diff --git a/commands/command_divelist.cpp b/commands/command_divelist.cpp
index c55652ab1..261e492c1 100644
--- a/commands/command_divelist.cpp
+++ b/commands/command_divelist.cpp
@@ -234,7 +234,7 @@ DivesAndSitesToRemove DiveListBase::addDives(DivesAndTripsToAdd &toAdd)
 	if (!change.newShown.empty() || !change.newHidden.empty())
 		emit diveListNotifier.numShownChanged();
 
-	return { res, sites };
+	return { std::move(res), std::move(sites) };
 }
 
 // This helper function renumbers dives according to an array of id/number pairs.
diff --git a/commands/command_pictures.cpp b/commands/command_pictures.cpp
index 9a17ca9bf..604f7dfea 100644
--- a/commands/command_pictures.cpp
+++ b/commands/command_pictures.cpp
@@ -83,7 +83,7 @@ static std::vector<PictureListForAddition> removePictures(std::vector<PictureLis
 		if (!toAdd.pics.empty())
 			res.push_back(toAdd);
 		invalidate_dive_cache(list.d);
-		emit diveListNotifier.picturesRemoved(list.d, filenames);
+		emit diveListNotifier.picturesRemoved(list.d, std::move(filenames));
 	}
 	picturesToRemove.clear();
 	return res;
diff --git a/core/configuredivecomputer.cpp b/core/configuredivecomputer.cpp
index d3a398933..177766c5d 100644
--- a/core/configuredivecomputer.cpp
+++ b/core/configuredivecomputer.cpp
@@ -65,7 +65,7 @@ static QString writeGasDetails(gas g)
 		}).join(QLatin1Char(','));
 }
 
-bool ConfigureDiveComputer::saveXMLBackup(QString fileName, DeviceDetails *details, device_data_t *data)
+bool ConfigureDiveComputer::saveXMLBackup(const QString &fileName, DeviceDetails *details, device_data_t *data)
 {
 	QString xml = "";
 	QString vendor = data->vendor;
@@ -192,7 +192,7 @@ bool ConfigureDiveComputer::saveXMLBackup(QString fileName, DeviceDetails *detai
 	return true;
 }
 
-bool ConfigureDiveComputer::restoreXMLBackup(QString fileName, DeviceDetails *details)
+bool ConfigureDiveComputer::restoreXMLBackup(const QString &fileName, DeviceDetails *details)
 {
 	QFile file(fileName);
 	if (!file.open(QIODevice::ReadOnly)) {
@@ -491,7 +491,7 @@ bool ConfigureDiveComputer::restoreXMLBackup(QString fileName, DeviceDetails *de
 	return true;
 }
 
-void ConfigureDiveComputer::startFirmwareUpdate(QString fileName, device_data_t *data, bool forceUpdate)
+void ConfigureDiveComputer::startFirmwareUpdate(const QString &fileName, device_data_t *data, bool forceUpdate)
 {
 	setState(FWUPDATE);
 	if (firmwareThread)
diff --git a/core/configuredivecomputer.h b/core/configuredivecomputer.h
index 04a18be4b..3abe72b9e 100644
--- a/core/configuredivecomputer.h
+++ b/core/configuredivecomputer.h
@@ -34,9 +34,9 @@ public:
 	states currentState;
 	void saveDeviceDetails(DeviceDetails *details, device_data_t *data);
 	void fetchDeviceDetails();
-	bool saveXMLBackup(QString fileName, DeviceDetails *details, device_data_t *data);
-	bool restoreXMLBackup(QString fileName, DeviceDetails *details);
-	void startFirmwareUpdate(QString fileName, device_data_t *data, bool forceUpdate);
+	bool saveXMLBackup(const QString &fileName, DeviceDetails *details, device_data_t *data);
+	bool restoreXMLBackup(const QString &fileName, DeviceDetails *details);
+	void startFirmwareUpdate(const QString &fileName, device_data_t *data, bool forceUpdate);
 	void resetSettings(device_data_t *data);
 
 	QString dc_open(device_data_t *data);
diff --git a/core/divefilter.cpp b/core/divefilter.cpp
index 62ad820c9..3bc1ba9fd 100644
--- a/core/divefilter.cpp
+++ b/core/divefilter.cpp
@@ -145,10 +145,10 @@ bool DiveFilter::showDive(const struct dive *d) const
 void DiveFilter::startFilterDiveSites(QVector<dive_site *> ds)
 {
 	if (++diveSiteRefCount > 1) {
-		setFilterDiveSite(ds);
+		setFilterDiveSite(std::move(ds));
 	} else {
 		std::sort(ds.begin(), ds.end());
-		dive_sites = ds;
+		dive_sites = std::move(ds);
 		// When switching into dive site mode, reload the dive sites.
 		// TODO: why here? why not catch the filterReset signal in the map widget
 #ifdef MAP_SUPPORT
@@ -176,7 +176,7 @@ void DiveFilter::setFilterDiveSite(QVector<dive_site *> ds)
 	std::sort(ds.begin(), ds.end());
 	if (ds == dive_sites)
 		return;
-	dive_sites = ds;
+	dive_sites = std::move(ds);
 
 	emit diveListNotifier.filterReset();
 #ifdef MAP_SUPPORT
diff --git a/core/format.cpp b/core/format.cpp
index 3da97293a..e9a7c9525 100644
--- a/core/format.cpp
+++ b/core/format.cpp
@@ -33,7 +33,7 @@ enum length_modifier_t {
 };
 
 // Helper function to insert '+' or ' ' after last space
-static QString insert_sign(QString s, char sign)
+static QString insert_sign(const QString &s, char sign)
 {
 	// For space we can take a shortcut: insert in front
 	if (sign == ' ')
diff --git a/core/imagedownloader.cpp b/core/imagedownloader.cpp
index 6c2837b20..c90ac9f5f 100644
--- a/core/imagedownloader.cpp
+++ b/core/imagedownloader.cpp
@@ -186,7 +186,7 @@ Thumbnailer::Thumbnail Thumbnailer::getPictureThumbnailFromStream(QDataStream &s
 {
 	QImage res;
 	stream >> res;
-	return { res, MEDIATYPE_PICTURE, zero_duration };
+	return { std::move(res), MEDIATYPE_PICTURE, zero_duration };
 }
 
 void Thumbnailer::markVideoThumbnail(QImage &img)
@@ -362,7 +362,7 @@ void Thumbnailer::frameExtracted(QString filename, QImage thumbnail, duration_t
 		addVideoThumbnailToCache(filename, duration, thumbnail, offset);
 		QMutexLocker l(&lock);
 		workingOn.remove(filename);
-		emit thumbnailChanged(filename, thumbnail, duration);
+		emit thumbnailChanged(filename, std::move(thumbnail), duration);
 	}
 }
 
diff --git a/desktop-widgets/configuredivecomputerdialog.cpp b/desktop-widgets/configuredivecomputerdialog.cpp
index da916be7f..de43658dc 100644
--- a/desktop-widgets/configuredivecomputerdialog.cpp
+++ b/desktop-widgets/configuredivecomputerdialog.cpp
@@ -267,7 +267,7 @@ ConfigureDiveComputerDialog::ConfigureDiveComputerDialog(QWidget *parent) : QDia
 	settings.endGroup();
 }
 
-OstcFirmwareCheck::OstcFirmwareCheck(QString product) : parent(0)
+OstcFirmwareCheck::OstcFirmwareCheck(const QString &product) : parent(0)
 {
 	QUrl url;
 	memset(&devData, 1, sizeof(devData));
diff --git a/desktop-widgets/configuredivecomputerdialog.h b/desktop-widgets/configuredivecomputerdialog.h
index ec833a264..63117088a 100644
--- a/desktop-widgets/configuredivecomputerdialog.h
+++ b/desktop-widgets/configuredivecomputerdialog.h
@@ -123,7 +123,7 @@ private:
 class OstcFirmwareCheck : public QObject {
 	Q_OBJECT
 public:
-	explicit OstcFirmwareCheck(QString product);
+	explicit OstcFirmwareCheck(const QString &product);
 	void checkLatest(QWidget *parent, device_data_t *data);
 public
 slots:
diff --git a/desktop-widgets/divelistview.cpp b/desktop-widgets/divelistview.cpp
index 7a7e09fed..864cd7afc 100644
--- a/desktop-widgets/divelistview.cpp
+++ b/desktop-widgets/divelistview.cpp
@@ -823,7 +823,7 @@ void DiveListView::loadImages()
 	matchImagesToDives(fileNames);
 }
 
-void DiveListView::matchImagesToDives(QStringList fileNames)
+void DiveListView::matchImagesToDives(const QStringList &fileNames)
 {
 	ShiftImageTimesDialog shiftDialog(this, fileNames);
 	shiftDialog.setOffset(lastImageTimeOffset());
@@ -843,9 +843,9 @@ void DiveListView::matchImagesToDives(QStringList fileNames)
 
 		auto it = std::find_if(pics.begin(), pics.end(), [d](const Command::PictureListForAddition &l) { return l.d == d; });
 		if (it == pics.end())
-			pics.push_back(Command::PictureListForAddition { d, { pObj } });
+			pics.push_back(Command::PictureListForAddition { d, { std::move(pObj) } });
 		else
-			it->pics.push_back(pObj);
+			it->pics.push_back(std::move(pObj));
 	}
 
 	if (pics.empty())
@@ -862,7 +862,7 @@ void DiveListView::loadWebImages()
 	loadImagesFromURLs(urlDialog.url());
 }
 
-void DiveListView::loadImagesFromURLs(QString urls)
+void DiveListView::loadImagesFromURLs(const QString &urls)
 {
 	QStringList validUrls;
 	QStringList urlList = urls.split('\n');
diff --git a/desktop-widgets/divelistview.h b/desktop-widgets/divelistview.h
index 2d458b801..3d6051035 100644
--- a/desktop-widgets/divelistview.h
+++ b/desktop-widgets/divelistview.h
@@ -76,8 +76,8 @@ private:
 	void updateLastImageTimeOffset(int offset);
 	int lastImageTimeOffset();
 	void addToTrip(int delta);
-	void matchImagesToDives(QStringList fileNames);
-	void loadImagesFromURLs(QString urls);
+	void matchImagesToDives(const QStringList &fileNames);
+	void loadImagesFromURLs(const QString &urls);
 	bool eventFilter(QObject *, QEvent *) override;
 	void mouseDoubleClickEvent(QMouseEvent *event) override;
 	void contextMenuEvent(QContextMenuEvent *event) override;
diff --git a/desktop-widgets/divelogimportdialog.cpp b/desktop-widgets/divelogimportdialog.cpp
index b6633e7bd..faab2d6ad 100644
--- a/desktop-widgets/divelogimportdialog.cpp
+++ b/desktop-widgets/divelogimportdialog.cpp
@@ -361,7 +361,7 @@ DiveLogImportDialog::DiveLogImportDialog(QStringList fn, QWidget *parent) : QDia
 	ui(new Ui::DiveLogImportDialog)
 {
 	ui->setupUi(this);
-	fileNames = fn;
+	fileNames = std::move(fn);
 	column = 0;
 	delta = "0";
 	hw = "";
diff --git a/desktop-widgets/findmovedimagesdialog.cpp b/desktop-widgets/findmovedimagesdialog.cpp
index 088f195f6..a68291b14 100644
--- a/desktop-widgets/findmovedimagesdialog.cpp
+++ b/desktop-widgets/findmovedimagesdialog.cpp
@@ -94,7 +94,8 @@ struct Dir {
 	double progressFrom, progressTo;
 };
 
-QVector<FindMovedImagesDialog::Match> FindMovedImagesDialog::learnImages(const QString &rootdir, int maxRecursions, QVector<QString> imagePathsIn)
+QVector<FindMovedImagesDialog::Match> FindMovedImagesDialog::learnImages(const QString &rootdir, int maxRecursions,
+									 QVector<QString> imagePathsIn)
 {
 	QMap<QString, ImageMatch> matches;
 
@@ -193,7 +194,7 @@ void FindMovedImagesDialog::on_scanButton_clicked()
 	QFuture<QVector<Match>> future = QtConcurrent::run(
 			// Note that we capture everything but "this" by copy to avoid dangling references.
 			[this, dirName, imagePaths]()
-			{ return learnImages(dirName, 20, imagePaths);}
+			{ return learnImages(dirName, 20, std::move(imagePaths)); }
 	);
 	watcher.setFuture(future);
 }
diff --git a/desktop-widgets/mainwindow.cpp b/desktop-widgets/mainwindow.cpp
index 9c03f2e5b..7bbe669ff 100644
--- a/desktop-widgets/mainwindow.cpp
+++ b/desktop-widgets/mainwindow.cpp
@@ -1273,7 +1273,7 @@ void MainWindow::setTitle()
 	setWindowTitle("Subsurface: " + displayedFilename(existing_filename) + unsaved + shown);
 }
 
-void MainWindow::importFiles(const QStringList fileNames)
+void MainWindow::importFiles(const QStringList &fileNames)
 {
 	if (fileNames.isEmpty())
 		return;
@@ -1289,7 +1289,7 @@ void MainWindow::importFiles(const QStringList fileNames)
 	Command::importDives(&log, IMPORT_MERGE_ALL_TRIPS, source);
 }
 
-void MainWindow::loadFiles(const QStringList fileNames)
+void MainWindow::loadFiles(const QStringList &fileNames)
 {
 	if (fileNames.isEmpty()) {
 		refreshDisplay();
@@ -1359,7 +1359,7 @@ void MainWindow::on_actionImportDiveLog_triggered()
 	}
 
 	if (csvFiles.size()) {
-		DiveLogImportDialog diveLogImport(csvFiles, this);
+		DiveLogImportDialog diveLogImport(std::move(csvFiles), this);
 		diveLogImport.exec();
 	}
 }
diff --git a/desktop-widgets/mainwindow.h b/desktop-widgets/mainwindow.h
index 8055f2142..7df68750e 100644
--- a/desktop-widgets/mainwindow.h
+++ b/desktop-widgets/mainwindow.h
@@ -67,8 +67,8 @@ public:
 		Count
 	};
 
-	void loadFiles(const QStringList files);
-	void importFiles(const QStringList importFiles);
+	void loadFiles(const QStringList &files);
+	void importFiles(const QStringList &importFiles);
 	void setToolButtonsEnabled(bool enabled);
 	void setApplicationState(ApplicationState state);
 	void enterPreviousState();
diff --git a/desktop-widgets/simplewidgets.cpp b/desktop-widgets/simplewidgets.cpp
index 5b1c13044..07edfb5b7 100644
--- a/desktop-widgets/simplewidgets.cpp
+++ b/desktop-widgets/simplewidgets.cpp
@@ -515,7 +515,7 @@ QString TextHyperlinkEventFilter::tryToFormulateUrl(QTextCursor *cursor)
 		maybeUrlStr = left + right;
 	}
 
-	return stringMeetsOurUrlRequirements(maybeUrlStr) ? maybeUrlStr : QString();
+	return stringMeetsOurUrlRequirements(maybeUrlStr) ? std::move(maybeUrlStr) : QString();
 }
 
 QString TextHyperlinkEventFilter::fromCursorTilWhitespace(QTextCursor *cursor, bool searchBackwards)
diff --git a/desktop-widgets/templatelayout.cpp b/desktop-widgets/templatelayout.cpp
index 81ee337be..9edc15a40 100644
--- a/desktop-widgets/templatelayout.cpp
+++ b/desktop-widgets/templatelayout.cpp
@@ -59,7 +59,7 @@ void set_bundled_templates_as_read_only()
 		QFile::setPermissions(pathUser + QDir::separator() + f, QFileDevice::ReadOwner | QFileDevice::ReadUser);
 }
 
-void copy_bundled_templates(QString src, QString dst, QStringList *templateBackupList)
+void copy_bundled_templates(QString src, const QString &dst, QStringList *templateBackupList)
 {
 	QDir dir(src);
 	if (!dir.exists())
diff --git a/desktop-widgets/templatelayout.h b/desktop-widgets/templatelayout.h
index 724b43b59..85bfeb840 100644
--- a/desktop-widgets/templatelayout.h
+++ b/desktop-widgets/templatelayout.h
@@ -12,7 +12,7 @@ class QTextStream;
 
 void find_all_templates();
 void set_bundled_templates_as_read_only();
-void copy_bundled_templates(QString src, QString dst, QStringList *templateBackupList);
+void copy_bundled_templates(QString src, const QString &dst, QStringList *templateBackupList);
 
 enum token_t {LITERAL, FORSTART, FORSTOP, BLOCKSTART, BLOCKSTOP, IFSTART, IFSTOP, PARSERERROR};
 
diff --git a/qt-models/divetripmodel.cpp b/qt-models/divetripmodel.cpp
index 8ecd16f9e..e7ded819d 100644
--- a/qt-models/divetripmodel.cpp
+++ b/qt-models/divetripmodel.cpp
@@ -179,7 +179,7 @@ static QString displaySac(const struct dive *d, bool units)
 	if (!d->sac)
 		return QString();
 	QString s = get_volume_string(d->sac, units);
-	return units ? s + gettextFromC::tr("/min") : s;
+	return units ? s + gettextFromC::tr("/min") : std::move(s);
 }
 
 static QString displayWeight(const struct dive *d, bool units)
diff --git a/stats/chartlistmodel.cpp b/stats/chartlistmodel.cpp
index 1cf35e6e0..88fa64edc 100644
--- a/stats/chartlistmodel.cpp
+++ b/stats/chartlistmodel.cpp
@@ -35,8 +35,8 @@ void ChartListModel::initIcon(ChartSubType type, const char *name, int iconSize)
 	QPixmap iconWarning = icon.copy();
 	QPainter painter(&iconWarning);
 	painter.drawPixmap(0, 0, warningPixmap);
-	subTypeIcons[(size_t)type].normal = icon;
-	subTypeIcons[(size_t)type].warning = iconWarning;
+	subTypeIcons[(size_t)type].normal = std::move(icon);
+	subTypeIcons[(size_t)type].warning = std::move(iconWarning);
 }
 
 const QPixmap &ChartListModel::getIcon(ChartSubType type, bool warning) const
diff --git a/stats/statsvariables.cpp b/stats/statsvariables.cpp
index ad27c4404..9f67bd42c 100644
--- a/stats/statsvariables.cpp
+++ b/stats/statsvariables.cpp
@@ -271,7 +271,7 @@ QString StatsBinner::formatWithUnit(const StatsBin &bin) const
 {
 	QString unit = unitSymbol();
 	QString name = format(bin);
-	return unit.isEmpty() ? name : QStringLiteral("%1 %2").arg(name, unit);
+	return unit.isEmpty() ? std::move(name) : QStringLiteral("%1 %2").arg(name, unit);
 }
 
 QString StatsBinner::formatLowerBound(const StatsBin &bin) const
diff --git a/stats/statsview.cpp b/stats/statsview.cpp
index 3b21058aa..cc8064040 100644
--- a/stats/statsview.cpp
+++ b/stats/statsview.cpp
@@ -710,7 +710,7 @@ static std::vector<QString> makePercentageLabels(int count, int total, bool isHo
 	if (isHorizontal)
 		return { QString("%1 (%2)").arg(countString, percentageString) };
 	else
-		return { countString, percentageString };
+		return { std::move(countString), std::move(percentageString) };
 }
 
 // From a list of dive bins, make (dives, label) pairs, where the label