diff --git a/src/client/clientmap.cpp b/src/client/clientmap.cpp
index be8343009..c5b47532c 100644
--- a/src/client/clientmap.cpp
+++ b/src/client/clientmap.cpp
@@ -499,12 +499,12 @@ int ClientMap::getBackgroundBrightness(float max_d, u32 daylight_factor,
 	static v3f z_directions[50] = {
 		v3f(-100, 0, 0)
 	};
-	static f32 z_offsets[sizeof(z_directions)/sizeof(*z_directions)] = {
+	static f32 z_offsets[50] = {
 		-1000,
 	};
 
-	if(z_directions[0].X < -99){
-		for(u32 i=0; i<sizeof(z_directions)/sizeof(*z_directions); i++){
+	if (z_directions[0].X < -99) {
+		for (u32 i = 0; i < ARRLEN(z_directions); i++) {
 			// Assumes FOV of 72 and 16/9 aspect ratio
 			z_directions[i] = v3f(
 				0.02 * myrand_range(-100, 100),
@@ -520,7 +520,8 @@ int ClientMap::getBackgroundBrightness(float max_d, u32 daylight_factor,
 	if(sunlight_min_d > 35*BS)
 		sunlight_min_d = 35*BS;
 	std::vector<int> values;
-	for(u32 i=0; i<sizeof(z_directions)/sizeof(*z_directions); i++){
+	values.reserve(ARRLEN(z_directions));
+	for (u32 i = 0; i < ARRLEN(z_directions); i++) {
 		v3f z_dir = z_directions[i];
 		core::CMatrix4<f32> a;
 		a.buildRotateFromTo(v3f(0,1,0), z_dir);
diff --git a/src/client/clouds.cpp b/src/client/clouds.cpp
index 253dee8b9..5a075aaf0 100644
--- a/src/client/clouds.cpp
+++ b/src/client/clouds.cpp
@@ -170,7 +170,7 @@ void Clouds::render()
 
 	// Read noise
 
-	std::vector<char> grid(m_cloud_radius_i * 2 * m_cloud_radius_i * 2); // vector<bool> is broken
+	std::vector<bool> grid(m_cloud_radius_i * 2 * m_cloud_radius_i * 2);
 	std::vector<video::S3DVertex> vertices;
 	vertices.reserve(16 * m_cloud_radius_i * m_cloud_radius_i);
 
diff --git a/src/client/hud.cpp b/src/client/hud.cpp
index e5c7a4cfd..6d332490c 100644
--- a/src/client/hud.cpp
+++ b/src/client/hud.cpp
@@ -336,22 +336,22 @@ void Hud::drawLuaElements(const v3s16 &camera_offset)
 	irr::gui::IGUIFont* font = g_fontengine->getFont();
 
 	// Reorder elements by z_index
-	std::vector<size_t> ids;
+	std::vector<HudElement*> elems;
+	elems.reserve(player->maxHudId());
 
 	for (size_t i = 0; i != player->maxHudId(); i++) {
 		HudElement *e = player->getHud(i);
 		if (!e)
 			continue;
 
-		auto it = ids.begin();
-		while (it != ids.end() && player->getHud(*it)->z_index <= e->z_index)
+		auto it = elems.begin();
+		while (it != elems.end() && (*it)->z_index <= e->z_index)
 			++it;
 
-		ids.insert(it, i);
+		elems.insert(it, e);
 	}
 
-	for (size_t i : ids) {
-		HudElement *e = player->getHud(i);
+	for (HudElement *e : elems) {
 
 		v2s32 pos(floor(e->pos.X * (float) m_screensize.X + 0.5),
 				floor(e->pos.Y * (float) m_screensize.Y + 0.5));
@@ -522,8 +522,8 @@ void Hud::drawLuaElements(const v3s16 &camera_offset)
 				client->getMinimap()->drawMinimap(rect);
 				break; }
 			default:
-				infostream << "Hud::drawLuaElements: ignoring drawform " << e->type <<
-					" of hud element ID " << i << " due to unrecognized type" << std::endl;
+				infostream << "Hud::drawLuaElements: ignoring drawform " << e->type
+					<< " due to unrecognized type" << std::endl;
 		}
 	}
 }
diff --git a/src/client/sky.cpp b/src/client/sky.cpp
index caf695e7a..44c8f1574 100644
--- a/src/client/sky.cpp
+++ b/src/client/sky.cpp
@@ -82,13 +82,13 @@ Sky::Sky(s32 id, ITextureSource *tsrc, IShaderSource *ssrc) :
 	// Ensures that sun and moon textures and tonemaps are correct.
 	setSkyDefaults();
 	m_sun_texture = tsrc->isKnownSourceImage(m_sun_params.texture) ?
-		tsrc->getTextureForMesh(m_sun_params.texture) : NULL;
+		tsrc->getTextureForMesh(m_sun_params.texture) : nullptr;
 	m_moon_texture = tsrc->isKnownSourceImage(m_moon_params.texture) ?
-		tsrc->getTextureForMesh(m_moon_params.texture) : NULL;
+		tsrc->getTextureForMesh(m_moon_params.texture) : nullptr;
 	m_sun_tonemap = tsrc->isKnownSourceImage(m_sun_params.tonemap) ?
-		tsrc->getTexture(m_sun_params.tonemap) : NULL;
+		tsrc->getTexture(m_sun_params.tonemap) : nullptr;
 	m_moon_tonemap = tsrc->isKnownSourceImage(m_moon_params.tonemap) ?
-		tsrc->getTexture(m_moon_params.tonemap) : NULL;
+		tsrc->getTexture(m_moon_params.tonemap) : nullptr;
 
 	if (m_sun_texture) {
 		m_materials[3] = baseMaterial();
@@ -744,14 +744,14 @@ void Sky::place_sky_body(
 	}
 }
 
-void Sky::setSunTexture(std::string sun_texture,
-		std::string sun_tonemap, ITextureSource *tsrc)
+void Sky::setSunTexture(const std::string &sun_texture,
+		const std::string &sun_tonemap, ITextureSource *tsrc)
 {
 	// Ignore matching textures (with modifiers) entirely,
 	// but lets at least update the tonemap before hand.
 	m_sun_params.tonemap = sun_tonemap;
 	m_sun_tonemap = tsrc->isKnownSourceImage(m_sun_params.tonemap) ?
-		tsrc->getTexture(m_sun_params.tonemap) : NULL;
+		tsrc->getTexture(m_sun_params.tonemap) : nullptr;
 	m_materials[3].Lighting = !!m_sun_tonemap;
 
 	if (m_sun_params.texture == sun_texture)
@@ -780,7 +780,7 @@ void Sky::setSunTexture(std::string sun_texture,
 	}
 }
 
-void Sky::setSunriseTexture(std::string sunglow_texture,
+void Sky::setSunriseTexture(const std::string &sunglow_texture,
 		ITextureSource* tsrc)
 {
 	// Ignore matching textures (with modifiers) entirely.
@@ -792,14 +792,14 @@ void Sky::setSunriseTexture(std::string sunglow_texture,
 	);
 }
 
-void Sky::setMoonTexture(std::string moon_texture,
-		std::string moon_tonemap, ITextureSource *tsrc)
+void Sky::setMoonTexture(const std::string &moon_texture,
+	const std::string &moon_tonemap, ITextureSource *tsrc)
 {
 	// Ignore matching textures (with modifiers) entirely,
 	// but lets at least update the tonemap before hand.
 	m_moon_params.tonemap = moon_tonemap;
 	m_moon_tonemap = tsrc->isKnownSourceImage(m_moon_params.tonemap) ?
-		tsrc->getTexture(m_moon_params.tonemap) : NULL;
+		tsrc->getTexture(m_moon_params.tonemap) : nullptr;
 	m_materials[4].Lighting = !!m_moon_tonemap;
 
 	if (m_moon_params.texture == moon_texture)
@@ -893,7 +893,7 @@ void Sky::setSkyColors(const SkyColor &sky_color)
 }
 
 void Sky::setHorizonTint(video::SColor sun_tint, video::SColor moon_tint,
-		std::string use_sun_tint)
+	const std::string &use_sun_tint)
 {
 	// Change sun and moon tinting:
 	m_sky_params.fog_sun_tint = sun_tint;
@@ -907,7 +907,7 @@ void Sky::setHorizonTint(video::SColor sun_tint, video::SColor moon_tint,
 		m_default_tint = true;
 }
 
-void Sky::addTextureToSkybox(std::string texture, int material_id,
+void Sky::addTextureToSkybox(const std::string &texture, int material_id,
 		ITextureSource *tsrc)
 {
 	// Sanity check for more than six textures.
diff --git a/src/client/sky.h b/src/client/sky.h
index 342a97596..dc7da5021 100644
--- a/src/client/sky.h
+++ b/src/client/sky.h
@@ -65,15 +65,15 @@ public:
 	}
 
 	void setSunVisible(bool sun_visible) { m_sun_params.visible = sun_visible; }
-	void setSunTexture(std::string sun_texture,
-		std::string sun_tonemap, ITextureSource *tsrc);
+	void setSunTexture(const std::string &sun_texture,
+		const std::string &sun_tonemap, ITextureSource *tsrc);
 	void setSunScale(f32 sun_scale) { m_sun_params.scale = sun_scale; }
 	void setSunriseVisible(bool glow_visible) { m_sun_params.sunrise_visible = glow_visible; }
-	void setSunriseTexture(std::string sunglow_texture, ITextureSource* tsrc);
+	void setSunriseTexture(const std::string &sunglow_texture, ITextureSource* tsrc);
 
 	void setMoonVisible(bool moon_visible) { m_moon_params.visible = moon_visible; }
-	void setMoonTexture(std::string moon_texture,
-		std::string moon_tonemap, ITextureSource *tsrc);
+	void setMoonTexture(const std::string &moon_texture,
+		const std::string &moon_tonemap, ITextureSource *tsrc);
 	void setMoonScale(f32 moon_scale) { m_moon_params.scale = moon_scale; }
 
 	void setStarsVisible(bool stars_visible) { m_star_params.visible = stars_visible; }
@@ -87,21 +87,21 @@ public:
 	void setVisible(bool visible) { m_visible = visible; }
 	// Set only from set_sky API
 	void setCloudsEnabled(bool clouds_enabled) { m_clouds_enabled = clouds_enabled; }
-	void setFallbackBgColor(const video::SColor &fallback_bg_color)
+	void setFallbackBgColor(video::SColor fallback_bg_color)
 	{
 		m_fallback_bg_color = fallback_bg_color;
 	}
-	void overrideColors(const video::SColor &bgcolor, const video::SColor &skycolor)
+	void overrideColors(video::SColor bgcolor, video::SColor skycolor)
 	{
 		m_bgcolor = bgcolor;
 		m_skycolor = skycolor;
 	}
 	void setSkyColors(const SkyColor &sky_color);
 	void setHorizonTint(video::SColor sun_tint, video::SColor moon_tint,
-		std::string use_sun_tint);
+		const std::string &use_sun_tint);
 	void setInClouds(bool clouds) { m_in_clouds = clouds; }
 	void clearSkyboxTextures() { m_sky_params.textures.clear(); }
-	void addTextureToSkybox(std::string texture, int material_id,
+	void addTextureToSkybox(const  std::string &texture, int material_id,
 		ITextureSource *tsrc);
 	const video::SColorf &getCurrentStarColor() const { return m_star_color; }
 
@@ -126,7 +126,7 @@ private:
 	}
 
 	// Mix two colors by a given amount
-	video::SColor m_mix_scolor(video::SColor col1, video::SColor col2, f32 factor)
+	static video::SColor m_mix_scolor(video::SColor col1, video::SColor col2, f32 factor)
 	{
 		video::SColor result = video::SColor(
 				col1.getAlpha() * (1 - factor) + col2.getAlpha() * factor,
@@ -135,7 +135,7 @@ private:
 				col1.getBlue() * (1 - factor) + col2.getBlue() * factor);
 		return result;
 	}
-	video::SColorf m_mix_scolorf(video::SColorf col1, video::SColorf col2, f32 factor)
+	static video::SColorf m_mix_scolorf(video::SColorf col1, video::SColorf col2, f32 factor)
 	{
 		video::SColorf result =
 				video::SColorf(col1.r * (1 - factor) + col2.r * factor,
diff --git a/src/clientiface.cpp b/src/clientiface.cpp
index 797afd3c1..f35dcd0eb 100644
--- a/src/clientiface.cpp
+++ b/src/clientiface.cpp
@@ -671,7 +671,6 @@ void ClientInterface::UpdatePlayerList()
 		std::vector<session_t> clients = getClientIDs();
 		m_clients_names.clear();
 
-
 		if (!clients.empty())
 			infostream<<"Players:"<<std::endl;
 
diff --git a/src/gui/guiButtonItemImage.cpp b/src/gui/guiButtonItemImage.cpp
index 39272fe37..d9ab4b935 100644
--- a/src/gui/guiButtonItemImage.cpp
+++ b/src/gui/guiButtonItemImage.cpp
@@ -30,7 +30,7 @@ using namespace gui;
 
 GUIButtonItemImage::GUIButtonItemImage(gui::IGUIEnvironment *environment,
 		gui::IGUIElement *parent, s32 id, core::rect<s32> rectangle,
-		ISimpleTextureSource *tsrc, std::string item, Client *client,
+		ISimpleTextureSource *tsrc, const std::string &item, Client *client,
 		bool noclip)
 		: GUIButton (environment, parent, id, rectangle, tsrc, noclip)
 {
@@ -44,7 +44,7 @@ GUIButtonItemImage::GUIButtonItemImage(gui::IGUIEnvironment *environment,
 
 GUIButtonItemImage *GUIButtonItemImage::addButton(IGUIEnvironment *environment,
 		const core::rect<s32> &rectangle, ISimpleTextureSource *tsrc,
-		IGUIElement *parent, s32 id, const wchar_t *text, std::string item,
+		IGUIElement *parent, s32 id, const wchar_t *text, const std::string &item,
 		Client *client)
 {
 	GUIButtonItemImage *button = new GUIButtonItemImage(environment,
diff --git a/src/gui/guiButtonItemImage.h b/src/gui/guiButtonItemImage.h
index b90ac757e..205e957a7 100644
--- a/src/gui/guiButtonItemImage.h
+++ b/src/gui/guiButtonItemImage.h
@@ -33,13 +33,13 @@ public:
 	//! constructor
 	GUIButtonItemImage(gui::IGUIEnvironment *environment, gui::IGUIElement *parent,
 			s32 id, core::rect<s32> rectangle, ISimpleTextureSource *tsrc,
-			std::string item, Client *client, bool noclip = false);
+			const std::string &item, Client *client, bool noclip = false);
 
 	//! Do not drop returned handle
 	static GUIButtonItemImage *addButton(gui::IGUIEnvironment *environment,
 			const core::rect<s32> &rectangle, ISimpleTextureSource *tsrc,
-			IGUIElement *parent, s32 id, const wchar_t *text, std::string item,
-			Client *client);
+			IGUIElement *parent, s32 id, const wchar_t *text,
+			const std::string &item, Client *client);
 
 private:
 	Client *m_client;
diff --git a/src/inventory.cpp b/src/inventory.cpp
index 1ef9b13cd..fc1aaf371 100644
--- a/src/inventory.cpp
+++ b/src/inventory.cpp
@@ -965,13 +965,14 @@ InventoryList * Inventory::getList(const std::string &name)
 {
 	s32 i = getListIndex(name);
 	if(i == -1)
-		return NULL;
+		return nullptr;
 	return m_lists[i];
 }
 
 std::vector<const InventoryList*> Inventory::getLists()
 {
 	std::vector<const InventoryList*> lists;
+	lists.reserve(m_lists.size());
 	for (auto list : m_lists) {
 		lists.push_back(list);
 	}
@@ -990,11 +991,11 @@ bool Inventory::deleteList(const std::string &name)
 	return true;
 }
 
-const InventoryList * Inventory::getList(const std::string &name) const
+const InventoryList *Inventory::getList(const std::string &name) const
 {
 	s32 i = getListIndex(name);
 	if(i == -1)
-		return NULL;
+		return nullptr;
 	return m_lists[i];
 }
 
diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 3dcac439f..dd862e606 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -1544,10 +1544,10 @@ void NodeDefManager::deSerialize(std::istream &is)
 }
 
 
-void NodeDefManager::addNameIdMapping(content_t i, std::string name)
+void NodeDefManager::addNameIdMapping(content_t i, const std::string &name)
 {
 	m_name_id_mapping.set(i, name);
-	m_name_id_mapping_with_aliases.insert(std::make_pair(name, i));
+	m_name_id_mapping_with_aliases.emplace(name, i);
 }
 
 
diff --git a/src/nodedef.h b/src/nodedef.h
index b8cf7c14d..0de4dbc21 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -725,7 +725,7 @@ private:
 	 * @param i a content ID
 	 * @param name a node name
 	 */
-	void addNameIdMapping(content_t i, std::string name);
+	void addNameIdMapping(content_t i, const std::string &name);
 
 	/*!
 	 * Removes a content ID from all groups.
diff --git a/src/nodemetadata.cpp b/src/nodemetadata.cpp
index 6447c8785..f98732385 100644
--- a/src/nodemetadata.cpp
+++ b/src/nodemetadata.cpp
@@ -206,10 +206,9 @@ NodeMetadataList::~NodeMetadataList()
 std::vector<v3s16> NodeMetadataList::getAllKeys()
 {
 	std::vector<v3s16> keys;
-
-	NodeMetadataMap::const_iterator it;
-	for (it = m_data.begin(); it != m_data.end(); ++it)
-		keys.push_back(it->first);
+	keys.reserve(m_data.size());
+	for (const auto &it : m_data)
+		keys.push_back(it.first);
 
 	return keys;
 }
@@ -218,7 +217,7 @@ NodeMetadata *NodeMetadataList::get(v3s16 p)
 {
 	NodeMetadataMap::const_iterator n = m_data.find(p);
 	if (n == m_data.end())
-		return NULL;
+		return nullptr;
 	return n->second;
 }
 
@@ -235,7 +234,7 @@ void NodeMetadataList::remove(v3s16 p)
 void NodeMetadataList::set(v3s16 p, NodeMetadata *d)
 {
 	remove(p);
-	m_data.insert(std::make_pair(p, d));
+	m_data.emplace(p, d);
 }
 
 void NodeMetadataList::clear()
@@ -251,9 +250,8 @@ void NodeMetadataList::clear()
 int NodeMetadataList::countNonEmpty() const
 {
 	int n = 0;
-	NodeMetadataMap::const_iterator it;
-	for (it = m_data.begin(); it != m_data.end(); ++it) {
-		if (!it->second->empty())
+	for (const auto &it : m_data) {
+		if (!it.second->empty())
 			n++;
 	}
 	return n;
diff --git a/src/pathfinder.cpp b/src/pathfinder.cpp
index 1cb84997a..c45ce9158 100644
--- a/src/pathfinder.cpp
+++ b/src/pathfinder.cpp
@@ -1428,7 +1428,7 @@ std::string Pathfinder::dirToName(PathDirections dir)
 }
 
 /******************************************************************************/
-void Pathfinder::printPath(std::vector<v3s16> path)
+void Pathfinder::printPath(const std::vector<v3s16> &path)
 {
 	unsigned int current = 0;
 	for (std::vector<v3s16>::iterator i = path.begin();
diff --git a/src/settings.cpp b/src/settings.cpp
index 3415ff818..cff393e5f 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -43,11 +43,11 @@ std::unordered_map<std::string, const FlagDesc *> Settings::s_flags;
 Settings *Settings::createLayer(SettingsLayer sl, const std::string &end_tag)
 {
 	if ((int)sl < 0 || sl >= SL_TOTAL_COUNT)
-		throw new BaseException("Invalid settings layer");
+		throw BaseException("Invalid settings layer");
 
 	Settings *&pos = s_layers[(size_t)sl];
 	if (pos)
-		throw new BaseException("Setting layer " + std::to_string(sl) + " already exists");
+		throw BaseException("Setting layer " + std::to_string(sl) + " already exists");
 
 	pos = new Settings(end_tag);
 	pos->m_settingslayer = sl;
@@ -638,6 +638,7 @@ std::vector<std::string> Settings::getNames() const
 	MutexAutoLock lock(m_mutex);
 
 	std::vector<std::string> names;
+	names.reserve(m_settings.size());
 	for (const auto &settings_it : m_settings) {
 		names.push_back(settings_it.first);
 	}
diff --git a/src/util/areastore.cpp b/src/util/areastore.cpp
index cea526336..67bfef0c0 100644
--- a/src/util/areastore.cpp
+++ b/src/util/areastore.cpp
@@ -96,16 +96,15 @@ void AreaStore::deserialize(std::istream &is)
 
 	u16 num_areas = readU16(is);
 	std::vector<Area> areas;
+	areas.reserve(num_areas);
 	for (u32 i = 0; i < num_areas; ++i) {
 		Area a(U32_MAX);
 		a.minedge = readV3S16(is);
 		a.maxedge = readV3S16(is);
 		u16 data_len = readU16(is);
-		char *data = new char[data_len];
-		is.read(data, data_len);
-		a.data = std::string(data, data_len);
-		areas.emplace_back(a);
-		delete [] data;
+		a.data = std::string(data_len, '\0');
+		is.read(&a.data[0], data_len);
+		areas.emplace_back(std::move(a));
 	}
 
 	bool read_ids = is.good(); // EOF for old formats
diff --git a/src/util/container.h b/src/util/container.h
index 2ad2bbfc7..1c4a219f0 100644
--- a/src/util/container.h
+++ b/src/util/container.h
@@ -90,8 +90,7 @@ public:
 	bool get(const Key &name, Value *result) const
 	{
 		MutexAutoLock lock(m_mutex);
-		typename std::map<Key, Value>::const_iterator n =
-			m_values.find(name);
+		auto n = m_values.find(name);
 		if (n == m_values.end())
 			return false;
 		if (result)
@@ -103,11 +102,9 @@ public:
 	{
 		MutexAutoLock lock(m_mutex);
 		std::vector<Value> result;
-		for (typename std::map<Key, Value>::const_iterator
-				it = m_values.begin();
-				it != m_values.end(); ++it){
+		result.reserve(m_values.size());
+		for (auto it = m_values.begin(); it != m_values.end(); ++it)
 			result.push_back(it->second);
-		}
 		return result;
 	}
 
@@ -136,7 +133,7 @@ public:
 		return m_queue.empty();
 	}
 
-	void push_back(T t)
+	void push_back(const T &t)
 	{
 		MutexAutoLock lock(m_mutex);
 		m_queue.push_back(t);
@@ -151,7 +148,7 @@ public:
 		if (m_signal.wait(wait_time_max_ms)) {
 			MutexAutoLock lock(m_mutex);
 
-			T t = m_queue.front();
+			T t = std::move(m_queue.front());
 			m_queue.pop_front();
 			return t;
 		}
@@ -164,7 +161,7 @@ public:
 		if (m_signal.wait(wait_time_max_ms)) {
 			MutexAutoLock lock(m_mutex);
 
-			T t = m_queue.front();
+			T t = std::move(m_queue.front());
 			m_queue.pop_front();
 			return t;
 		}
@@ -178,7 +175,7 @@ public:
 
 		MutexAutoLock lock(m_mutex);
 
-		T t = m_queue.front();
+		T t = std::move(m_queue.front());
 		m_queue.pop_front();
 		return t;
 	}
@@ -188,7 +185,7 @@ public:
 		if (m_signal.wait(wait_time_max_ms)) {
 			MutexAutoLock lock(m_mutex);
 
-			T t = m_queue.back();
+			T t = std::move(m_queue.back());
 			m_queue.pop_back();
 			return t;
 		}
@@ -204,7 +201,7 @@ public:
 		if (m_signal.wait(wait_time_max_ms)) {
 			MutexAutoLock lock(m_mutex);
 
-			T t = m_queue.back();
+			T t = std::move(m_queue.back());
 			m_queue.pop_back();
 			return t;
 		}
@@ -218,7 +215,7 @@ public:
 
 		MutexAutoLock lock(m_mutex);
 
-		T t = m_queue.back();
+		T t = std::move(m_queue.back());
 		m_queue.pop_back();
 		return t;
 	}
diff --git a/src/util/enriched_string.cpp b/src/util/enriched_string.cpp
index 762d094eb..b1f95215e 100644
--- a/src/util/enriched_string.cpp
+++ b/src/util/enriched_string.cpp
@@ -65,12 +65,14 @@ void EnrichedString::operator=(const wchar_t *str)
 	addAtEnd(translate_string(std::wstring(str)), m_default_color);
 }
 
-void EnrichedString::addAtEnd(const std::wstring &s, const SColor &initial_color)
+void EnrichedString::addAtEnd(const std::wstring &s, SColor initial_color)
 {
 	SColor color(initial_color);
 	bool use_default = (m_default_length == m_string.size() &&
 		color == m_default_color);
 
+	m_colors.reserve(m_colors.size() + s.size());
+
 	size_t i = 0;
 	while (i < s.length()) {
 		if (s[i] != L'\x1b') {
@@ -200,12 +202,6 @@ const std::wstring &EnrichedString::getString() const
 	return m_string;
 }
 
-void EnrichedString::setDefaultColor(const irr::video::SColor &color)
-{
-	m_default_color = color;
-	updateDefaultColor();
-}
-
 void EnrichedString::updateDefaultColor()
 {
 	sanity_check(m_default_length <= m_colors.size());
diff --git a/src/util/enriched_string.h b/src/util/enriched_string.h
index c8a095887..16a0eef74 100644
--- a/src/util/enriched_string.h
+++ b/src/util/enriched_string.h
@@ -23,18 +23,22 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <vector>
 #include <SColor.h>
 
+using namespace irr;
+
 class EnrichedString {
 public:
 	EnrichedString();
 	EnrichedString(const std::wstring &s,
-		const irr::video::SColor &color = irr::video::SColor(255, 255, 255, 255));
+		const video::SColor &color = video::SColor(255, 255, 255, 255));
 	EnrichedString(const wchar_t *str,
-		const irr::video::SColor &color = irr::video::SColor(255, 255, 255, 255));
+		const video::SColor &color = video::SColor(255, 255, 255, 255));
 	EnrichedString(const std::wstring &string,
-		const std::vector<irr::video::SColor> &colors);
-	void clear();
+		const std::vector<video::SColor> &colors);
 	void operator=(const wchar_t *str);
-	void addAtEnd(const std::wstring &s, const irr::video::SColor &color);
+
+	void clear();
+
+	void addAtEnd(const std::wstring &s, video::SColor color);
 
 	// Adds the character source[i] at the end.
 	// An EnrichedString should always be able to be copied
@@ -49,12 +53,16 @@ public:
 	EnrichedString operator+(const EnrichedString &other) const;
 	void operator+=(const EnrichedString &other);
 	const wchar_t *c_str() const;
-	const std::vector<irr::video::SColor> &getColors() const;
+	const std::vector<video::SColor> &getColors() const;
 	const std::wstring &getString() const;
 
-	void setDefaultColor(const irr::video::SColor &color);
+	inline void setDefaultColor(video::SColor color)
+	{
+		m_default_color = color;
+		updateDefaultColor();
+	}
 	void updateDefaultColor();
-	inline const irr::video::SColor &getDefaultColor() const
+	inline const video::SColor &getDefaultColor() const
 	{
 		return m_default_color;
 	}
@@ -80,11 +88,11 @@ public:
 	{
 		return m_has_background;
 	}
-	inline irr::video::SColor getBackground() const
+	inline video::SColor getBackground() const
 	{
 		return m_background;
 	}
-	inline void setBackground(const irr::video::SColor &color)
+	inline void setBackground(video::SColor color)
 	{
 		m_background = color;
 		m_has_background = true;
@@ -92,10 +100,10 @@ public:
 
 private:
 	std::wstring m_string;
-	std::vector<irr::video::SColor> m_colors;
+	std::vector<video::SColor> m_colors;
 	bool m_has_background;
-	irr::video::SColor m_default_color;
-	irr::video::SColor m_background;
+	video::SColor m_default_color;
+	video::SColor m_background;
 	// This variable defines the length of the default-colored text.
 	// Change this to a std::vector if an "end coloring" tag is wanted.
 	size_t m_default_length = 0;
diff --git a/src/voxelalgorithms.cpp b/src/voxelalgorithms.cpp
index 62fd68890..ffb70aa71 100644
--- a/src/voxelalgorithms.cpp
+++ b/src/voxelalgorithms.cpp
@@ -65,7 +65,7 @@ struct ChangingLight {
 
 	ChangingLight() = default;
 
-	ChangingLight(const relative_v3 &rel_pos, const mapblock_v3 &block_pos,
+	ChangingLight(relative_v3 rel_pos, mapblock_v3 block_pos,
 		MapBlock *b, direction source_dir) :
 		rel_position(rel_pos),
 		block_position(block_pos),
@@ -125,8 +125,8 @@ struct LightQueue {
 	 * The parameters are the same as in ChangingLight's constructor.
 	 * \param light light level of the ChangingLight
 	 */
-	inline void push(u8 light, const relative_v3 &rel_pos,
-		const mapblock_v3 &block_pos, MapBlock *block,
+	inline void push(u8 light, relative_v3 rel_pos,
+		mapblock_v3 block_pos, MapBlock *block,
 		direction source_dir)
 	{
 		assert(light <= LIGHT_SUN);
@@ -467,7 +467,7 @@ bool is_sunlight_above(Map *map, v3s16 pos, const NodeDefManager *ndef)
 static const LightBank banks[] = { LIGHTBANK_DAY, LIGHTBANK_NIGHT };
 
 void update_lighting_nodes(Map *map,
-	std::vector<std::pair<v3s16, MapNode> > &oldnodes,
+	const std::vector<std::pair<v3s16, MapNode>> &oldnodes,
 	std::map<v3s16, MapBlock*> &modified_blocks)
 {
 	const NodeDefManager *ndef = map->getNodeDefManager();
@@ -482,8 +482,7 @@ void update_lighting_nodes(Map *map,
 		// won't change, since they didn't get their light from a
 		// modified node.
 		u8 min_safe_light = 0;
-		for (std::vector<std::pair<v3s16, MapNode> >::iterator it =
-				oldnodes.begin(); it < oldnodes.end(); ++it) {
+		for (auto it = oldnodes.cbegin(); it < oldnodes.cend(); ++it) {
 			u8 old_light = it->second.getLight(bank, ndef);
 			if (old_light > min_safe_light) {
 				min_safe_light = old_light;
@@ -495,8 +494,7 @@ void update_lighting_nodes(Map *map,
 			min_safe_light++;
 		}
 		// For each changed node process sunlight and initialize
-		for (std::vector<std::pair<v3s16, MapNode> >::iterator it =
-				oldnodes.begin(); it < oldnodes.end(); ++it) {
+		for (auto it = oldnodes.cbegin(); it < oldnodes.cend(); ++it) {
 			// Get position and block of the changed node
 			v3s16 p = it->first;
 			relative_v3 rel_pos;
diff --git a/src/voxelalgorithms.h b/src/voxelalgorithms.h
index 1452f30f4..bcbd3b586 100644
--- a/src/voxelalgorithms.h
+++ b/src/voxelalgorithms.h
@@ -45,7 +45,7 @@ namespace voxalgo
  */
 void update_lighting_nodes(
 	Map *map,
-	std::vector<std::pair<v3s16, MapNode> > &oldnodes,
+	const std::vector<std::pair<v3s16, MapNode>> &oldnodes,
 	std::map<v3s16, MapBlock*> &modified_blocks);
 
 /*!