
 
 				if (k-> resend_count > MAX_RELIABLE_RETRY) {
@@ -1421,7 +1392,7 @@ void ConnectionSendThread::runTimeouts(float dtime)
 				break; /* no need to check other channels if we already did timeout */
 			}
 
-			channel->UpdateTimers(dtime,dynamic_cast<UDPPeer*>(&peer)->getLegacyPeer());
+			channel.UpdateTimers(dtime,dynamic_cast<UDPPeer*>(&peer)->getLegacyPeer());
 		}
 
 		/* skip to next peer if we did timeout */
@@ -1447,12 +1418,10 @@ void ConnectionSendThread::runTimeouts(float dtime)
 	}
 
 	// Remove timed out peers
-	for(std::list<u16>::iterator i = timeouted_peers.begin();
-		i != timeouted_peers.end(); ++i)
-	{
+	for (u16 timeouted_peer : timeouted_peers) {
 		LOG(derr_con << m_connection->getDesc()
-				<<"RunTimeouts(): Removing peer "<<(*i)<<std::endl);
-		m_connection->deletePeer(*i, true);
+				<< "RunTimeouts(): Removing peer "<< timeouted_peer <<std::endl);
+		m_connection->deletePeer(timeouted_peer, true);
 	}
 }
 
@@ -1532,7 +1501,7 @@ bool ConnectionSendThread::rawSendAsPacket(u16 peer_id, u8 channelnum,
 			sendAsPacketReliable(p,channel);
 			return true;
 		}
-		else {
+
 		LOG(dout_con<<m_connection->getDesc()
 				<<" INFO: queueing reliable packet for peer_id: " << peer_id
 				<<" channel: " << channelnum
@@ -1540,13 +1509,9 @@ bool ConnectionSendThread::rawSendAsPacket(u16 peer_id, u8 channelnum,
 		channel->queued_reliables.push(p);
 		return false;
 	}
-	}
-	else
-	{
-		Address peer_address;
 
-		if (peer->getAddress(MTP_UDP, peer_address))
-		{
+	Address peer_address;
+	if (peer->getAddress(MTP_UDP, peer_address)) {
 		// Add base headers and make a packet
 		BufferedPacket p = con::makePacket(peer_address, data,
 				m_connection->GetProtocolID(), m_connection->GetPeerID(),
@@ -1556,17 +1521,12 @@ bool ConnectionSendThread::rawSendAsPacket(u16 peer_id, u8 channelnum,
 		rawSend(p);
 		return true;
 	}
-		else {
+
 	LOG(dout_con << m_connection->getDesc()
 			<< " INFO: dropped unreliable packet for peer_id: " << peer_id
 			<< " because of (yet) missing udp address" << std::endl);
 	return false;
 }
-	}
-
-	//never reached
-	return false;
-}
 
 void ConnectionSendThread::processReliableCommand(ConnectionCommand &c)
 {
@@ -1731,11 +1691,8 @@ void ConnectionSendThread::disconnect()
 	// Send to all
 	std::list<u16> peerids = m_connection->getPeerIDs();
 
-	for (std::list<u16>::iterator i = peerids.begin();
-			i != peerids.end();
-			++i)
-	{
-		sendAsPacket(*i, 0,data,false);
+	for (u16 peerid : peerids) {
+		sendAsPacket(peerid, 0,data,false);
 	}
 }
 
@@ -1790,10 +1747,7 @@ void ConnectionSendThread::send(u16 peer_id, u8 channelnum,
 
 	peer->setNextSplitSequenceNumber(channelnum,split_sequence_number);
 
-	for(std::list<SharedBuffer<u8> >::iterator i = originals.begin();
-		i != originals.end(); ++i)
-	{
-		SharedBuffer<u8> original = *i;
+	for (const SharedBuffer<u8> &original : originals) {
 		sendAsPacket(peer_id, channelnum, original);
 	}
 }
@@ -1811,11 +1765,8 @@ void ConnectionSendThread::sendToAll(u8 channelnum, SharedBuffer<u8> data)
 {
 	std::list<u16> peerids = m_connection->getPeerIDs();
 
-	for (std::list<u16>::iterator i = peerids.begin();
-			i != peerids.end();
-			++i)
-	{
-		send(*i, channelnum, data);
+	for (u16 peerid : peerids) {
+		send(peerid, channelnum, data);
 	}
 }
 
@@ -1823,11 +1774,8 @@ void ConnectionSendThread::sendToAllReliable(ConnectionCommand &c)
 {
 	std::list<u16> peerids = m_connection->getPeerIDs();
 
-	for (std::list<u16>::iterator i = peerids.begin();
-			i != peerids.end();
-			++i)
-	{
-		PeerHelper peer = m_connection->getPeerNoEx(*i);
+	for (u16 peerid : peerids) {
+		PeerHelper peer = m_connection->getPeerNoEx(peerid);
 
 		if (!peer)
 			continue;
@@ -1842,85 +1790,84 @@ void ConnectionSendThread::sendPackets(float dtime)
 	std::list<u16> pendingDisconnect;
 	std::map<u16,bool> pending_unreliable;
 
-	for(std::list<u16>::iterator
-			j = peerIds.begin();
-			j != peerIds.end(); ++j)
-	{
-		PeerHelper peer = m_connection->getPeerNoEx(*j);
+	for (u16 peerId : peerIds) {
+		PeerHelper peer = m_connection->getPeerNoEx(peerId);
 		//peer may have been removed
 		if (!peer) {
-			LOG(dout_con<<m_connection->getDesc()<< " Peer not found: peer_id=" << *j << std::endl);
+			LOG(dout_con<<m_connection->getDesc()<< " Peer not found: peer_id=" << peerId
+				<< std::endl);
 			continue;
 		}
 		peer->m_increment_packets_remaining = m_iteration_packets_avaialble/m_connection->m_peers.size();
 
-		if (dynamic_cast<UDPPeer*>(&peer) == 0)
-		{
+		UDPPeer *udpPeer = dynamic_cast<UDPPeer*>(&peer);
+
+		if (!udpPeer) {
 			continue;
 		}
 
-		if (dynamic_cast<UDPPeer*>(&peer)->m_pending_disconnect)
-		{
-			pendingDisconnect.push_back(*j);
+		if (udpPeer->m_pending_disconnect) {
+			pendingDisconnect.push_back(peerId);
 		}
 
 		PROFILE(std::stringstream peerIdentifier);
-		PROFILE(peerIdentifier << "sendPackets[" << m_connection->getDesc() << ";" << *j << ";RELIABLE]");
+		PROFILE(peerIdentifier << "sendPackets[" << m_connection->getDesc() << ";" << peerId
+			<< ";RELIABLE]");
 		PROFILE(ScopeProfiler peerprofiler(g_profiler, peerIdentifier.str(), SPT_AVG));
 
 		LOG(dout_con<<m_connection->getDesc()
-				<< " Handle per peer queues: peer_id=" << *j
+				<< " Handle per peer queues: peer_id=" << peerId
 			<< " packet quota: " << peer->m_increment_packets_remaining << std::endl);
+
 		// first send queued reliable packets for all peers (if possible)
-		for (unsigned int i=0; i < CHANNEL_COUNT; i++)
-		{
+		for (unsigned int i=0; i < CHANNEL_COUNT; i++) {
+			Channel &channel = udpPeer->channels[i];
 			u16 next_to_ack = 0;
-			dynamic_cast<UDPPeer*>(&peer)->channels[i].outgoing_reliables_sent.getFirstSeqnum(next_to_ack);
+
+			channel.outgoing_reliables_sent.getFirstSeqnum(next_to_ack);
 			u16 next_to_receive = 0;
-			dynamic_cast<UDPPeer*>(&peer)->channels[i].incoming_reliables.getFirstSeqnum(next_to_receive);
+			channel.incoming_reliables.getFirstSeqnum(next_to_receive);
 
 			LOG(dout_con<<m_connection->getDesc()<< "\t channel: "
 						<< i << ", peer quota:"
 						<< peer->m_increment_packets_remaining
 						<< std::endl
 					<< "\t\t\treliables on wire: "
-						<< dynamic_cast<UDPPeer*>(&peer)->channels[i].outgoing_reliables_sent.size()
+						<< channel.outgoing_reliables_sent.size()
 						<< ", waiting for ack for " << next_to_ack
 						<< std::endl
 					<< "\t\t\tincoming_reliables: "
-						<< dynamic_cast<UDPPeer*>(&peer)->channels[i].incoming_reliables.size()
+						<< channel.incoming_reliables.size()
 						<< ", next reliable packet: "
-						<< dynamic_cast<UDPPeer*>(&peer)->channels[i].readNextIncomingSeqNum()
+						<< channel.readNextIncomingSeqNum()
 						<< ", next queued: " << next_to_receive
 						<< std::endl
 					<< "\t\t\treliables queued : "
-						<< dynamic_cast<UDPPeer*>(&peer)->channels[i].queued_reliables.size()
+						<< channel.queued_reliables.size()
 						<< std::endl
 					<< "\t\t\tqueued commands  : "
-						<< dynamic_cast<UDPPeer*>(&peer)->channels[i].queued_commands.size()
+						<< channel.queued_commands.size()
 						<< std::endl);
 
-			while ((dynamic_cast<UDPPeer*>(&peer)->channels[i].queued_reliables.size() > 0) &&
-					(dynamic_cast<UDPPeer*>(&peer)->channels[i].outgoing_reliables_sent.size()
-							< dynamic_cast<UDPPeer*>(&peer)->channels[i].getWindowSize())&&
+			while ((!channel.queued_reliables.empty()) &&
+					(channel.outgoing_reliables_sent.size()
+							< channel.getWindowSize())&&
 							(peer->m_increment_packets_remaining > 0))
 			{
-				BufferedPacket p = dynamic_cast<UDPPeer*>(&peer)->channels[i].queued_reliables.front();
-				dynamic_cast<UDPPeer*>(&peer)->channels[i].queued_reliables.pop();
-				Channel* channel = &(dynamic_cast<UDPPeer*>(&peer)->channels[i]);
+				BufferedPacket p = channel.queued_reliables.front();
+				channel.queued_reliables.pop();
 				LOG(dout_con<<m_connection->getDesc()
 						<<" INFO: sending a queued reliable packet "
 						<<" channel: " << i
 						<<", seqnum: " << readU16(&p.data[BASE_HEADER_SIZE+1])
 						<< std::endl);
-				sendAsPacketReliable(p,channel);
+				sendAsPacketReliable(p, &channel);
 				peer->m_increment_packets_remaining--;
 			}
 		}
 	}
 
-	if (m_outgoing_queue.size())
-	{
+	if (!m_outgoing_queue.empty()) {
 		LOG(dout_con<<m_connection->getDesc()
 				<< " Handle non reliable queue ("
 				<< m_outgoing_queue.size() << " pkts)" << std::endl);
@@ -1944,9 +1891,9 @@ void ConnectionSendThread::sendPackets(float dtime)
 							<< ", size: " << packet.data.getSize() <<std::endl);
 			continue;
 		}
+
 		/* send acks immediately */
-		else if (packet.ack)
-		{
+		if (packet.ack) {
 			rawSendAsPacket(packet.peer_id, packet.channelnum,
 								packet.data, packet.reliable);
 			peer->m_increment_packets_remaining =
@@ -1965,13 +1912,10 @@ void ConnectionSendThread::sendPackets(float dtime)
 		}
 	}
 
-	for(std::list<u16>::iterator
-				k = pendingDisconnect.begin();
-				k != pendingDisconnect.end(); ++k)
+	for (u16 peerId : pendingDisconnect) {
+		if (!pending_unreliable[peerId])
 		{
-		if (!pending_unreliable[*k])
-		{
-			m_connection->deletePeer(*k,false);
+			m_connection->deletePeer(peerId,false);
 		}
 	}
 }
@@ -2237,21 +2181,16 @@ bool ConnectionReceiveThread::getFromBuffers(u16 &peer_id, SharedBuffer<u8> &dst
 {
 	std::list<u16> peerids = m_connection->getPeerIDs();
 
-	for(std::list<u16>::iterator j = peerids.begin();
-		j != peerids.end(); ++j)
-	{
-		PeerHelper peer = m_connection->getPeerNoEx(*j);
+	for (u16 peerid : peerids) {
+		PeerHelper peer = m_connection->getPeerNoEx(peerid);
 		if (!peer)
 			continue;
 
 		if (dynamic_cast<UDPPeer*>(&peer) == 0)
 			continue;
 
-		for(u16 i=0; i<CHANNEL_COUNT; i++)
-		{
-			Channel *channel = &(dynamic_cast<UDPPeer*>(&peer))->channels[i];
-
-			if (checkIncomingBuffers(channel, peer_id, dst)) {
+		for (Channel &channel : (dynamic_cast<UDPPeer *>(&peer))->channels) {
+			if (checkIncomingBuffers(&channel, peer_id, dst)) {
 				return true;
 			}
 		}
@@ -2425,8 +2364,7 @@ SharedBuffer<u8> ConnectionReceiveThread::processPacket(Channel *channel,
 			LOG(dout_con<<m_connection->getDesc()
 					<<"DISCO: Removing peer "<<(peer_id)<<std::endl);
 
-			if (m_connection->deletePeer(peer_id, false) == false)
-			{
+			if (!m_connection->deletePeer(peer_id, false)) {
 				derr_con<<m_connection->getDesc()
 						<<"DISCO: Peer not found"<<std::endl;
 			}
@@ -2662,11 +2600,8 @@ Connection::~Connection()
 	m_receiveThread.wait();
 
 	// Delete peers
-	for(std::map<u16, Peer*>::iterator
-			j = m_peers.begin();
-			j != m_peers.end(); ++j)
-	{
-		delete j->second;
+	for (auto &peer : m_peers) {
+		delete peer.second;
 	}
 }
 
@@ -2734,10 +2669,8 @@ u16 Connection::lookupPeer(Address& sender)
 std::list<Peer*> Connection::getPeers()
 {
 	std::list<Peer*> list;
-	for(std::map<u16, Peer*>::iterator j = m_peers.begin();
-		j != m_peers.end(); ++j)
-	{
-		Peer *peer = j->second;
+	for (auto &p : m_peers) {
+		Peer *peer = p.second;
 		list.push_back(peer);
 	}
 	return list;
@@ -2904,25 +2837,25 @@ float Connection::getLocalStat(rate_stat_type type)
 
 	float retval = 0.0;
 
-	for (u16 j=0; j<CHANNEL_COUNT; j++) {
+	for (Channel &channel : dynamic_cast<UDPPeer *>(&peer)->channels) {
 		switch(type) {
 			case CUR_DL_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getCurrentDownloadRateKB();
+				retval += channel.getCurrentDownloadRateKB();
 				break;
 			case AVG_DL_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getAvgDownloadRateKB();
+				retval += channel.getAvgDownloadRateKB();
 				break;
 			case CUR_INC_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getCurrentIncomingRateKB();
+				retval += channel.getCurrentIncomingRateKB();
 				break;
 			case AVG_INC_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getAvgIncomingRateKB();
+				retval += channel.getAvgIncomingRateKB();
 				break;
 			case AVG_LOSS_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getAvgLossRateKB();
+				retval += channel.getAvgLossRateKB();
 				break;
 			case CUR_LOSS_RATE:
-				retval += dynamic_cast<UDPPeer*>(&peer)->channels[j].getCurrentLossRateKB();
+				retval += channel.getCurrentLossRateKB();
 				break;
 		default:
 			FATAL_ERROR("Connection::getLocalStat Invalid stat type");

src/network/connection.h

@@ -133,32 +133,28 @@ inline bool seqnum_higher(u16 totest, u16 base)
 	{
 		if ((totest - base) > (SEQNUM_MAX/2))
 			return false;
-		else
+
 		return true;
 	}
-	else
-	{
+
 	if ((base - totest) > (SEQNUM_MAX/2))
 		return true;
-		else
+
 	return false;
 }
-}
 
 inline bool seqnum_in_window(u16 seqnum, u16 next,u16 window_size)
 {
 	u16 window_start = next;
 	u16 window_end   = ( next + window_size ) % (SEQNUM_MAX+1);
 
-	if (window_start < window_end)
-	{
+	if (window_start < window_end) {
 		return ((seqnum >= window_start) && (seqnum < window_end));
 	}
-	else
-	{
+
+
 	return ((seqnum < window_end) || (seqnum >= window_start));
 }
-}
 
 struct BufferedPacket
 {
@@ -166,8 +162,7 @@ struct BufferedPacket
 		data(a_data, a_size)
 	{}
 	BufferedPacket(u32 a_size):
-		data(a_size), time(0.0), totaltime(0.0), absolute_send_time(-1),
-		resend_count(0)
+		data(a_size)
 	{}
 	Buffer<u8> data; // Data of the packet, including headers
 	float time = 0.0f; // Seconds from buffering the packet or re-sending
@@ -202,12 +197,13 @@ std::list<SharedBuffer<u8> > makeAutoSplitPacket(
 
 // Add the TYPE_RELIABLE header to the data
 SharedBuffer<u8> makeReliablePacket(
-		SharedBuffer<u8> data,
+		const SharedBuffer<u8> &data,
 		u16 seqnum);
 
 struct IncomingSplitPacket
 {
-	IncomingSplitPacket() {}
+	IncomingSplitPacket() = default;
+
 	// Key is chunk number, value is data without headers
 	std::map<u16, SharedBuffer<u8> > chunks;
 	u32 chunk_count;
@@ -315,7 +311,7 @@ typedef std::list<BufferedPacket>::iterator RPBSearchResult;
 class ReliablePacketBuffer
 {
 public:
-	ReliablePacketBuffer() {};
+	ReliablePacketBuffer() = default;
 
 	bool getFirstSeqnum(u16& result);
 
@@ -410,7 +406,7 @@ struct ConnectionCommand
 	bool reliable = false;
 	bool raw = false;
 
-	ConnectionCommand() {}
+	ConnectionCommand() = default;
 
 	void serve(Address address_)
 	{
@@ -501,8 +497,8 @@ public:
 
 	IncomingSplitBuffer incoming_splits;
 
-	Channel() {};
-	~Channel() {};
+	Channel() = default;
+	~Channel() = default;
 
 	void UpdatePacketLossCounter(unsigned int count);
 	void UpdatePacketTooLateCounter();
@@ -590,12 +586,8 @@ class PeerHandler
 {
 public:
 
-	PeerHandler()
-	{
-	}
-	virtual ~PeerHandler()
-	{
-	}
+	PeerHandler() = default;
+	virtual ~PeerHandler() = default;
 
 	/*
 		This is called after the Peer has been inserted into the
@@ -612,7 +604,7 @@ public:
 class PeerHelper
 {
 public:
-	PeerHelper() {};
+	PeerHelper() = default;;
 	PeerHelper(Peer* peer);
 	~PeerHelper();
 
@@ -744,7 +736,7 @@ class Peer {
 			float max_rtt = 0.0f;
 			float avg_rtt = -1.0f;
 
-			rttstats() {};
+			rttstats() = default;
 		};
 
 		rttstats m_rtt;
@@ -769,7 +761,7 @@ public:
 	friend class Connection;
 
 	UDPPeer(u16 a_id, Address a_address, Connection* connection);
-	virtual ~UDPPeer() {};
+	virtual ~UDPPeer() = default;
 
 	void PutReliableSendCommand(ConnectionCommand &c,
 							unsigned int max_packet_size);
@@ -841,7 +833,7 @@ struct ConnectionEvent
 	bool timeout = false;
 	Address address;
 
-	ConnectionEvent() {}
+	ConnectionEvent() = default;
 
 	std::string describe()
 	{

src/network/networkpacket.h

@@ -30,7 +30,8 @@ class NetworkPacket
 public:
 		NetworkPacket(u16 command, u32 datasize, u16 peer_id);
 		NetworkPacket(u16 command, u32 datasize);
-		NetworkPacket() {}
+		NetworkPacket() = default;
+
 		~NetworkPacket();
 
 		void putRawPacket(u8 *data, u32 datasize, u16 peer_id);

src/network/serverpackethandler.cpp

@@ -173,7 +173,7 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 		return;
 	}
 
-	if (string_allowed(playerName, PLAYERNAME_ALLOWED_CHARS) == false) {
+	if (!string_allowed(playerName, PLAYERNAME_ALLOWED_CHARS)) {
 		actionstream << "Server: Player with an invalid name "
 				<< "tried to connect from " << addr_s << std::endl;
 		DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_CHARS_IN_NAME);
@@ -199,8 +199,7 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 					<< "tried to connect from " << addr_s << " "
 					<< "but it was disallowed for the following reason: "
 					<< reason << std::endl;
-			DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_CUSTOM_STRING,
-					reason.c_str());
+			DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_CUSTOM_STRING, reason);
 			return;
 		}
 	}
@@ -468,7 +467,7 @@ void Server::handleCommand_Init_Legacy(NetworkPacket* pkt)
 		return;
 	}
 
-	if (string_allowed(playername, PLAYERNAME_ALLOWED_CHARS) == false) {
+	if (!string_allowed(playername, PLAYERNAME_ALLOWED_CHARS)) {
 		actionstream << "Server: Player with an invalid name "
 				<< "tried to connect from " << addr_s << std::endl;
 		DenyAccess_Legacy(pkt->getPeerId(), L"Name contains unallowed characters");
@@ -489,7 +488,7 @@ void Server::handleCommand_Init_Legacy(NetworkPacket* pkt)
 					<< "tried to connect from " << addr_s << " "
 					<< "but it was disallowed for the following reason: "
 					<< reason << std::endl;
-			DenyAccess_Legacy(pkt->getPeerId(), utf8_to_wide(reason.c_str()));
+			DenyAccess_Legacy(pkt->getPeerId(), utf8_to_wide(reason));
 			return;
 		}
 	}
@@ -539,7 +538,7 @@ void Server::handleCommand_Init_Legacy(NetworkPacket* pkt)
 	if (!has_auth) {
 		if (!isSingleplayer() &&
 				g_settings->getBool("disallow_empty_password") &&
-				std::string(given_password) == "") {
+				std::string(given_password).empty()) {
 			actionstream << "Server: " << playername
 					<< " supplied empty password" << std::endl;
 			DenyAccess_Legacy(pkt->getPeerId(), L"Empty passwords are "
@@ -1637,7 +1636,7 @@ void Server::handleCommand_Interact(NetworkPacket* pkt)
 		RemoteClient *client = getClient(pkt->getPeerId());
 		v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_above, BS));
 		v3s16 blockpos2 = getNodeBlockPos(floatToInt(pointed_pos_under, BS));
-		if (item.getDefinition(m_itemdef).node_placement_prediction != "") {
+		if (!item.getDefinition(m_itemdef).node_placement_prediction.empty()) {
 			client->SetBlockNotSent(blockpos);
 			if (blockpos2 != blockpos) {
 				client->SetBlockNotSent(blockpos2);
@@ -1895,11 +1894,11 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 		if (wantSudo) {
 			DenySudoAccess(pkt->getPeerId());
 			return;
-		} else {
+		}
+
 		DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
 		return;
 	}
-	}
 
 	std::string bytes_A;
 	u8 based_on;
@@ -1967,11 +1966,11 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 		if (wantSudo) {
 			DenySudoAccess(pkt->getPeerId());
 			return;
-		} else {
+		}
+
 		DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
 		return;
 	}
-	}
 
 	NetworkPacket resp_pkt(TOCLIENT_SRP_BYTES_S_B, 0, pkt->getPeerId());
 	resp_pkt << salt << std::string(bytes_B, len_B);
@@ -2004,11 +2003,11 @@ void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
 		if (wantSudo) {
 			DenySudoAccess(pkt->getPeerId());
 			return;
-		} else {
+		}
+
 		DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
 		return;
 	}
-	}
 
 	std::string bytes_M;
 	*pkt >> bytes_M;
@@ -2035,7 +2034,8 @@ void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
 				<< " (SRP) password for authentication." << std::endl;
 			DenySudoAccess(pkt->getPeerId());
 			return;
-		} else {
+		}
+
 		actionstream << "Server: User " << client->getName()
 			<< " at " << getPeerAddress(pkt->getPeerId()).serializeString()
 			<< " supplied wrong password (auth mechanism: SRP)."
@@ -2043,7 +2043,6 @@ void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
 		DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_PASSWORD);
 		return;
 	}
-	}
 
 	if (client->create_player_on_auth_success) {
 		std::string playername = client->getName();

src/script/lua_api/l_camera.h

@@ -48,7 +48,7 @@ private:
 
 public:
 	LuaCamera(Camera *m);
-	~LuaCamera() {}
+	~LuaCamera() = default;
 
 	static void create(lua_State *L, Camera *m);
 

src/script/lua_api/l_client.cpp

@@ -34,7 +34,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/string.h"
 #include "nodedef.h"
 
-extern MainGameCallback *g_gamecallback;
 
 int ModApiClient::l_get_current_modname(lua_State *L)
 {

src/script/lua_api/l_craft.cpp

@@ -57,7 +57,7 @@ bool ModApiCraft::readCraftRecipeShaped(lua_State *L, int index,
 			// key at index -2 and value at index -1
 			if(!lua_isstring(L, -1))
 				return false;
-			recipe.push_back(lua_tostring(L, -1));
+			recipe.emplace_back(lua_tostring(L, -1));
 			// removes value, keeps key for next iteration
 			lua_pop(L, 1);
 			colcount++;
@@ -90,7 +90,7 @@ bool ModApiCraft::readCraftRecipeShapeless(lua_State *L, int index,
 		// key at index -2 and value at index -1
 		if(!lua_isstring(L, -1))
 			return false;
-		recipe.push_back(lua_tostring(L, -1));
+		recipe.emplace_back(lua_tostring(L, -1));
 		// removes value, keeps key for next iteration
 		lua_pop(L, 1);
 	}
@@ -122,8 +122,7 @@ bool ModApiCraft::readCraftReplacements(lua_State *L, int index,
 			return false;
 		std::string replace_to = lua_tostring(L, -1);
 		lua_pop(L, 1);
-		replacements.pairs.push_back(
-				std::make_pair(replace_from, replace_to));
+		replacements.pairs.emplace_back(replace_from, replace_to);
 		// removes value, keeps key for next iteration
 		lua_pop(L, 1);
 	}
@@ -148,7 +147,7 @@ int ModApiCraft::l_register_craft(lua_State *L)
 	*/
 	if(type == "shaped"){
 		std::string output = getstringfield_default(L, table, "output", "");
-		if(output == "")
+		if (output.empty())
 			throw LuaError("Crafting definition is missing an output");
 
 		int width = 0;
@@ -179,7 +178,7 @@ int ModApiCraft::l_register_craft(lua_State *L)
 	*/
 	else if(type == "shapeless"){
 		std::string output = getstringfield_default(L, table, "output", "");
-		if(output == "")
+		if (output.empty())
 			throw LuaError("Crafting definition (shapeless)"
 					" is missing an output");
 
@@ -222,12 +221,12 @@ int ModApiCraft::l_register_craft(lua_State *L)
 	*/
 	else if(type == "cooking"){
 		std::string output = getstringfield_default(L, table, "output", "");
-		if(output == "")
+		if (output.empty())
 			throw LuaError("Crafting definition (cooking)"
 					" is missing an output");
 
 		std::string recipe = getstringfield_default(L, table, "recipe", "");
-		if(recipe == "")
+		if (recipe.empty())
 			throw LuaError("Crafting definition (cooking)"
 					" is missing a recipe"
 					" (output=\"" + output + "\")");
@@ -252,7 +251,7 @@ int ModApiCraft::l_register_craft(lua_State *L)
 	*/
 	else if(type == "fuel"){
 		std::string recipe = getstringfield_default(L, table, "recipe", "");
-		if(recipe == "")
+		if (recipe.empty())
 			throw LuaError("Crafting definition (fuel)"
 					" is missing a recipe");
 
@@ -294,10 +293,10 @@ int ModApiCraft::l_clear_craft(lua_State *L)
 	std::string output = getstringfield_default(L, table, "output", "");
 	std::string type = getstringfield_default(L, table, "type", "shaped");
 	CraftOutput c_output(output, 0);
-	if (output != "") {
+	if (!output.empty()) {
 		if (craftdef->clearCraftRecipesByOutput(c_output, getServer(L)))
 			return 0;
-		else
+
 		throw LuaError("No craft recipe known for output"
 				" (output=\"" + output + "\")");
 	}
@@ -330,7 +329,7 @@ int ModApiCraft::l_clear_craft(lua_State *L)
 	else if (type == "cooking") {
 		method = CRAFT_METHOD_COOKING;
 		std::string rec = getstringfield_default(L, table, "recipe", "");
-		if (rec == "")
+		if (rec.empty())
 			throw LuaError("Crafting definition (cooking)"
 					" is missing a recipe");
 		recipe.push_back(rec);
@@ -341,7 +340,7 @@ int ModApiCraft::l_clear_craft(lua_State *L)
 	else if (type == "fuel") {
 		method = CRAFT_METHOD_FUEL;
 		std::string rec = getstringfield_default(L, table, "recipe", "");
-		if (rec == "")
+		if (rec.empty())
 			throw LuaError("Crafting definition (fuel)"
 					" is missing a recipe");
 		recipe.push_back(rec);

src/script/lua_api/l_env.cpp

@@ -743,9 +743,8 @@ int ModApiEnvMod::l_find_node_near(lua_State *L)
 
 	for (int d = start_radius; d <= radius; d++) {
 		std::vector<v3s16> list = FacePositionCache::getFacePositions(d);
-		for (std::vector<v3s16>::iterator i = list.begin();
-				i != list.end(); ++i) {
-			v3s16 p = pos + (*i);
+		for (v3s16 i : list) {
+			v3s16 p = pos + i;
 			content_t c = env->getMap().getNodeNoEx(p).getContent();
 			if (filter.count(c) != 0) {
 				push_v3s16(L, p);
@@ -809,10 +808,9 @@ int ModApiEnvMod::l_find_nodes_in_area(lua_State *L)
 		}
 	}
 	lua_newtable(L);
-	for (std::set<content_t>::const_iterator it = filter.begin();
-			it != filter.end(); ++it) {
-		lua_pushnumber(L, individual_count[*it]);
-		lua_setfield(L, -2, ndef->get(*it).name.c_str());
+	for (content_t it : filter) {
+		lua_pushnumber(L, individual_count[it]);
+		lua_setfield(L, -2, ndef->get(it).name.c_str());
 	}
 	return 2;
 }
@@ -1004,12 +1002,11 @@ int ModApiEnvMod::l_fix_light(lua_State *L)
 	for (blockpos.Z = blockpos1.Z; blockpos.Z <= blockpos2.Z; blockpos.Z++) {
 		success = success & map.repairBlockLight(blockpos, &modified_blocks);
 	}
-	if (modified_blocks.size() > 0) {
+	if (!modified_blocks.empty()) {
 		MapEditEvent event;
 		event.type = MEET_OTHER;
-		for (std::map<v3s16, MapBlock *>::iterator it = modified_blocks.begin();
-				it != modified_blocks.end(); ++it)
-			event.modified_blocks.insert(it->first);
+		for (auto &modified_block : modified_blocks)
+			event.modified_blocks.insert(modified_block.first);
 
 		map.dispatchEvent(&event);
 	}
@@ -1126,14 +1123,13 @@ int ModApiEnvMod::l_find_path(lua_State *L)
 	std::vector<v3s16> path = get_path(env, pos1, pos2,
 		searchdistance, max_jump, max_drop, algo);
 
-	if (path.size() > 0)
-	{
+	if (!path.empty()) {
 		lua_newtable(L);
 		int top = lua_gettop(L);
 		unsigned int index = 1;
-		for (std::vector<v3s16>::iterator i = path.begin(); i != path.end(); ++i) {
+		for (v3s16 i : path) {
 			lua_pushnumber(L,index);
-			push_v3s16(L, *i);
+			push_v3s16(L, i);
 			lua_settable(L, top);
 			index++;
 		}
@@ -1167,8 +1163,7 @@ int ModApiEnvMod::l_spawn_tree(lua_State *L)
 		tree_def.leavesnode=ndef->getId(leaves);
 		tree_def.leaves2_chance=0;
 		getstringfield(L, 2, "leaves2", leaves);
-		if (leaves !="")
-		{
+		if (!leaves.empty()) {
 			tree_def.leaves2node=ndef->getId(leaves);
 			getintfield(L, 2, "leaves2_chance", tree_def.leaves2_chance);
 		}
@@ -1180,8 +1175,7 @@ int ModApiEnvMod::l_spawn_tree(lua_State *L)
 		getboolfield(L, 2, "thin_branches", tree_def.thin_branches);
 		tree_def.fruit_chance=0;
 		getstringfield(L, 2, "fruit", fruit);
-		if (fruit != "")
-		{
+		if (!fruit.empty()) {
 			tree_def.fruitnode=ndef->getId(fruit);
 			getintfield(L, 2, "fruit_chance",tree_def.fruit_chance);
 		}

src/script/lua_api/l_http.cpp

@@ -69,7 +69,7 @@ void ModApiHttp::read_http_fetch_request(lua_State *L, HTTPFetchRequest &req)
 		while (lua_next(L, 2) != 0)
 		{
 			const char *header = luaL_checkstring(L, -1);
-			req.extra_headers.push_back(header);
+			req.extra_headers.emplace_back(header);
 			lua_pop(L, 1);
 		}
 	}

src/script/lua_api/l_inventory.cpp

@@ -409,10 +409,6 @@ InvRef::InvRef(const InventoryLocation &loc):
 {
 }
 
-InvRef::~InvRef()
-{
-}
-
 // Creates an InvRef and leaves it on top of stack
 // Not callable from Lua; all references are created on the C side.
 void InvRef::create(lua_State *L, const InventoryLocation &loc)

src/script/lua_api/l_inventory.h

@@ -106,7 +106,7 @@ private:
 public:
 	InvRef(const InventoryLocation &loc);
 
-	~InvRef();
+	~InvRef() = default;
 
 	// Creates an InvRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.

src/script/lua_api/l_item.cpp

@@ -67,7 +67,7 @@ int LuaItemStack::l_set_name(lua_State *L)
 
 	bool status = true;
 	item.name = luaL_checkstring(L, 2);
-	if (item.name == "" || item.empty()) {
+	if (item.name.empty() || item.empty()) {
 		item.clear();
 		status = false;
 	}
@@ -231,12 +231,11 @@ int LuaItemStack::l_to_table(lua_State *L)
 
 		lua_newtable(L);
 		const StringMap &fields = item.metadata.getStrings();
-		for (StringMap::const_iterator it = fields.begin();
-				it != fields.end(); ++it) {
-			const std::string &name = it->first;
+		for (const auto &field : fields) {
+			const std::string &name = field.first;
 			if (name.empty())
 				continue;
-			const std::string &value = it->second;
+			const std::string &value = field.second;
 			lua_pushlstring(L, name.c_str(), name.size());
 			lua_pushlstring(L, value.c_str(), value.size());
 			lua_settable(L, -3);
@@ -391,10 +390,6 @@ LuaItemStack::LuaItemStack(const ItemStack &item):
 {
 }
 
-LuaItemStack::~LuaItemStack()
-{
-}
-
 const ItemStack& LuaItemStack::getItem() const
 {
 	return m_stack;

src/script/lua_api/l_item.h

@@ -121,7 +121,7 @@ private:
 
 public:
 	LuaItemStack(const ItemStack &item);
-	~LuaItemStack();
+	~LuaItemStack() = default;
 
 	const ItemStack& getItem() const;
 	ItemStack& getItem();

src/script/lua_api/l_itemstackmeta.h

@@ -46,7 +46,7 @@ private:
 	static int gc_object(lua_State *L);
 public:
 	ItemStackMetaRef(ItemStack *istack): istack(istack) {}
-	~ItemStackMetaRef() {}
+	~ItemStackMetaRef() = default;
 
 	// Creates an ItemStackMetaRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.

src/script/lua_api/l_localplayer.h

@@ -70,7 +70,7 @@ private:
 
 public:
 	LuaLocalPlayer(LocalPlayer *m);
-	~LuaLocalPlayer() {}
+	~LuaLocalPlayer() = default;
 
 	static void create(lua_State *L, LocalPlayer *m);
 

src/script/lua_api/l_minimap.h

@@ -51,7 +51,7 @@ private:
 
 public:
 	LuaMinimap(Minimap *m);
-	~LuaMinimap() {}
+	~LuaMinimap() = default;
 
 	static void create(lua_State *L, Minimap *object);
 

src/script/lua_api/l_nodemeta.cpp

@@ -182,10 +182,6 @@ NodeMetaRef::NodeMetaRef(Metadata *meta):
 {
 }
 
-NodeMetaRef::~NodeMetaRef()
-{
-}
-
 // Creates an NodeMetaRef and leaves it on top of stack
 // Not callable from Lua; all references are created on the C side.
 void NodeMetaRef::create(lua_State *L, v3s16 p, ServerEnvironment *env)

src/script/lua_api/l_nodemeta.h

@@ -80,7 +80,7 @@ public:
 	NodeMetaRef(v3s16 p, ServerEnvironment *env);
 	NodeMetaRef(Metadata *meta);
 
-	~NodeMetaRef();
+	~NodeMetaRef() = default;
 
 	// Creates an NodeMetaRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.

src/script/lua_api/l_nodetimer.cpp

@@ -113,10 +113,6 @@ NodeTimerRef::NodeTimerRef(v3s16 p, ServerEnvironment *env):
 {
 }
 
-NodeTimerRef::~NodeTimerRef()
-{
-}
-
 // Creates an NodeTimerRef and leaves it on top of stack
 // Not callable from Lua; all references are created on the C side.
 void NodeTimerRef::create(lua_State *L, v3s16 p, ServerEnvironment *env)

src/script/lua_api/l_nodetimer.h

@@ -51,7 +51,7 @@ private:
 
 public:
 	NodeTimerRef(v3s16 p, ServerEnvironment *env);
-	~NodeTimerRef();
+	~NodeTimerRef() = default;
 
 	// Creates an NodeTimerRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.

src/script/lua_api/l_noise.cpp

@@ -36,11 +36,6 @@ LuaPerlinNoise::LuaPerlinNoise(NoiseParams *params) :
 }
 
 
-LuaPerlinNoise::~LuaPerlinNoise()
-{
-}
-
-
 int LuaPerlinNoise::l_get2d(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;

src/script/lua_api/l_noise.h

@@ -43,7 +43,7 @@ private:
 
 public:
 	LuaPerlinNoise(NoiseParams *params);
-	~LuaPerlinNoise();
+	~LuaPerlinNoise() = default;
 
 	// LuaPerlinNoise(seed, octaves, persistence, scale)
 	// Creates an LuaPerlinNoise and leaves it on top of stack

src/script/lua_api/l_object.cpp

@@ -551,8 +551,8 @@ int ObjectRef::l_get_local_animation(lua_State *L)
 	float frame_speed;
 	player->getLocalAnimations(frames, &frame_speed);
 
-	for (int i = 0; i < 4; i++) {
-		push_v2s32(L, frames[i]);
+	for (v2s32 frame : frames) {
+		push_v2s32(L, frame);
 	}
 
 	lua_pushnumber(L, frame_speed);
@@ -611,7 +611,7 @@ int ObjectRef::l_set_bone_position(lua_State *L)
 	ServerActiveObject *co = getobject(ref);
 	if (co == NULL) return 0;
 	// Do it
-	std::string bone = "";
+	std::string bone;
 	if (!lua_isnil(L, 2))
 		bone = lua_tostring(L, 2);
 	v3f position = v3f(0, 0, 0);
@@ -633,7 +633,7 @@ int ObjectRef::l_get_bone_position(lua_State *L)
 	if (co == NULL)
 		return 0;
 	// Do it
-	std::string bone = "";
+	std::string bone;
 	if (!lua_isnil(L, 2))
 		bone = lua_tostring(L, 2);
 
@@ -661,7 +661,7 @@ int ObjectRef::l_set_attach(lua_State *L)
 		return 0;
 	// Do it
 	int parent_id = 0;
-	std::string bone = "";
+	std::string bone;
 	v3f position = v3f(0, 0, 0);
 	v3f rotation = v3f(0, 0, 0);
 	co->getAttachment(&parent_id, &bone, &position, &rotation);
@@ -696,7 +696,7 @@ int ObjectRef::l_get_attach(lua_State *L)
 
 	// Do it
 	int parent_id = 0;
-	std::string bone = "";
+	std::string bone;
 	v3f position = v3f(0, 0, 0);
 	v3f rotation = v3f(0, 0, 0);
 	co->getAttachment(&parent_id, &bone, &position, &rotation);
@@ -722,7 +722,7 @@ int ObjectRef::l_set_detach(lua_State *L)
 		return 0;
 
 	int parent_id = 0;
-	std::string bone = "";
+	std::string bone;
 	v3f position;
 	v3f rotation;
 	co->getAttachment(&parent_id, &bone, &position, &rotation);
@@ -1223,7 +1223,7 @@ int ObjectRef::l_get_attribute(lua_State *L)
 
 	std::string attr = luaL_checkstring(L, 2);
 
-	std::string value = "";
+	std::string value;
 	if (co->getExtendedAttribute(attr, &value)) {
 		lua_pushstring(L, value.c_str());
 		return 1;
@@ -1684,9 +1684,9 @@ int ObjectRef::l_set_sky(lua_State *L)
 		while (lua_next(L, 4) != 0) {
 			// key at index -2 and value at index -1
 			if (lua_isstring(L, -1))
-				params.push_back(lua_tostring(L, -1));
+				params.emplace_back(lua_tostring(L, -1));
 			else
-				params.push_back("");
+				params.emplace_back("");
 			// removes value, keeps key for next iteration
 			lua_pop(L, 1);
 		}
@@ -1720,15 +1720,14 @@ int ObjectRef::l_get_sky(lua_State *L)
 	bool clouds;
 
 	player->getSky(&bgcolor, &type, &params, &clouds);
-	type = type == "" ? "regular" : type;
+	type = type.empty() ? "regular" : type;
 
 	push_ARGB8(L, bgcolor);
 	lua_pushlstring(L, type.c_str(), type.size());
 	lua_newtable(L);
 	s16 i = 1;
-	for (std::vector<std::string>::iterator it = params.begin();
-			it != params.end(); ++it) {
-		lua_pushlstring(L, it->c_str(), it->size());
+	for (const std::string &param : params) {
+		lua_pushlstring(L, param.c_str(), param.size());
 		lua_rawseti(L, -2, i);
 		i++;
 	}
@@ -1865,15 +1864,6 @@ ObjectRef::ObjectRef(ServerActiveObject *object):
 	//infostream<<"ObjectRef created for id="<<m_object->getId()<<std::endl;
 }
 
-ObjectRef::~ObjectRef()
-{
-	/*if (m_object)
-		infostream<<"ObjectRef destructing for id="
-				<<m_object->getId()<<std::endl;
-	else
-		infostream<<"ObjectRef destructing for id=unknown"<<std::endl;*/
-}
-
 // Creates an ObjectRef and leaves it on top of stack
 // Not callable from Lua; all references are created on the C side.
 void ObjectRef::create(lua_State *L, ServerActiveObject *object)

src/script/lua_api/l_object.h

@@ -35,7 +35,7 @@ class ObjectRef : public ModApiBase {
 public:
 	ObjectRef(ServerActiveObject *object);
 
-	~ObjectRef();
+	~ObjectRef() = default;
 
 	// Creates an ObjectRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.

src/script/lua_api/l_particles.cpp

@@ -53,8 +53,8 @@ int ModApiParticles::l_add_particle(lua_State *L)
 	struct TileAnimationParams animation;
 	animation.type = TAT_NONE;
 
-	std::string texture = "";
-	std::string playername = "";
+	std::string texture;
+	std::string playername;
 
 	u8 glow = 0;
 
@@ -158,8 +158,8 @@ int ModApiParticles::l_add_particlespawner(lua_State *L)
 	struct TileAnimationParams animation;
 	animation.type = TAT_NONE;
 	ServerActiveObject *attached = NULL;
-	std::string texture = "";
-	std::string playername = "";
+	std::string texture;
+	std::string playername;
 	u8 glow = 0;
 
 	if (lua_gettop(L) > 1) //deprecated
@@ -262,7 +262,7 @@ int ModApiParticles::l_delete_particlespawner(lua_State *L)
 
 	// Get parameters
 	u32 id = luaL_checknumber(L, 1);
-	std::string playername = "";
+	std::string playername;
 	if (lua_gettop(L) == 2) {
 		playername = luaL_checkstring(L, 2);
 	}

src/script/lua_api/l_settings.cpp

@@ -198,10 +198,9 @@ int LuaSettings::l_to_table(lua_State* L)
 	std::vector<std::string> keys = o->m_settings->getNames();
 
 	lua_newtable(L);
-	for (unsigned int i=0; i < keys.size(); i++)
-	{
-		lua_pushstring(L, o->m_settings->get(keys[i]).c_str());
-		lua_setfield(L, -2, keys[i].c_str());
+	for (const std::string &key : keys) {
+		lua_pushstring(L, o->m_settings->get(key).c_str());
+		lua_setfield(L, -2, key.c_str());
 	}
 
 	return 1;

src/script/lua_api/l_storage.h

@@ -50,7 +50,7 @@ private:
 
 public:
 	StorageRef(ModMetadata *object);
-	~StorageRef() {}
+	~StorageRef() = default;
 
 	static void Register(lua_State *L);
 	static void create(lua_State *L, ModMetadata *object);

src/script/lua_api/l_util.cpp

@@ -344,9 +344,9 @@ int ModApiUtil::l_get_dir_list(lua_State *L)
 	int index = 0;
 	lua_newtable(L);
 
-	for (size_t i = 0; i < list.size(); i++) {
-		if (list_all || list_dirs == list[i].dir) {
-			lua_pushstring(L, list[i].name.c_str());
+	for (const fs::DirListNode &dln : list) {
+		if (list_all || list_dirs == dln.dir) {
+			lua_pushstring(L, dln.name.c_str());
 			lua_rawseti(L, -2, ++index);
 		}
 	}
@@ -414,7 +414,7 @@ int ModApiUtil::l_get_version(lua_State *L)
 	lua_pushstring(L, g_version_string);
 	lua_setfield(L, table, "string");
 
-	if (strcmp(g_version_string, g_version_hash)) {
+	if (strcmp(g_version_string, g_version_hash) != 0) {
 		lua_pushstring(L, g_version_hash);
 		lua_setfield(L, table, "hash");
 	}

src/script/lua_api/l_vmanip.cpp

@@ -111,7 +111,7 @@ int LuaVoxelManip::l_write_to_map(lua_State *L)
 	MAP_LOCK_REQUIRED;
 
 	LuaVoxelManip *o = checkobject(L, 1);
-	bool update_light = lua_isboolean(L, 2) ? lua_toboolean(L, 2) : true;
+	bool update_light = !lua_isboolean(L, 2) || lua_toboolean(L, 2);
 	GET_ENV_PTR;
 	ServerMap *map = &(env->getServerMap());
 	if (o->is_mapgen_vm || !update_light) {
@@ -123,9 +123,8 @@ int LuaVoxelManip::l_write_to_map(lua_State *L)
 
 	MapEditEvent event;
 	event.type = MEET_OTHER;
-	for (std::map<v3s16, MapBlock *>::iterator it = o->modified_blocks.begin();
-			it != o->modified_blocks.end(); ++it)
-		event.modified_blocks.insert(it->first);
+	for (const auto &modified_block : o->modified_blocks)
+		event.modified_blocks.insert(modified_block.first);
 
 	map->dispatchEvent(&event);
 
@@ -198,7 +197,7 @@ int LuaVoxelManip::l_calc_lighting(lua_State *L)
 	v3s16 fpmax  = vm->m_area.MaxEdge;
 	v3s16 pmin   = lua_istable(L, 2) ? check_v3s16(L, 2) : fpmin + yblock;
 	v3s16 pmax   = lua_istable(L, 3) ? check_v3s16(L, 3) : fpmax - yblock;
-	bool propagate_shadow = lua_isboolean(L, 4) ? lua_toboolean(L, 4) : true;
+	bool propagate_shadow = !lua_isboolean(L, 4) || lua_toboolean(L, 4);
 
 	sortBoxVerticies(pmin, pmax);
 	if (!vm->m_area.contains(VoxelArea(pmin, pmax)))

src/threading/semaphore.h

@@ -35,6 +35,8 @@ public:
 	Semaphore(int val = 0);
 	~Semaphore();
 
+	DISABLE_CLASS_COPY(Semaphore);
+
 	void post(unsigned int num = 1);
 	void wait();
 	bool wait(unsigned int time_ms);
@@ -47,6 +49,4 @@ private:
 #else
 	sem_t semaphore;
 #endif
-
-	DISABLE_CLASS_COPY(Semaphore);
 };

src/unittest/test.h

@@ -31,7 +31,7 @@ class TestFailedException : public std::exception {
 };
 
 // Runs a unit test and reports results
-#define TEST(fxn, ...) do {                                                   \
+#define TEST(fxn, ...) {                                                      \
 	u64 t1 = porting::getTimeMs();                                            \
 	try {                                                                     \
 		fxn(__VA_ARGS__);                                                     \
@@ -47,21 +47,20 @@ class TestFailedException : public std::exception {
 	num_tests_run++;                                                          \
 	u64 tdiff = porting::getTimeMs() - t1;                                    \
 	rawstream << #fxn << " - " << tdiff << "ms" << std::endl;                 \
-} while (0)
+}
 
 // Asserts the specified condition is true, or fails the current unit test
-#define UASSERT(x) do {                                         \
+#define UASSERT(x)                                              \
 	if (!(x)) {                                                 \
 		rawstream << "Test assertion failed: " #x << std::endl  \
 			<< "    at " << fs::GetFilenameFromPath(__FILE__)   \
 			<< ":" << __LINE__ << std::endl;                    \
 		throw TestFailedException();                            \
-	}                                                           \
-} while (0)
+	}
 
 // Asserts the specified condition is true, or fails the current unit test
 // and prints the format specifier fmt
-#define UTEST(x, fmt, ...) do {                                          \
+#define UTEST(x, fmt, ...)                                               \
 	if (!(x)) {                                                          \
 		char utest_buf[1024];                                            \
 		snprintf(utest_buf, sizeof(utest_buf), fmt, __VA_ARGS__);        \
@@ -69,8 +68,7 @@ class TestFailedException : public std::exception {
 			<< "    at " << fs::GetFilenameFromPath(__FILE__)            \
 			<< ":" << __LINE__ << std::endl;                             \
 		throw TestFailedException();                                     \
-	}                                                                    \
-} while (0)
+	}
 
 // Asserts the comparison specified by CMP is true, or fails the current unit test
 #define UASSERTCMP(T, CMP, actual, expected) do {                         \

src/unittest/test_noderesolver.cpp

@@ -109,28 +109,28 @@ void TestNodeResolver::testNodeResolving(IWritableNodeDefManager *ndef)
 	Foobar foobar;
 	size_t i;
 
-	foobar.m_nodenames.push_back("default:torch");
+	foobar.m_nodenames.emplace_back("default:torch");
 
-	foobar.m_nodenames.push_back("default:dirt_with_grass");
-	foobar.m_nodenames.push_back("default:water");
-	foobar.m_nodenames.push_back("default:abloobloobloo");
-	foobar.m_nodenames.push_back("default:stone");
-	foobar.m_nodenames.push_back("default:shmegoldorf");
+	foobar.m_nodenames.emplace_back("default:dirt_with_grass");
+	foobar.m_nodenames.emplace_back("default:water");
+	foobar.m_nodenames.emplace_back("default:abloobloobloo");
+	foobar.m_nodenames.emplace_back("default:stone");
+	foobar.m_nodenames.emplace_back("default:shmegoldorf");
 	foobar.m_nnlistsizes.push_back(5);
 
-	foobar.m_nodenames.push_back("group:liquids");
+	foobar.m_nodenames.emplace_back("group:liquids");
 	foobar.m_nnlistsizes.push_back(1);
 
-	foobar.m_nodenames.push_back("default:warf");
-	foobar.m_nodenames.push_back("default:stone");
-	foobar.m_nodenames.push_back("default:bloop");
+	foobar.m_nodenames.emplace_back("default:warf");
+	foobar.m_nodenames.emplace_back("default:stone");
+	foobar.m_nodenames.emplace_back("default:bloop");
 	foobar.m_nnlistsizes.push_back(3);
 
 	foobar.m_nnlistsizes.push_back(0);
 
-	foobar.m_nodenames.push_back("default:brick");
-	foobar.m_nodenames.push_back("default:desert_stone");
-	foobar.m_nodenames.push_back("default:shnitzle");
+	foobar.m_nodenames.emplace_back("default:brick");
+	foobar.m_nodenames.emplace_back("default:desert_stone");
+	foobar.m_nodenames.emplace_back("default:shnitzle");
 
 	ndef->pendNodeResolve(&foobar);
 	UASSERT(foobar.m_ndef == ndef);
@@ -187,15 +187,15 @@ void TestNodeResolver::testPendingResolveCancellation(IWritableNodeDefManager *n
 	Foobaz foobaz1;
 	foobaz1.test_content1 = 1234;
 	foobaz1.test_content2 = 5678;
-	foobaz1.m_nodenames.push_back("default:dirt_with_grass");
-	foobaz1.m_nodenames.push_back("default:abloobloobloo");
+	foobaz1.m_nodenames.emplace_back("default:dirt_with_grass");
+	foobaz1.m_nodenames.emplace_back("default:abloobloobloo");
 	ndef->pendNodeResolve(&foobaz1);
 
 	Foobaz foobaz2;
 	foobaz2.test_content1 = 1234;
 	foobaz2.test_content2 = 5678;
-	foobaz2.m_nodenames.push_back("default:dirt_with_grass");
-	foobaz2.m_nodenames.push_back("default:abloobloobloo");
+	foobaz2.m_nodenames.emplace_back("default:dirt_with_grass");
+	foobaz2.m_nodenames.emplace_back("default:abloobloobloo");
 	ndef->pendNodeResolve(&foobaz2);
 
 	ndef->cancelNodeResolveCallback(&foobaz1);

src/unittest/test_schematic.cpp

@@ -67,10 +67,10 @@ void TestSchematic::testMtsSerializeDeserialize(INodeDefManager *ndef)
 		std::ios_base::in | std::ios_base::out);
 
 	std::vector<std::string> names;
-	names.push_back("foo");
-	names.push_back("bar");
-	names.push_back("baz");
-	names.push_back("qux");
+	names.emplace_back("foo");
+	names.emplace_back("bar");
+	names.emplace_back("baz");
+	names.emplace_back("qux");
 
 	Schematic schem, schem2;
 
@@ -121,9 +121,9 @@ void TestSchematic::testLuaTableSerialize(INodeDefManager *ndef)
 		schem.slice_probs[y] = MTSCHEM_PROB_ALWAYS;
 
 	std::vector<std::string> names;
-	names.push_back("air");
-	names.push_back("default:lava_source");
-	names.push_back("default:glass");
+	names.emplace_back("air");
+	names.emplace_back("default:lava_source");
+	names.emplace_back("default:glass");
 
 	std::ostringstream ss(std::ios_base::binary);
 

src/unittest/test_threading.cpp

@@ -166,16 +166,16 @@ void TestThreading::testAtomicSemaphoreThread()
 	static const u8 num_threads = 4;
 
 	AtomicTestThread *threads[num_threads];
-	for (u8 i = 0; i < num_threads; ++i) {
-		threads[i] = new AtomicTestThread(val, trigger);
-		UASSERT(threads[i]->start());
+	for (auto &thread : threads) {
+		thread = new AtomicTestThread(val, trigger);
+		UASSERT(thread->start());
 	}
 
 	trigger.post(num_threads);
 
-	for (u8 i = 0; i < num_threads; ++i) {
-		threads[i]->wait();
-		delete threads[i];
+	for (AtomicTestThread *thread : threads) {
+		thread->wait();
+		delete thread;
 	}
 
 	UASSERT(val == num_threads * 0x10000);

src/unittest/test_voxelmanipulator.cpp

@@ -61,8 +61,8 @@ void TestVoxelManipulator::testVoxelArea()
 
 	// Correct results
 	std::vector<VoxelArea> results;
-	results.push_back(VoxelArea(v3s16(-2,-2,-3), v3s16(3,2,-3)));
-	results.push_back(VoxelArea(v3s16(3,-2,-2), v3s16(3,2,2)));
+	results.emplace_back(v3s16(-2,-2,-3), v3s16(3,2,-3));
+	results.emplace_back(v3s16(3,-2,-2), v3s16(3,2,2));
 
 	UASSERT(aa.size() == results.size());
 

src/util/auth.cpp

@@ -23,7 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "base64.h"
 #include "sha1.h"
 #include "srp.h"
-#include "string.h"
+#include "util/string.h"
 #include "debug.h"
 
 // Get an sha-1 hash of the player's name combined with

src/util/base64.cpp

@@ -40,8 +40,9 @@ static inline bool is_base64(unsigned char c) {
 
 bool base64_is_valid(std::string const& s)
 {
-	for(size_t i=0; i<s.size(); i++)
-		if(!is_base64(s[i])) return false;
+	for (char i : s)
+		if (!is_base64(i))
+			return false;
 	return true;
 }
 

src/util/container.h

@@ -79,7 +79,7 @@ template<typename Key, typename Value>
 class MutexedMap
 {
 public:
-	MutexedMap() {}
+	MutexedMap() = default;
 
 	void set(const Key &name, const Value &value)
 	{
@@ -128,7 +128,8 @@ public:
 	template<typename Key, typename U, typename Caller, typename CallerData>
 	friend class RequestQueue;
 
-	MutexedQueue() {}
+	MutexedQueue() = default;
+
 	bool empty() const
 	{
 		MutexAutoLock lock(m_mutex);
@@ -153,9 +154,9 @@ public:
 			T t = m_queue.front();
 			m_queue.pop_front();
 			return t;
-		} else {
-			return T();
 		}
+
+		return T();
 	}
 
 	T pop_front(u32 wait_time_max_ms)
@@ -166,9 +167,9 @@ public:
 			T t = m_queue.front();
 			m_queue.pop_front();
 			return t;
-		} else {
-			throw ItemNotFoundException("MutexedQueue: queue is empty");
 		}
+
+		throw ItemNotFoundException("MutexedQueue: queue is empty");
 	}
 
 	T pop_frontNoEx()
@@ -190,9 +191,9 @@ public:
 			T t = m_queue.back();
 			m_queue.pop_back();
 			return t;
-		} else {
-			throw ItemNotFoundException("MutexedQueue: queue is empty");
 		}
+
+		throw ItemNotFoundException("MutexedQueue: queue is empty");
 	}
 
 	/* this version of pop_back returns a empty element of T on timeout.
@@ -206,9 +207,9 @@ public:
 			T t = m_queue.back();
 			m_queue.pop_back();
 			return t;
-		} else {
-			return T();
 		}
+
+		return T();
 	}
 
 	T pop_backNoEx()

src/util/numeric.cpp

@@ -23,7 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "../constants.h" // BS, MAP_BLOCKSIZE
 #include "../noise.h" // PseudoRandom, PcgRandom
 #include "../threading/mutex_auto_lock.h"
-#include <string.h>
+#include <cstring>
 
 
 // myrand

src/util/pointedthing.h

@@ -81,7 +81,7 @@ struct PointedThing
 	f32 distanceSq = 0;
 
 	//! Constructor for POINTEDTHING_NOTHING
-	PointedThing() {};
+	PointedThing() = default;
 	//! Constructor for POINTEDTHING_NODE
 	PointedThing(const v3s16 &under, const v3s16 &above,
 		const v3s16 &real_under, const v3f &point, const v3s16 &normal,

src/util/serialize.cpp

@@ -156,8 +156,8 @@ std::string serializeWideString(const std::wstring &plain)
 	writeU16((u8 *)buf, plain.size());
 	s.append(buf, 2);
 
-	for (u32 i = 0; i < plain.size(); i++) {
-		writeU16((u8 *)buf, plain[i]);
+	for (wchar_t i : plain) {
+		writeU16((u8 *)buf, i);
 		s.append(buf, 2);
 	}
 	return s;
@@ -246,8 +246,7 @@ std::string serializeJsonString(const std::string &plain)
 	std::ostringstream os(std::ios::binary);
 	os << "\"";
 
-	for (size_t i = 0; i < plain.size(); i++) {
-		char c = plain[i];
+	for (char c : plain) {
 		switch (c) {
 			case '"':
 				os << "\\\"";
@@ -308,7 +307,9 @@ std::string deSerializeJsonString(std::istream &is)
 
 		if (c == '"') {
 			return os.str();
-		} else if (c == '\\') {
+		}
+
+		if (c == '\\') {
 			c2 = is.get();
 			if (is.eof())
 				throw SerializationError("JSON string ended prematurely");
@@ -390,16 +391,17 @@ std::string deSerializeJsonStringIfNeeded(std::istream &is)
 				// Found end of word
 				is.unget();
 				break;
-			} else {
-				tmp_os << c;
 			}
+
+			tmp_os << c;
 		}
 		expect_initial_quote = false;
 	}
 	if (is_json) {
 		std::istringstream tmp_is(tmp_os.str(), std::ios::binary);
 		return deSerializeJsonString(tmp_is);
-	} else
+	}
+
 	return tmp_os.str();
 }
 

src/util/serialize.h

@@ -37,7 +37,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 		#include <endian.h>
 	#endif
 #endif
-#include <string.h> // for memcpy
+#include <cstring> // for memcpy
 #include <iostream>
 #include <string>
 #include <vector>

src/util/sha1.cpp

@@ -24,10 +24,10 @@ SOFTWARE.
 
 */
 
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <assert.h>
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <cassert>
 
 #include "sha1.h"
 

src/util/srp.cpp

@@ -31,13 +31,14 @@
 	#include <windows.h>
 	#include <wincrypt.h>
 #else
-	#include <time.h>
+	#include <ctime>
+
 #endif
 // clang-format on
 
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
+#include <cstdlib>
+#include <cstring>
+#include <cstdio>
 
 #include <config.h>
 

src/util/thread.h

@@ -78,8 +78,8 @@ public:
 template<typename Key, typename T, typename Caller, typename CallerData>
 class GetRequest {
 public:
-	GetRequest() {}
-	~GetRequest() {}
+	GetRequest() = default;
+	~GetRequest() = default;
 
 	GetRequest(const Key &a_key): key(a_key)
 	{
@@ -189,7 +189,7 @@ class UpdateThread : public Thread
 {
 public:
 	UpdateThread(const std::string &name) : Thread(name + "Update") {}
-	~UpdateThread() {}
+	~UpdateThread() = default;
 
 	void deferUpdate() { m_update_sem.post(); }