diff --git a/ext/libstrawberry-common/core/logging.cpp b/ext/libstrawberry-common/core/logging.cpp
index 8c05db68a..380f3f426 100644
--- a/ext/libstrawberry-common/core/logging.cpp
+++ b/ext/libstrawberry-common/core/logging.cpp
@@ -24,7 +24,9 @@
 #include <cstring>
 
 #include <iostream>
+#include <utility>
 #include <memory>
+#include <chrono>
 
 #ifndef _MSC_VER
 #  include <cxxabi.h>
@@ -157,7 +159,8 @@ static void MessageHandler(QtMsgType type, const QMessageLogContext&, const QStr
       break;
   }
 
-  for (const QString &line : message.split(QLatin1Char('\n'))) {
+  const QStringList lines = message.split(QLatin1Char('\n'));
+  for (const QString &line : lines) {
     BufferedDebug d = CreateLogger<BufferedDebug>(level, QStringLiteral("unknown"), -1, nullptr);
     d << line.toLocal8Bit().constData();
     if (d.buf_) {
@@ -193,7 +196,8 @@ void SetLevels(const QString &levels) {
 
   if (!sClassLevels) return;
 
-  for (const QString &item : levels.split(QLatin1Char(','))) {
+  const QStringList items = levels.split(QLatin1Char(','));
+  for (const QString &item : items) {
     const QStringList class_level = item.split(QLatin1Char(':'));
 
     QString class_name;
diff --git a/ext/strawberry-tagreader/tagreaderworker.cpp b/ext/strawberry-tagreader/tagreaderworker.cpp
index cf33fb28b..0bfd35739 100644
--- a/ext/strawberry-tagreader/tagreaderworker.cpp
+++ b/ext/strawberry-tagreader/tagreaderworker.cpp
@@ -18,6 +18,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 #include <string>
 
@@ -73,7 +74,7 @@ void TagReaderWorker::DeviceClosed() {
 
 void TagReaderWorker::HandleMessage(const spb::tagreader::Message &message, spb::tagreader::Message &reply) {
 
-  for (shared_ptr<TagReaderBase> reader : tagreaders_) {
+  for (shared_ptr<TagReaderBase> reader : std::as_const(tagreaders_)) {
 
     if (message.has_is_media_file_request()) {
       const QString filename = QString::fromStdString(message.is_media_file_request().filename());
diff --git a/src/collection/collectionmodel.cpp b/src/collection/collectionmodel.cpp
index 62e6a96ba..8182685ab 100644
--- a/src/collection/collectionmodel.cpp
+++ b/src/collection/collectionmodel.cpp
@@ -629,7 +629,7 @@ void CollectionModel::UpdateSongsInternal(const SongList &songs) {
     }
   }
 
-  for (CollectionItem *item : album_parents) {
+  for (CollectionItem *item : std::as_const(album_parents)) {
     ClearItemPixmapCache(item);
     const QModelIndex idx = ItemToIndex(item);
     if (idx.isValid()) {
diff --git a/src/collection/collectionquery.cpp b/src/collection/collectionquery.cpp
index 3599b4c70..ef59d2843 100644
--- a/src/collection/collectionquery.cpp
+++ b/src/collection/collectionquery.cpp
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QMetaType>
 #include <QDateTime>
@@ -65,7 +67,7 @@ void CollectionQuery::AddWhere(const QString &column, const QVariant &value, con
     QStringList values = value.toStringList();
     QStringList final_values;
     final_values.reserve(values.count());
-    for (const QString &single_value : values) {
+    for (const QString &single_value : std::as_const(values)) {
       final_values.append(QStringLiteral("?"));
       bound_values_ << single_value;
     }
@@ -134,7 +136,7 @@ bool CollectionQuery::Exec() {
   if (!QSqlQuery::prepare(sql)) return false;
 
   // Bind values
-  for (const QVariant &value : bound_values_) {
+  for (const QVariant &value : std::as_const(bound_values_)) {
     QSqlQuery::addBindValue(value);
   }
 
diff --git a/src/context/contextalbum.cpp b/src/context/contextalbum.cpp
index 91bb2abb1..ea93dc3e3 100644
--- a/src/context/contextalbum.cpp
+++ b/src/context/contextalbum.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QtGlobal>
@@ -202,7 +203,7 @@ void ContextAlbum::DrawSpinner(QPainter *p) {
 
 void ContextAlbum::DrawPreviousCovers(QPainter *p) {
 
-  for (SharedPtr<PreviousCover> previous_cover : previous_covers_) {
+  for (SharedPtr<PreviousCover> previous_cover : std::as_const(previous_covers_)) {
     DrawImage(p, previous_cover->pixmap, previous_cover->opacity);
   }
 
@@ -254,7 +255,7 @@ void ContextAlbum::ScaleCover() {
 
 void ContextAlbum::ScalePreviousCovers() {
 
-  for (SharedPtr<PreviousCover> previous_cover : previous_covers_) {
+  for (SharedPtr<PreviousCover> previous_cover : std::as_const(previous_covers_)) {
     QImage image = ImageUtils::ScaleImage(previous_cover->image, QSize(desired_height_, desired_height_), devicePixelRatioF(), true);
     if (image.isNull()) {
       previous_cover->pixmap = QPixmap();
diff --git a/src/context/contextview.cpp b/src/context/contextview.cpp
index df2383ced..140320b44 100644
--- a/src/context/contextview.cpp
+++ b/src/context/contextview.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QObject>
 #include <QWidget>
@@ -429,10 +431,10 @@ void ContextView::NoSong() {
 
 void ContextView::UpdateFonts() {
 
-  for (QLabel *l : labels_play_all_) {
+  for (QLabel *l : std::as_const(labels_play_all_)) {
     l->setFont(font_normal_);
   }
-  for (QTextEdit *e : textedit_play_) {
+  for (QTextEdit *e : std::as_const(textedit_play_)) {
     e->setFont(font_normal_);
   }
 
@@ -620,11 +622,11 @@ void ContextView::UpdateSong(const Song &song) {
 
 void ContextView::ResetSong() {
 
-  for (QLabel *l : labels_play_data_) {
+  for (QLabel *l : std::as_const(labels_play_data_)) {
     l->clear();
   }
 
-  for (QTextEdit *l : textedit_play_) {
+  for (QTextEdit *l : std::as_const(textedit_play_)) {
     l->clear();
   }
 
diff --git a/src/core/application.cpp b/src/core/application.cpp
index 45bdeb320..a9c1b867b 100644
--- a/src/core/application.cpp
+++ b/src/core/application.cpp
@@ -24,6 +24,7 @@
 
 #include "application.h"
 
+#include <utility>
 #include <functional>
 #include <chrono>
 
@@ -257,11 +258,11 @@ Application::~Application() {
 
    qLog(Debug) << "Terminating application";
 
-  for (QThread *thread : threads_) {
+  for (QThread *thread : std::as_const(threads_)) {
     thread->quit();
   }
 
-  for (QThread *thread : threads_) {
+  for (QThread *thread : std::as_const(threads_)) {
     thread->wait();
     thread->deleteLater();
   }
diff --git a/src/core/mainwindow.cpp b/src/core/mainwindow.cpp
index 5b555333a..7cbd94d40 100644
--- a/src/core/mainwindow.cpp
+++ b/src/core/mainwindow.cpp
@@ -23,8 +23,9 @@
 #include "version.h"
 
 #include <cmath>
-#include <functional>
 #include <algorithm>
+#include <utility>
+#include <functional>
 #include <chrono>
 #include <memory>
 
@@ -1907,7 +1908,8 @@ void MainWindow::AddToPlaylistFromAction(QAction *action) {
   SongList songs;
 
   // Get the selected playlist items
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -1974,7 +1976,7 @@ void MainWindow::PlaylistRightClick(const QPoint global_pos, const QModelIndex &
   playlist_stop_after_->setEnabled(source_index.isValid());
 
   // Are any of the selected songs editable or queued?
-  QModelIndexList selection = ui_->playlist->view()->selectionModel()->selectedRows();
+  const QModelIndexList selection = ui_->playlist->view()->selectionModel()->selectedRows();
   bool cue_selected = false;
   qint64 selected = ui_->playlist->view()->selectionModel()->selectedRows().count();
   int editable = 0;
@@ -2121,7 +2123,7 @@ void MainWindow::PlaylistRightClick(const QPoint global_pos, const QModelIndex &
 #endif
 
     // Remove old item actions, if any.
-    for (QAction *action : playlistitem_actions_) {
+    for (QAction *action : std::as_const(playlistitem_actions_)) {
       playlist_menu_->removeAction(action);
     }
 
@@ -2143,7 +2145,8 @@ void MainWindow::PlaylistRightClick(const QPoint global_pos, const QModelIndex &
     QMenu *add_to_another_menu = new QMenu(tr("Add to another playlist"), this);
     add_to_another_menu->setIcon(IconLoader::Load(QStringLiteral("list-add")));
 
-    for (const PlaylistBackend::Playlist &playlist : app_->playlist_backend()->GetAllOpenPlaylists()) {
+    const PlaylistBackend::PlaylistList playlists = app_->playlist_backend()->GetAllOpenPlaylists();
+    for (const PlaylistBackend::Playlist &playlist : playlists) {
       // don't add the current playlist
       if (playlist.id != app_->playlist_manager()->current()->id()) {
         QAction *existing_playlist = new QAction(this);
@@ -2188,7 +2191,8 @@ void MainWindow::RescanSongs() {
 
   SongList songs;
 
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item(app_->playlist_manager()->current()->item_at(source_index.row()));
@@ -2213,7 +2217,8 @@ void MainWindow::EditTracks() {
   SongList songs;
   PlaylistItemPtrList items;
 
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item(app_->playlist_manager()->current()->item_at(source_index.row()));
@@ -2235,7 +2240,8 @@ void MainWindow::EditTracks() {
 
 void MainWindow::EditTagDialogAccepted() {
 
-  for (PlaylistItemPtr item : edit_tag_dialog_->playlist_items()) {
+  const PlaylistItemPtrList items = edit_tag_dialog_->playlist_items();
+  for (PlaylistItemPtr item : items) {
     item->Reload();
   }
 
@@ -2260,7 +2266,7 @@ void MainWindow::RenumberTracks() {
     if (first_song.track() > 0) track = first_song.track();
   }
 
-  for (const QModelIndex &proxy_index : indexes) {
+  for (const QModelIndex &proxy_index : std::as_const(indexes)) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -2291,7 +2297,8 @@ void MainWindow::SelectionSetValue() {
   Playlist::Column column = static_cast<Playlist::Column>(playlist_menu_index_.column());
   QVariant column_value = app_->playlist_manager()->current()->data(playlist_menu_index_);
 
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -2338,7 +2345,7 @@ void MainWindow::AddFile() {
   PlaylistParser parser(app_->collection_backend());
 
   // Show dialog
-  QStringList filenames = QFileDialog::getOpenFileNames(this, tr("Add file"), directory, QStringLiteral("%1 (%2);;%3;;%4").arg(tr("Music"), QLatin1String(FileView::kFileFilter), parser.filters(PlaylistParser::Type::Load), tr(kAllFilesFilterSpec)));
+  const QStringList filenames = QFileDialog::getOpenFileNames(this, tr("Add file"), directory, QStringLiteral("%1 (%2);;%3;;%4").arg(tr("Music"), QLatin1String(FileView::kFileFilter), parser.filters(PlaylistParser::Type::Load), tr(kAllFilesFilterSpec)));
 
   if (filenames.isEmpty()) return;
 
@@ -2405,7 +2412,8 @@ void MainWindow::ShowInCollection() {
   // Show the first valid selected track artist/album in CollectionView
 
   SongList songs;
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -2549,7 +2557,8 @@ void MainWindow::CommandlineOptionsReceived(const CommandlineOptions &options) {
   if (!options.urls().empty()) {
 
 #ifdef HAVE_TIDAL
-    for (const QUrl &url : options.urls()) {
+    const QList<QUrl> urls = options.urls();
+    for (const QUrl &url : urls) {
       if (url.scheme() == QLatin1String("tidal") && url.host() == QLatin1String("login")) {
         emit AuthorizationUrlReceived(url);
         return;
@@ -2652,7 +2661,8 @@ void MainWindow::AddFilesToTranscoder() {
 
   QStringList filenames;
 
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item(app_->playlist_manager()->current()->item_at(source_index.row()));
@@ -2764,7 +2774,8 @@ void MainWindow::PlaylistMoveToCollection() {
 void MainWindow::PlaylistOrganizeSelected(const bool copy) {
 
   SongList songs;
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -2786,7 +2797,8 @@ void MainWindow::PlaylistOrganizeSelected(const bool copy) {
 void MainWindow::PlaylistOpenInBrowser() {
 
   QList<QUrl> urls;
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     urls << QUrl(source_index.sibling(source_index.row(), static_cast<int>(Playlist::Column::Filename)).data().toString());
@@ -2799,7 +2811,8 @@ void MainWindow::PlaylistOpenInBrowser() {
 void MainWindow::PlaylistCopyUrl() {
 
   QList<QUrl> urls;
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -2830,7 +2843,7 @@ void MainWindow::PlaylistQueue() {
 
 void MainWindow::PlaylistQueuePlayNext() {
 
-  QModelIndexList selected_rows = ui_->playlist->view()->selectionModel()->selectedRows();
+  const QModelIndexList selected_rows = ui_->playlist->view()->selectionModel()->selectedRows();
   QModelIndexList indexes;
   indexes.reserve(selected_rows.count());
   for (const QModelIndex &proxy_index : selected_rows) {
@@ -2860,7 +2873,8 @@ void MainWindow::PlaylistCopyToDevice() {
 
   SongList songs;
 
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_index.row());
@@ -3061,7 +3075,8 @@ void MainWindow::AutoCompleteTags() {
 
   // Get the selected songs and start fetching tags for them
   SongList songs;
-  for (const QModelIndex &proxy_index : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex source_index = app_->playlist_manager()->current()->filter()->mapToSource(proxy_index);
     if (!source_index.isValid()) continue;
     PlaylistItemPtr item(app_->playlist_manager()->current()->item_at(source_index.row()));
@@ -3086,7 +3101,7 @@ void MainWindow::AutoCompleteTags() {
 
 void MainWindow::AutoCompleteTagsAccepted() {
 
-  for (PlaylistItemPtr item : autocomplete_tag_items_) {
+  for (PlaylistItemPtr item : std::as_const(autocomplete_tag_items_)) {
     item->Reload();
   }
   autocomplete_tag_items_.clear();
@@ -3278,7 +3293,8 @@ void MainWindow::PlaylistDelete() {
   SongList selected_songs;
   QStringList files;
   bool is_current_item = false;
-  for (const QModelIndex &proxy_idx : ui_->playlist->view()->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->playlist->view()->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_idx : proxy_indexes) {
     QModelIndex source_idx = app_->playlist_manager()->current()->filter()->mapToSource(proxy_idx);
     PlaylistItemPtr item = app_->playlist_manager()->current()->item_at(source_idx.row());
     if (!item || !item->Metadata().url().isLocalFile()) continue;
diff --git a/src/core/mpris2.cpp b/src/core/mpris2.cpp
index 906f2e6b5..4b3c79da5 100644
--- a/src/core/mpris2.cpp
+++ b/src/core/mpris2.cpp
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 #include <cmath>
 
 #include <QApplication>
@@ -141,7 +142,7 @@ Mpris2::Mpris2(Application *app, QObject *parent)
     data_dirs.append(QStringLiteral("/usr/share"));
   }
 
-  for (const QString &data_dir : data_dirs) {
+  for (const QString &data_dir : std::as_const(data_dirs)) {
     const QString desktopfilepath = QStringLiteral("%1/applications/%2.desktop").arg(data_dir, QGuiApplication::desktopFileName());
     if (QFile::exists(desktopfilepath)) {
       desktopfilepath_ = desktopfilepath;
@@ -618,7 +619,7 @@ MprisPlaylistList Mpris2::GetPlaylists(quint32 index, quint32 max_count, const Q
 
   Q_UNUSED(order);
 
-  QList<Playlist*> playlists = app_->playlist_manager()->GetAllPlaylists();
+  const QList<Playlist*> playlists = app_->playlist_manager()->GetAllPlaylists();
   MprisPlaylistList ret;
   ret.reserve(playlists.count());
   for (Playlist *p : playlists) {
diff --git a/src/covermanager/albumcoverchoicecontroller.cpp b/src/covermanager/albumcoverchoicecontroller.cpp
index ca2a34e33..2858ac096 100644
--- a/src/covermanager/albumcoverchoicecontroller.cpp
+++ b/src/covermanager/albumcoverchoicecontroller.cpp
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QGuiApplication>
 #include <QtConcurrentRun>
@@ -421,7 +423,7 @@ void AlbumCoverChoiceController::ShowCover(const Song &song, const QImage &image
     }
   }
 
-  for (const AlbumCoverLoaderOptions::Type type : cover_types_) {
+  for (const AlbumCoverLoaderOptions::Type type : std::as_const(cover_types_)) {
     switch (type) {
       case AlbumCoverLoaderOptions::Type::Unset:{
         if (song.art_unset()) {
@@ -757,7 +759,8 @@ bool AlbumCoverChoiceController::IsKnownImageExtension(const QString &suffix) {
 
 bool AlbumCoverChoiceController::CanAcceptDrag(const QDragEnterEvent *e) {
 
-  for (const QUrl &url : e->mimeData()->urls()) {
+  const QList<QUrl> urls = e->mimeData()->urls();
+  for (const QUrl &url : urls) {
     const QString suffix = QFileInfo(url.toLocalFile()).suffix().toLower();
     if (IsKnownImageExtension(suffix)) return true;
   }
@@ -767,7 +770,8 @@ bool AlbumCoverChoiceController::CanAcceptDrag(const QDragEnterEvent *e) {
 
 void AlbumCoverChoiceController::SaveCover(Song *song, const QDropEvent *e) {
 
-  for (const QUrl &url : e->mimeData()->urls()) {
+  const QList<QUrl> urls = e->mimeData()->urls();
+  for (const QUrl &url : urls) {
 
     const QString filename = url.toLocalFile();
     const QString suffix = QFileInfo(filename).suffix().toLower();
diff --git a/src/covermanager/albumcoverfetchersearch.cpp b/src/covermanager/albumcoverfetchersearch.cpp
index 408a6a9cd..006fe587a 100644
--- a/src/covermanager/albumcoverfetchersearch.cpp
+++ b/src/covermanager/albumcoverfetchersearch.cpp
@@ -23,6 +23,7 @@
 
 #include <cmath>
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QCoreApplication>
@@ -73,7 +74,7 @@ AlbumCoverFetcherSearch::~AlbumCoverFetcherSearch() {
 
 void AlbumCoverFetcherSearch::TerminateSearch() {
 
-  QList<int> ids = pending_requests_.keys();
+  const QList<int> ids = pending_requests_.keys();
   for (const int id : ids) {
     pending_requests_.take(id)->CancelSearch(id);
   }
@@ -93,7 +94,7 @@ void AlbumCoverFetcherSearch::Start(SharedPtr<CoverProviders> cover_providers) {
   QList<CoverProvider*> cover_providers_sorted = cover_providers->List();
   std::stable_sort(cover_providers_sorted.begin(), cover_providers_sorted.end(), ProviderCompareOrder);
 
-  for (CoverProvider *provider : cover_providers_sorted) {
+  for (CoverProvider *provider : std::as_const(cover_providers_sorted)) {
 
     if (!provider->is_enabled()) continue;
 
@@ -413,7 +414,7 @@ void AlbumCoverFetcherSearch::Cancel() {
     TerminateSearch();
   }
   else if (!pending_image_loads_.isEmpty()) {
-    QList<QNetworkReply*> replies = pending_image_loads_.keys();
+    const QList<QNetworkReply*> replies = pending_image_loads_.keys();
     for (QNetworkReply *reply : replies) {
       QObject::disconnect(reply, &QNetworkReply::finished, this, nullptr);
       reply->abort();
diff --git a/src/covermanager/albumcovermanager.cpp b/src/covermanager/albumcovermanager.cpp
index f2924d31e..00ea97c79 100644
--- a/src/covermanager/albumcovermanager.cpp
+++ b/src/covermanager/albumcovermanager.cpp
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QMainWindow>
@@ -351,7 +352,7 @@ void AlbumCoverManager::Reset() {
   QStringList artists(collection_backend_->GetAllArtistsWithAlbums());
   std::stable_sort(artists.begin(), artists.end(), CompareNocase);
 
-  for (const QString &artist : artists) {
+  for (const QString &artist : std::as_const(artists)) {
     if (artist.isEmpty()) continue;
     new QListWidgetItem(artist_icon_, artist, ui_->artists, Specific_Artist);
   }
@@ -388,7 +389,7 @@ void AlbumCoverManager::ArtistChanged(QListWidgetItem *current) {
   // Sort by album name.  The list is already sorted by sqlite but it was done case sensitively.
   std::stable_sort(albums.begin(), albums.end(), CompareAlbumNameNocase);
 
-  for (const CollectionBackend::Album &album_info : albums) {
+  for (const CollectionBackend::Album &album_info : std::as_const(albums)) {
 
     // Don't show songs without an album, obviously
     if (album_info.album.isEmpty()) continue;
@@ -499,7 +500,7 @@ bool AlbumCoverManager::ShouldHide(const AlbumItem &album_item, const QString &f
     return false;
   }
 
-  QStringList query = filter.split(QLatin1Char(' '));
+  const QStringList query = filter.split(QLatin1Char(' '));
   for (const QString &s : query) {
     bool in_text = album_item.text().contains(s, Qt::CaseInsensitive);
     bool in_albumartist = album_item.data(Role_AlbumArtist).toString().contains(s, Qt::CaseInsensitive);
@@ -590,7 +591,7 @@ bool AlbumCoverManager::eventFilter(QObject *obj, QEvent *e) {
     bool some_unset = false;
     bool some_clear = false;
 
-    for (QListWidgetItem *list_widget_item : context_menu_items_) {
+    for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
       AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
       if (ItemHasCover(*album_item)) some_with_covers = true;
       if (album_item->data(Role_ArtUnset).toBool()) {
@@ -672,7 +673,7 @@ void AlbumCoverManager::ShowCover() {
 
 void AlbumCoverManager::FetchSingleCover() {
 
-  for (QListWidgetItem *list_widget_item : context_menu_items_) {
+  for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
     AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
     quint64 id = cover_fetcher_->FetchAlbumCover(album_item->data(Role_AlbumArtist).toString(), album_item->data(Role_Album).toString(), QString(), false);
     cover_fetching_tasks_[id] = album_item;
@@ -713,7 +714,7 @@ void AlbumCoverManager::SaveCoverToFile() {
 
   // Load the image from disk
   AlbumCoverImageResult result;
-  for (const AlbumCoverLoaderOptions::Type cover_type : cover_types_) {
+  for (const AlbumCoverLoaderOptions::Type cover_type : std::as_const(cover_types_)) {
     switch (cover_type) {
       case AlbumCoverLoaderOptions::Type::Unset:
         return;
@@ -793,7 +794,7 @@ void AlbumCoverManager::SaveImageToAlbums(Song *song, const AlbumCoverImageResul
   // Force the found cover on all of the selected items
   QList<QUrl> urls;
   QList<AlbumItem*> album_items;
-  for (QListWidgetItem *list_widget_item : context_menu_items_) {
+  for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
     AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
     switch (album_cover_choice_controller_->get_save_album_cover_type()) {
       case CoverOptions::CoverType::Cache:
@@ -804,7 +805,7 @@ void AlbumCoverManager::SaveImageToAlbums(Song *song, const AlbumCoverImageResul
         break;
       }
       case CoverOptions::CoverType::Embedded:{
-        for (const QUrl &url : album_item->urls) {
+        for (const QUrl &url : std::as_const(album_item->urls)) {
           const bool art_embedded = !result.image_data.isEmpty();
           TagReaderReply *reply = app_->tag_reader_client()->SaveEmbeddedArt(url.toLocalFile(), TagReaderClient::SaveCoverOptions(result.image_data, result.mime_type));
           QObject::connect(reply, &TagReaderReply::Finished, this, [this, reply, album_item, url, art_embedded]() {
@@ -826,7 +827,7 @@ void AlbumCoverManager::UnsetCover() {
   if (context_menu_items_.isEmpty()) return;
 
   // Force the 'none' cover on all of the selected items
-  for (QListWidgetItem *list_widget_item : context_menu_items_) {
+  for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
     AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
     album_item->setIcon(icon_nocover_item_);
     album_item->setData(Role_ArtEmbedded, false);
@@ -845,7 +846,7 @@ void AlbumCoverManager::ClearCover() {
   if (context_menu_items_.isEmpty()) return;
 
   // Force the 'none' cover on all of the selected items
-  for (QListWidgetItem *list_widget_item : context_menu_items_) {
+  for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
     AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
     album_item->setIcon(icon_nocover_item_);
     album_item->setData(Role_ArtEmbedded, false);
@@ -861,7 +862,7 @@ void AlbumCoverManager::ClearCover() {
 
 void AlbumCoverManager::DeleteCover() {
 
-  for (QListWidgetItem *list_widget_item : context_menu_items_) {
+  for (QListWidgetItem *list_widget_item : std::as_const(context_menu_items_)) {
     AlbumItem *album_item = static_cast<AlbumItem*>(list_widget_item);
     Song song = AlbumItemAsSong(album_item);
     album_cover_choice_controller_->DeleteCover(&song);
diff --git a/src/covermanager/deezercoverprovider.cpp b/src/covermanager/deezercoverprovider.cpp
index 2eece7af9..d264817b3 100644
--- a/src/covermanager/deezercoverprovider.cpp
+++ b/src/covermanager/deezercoverprovider.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QtGlobal>
 #include <QObject>
@@ -214,7 +215,7 @@ void DeezerCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id)
 
   QMap<QUrl, CoverProviderSearchResult> results;
   int i = 0;
-  for (const QJsonValueRef json_value : array_data) {
+  for (const QJsonValue &json_value : std::as_const(array_data)) {
 
     if (!json_value.isObject()) {
       Error(QStringLiteral("Invalid Json reply, data array value is not a object."));
@@ -272,8 +273,8 @@ void DeezerCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id)
     cover_result.album = Song::AlbumRemoveDiscMisc(album);
 
     bool have_cover = false;
-    QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("cover_xl"), QSize(1000, 1000))
-                                                                              << qMakePair(QStringLiteral("cover_big"), QSize(500, 500));
+    const QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("cover_xl"), QSize(1000, 1000))
+                                                                                    << qMakePair(QStringLiteral("cover_big"), QSize(500, 500));
     for (const QPair<QString, QSize> &cover_size : cover_sizes) {
       if (!obj_album.contains(cover_size.first)) continue;
       QString cover = obj_album[cover_size.first].toString();
diff --git a/src/covermanager/discogscoverprovider.cpp b/src/covermanager/discogscoverprovider.cpp
index e974205c5..c7e86a111 100644
--- a/src/covermanager/discogscoverprovider.cpp
+++ b/src/covermanager/discogscoverprovider.cpp
@@ -146,9 +146,9 @@ void DiscogsCoverProvider::SendSearchRequest(SharedPtr<DiscogsCoverSearchContext
 
 QNetworkReply *DiscogsCoverProvider::CreateRequest(QUrl url, const ParamList &params_provided) {
 
-  ParamList params = ParamList() << Param(QStringLiteral("key"), QString::fromLatin1(QByteArray::fromBase64(kAccessKeyB64)))
-                                 << Param(QStringLiteral("secret"), QString::fromLatin1(QByteArray::fromBase64(kSecretKeyB64)))
-                                 << params_provided;
+  const ParamList params = ParamList() << Param(QStringLiteral("key"), QString::fromLatin1(QByteArray::fromBase64(kAccessKeyB64)))
+                                       << Param(QStringLiteral("secret"), QString::fromLatin1(QByteArray::fromBase64(kSecretKeyB64)))
+                                       << params_provided;
 
   QUrlQuery url_query;
   QStringList query_items;
@@ -266,8 +266,8 @@ void DiscogsCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id)
     return;
   }
 
-  QJsonArray array_results = value_results.toArray();
-  for (QJsonValueRef value_result : array_results) {
+  const QJsonArray array_results = value_results.toArray();
+  for (const QJsonValue &value_result : array_results) {
 
     if (!value_result.isObject()) {
       Error(QStringLiteral("Invalid Json reply, results value is not a object."));
@@ -371,10 +371,10 @@ void DiscogsCoverProvider::HandleReleaseReply(QNetworkReply *reply, const int se
     EndSearch(search, release.id);
     return;
   }
-  QJsonArray array_artists = value_artists.toArray();
+  const QJsonArray array_artists = value_artists.toArray();
   int i = 0;
   QString artist;
-  for (const QJsonValueRef value_artist : array_artists) {
+  for (const QJsonValue &value_artist : array_artists) {
     if (!value_artist.isObject()) {
       Error(QStringLiteral("Invalid Json reply, atists array value is not a object."));
       continue;
@@ -407,7 +407,7 @@ void DiscogsCoverProvider::HandleReleaseReply(QNetworkReply *reply, const int se
     EndSearch(search, release.id);
     return;
   }
-  QJsonArray array_images = value_images.toArray();
+  const QJsonArray array_images = value_images.toArray();
 
   if (array_images.isEmpty()) {
     Error(QStringLiteral("Invalid Json reply, images array is empty."));
@@ -415,7 +415,7 @@ void DiscogsCoverProvider::HandleReleaseReply(QNetworkReply *reply, const int se
     return;
   }
 
-  for (const QJsonValueRef value_image : array_images) {
+  for (const QJsonValue &value_image : array_images) {
 
     if (!value_image.isObject()) {
       Error(QStringLiteral("Invalid Json reply, images array value is not an object."));
diff --git a/src/covermanager/lastfmcoverprovider.cpp b/src/covermanager/lastfmcoverprovider.cpp
index 9d151ac40..ae668f6b2 100644
--- a/src/covermanager/lastfmcoverprovider.cpp
+++ b/src/covermanager/lastfmcoverprovider.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QLocale>
@@ -97,7 +98,7 @@ bool LastFmCoverProvider::StartSearch(const QString &artist, const QString &albu
 
   QUrlQuery url_query;
   QString data_to_sign;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
     data_to_sign += param.first + param.second;
   }
@@ -221,9 +222,9 @@ void LastFmCoverProvider::QueryFinished(QNetworkReply *reply, const int id, cons
     emit SearchFinished(id, results);
     return;
   }
-  QJsonArray array_type = value_type.toArray();
+  const QJsonArray array_type = value_type.toArray();
 
-  for (const QJsonValueRef value : array_type) {
+  for (const QJsonValue &value : array_type) {
 
     if (!value.isObject()) {
       Error(QStringLiteral("Invalid Json reply, value in albummatches/trackmatches array is not a object."));
@@ -245,10 +246,10 @@ void LastFmCoverProvider::QueryFinished(QNetworkReply *reply, const int id, cons
       Error(QStringLiteral("Invalid Json reply, album image is not a array."), json_image);
       continue;
     }
-    QJsonArray array_image = json_image.toArray();
+    const QJsonArray array_image = json_image.toArray();
     QString image_url_use;
-    LastFmImageSize image_size_use(LastFmImageSize::Unknown);
-    for (const QJsonValueRef value_image : array_image) {
+    LastFmImageSize image_size_use = LastFmImageSize::Unknown;
+    for (const QJsonValue value_image : array_image) {
       if (!value_image.isObject()) {
         Error(QStringLiteral("Invalid Json reply, album image value is not an object."));
         continue;
diff --git a/src/covermanager/musicbrainzcoverprovider.cpp b/src/covermanager/musicbrainzcoverprovider.cpp
index 5b174a80e..29ea2bbf5 100644
--- a/src/covermanager/musicbrainzcoverprovider.cpp
+++ b/src/covermanager/musicbrainzcoverprovider.cpp
@@ -158,14 +158,14 @@ void MusicbrainzCoverProvider::HandleSearchReply(QNetworkReply *reply, const int
     emit SearchFinished(search_id, results);
     return;
   }
-  QJsonArray array_releases = value_releases.toArray();
+  const QJsonArray array_releases = value_releases.toArray();
 
   if (array_releases.isEmpty()) {
     emit SearchFinished(search_id, results);
     return;
   }
 
-  for (const QJsonValueRef value_release : array_releases) {
+  for (const QJsonValue &value_release : array_releases) {
 
     if (!value_release.isObject()) {
       Error(QStringLiteral("Invalid Json reply, releases array value is not an object."));
@@ -182,10 +182,10 @@ void MusicbrainzCoverProvider::HandleSearchReply(QNetworkReply *reply, const int
       Error(QStringLiteral("Invalid Json reply, artist-credit is not a array."), json_artists);
       continue;
     }
-    QJsonArray array_artists = json_artists.toArray();
+    const QJsonArray array_artists = json_artists.toArray();
     int i = 0;
     QString artist;
-    for (const QJsonValueRef value_artist : array_artists) {
+    for (const QJsonValue value_artist : array_artists) {
       if (!value_artist.isObject()) {
         Error(QStringLiteral("Invalid Json reply, artist is not a object."));
         continue;
diff --git a/src/covermanager/musixmatchcoverprovider.cpp b/src/covermanager/musixmatchcoverprovider.cpp
index 8e48225b4..998b631f1 100644
--- a/src/covermanager/musixmatchcoverprovider.cpp
+++ b/src/covermanager/musixmatchcoverprovider.cpp
@@ -209,9 +209,9 @@ void MusixmatchCoverProvider::HandleSearchReply(QNetworkReply *reply, const int
     return;
   }
 
-  QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("coverImage800x800"), QSize(800, 800))
-                                                                            << qMakePair(QStringLiteral("coverImage500x500"), QSize(500, 500))
-                                                                            << qMakePair(QStringLiteral("coverImage350x350"), QSize(350, 350));
+  const QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("coverImage800x800"), QSize(800, 800))
+                                                                                  << qMakePair(QStringLiteral("coverImage500x500"), QSize(500, 500))
+                                                                                  << qMakePair(QStringLiteral("coverImage350x350"), QSize(350, 350));
 
   for (const QPair<QString, QSize> &cover_size : cover_sizes) {
     if (!obj_data.contains(cover_size.first)) continue;
diff --git a/src/covermanager/opentidalcoverprovider.cpp b/src/covermanager/opentidalcoverprovider.cpp
index f37287c8a..6025eaebb 100644
--- a/src/covermanager/opentidalcoverprovider.cpp
+++ b/src/covermanager/opentidalcoverprovider.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QObject>
 #include <QList>
@@ -284,7 +286,7 @@ QJsonObject OpenTidalCoverProvider::GetJsonObject(QNetworkReply *reply) {
     }
     QJsonObject json_obj = ExtractJsonObj(data);
     if (json_obj.contains(QLatin1String("errors")) && json_obj[QLatin1String("errors")].isArray()) {
-      QJsonArray array = json_obj[QLatin1String("errors")].toArray();
+      const QJsonArray array = json_obj[QLatin1String("errors")].toArray();
       for (const QJsonValue &value : array) {
         if (!value.isObject()) continue;
         QJsonObject obj = value.toObject();
@@ -367,7 +369,7 @@ void OpenTidalCoverProvider::HandleSearchReply(QNetworkReply *reply, SearchReque
     return;
   }
 
-  QJsonArray array_albums = json_obj[QLatin1String("albums")].toArray();
+  const QJsonArray array_albums = json_obj[QLatin1String("albums")].toArray();
   if (array_albums.isEmpty()) {
     emit SearchFinished(search_request->id, CoverProviderSearchResults());
     return;
@@ -375,7 +377,7 @@ void OpenTidalCoverProvider::HandleSearchReply(QNetworkReply *reply, SearchReque
 
   CoverProviderSearchResults results;
   int i = 0;
-  for (const QJsonValueRef value_album : array_albums) {
+  for (const QJsonValue &value_album : array_albums) {
 
     if (!value_album.isObject()) {
       qLog(Debug) << "OpenTidal: Invalid Json reply: Albums array value is not a object.";
@@ -407,8 +409,8 @@ void OpenTidalCoverProvider::HandleSearchReply(QNetworkReply *reply, SearchReque
     QString artist;
     const QString album = obj_resource[QLatin1String("title")].toString();
 
-    QJsonArray array_artists = obj_resource[QLatin1String("artists")].toArray();
-    for (const QJsonValueRef value_artist : array_artists) {
+    const QJsonArray array_artists = obj_resource[QLatin1String("artists")].toArray();
+    for (const QJsonValue &value_artist : array_artists) {
       if (!value_artist.isObject()) {
         continue;
       }
@@ -420,8 +422,8 @@ void OpenTidalCoverProvider::HandleSearchReply(QNetworkReply *reply, SearchReque
       break;
     }
 
-    QJsonArray array_covers = obj_resource[QLatin1String("imageCover")].toArray();
-    for (const QJsonValueRef value_cover : array_covers) {
+    const QJsonArray array_covers = obj_resource[QLatin1String("imageCover")].toArray();
+    for (const QJsonValue &value_cover : array_covers) {
       if (!value_cover.isObject()) {
         continue;
       }
diff --git a/src/covermanager/qobuzcoverprovider.cpp b/src/covermanager/qobuzcoverprovider.cpp
index 39717a6f2..b306f0f65 100644
--- a/src/covermanager/qobuzcoverprovider.cpp
+++ b/src/covermanager/qobuzcoverprovider.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QtGlobal>
 #include <QObject>
@@ -91,7 +92,7 @@ bool QobuzCoverProvider::StartSearch(const QString &artist, const QString &album
   std::sort(params.begin(), params.end());
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -209,9 +210,9 @@ void QobuzCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id) {
     emit SearchFinished(id, results);
     return;
   }
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
 
-  for (const QJsonValueRef value : array_items) {
+  for (const QJsonValue &value : array_items) {
 
     if (!value.isObject()) {
       Error(QStringLiteral("Invalid Json reply, value in items is not a object."));
diff --git a/src/covermanager/spotifycoverprovider.cpp b/src/covermanager/spotifycoverprovider.cpp
index 10117a840..fbe72cce3 100644
--- a/src/covermanager/spotifycoverprovider.cpp
+++ b/src/covermanager/spotifycoverprovider.cpp
@@ -96,9 +96,9 @@ bool SpotifyCoverProvider::StartSearch(const QString &artist, const QString &alb
     }
   }
 
-  ParamList params = ParamList() << Param(QStringLiteral("q"), query)
-                                 << Param(QStringLiteral("type"), type)
-                                 << Param(QStringLiteral("limit"), QString::number(kLimit));
+  const ParamList params = ParamList() << Param(QStringLiteral("q"), query)
+                                       << Param(QStringLiteral("type"), type)
+                                       << Param(QStringLiteral("limit"), QString::number(kLimit));
 
   QUrlQuery url_query;
   for (const Param &param : params) {
@@ -201,14 +201,14 @@ void SpotifyCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id,
     return;
   }
 
-  QJsonArray array_items = json_obj[QLatin1String("items")].toArray();
+  const QJsonArray array_items = json_obj[QLatin1String("items")].toArray();
   if (array_items.isEmpty()) {
     emit SearchFinished(id, CoverProviderSearchResults());
     return;
   }
 
   CoverProviderSearchResults results;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     if (!value_item.isObject()) {
       continue;
@@ -223,19 +223,19 @@ void SpotifyCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id,
     if (!obj_album.contains(QLatin1String("artists")) || !obj_album.contains(QLatin1String("name")) || !obj_album.contains(QLatin1String("images")) || !obj_album[QLatin1String("artists")].isArray() || !obj_album[QLatin1String("images")].isArray()) {
       continue;
     }
-    QJsonArray array_artists = obj_album[QLatin1String("artists")].toArray();
-    QJsonArray array_images = obj_album[QLatin1String("images")].toArray();
+    const QJsonArray array_artists = obj_album[QLatin1String("artists")].toArray();
+    const QJsonArray array_images = obj_album[QLatin1String("images")].toArray();
     QString album = obj_album[QLatin1String("name")].toString();
 
     QStringList artists;
-    for (const QJsonValueRef value_artist : array_artists) {
+    for (const QJsonValue &value_artist : array_artists) {
       if (!value_artist.isObject()) continue;
       QJsonObject obj_artist = value_artist.toObject();
       if (!obj_artist.contains(QLatin1String("name"))) continue;
       artists << obj_artist[QLatin1String("name")].toString();
     }
 
-    for (const QJsonValueRef value_image : array_images) {
+    for (const QJsonValue &value_image : array_images) {
       if (!value_image.isObject()) continue;
       QJsonObject obj_image = value_image.toObject();
       if (!obj_image.contains(QLatin1String("url")) || !obj_image.contains(QLatin1String("width")) || !obj_image.contains(QLatin1String("height"))) continue;
diff --git a/src/covermanager/tidalcoverprovider.cpp b/src/covermanager/tidalcoverprovider.cpp
index dda7afeb9..c0a21229b 100644
--- a/src/covermanager/tidalcoverprovider.cpp
+++ b/src/covermanager/tidalcoverprovider.cpp
@@ -85,9 +85,9 @@ bool TidalCoverProvider::StartSearch(const QString &artist, const QString &album
     }
   }
 
-  ParamList params = ParamList() << Param(QStringLiteral("query"), query)
-                                 << Param(QStringLiteral("limit"), QString::number(kLimit))
-                                 << Param(QStringLiteral("countryCode"), service_->country_code());
+  const ParamList params = ParamList() << Param(QStringLiteral("query"), query)
+                                       << Param(QStringLiteral("limit"), QString::number(kLimit))
+                                       << Param(QStringLiteral("countryCode"), service_->country_code());
 
   QUrlQuery url_query;
   for (const Param &param : params) {
@@ -191,7 +191,7 @@ void TidalCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id) {
     emit SearchFinished(id, CoverProviderSearchResults());
     return;
   }
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {
     emit SearchFinished(id, CoverProviderSearchResults());
     return;
@@ -199,7 +199,7 @@ void TidalCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id) {
 
   CoverProviderSearchResults results;
   int i = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     if (!value_item.isObject()) {
       Error(QStringLiteral("Invalid Json reply, items array item is not a object."));
@@ -250,9 +250,9 @@ void TidalCoverProvider::HandleSearchReply(QNetworkReply *reply, const int id) {
     cover_result.album = Song::AlbumRemoveDiscMisc(album);
     cover_result.number = ++i;
 
-    QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("1280x1280"), QSize(1280, 1280))
-                                                                              << qMakePair(QStringLiteral("750x750"), QSize(750, 750))
-                                                                              << qMakePair(QStringLiteral("640x640"), QSize(640, 640));
+    const QList<QPair<QString, QSize>> cover_sizes = QList<QPair<QString, QSize>>() << qMakePair(QStringLiteral("1280x1280"), QSize(1280, 1280))
+                                                                                    << qMakePair(QStringLiteral("750x750"), QSize(750, 750))
+                                                                                    << qMakePair(QStringLiteral("640x640"), QSize(640, 640));
     for (const QPair<QString, QSize> &cover_size : cover_sizes) {
       QUrl cover_url(QStringLiteral("%1/images/%2/%3.jpg").arg(QLatin1String(TidalService::kResourcesUrl), cover).arg(cover_size.first));
       cover_result.image_url = cover_url;
diff --git a/src/device/devicemanager.cpp b/src/device/devicemanager.cpp
index 0fd870500..207689c87 100644
--- a/src/device/devicemanager.cpp
+++ b/src/device/devicemanager.cpp
@@ -21,6 +21,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <functional>
 #include <memory>
 
@@ -146,7 +147,7 @@ DeviceManager::DeviceManager(Application *app, QObject *parent)
 
 DeviceManager::~DeviceManager() {
 
-  for (DeviceLister *lister : listers_) {
+  for (DeviceLister *lister : std::as_const(listers_)) {
     lister->ShutDown();
     delete lister;
   }
@@ -163,7 +164,7 @@ void DeviceManager::Exit() {
 
 void DeviceManager::CloseDevices() {
 
-  for (DeviceInfo *info : devices_) {
+  for (DeviceInfo *info : std::as_const(devices_)) {
     if (!info->device_) continue;
     if (wait_for_exit_.contains(&*info->device_)) continue;
     wait_for_exit_ << &*info->device_;
@@ -176,7 +177,7 @@ void DeviceManager::CloseDevices() {
 
 void DeviceManager::CloseListers() {
 
-  for (DeviceLister *lister : listers_) {
+  for (DeviceLister *lister : std::as_const(listers_)) {
     if (wait_for_exit_.contains(lister)) continue;
     wait_for_exit_ << lister;
     QObject::connect(lister, &DeviceLister::ExitFinished, this, &DeviceManager::ListerClosed);
@@ -231,7 +232,7 @@ void DeviceManager::LoadAllDevices() {
 
   Q_ASSERT(QThread::currentThread() != qApp->thread());
 
-  DeviceDatabaseBackend::DeviceList devices = backend_->GetAllDevices();
+  const DeviceDatabaseBackend::DeviceList devices = backend_->GetAllDevices();
   for (const DeviceDatabaseBackend::Device &device : devices) {
     DeviceInfo *info = new DeviceInfo(DeviceInfo::Type::Device, root_);
     info->InitFromDb(device);
@@ -245,7 +246,7 @@ void DeviceManager::LoadAllDevices() {
 
 void DeviceManager::AddDeviceFromDB(DeviceInfo *info) {
 
-  QStringList icon_names = info->icon_name_.split(QLatin1Char(','));
+  const QStringList icon_names = info->icon_name_.split(QLatin1Char(','));
   QVariantList icons;
   icons.reserve(icon_names.count());
   for (const QString &icon_name : icon_names) {
@@ -404,7 +405,7 @@ void DeviceManager::AddLister(DeviceLister *lister) {
 DeviceInfo *DeviceManager::FindDeviceById(const QString &id) const {
 
   for (int i = 0; i < devices_.count(); ++i) {
-    for (const DeviceInfo::Backend &backend : devices_[i]->backends_) {
+    for (const DeviceInfo::Backend &backend : std::as_const(devices_[i]->backends_)) {
       if (backend.unique_id_ == id) return devices_[i];
     }
   }
@@ -418,10 +419,10 @@ DeviceInfo *DeviceManager::FindDeviceByUrl(const QList<QUrl> &urls) const {
   if (urls.isEmpty()) return nullptr;
 
   for (int i = 0; i < devices_.count(); ++i) {
-    for (const DeviceInfo::Backend &backend : devices_[i]->backends_) {
+    for (const DeviceInfo::Backend &backend : std::as_const(devices_[i]->backends_)) {
       if (!backend.lister_) continue;
 
-      QList<QUrl> device_urls = backend.lister_->MakeDeviceUrls(backend.unique_id_);
+      const QList<QUrl> device_urls = backend.lister_->MakeDeviceUrls(backend.unique_id_);
       for (const QUrl &url : device_urls) {
         if (urls.contains(url)) return devices_[i];
       }
@@ -434,7 +435,7 @@ DeviceInfo *DeviceManager::FindDeviceByUrl(const QList<QUrl> &urls) const {
 
 DeviceInfo *DeviceManager::FindEquivalentDevice(DeviceInfo *info) const {
 
-  for (const DeviceInfo::Backend &backend : info->backends_) {
+  for (const DeviceInfo::Backend &backend : std::as_const(info->backends_)) {
     DeviceInfo *match = FindDeviceById(backend.unique_id_);
     if (match) return match;
   }
@@ -588,7 +589,7 @@ SharedPtr<ConnectedDevice> DeviceManager::Connect(DeviceInfo *info) {
   }
 
   // Get the device URLs
-  QList<QUrl> urls = info->BestBackend()->lister_->MakeDeviceUrls(info->BestBackend()->unique_id_);
+  const QList<QUrl> urls = info->BestBackend()->lister_->MakeDeviceUrls(info->BestBackend()->unique_id_);
   if (urls.isEmpty()) return ret;
 
   // Take the first URL that we have a handler for
@@ -844,13 +845,13 @@ void DeviceManager::DeviceTaskStarted(const int id) {
 
 void DeviceManager::TasksChanged() {
 
-  QList<TaskManager::Task> tasks = app_->task_manager()->GetTasks();
+  const QList<TaskManager::Task> tasks = app_->task_manager()->GetTasks();
   QList<QPersistentModelIndex> finished_tasks = active_tasks_.values();
 
   for (const TaskManager::Task &task : tasks) {
     if (!active_tasks_.contains(task.id)) continue;
 
-    QPersistentModelIndex idx = active_tasks_[task.id];
+    const QPersistentModelIndex idx = active_tasks_[task.id];
     if (!idx.isValid()) continue;
 
     DeviceInfo *info = IndexToItem(idx);
@@ -866,7 +867,7 @@ void DeviceManager::TasksChanged() {
 
   }
 
-  for (const QPersistentModelIndex &idx : finished_tasks) {
+  for (const QPersistentModelIndex &idx : std::as_const(finished_tasks)) {
 
     if (!idx.isValid()) continue;
 
diff --git a/src/device/udisks2lister.cpp b/src/device/udisks2lister.cpp
index 6993104f7..410ceb38a 100644
--- a/src/device/udisks2lister.cpp
+++ b/src/device/udisks2lister.cpp
@@ -21,8 +21,8 @@
 
 #include "config.h"
 
-#include <memory>
 #include <utility>
+#include <memory>
 
 #include <QtGlobal>
 #include <QMutex>
@@ -200,7 +200,7 @@ bool Udisks2Lister::Init() {
     return false;
   }
 
-  QList<QDBusObjectPath> paths = reply.value().keys();
+  const QList<QDBusObjectPath> paths = reply.value().keys();
   for (const QDBusObjectPath &path : paths) {
     PartitionData partition_data = ReadPartitionData(path);
 
@@ -210,7 +210,7 @@ bool Udisks2Lister::Init() {
     }
   }
 
-  QStringList ids = device_data_.keys();
+  const QStringList ids = device_data_.keys();
   for (const QString &id : ids) {
     emit DeviceAdded(id);
   }
@@ -326,7 +326,7 @@ void Udisks2Lister::JobCompleted(const bool success, const QString &message) {
 
   qLog(Debug) << "Pending Job Completed | Path = " << job->path() << " | Mount? = " << mounting_jobs_[jobPath].is_mount << " | Success = " << success;
 
-  for (const auto &mounted_object : mounting_jobs_[jobPath].mounted_partitions) {
+  for (const auto &mounted_object : std::as_const(mounting_jobs_[jobPath].mounted_partitions)) {
     auto partition_data = ReadPartitionData(mounted_object);
     if (partition_data.dbus_path.isEmpty()) continue;
 
@@ -394,7 +394,8 @@ Udisks2Lister::PartitionData Udisks2Lister::ReadPartitionData(const QDBusObjectP
         result.friendly_name = result.label;
       }
 
-      for (const QByteArray &p : filesystem.mountPoints()) {
+      const QList<QByteArray> mountpoints = filesystem.mountPoints();
+      for (const QByteArray &p : mountpoints) {
         const QString mountpoint = QString::fromUtf8(p.data(), static_cast<qint64>(qstrlen(p.data())));
         result.mount_paths.push_back(mountpoint);
       }
diff --git a/src/dialogs/edittagdialog.cpp b/src/dialogs/edittagdialog.cpp
index 1c0f8ad37..a716f92a9 100644
--- a/src/dialogs/edittagdialog.cpp
+++ b/src/dialogs/edittagdialog.cpp
@@ -21,8 +21,9 @@
 
 #include "config.h"
 
-#include <functional>
 #include <algorithm>
+#include <utility>
+#include <functional>
 #include <iterator>
 #include <limits>
 
@@ -152,7 +153,8 @@ EditTagDialog::EditTagDialog(Application *app, QWidget *parent)
 
   // An editable field is one that has a label as a buddy.
   // The label is important because it gets turned bold when the field is changed.
-  for (QLabel *label : findChildren<QLabel*>()) {
+  QList<QLabel*> labels = findChildren<QLabel*>();
+  for (QLabel *label : std::as_const(labels)) {
     QWidget *widget = label->buddy();
     if (widget) {
       // Store information about the field
@@ -191,7 +193,8 @@ EditTagDialog::EditTagDialog(Application *app, QWidget *parent)
   QPalette summary_label_palette(palette());
   summary_label_palette.setColor(QPalette::WindowText, light ? color.lighter(150) : color.darker(150));
 
-  for (QLabel *label : ui_->tab_summary->findChildren<QLabel*>()) {
+  labels = ui_->tab_summary->findChildren<QLabel*>();
+  for (QLabel *label : std::as_const(labels)) {
     if (label->property("field_label").toBool()) {
       label->setPalette(summary_label_palette);
     }
@@ -453,7 +456,7 @@ void EditTagDialog::SetSongsFinished() {
   }
 
   // Add the filenames to the list
-  for (const Data &tag_data : data_) {
+  for (const Data &tag_data : std::as_const(data_)) {
     ui_->song_list->addItem(tag_data.current_.basefilename());
   }
 
@@ -757,7 +760,7 @@ void EditTagDialog::SelectionChanged() {
 void EditTagDialog::UpdateUI(const QModelIndexList &indexes) {
 
   ignore_edits_ = true;
-  for (const FieldData &field : fields_) {
+  for (const FieldData &field : std::as_const(fields_)) {
     InitFieldValue(field, indexes);
   }
   ignore_edits_ = false;
@@ -926,7 +929,8 @@ void EditTagDialog::AlbumCoverLoaded(const quint64 id, const AlbumCoverLoaderRes
     }
     Song first_song;
     UpdateCoverAction cover_action = UpdateCoverAction::None;
-    for (const QModelIndex &idx : ui_->song_list->selectionModel()->selectedIndexes()) {
+    const QModelIndexList indexes = ui_->song_list->selectionModel()->selectedIndexes();
+    for (const QModelIndex &idx : indexes) {
       data_[idx.row()].cover_result_ = result.album_cover;
       if (!first_song.is_valid()) {
         first_song = data_[idx.row()].current_;
@@ -967,7 +971,7 @@ void EditTagDialog::FieldValueEdited() {
   QWidget *w = qobject_cast<QWidget*>(sender());
 
   // Find the field
-  for (const FieldData &field : fields_) {
+  for (const FieldData &field : std::as_const(fields_)) {
     if (field.editor_ == w) {
       UpdateFieldValue(field, sel);
       return;
@@ -986,7 +990,7 @@ void EditTagDialog::ResetField() {
   QWidget *w = qobject_cast<QWidget*>(sender());
 
   // Find the field
-  for (const FieldData &field : fields_) {
+  for (const FieldData &field : std::as_const(fields_)) {
     if (field.editor_ == w) {
       ignore_edits_ = true;
       ResetFieldValue(field, sel);
diff --git a/src/equalizer/equalizer.cpp b/src/equalizer/equalizer.cpp
index f79e70e6e..7e6179bfa 100644
--- a/src/equalizer/equalizer.cpp
+++ b/src/equalizer/equalizer.cpp
@@ -329,7 +329,7 @@ void Equalizer::Save() {
   // Presets
   s.beginWriteArray("presets", static_cast<int>(presets_.count()));
   int i = 0;
-  QStringList presets = presets_.keys();
+  const QStringList presets = presets_.keys();
   for (const QString &name : presets) {
     s.setArrayIndex(i++);
     s.setValue("name", name);
diff --git a/src/globalshortcuts/globalshortcutsbackend-kde.cpp b/src/globalshortcuts/globalshortcutsbackend-kde.cpp
index ff76f5f2e..f93b19683 100644
--- a/src/globalshortcuts/globalshortcutsbackend-kde.cpp
+++ b/src/globalshortcuts/globalshortcutsbackend-kde.cpp
@@ -17,6 +17,8 @@
  *
  */
 
+#include <utility>
+
 #include <QCoreApplication>
 #include <QList>
 #include <QString>
@@ -83,7 +85,7 @@ bool GlobalShortcutsBackendKDE::DoRegister() {
     interface_ = new OrgKdeKGlobalAccelInterface(QLatin1String(kKdeService), QLatin1String(kKdePath), QDBusConnection::sessionBus(), this);
   }
 
-  QList<GlobalShortcutsManager::Shortcut> shortcuts = manager_->shortcuts().values();
+  const QList<GlobalShortcutsManager::Shortcut> shortcuts = manager_->shortcuts().values();
   for (const GlobalShortcutsManager::Shortcut &shortcut : shortcuts) {
     RegisterShortcut(shortcut);
   }
@@ -129,7 +131,7 @@ void GlobalShortcutsBackendKDE::DoUnregister() {
 
   qLog(Debug) << "Unregistering";
 
-  QMap<QString, GlobalShortcutsManager::Shortcut> shortcuts = manager_->shortcuts();
+  const QMap<QString, GlobalShortcutsManager::Shortcut> shortcuts = manager_->shortcuts();
   for (const GlobalShortcutsManager::Shortcut &shortcut : shortcuts) {
     if (actions_.contains(shortcut.id)) {
       interface_->unRegister(GetActionId(shortcut.id, shortcut.action));
@@ -214,7 +216,8 @@ QList<QKeySequence> GlobalShortcutsBackendKDE::ToKeySequenceList(const QList<int
 void GlobalShortcutsBackendKDE::GlobalShortcutPressed(const QString &component_unique, const QString &shortcut_unique, qint64) {
 
   if (QCoreApplication::applicationName() == component_unique && actions_.contains(shortcut_unique)) {
-    for (QAction *action : actions_.values(shortcut_unique)) {
+    const QList<QAction*> actions = actions_.values(shortcut_unique);
+    for (QAction *action : actions) {
       qLog(Debug) << "Key" << action->shortcut() << "pressed.";
       if (action->isEnabled()) action->trigger();
     }
diff --git a/src/lyrics/geniuslyricsprovider.cpp b/src/lyrics/geniuslyricsprovider.cpp
index a3950e04f..c4e80bcb2 100644
--- a/src/lyrics/geniuslyricsprovider.cpp
+++ b/src/lyrics/geniuslyricsprovider.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QObject>
@@ -382,9 +383,9 @@ void GeniusLyricsProvider::HandleSearchReply(QNetworkReply *reply, const int id)
     EndSearch(search);
     return;
   }
-  QJsonArray array_hits = obj_response[QLatin1String("hits")].toArray();
+  const QJsonArray array_hits = obj_response[QLatin1String("hits")].toArray();
 
-  for (const QJsonValueRef value_hit : array_hits) {
+  for (const QJsonValue &value_hit : array_hits) {
     if (!value_hit.isObject()) {
       continue;
     }
@@ -491,7 +492,7 @@ void GeniusLyricsProvider::AuthError(const QString &error, const QVariant &debug
 
   if (!error.isEmpty()) login_errors_ << error;
 
-  for (const QString &e : login_errors_) Error(e);
+  for (const QString &e : std::as_const(login_errors_)) Error(e);
   if (debug.isValid()) qLog(Debug) << debug;
 
   emit AuthenticationFailure(login_errors_);
diff --git a/src/lyrics/musixmatchlyricsprovider.cpp b/src/lyrics/musixmatchlyricsprovider.cpp
index 365d37100..78dafa228 100644
--- a/src/lyrics/musixmatchlyricsprovider.cpp
+++ b/src/lyrics/musixmatchlyricsprovider.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QObject>
@@ -189,9 +190,9 @@ void MusixmatchLyricsProvider::HandleSearchReply(QNetworkReply *reply, LyricsSea
     EndSearch(search);
     return;
   }
-  QJsonArray array_tracklist = obj_body[QLatin1String("track_list")].toArray();
+  const QJsonArray array_tracklist = obj_body[QLatin1String("track_list")].toArray();
 
-  for (const QJsonValueRef value_track : array_tracklist) {
+  for (const QJsonValue &value_track : array_tracklist) {
     if (!value_track.isObject()) {
       continue;
     }
@@ -235,7 +236,7 @@ void MusixmatchLyricsProvider::HandleSearchReply(QNetworkReply *reply, LyricsSea
     EndSearch(search);
   }
   else {
-    for (const QUrl &url : search->requests_lyrics_) {
+    for (const QUrl &url : std::as_const(search->requests_lyrics_)) {
       SendLyricsRequest(search, url);
     }
   }
diff --git a/src/musicbrainz/acoustidclient.cpp b/src/musicbrainz/acoustidclient.cpp
index 1d1269057..081279c07 100644
--- a/src/musicbrainz/acoustidclient.cpp
+++ b/src/musicbrainz/acoustidclient.cpp
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QtGlobal>
 #include <QObject>
@@ -161,16 +162,16 @@ void AcoustidClient::RequestFinished(QNetworkReply *reply, const int request_id)
   // -then sort results by number of sources (the results are originally
   //  unsorted but results with more sources are likely to be more accurate)
   // -keep only the ids, as sources where useful only to sort the results
-  QJsonArray json_results = json_object[QLatin1String("results")].toArray();
+  const QJsonArray json_results = json_object[QLatin1String("results")].toArray();
 
   // List of <id, nb of sources> pairs
   QList<IdSource> id_source_list;
 
-  for (const QJsonValueRef v : json_results) {
+  for (const QJsonValue &v : json_results) {
     QJsonObject r = v.toObject();
     if (!r[QLatin1String("recordings")].isUndefined()) {
-      QJsonArray json_recordings = r[QLatin1String("recordings")].toArray();
-      for (const QJsonValueRef recording : json_recordings) {
+      const QJsonArray json_recordings = r[QLatin1String("recordings")].toArray();
+      for (const QJsonValue &recording : json_recordings) {
         QJsonObject o = recording.toObject();
         if (!o[QLatin1String("id")].isUndefined()) {
           id_source_list << IdSource(o[QLatin1String("id")].toString(), o[QLatin1String("sources")].toInt());
@@ -183,11 +184,10 @@ void AcoustidClient::RequestFinished(QNetworkReply *reply, const int request_id)
 
   QStringList id_list;
   id_list.reserve(id_source_list.count());
-  for (const IdSource &is : id_source_list) {
+  for (const IdSource &is : std::as_const(id_source_list)) {
     id_list << is.id_;
   }
 
   emit Finished(request_id, id_list);
 
 }
-
diff --git a/src/musicbrainz/musicbrainzclient.cpp b/src/musicbrainz/musicbrainzclient.cpp
index ed5d81c4d..3be48ca7d 100644
--- a/src/musicbrainz/musicbrainzclient.cpp
+++ b/src/musicbrainz/musicbrainzclient.cpp
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QSet>
@@ -213,7 +214,7 @@ void MusicBrainzClient::RequestFinished(QNetworkReply *reply, const int id, cons
     ResultList res;
     while (!reader.atEnd()) {
       if (reader.readNext() == QXmlStreamReader::StartElement && reader.name().toString() == QLatin1String("recording")) {
-        ResultList tracks = ParseTrack(&reader);
+        const ResultList tracks = ParseTrack(&reader);
         for (const Result &track : tracks) {
           if (!track.title_.isEmpty()) {
             res << track;
@@ -230,7 +231,7 @@ void MusicBrainzClient::RequestFinished(QNetworkReply *reply, const int id, cons
     ResultList ret;
     QList<PendingResults> result_list_list = pending_results_.take(id);
     std::sort(result_list_list.begin(), result_list_list.end());
-    for (const PendingResults &result_list : result_list_list) {
+    for (const PendingResults &result_list : std::as_const(result_list_list)) {
       ret << result_list.results_;
     }
     emit Finished(id, UniqueResults(ret, UniqueResultsSortOption::KeepOriginalOrder), error);
@@ -292,7 +293,7 @@ void MusicBrainzClient::DiscIdRequestFinished(const QString &discid, QNetworkRep
     if (token == QXmlStreamReader::StartElement && name == QLatin1String("medium")) {
       // Get the medium with a matching discid.
       if (MediumHasDiscid(discid, &reader)) {
-        ResultList tracks = ParseMedium(&reader);
+        const ResultList tracks = ParseMedium(&reader);
         for (const Result &track : tracks) {
           if (!track.title_.isEmpty()) {
             ret << track;
@@ -387,6 +388,7 @@ MusicBrainzClient::Result MusicBrainzClient::ParseTrackFromDisc(QXmlStreamReader
   }
 
   return result;
+
 }
 
 MusicBrainzClient::ResultList MusicBrainzClient::ParseTrack(QXmlStreamReader *reader) {
@@ -426,11 +428,13 @@ MusicBrainzClient::ResultList MusicBrainzClient::ParseTrack(QXmlStreamReader *re
   else {
     std::stable_sort(releases.begin(), releases.end());
     ret.reserve(releases.count());
-    for (const Release &release : releases) {
+    for (const Release &release : std::as_const(releases)) {
       ret << release.CopyAndMergeInto(result);
     }
   }
+
   return ret;
+
 }
 
 // Parse the artist. Multiple artists are joined together with the joinphrase from musicbrainz.
diff --git a/src/musicbrainz/tagfetcher.cpp b/src/musicbrainz/tagfetcher.cpp
index 7d8985daa..e2f9a8fa2 100644
--- a/src/musicbrainz/tagfetcher.cpp
+++ b/src/musicbrainz/tagfetcher.cpp
@@ -154,4 +154,3 @@ void TagFetcher::TagsFetched(const int index, const MusicBrainzClient::ResultLis
   emit ResultAvailable(original_song, songs_guessed, error);
 
 }
-
diff --git a/src/organize/organizedialog.cpp b/src/organize/organizedialog.cpp
index 91b42c065..f133cd43b 100644
--- a/src/organize/organizedialog.cpp
+++ b/src/organize/organizedialog.cpp
@@ -21,8 +21,9 @@
 
 #include "config.h"
 
-#include <functional>
 #include <algorithm>
+#include <utility>
+#include <functional>
 #include <memory>
 
 #include <QtGlobal>
@@ -141,7 +142,7 @@ OrganizeDialog::OrganizeDialog(SharedPtr<TaskManager> task_manager, SharedPtr<Co
 
   // Build the insert menu
   QMenu *tag_menu = new QMenu(this);
-  for (const QString &title : tag_titles) {
+  for (const QString &title : std::as_const(tag_titles)) {
     QAction *action = tag_menu->addAction(title);
     QString tag = tags[title];
     QObject::connect(action, &QAction::triggered, this, [this, tag]() { InsertTag(tag); });
@@ -409,7 +410,8 @@ SongList OrganizeDialog::LoadSongsBlocking(const QStringList &filenames) {
     // If it's a directory, add all the files inside.
     if (QFileInfo(filename).isDir()) {
       const QDir dir(filename);
-      for (const QString &entry : dir.entryList(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable)) {
+      const QStringList entries = dir.entryList(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable);
+      for (const QString &entry : entries) {
         filenames_copy << dir.filePath(entry);
       }
       continue;
@@ -535,7 +537,7 @@ void OrganizeDialog::UpdatePreviews() {
   ui_->groupbox_preview->setVisible(has_local_destination);
   ui_->groupbox_naming->setVisible(has_local_destination);
   if (has_local_destination) {
-    for (const Organize::NewSongInfo &song_info : new_songs_info_) {
+    for (const Organize::NewSongInfo &song_info : std::as_const(new_songs_info_)) {
       QString filename = storage->LocalPath() + QLatin1Char('/') + song_info.new_filename_;
       QListWidgetItem *item = new QListWidgetItem(song_info.unique_filename_ ? IconLoader::Load(QStringLiteral("dialog-ok-apply")) : IconLoader::Load(QStringLiteral("dialog-warning")), QDir::toNativeSeparators(filename), ui_->preview);
       ui_->preview->addItem(item);
diff --git a/src/playlist/playlist.cpp b/src/playlist/playlist.cpp
index 51ea16c0c..3f14ac7b2 100644
--- a/src/playlist/playlist.cpp
+++ b/src/playlist/playlist.cpp
@@ -22,9 +22,9 @@
 #include "config.h"
 
 #include <cstdlib>
-#include <memory>
-#include <utility>
 #include <algorithm>
+#include <utility>
+#include <memory>
 #include <functional>
 #include <unordered_map>
 #include <random>
@@ -861,7 +861,7 @@ bool Playlist::dropMimeData(const QMimeData *data, Qt::DropAction action, const
       // Drag from a different playlist
       PlaylistItemPtrList items;
       items.reserve(source_rows.count());
-      for (const int i : source_rows) items << source_playlist->item_at(i);
+      for (const int i : std::as_const(source_rows)) items << source_playlist->item_at(i);
 
       if (items.count() > kUndoItemLimit) {
         // Too big to keep in the undo stack. Also clear the stack because it might have been invalidated.
@@ -874,7 +874,7 @@ bool Playlist::dropMimeData(const QMimeData *data, Qt::DropAction action, const
 
       // Remove the items from the source playlist if it was a move event
       if (action == Qt::MoveAction) {
-        for (const int i : source_rows) {
+        for (const int i : std::as_const(source_rows)) {
           source_playlist->undo_stack()->push(new PlaylistUndoCommands::RemoveItems(source_playlist, i, 1));
         }
       }
@@ -965,7 +965,8 @@ void Playlist::MoveItemsWithoutUndo(const QList<int> &source_rows, int pos) {
   }
 
   // Update persistent indexes
-  for (const QModelIndex &pidx : persistentIndexList()) {
+  const QModelIndexList pidx_list = persistentIndexList();
+  for (const QModelIndex &pidx : pidx_list) {
     const int dest_offset = static_cast<int>(source_rows.indexOf(pidx.row()));
     if (dest_offset != -1) {
       // This index was moved
@@ -1034,7 +1035,8 @@ void Playlist::MoveItemsWithoutUndo(int start, const QList<int> &dest_rows) {
   }
 
   // Update persistent indexes
-  for (const QModelIndex &pidx : persistentIndexList()) {
+  const QModelIndexList pidx_list = persistentIndexList();
+  for (const QModelIndex &pidx : pidx_list) {
     if (pidx.row() >= start && pidx.row() < start + dest_rows.count()) {
       // This index was moved
       const int i = pidx.row() - start;
@@ -1494,7 +1496,8 @@ void Playlist::ReOrderWithoutUndo(const PlaylistItemPtrList &new_items) {
     new_rows[&*new_items[i]] = i;
   }
 
-  for (const QModelIndex &idx : persistentIndexList()) {
+  const QModelIndexList indexes = persistentIndexList();
+  for (const QModelIndex &idx : indexes) {
     const PlaylistItem *item = &*old_items[idx.row()];
     changePersistentIndex(idx, index(new_rows[item], idx.column(), idx.parent()));
   }
@@ -2097,7 +2100,7 @@ void Playlist::TracksAboutToBeDequeued(const QModelIndex&, const int begin, cons
 
 void Playlist::TracksDequeued() {
 
-  for (const QModelIndex &idx : temp_dequeue_change_indexes_) {
+  for (const QModelIndex &idx : std::as_const(temp_dequeue_change_indexes_)) {
     emit dataChanged(idx, idx);
   }
   temp_dequeue_change_indexes_.clear();
diff --git a/src/playlist/playlistmanager.cpp b/src/playlist/playlistmanager.cpp
index 6e9b4f03d..3eda0f74a 100644
--- a/src/playlist/playlistmanager.cpp
+++ b/src/playlist/playlistmanager.cpp
@@ -83,7 +83,7 @@ PlaylistManager::PlaylistManager(Application *app, QObject *parent)
 
 PlaylistManager::~PlaylistManager() {
 
-  QList<Data> datas = playlists_.values();
+  const QList<Data> datas = playlists_.values();
   for (const Data &data : datas) delete data.p;
 
 }
@@ -102,7 +102,8 @@ void PlaylistManager::Init(SharedPtr<CollectionBackend> collection_backend, Shar
 
   QObject::connect(parser_, &PlaylistParser::Error, this, &PlaylistManager::Error);
 
-  for (const PlaylistBackend::Playlist &p : playlist_backend->GetAllOpenPlaylists()) {
+  const PlaylistBackend::PlaylistList playlists = playlist_backend->GetAllOpenPlaylists();
+  for (const PlaylistBackend::Playlist &p : playlists) {
     ++playlists_loading_;
     Playlist *ret = AddPlaylist(p.id, p.name, p.special_type, p.ui_path, p.favorite);
     QObject::connect(ret, &Playlist::PlaylistLoaded, this, &PlaylistManager::PlaylistLoaded);
@@ -131,7 +132,7 @@ QList<Playlist*> PlaylistManager::GetAllPlaylists() const {
 
   QList<Playlist*> result;
 
-  QList<Data> datas = playlists_.values();
+  const QList<Data> datas = playlists_.values();
   result.reserve(datas.count());
   for (const Data &data : datas) {
     result.append(data.p);
@@ -318,7 +319,7 @@ bool PlaylistManager::Close(const int id) {
   if (playlists_.count() <= 1 || !playlists_.contains(id)) return false;
 
   int next_id = -1;
-  QList<int> playlist_ids = playlists_.keys();
+  const QList<int> playlist_ids = playlists_.keys();
   for (const int possible_next_id : playlist_ids) {
     if (possible_next_id != id) {
       next_id = possible_next_id;
@@ -430,7 +431,7 @@ void PlaylistManager::UpdateSummaryText() {
   int selected = 0;
 
   // Get the length of the selected tracks
-  for (const QItemSelectionRange &range : playlists_[current_id()].selection) {
+  for (const QItemSelectionRange &range : std::as_const(playlists_[current_id()].selection)) {
     if (!range.isValid()) continue;
 
     selected += range.bottom() - range.top() + 1;
@@ -471,7 +472,7 @@ void PlaylistManager::UpdateCollectionSongs(const SongList &songs) {
 
   for (const Song &song : songs) {
     for (const Data &data : std::as_const(playlists_)) {
-      PlaylistItemPtrList items = data.p->collection_items_by_id(song.id());
+      const PlaylistItemPtrList items = data.p->collection_items_by_id(song.id());
       for (PlaylistItemPtr item : items) {
         if (item->Metadata().directory_id() != song.directory_id()) continue;
         data.p->UpdateItemMetadata(item, song, false);
@@ -484,7 +485,8 @@ void PlaylistManager::UpdateCollectionSongs(const SongList &songs) {
 // When Player has processed the new song chosen by the user...
 void PlaylistManager::SongChangeRequestProcessed(const QUrl &url, const bool valid) {
 
-  for (Playlist *playlist : GetAllPlaylists()) {
+  const QList<Playlist*> playlists = GetAllPlaylists();
+  for (Playlist *playlist : playlists) {
     if (playlist->ApplyValidityOnCurrentSong(url, valid)) {
       return;
     }
@@ -521,14 +523,18 @@ void PlaylistManager::RemoveCurrentSong() const {
 }
 
 void PlaylistManager::InvalidateDeletedSongs() {
-  for (Playlist *playlist : GetAllPlaylists()) {
+
+  const QList<Playlist*> playlists = GetAllPlaylists();
+  for (Playlist *playlist : playlists) {
     playlist->InvalidateDeletedSongs();
   }
+
 }
 
 void PlaylistManager::RemoveDeletedSongs() {
 
-  for (Playlist *playlist : GetAllPlaylists()) {
+  const QList<Playlist*> playlists = GetAllPlaylists();
+  for (Playlist *playlist : playlists) {
     playlist->RemoveDeletedSongs();
   }
 
diff --git a/src/playlist/playlistsequence.cpp b/src/playlist/playlistsequence.cpp
index 5c6c486fe..e2eb050e9 100644
--- a/src/playlist/playlistsequence.cpp
+++ b/src/playlist/playlistsequence.cpp
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QWidget>
 #include <QVariant>
 #include <QIcon>
@@ -113,7 +115,8 @@ void PlaylistSequence::Save() {
 QIcon PlaylistSequence::AddDesaturatedIcon(const QIcon &icon) {
 
   QIcon ret;
-  for (const QSize &size : icon.availableSizes()) {
+  const QList<QSize> sizes = icon.availableSizes();
+  for (const QSize &size : sizes) {
     QPixmap on(icon.pixmap(size));
     QPixmap off(DesaturatedPixmap(on));
 
diff --git a/src/playlist/songloaderinserter.cpp b/src/playlist/songloaderinserter.cpp
index b69548c54..30dbbf98f 100644
--- a/src/playlist/songloaderinserter.cpp
+++ b/src/playlist/songloaderinserter.cpp
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtConcurrent>
 #include <QtAlgorithms>
 #include <QList>
@@ -72,7 +74,8 @@ void SongLoaderInserter::Load(Playlist *destination, int row, bool play_now, boo
       songs_ << loader->songs();
     }
     else {
-      for (const QString &error : loader->errors()) {
+      const QStringList errors = loader->errors();
+      for (const QString &error : errors) {
         emit Error(error);
       }
     }
@@ -113,7 +116,8 @@ void SongLoaderInserter::LoadAudioCD(Playlist *destination, int row, bool play_n
     if (loader->errors().isEmpty())
       emit Error(tr("Error while loading audio CD."));
     else {
-      for (const QString &error : loader->errors()) {
+      const QStringList errors = loader->errors();
+      for (const QString &error : errors) {
         emit Error(error);
       }
     }
@@ -129,7 +133,8 @@ void SongLoaderInserter::AudioCDTracksLoadFinished(SongLoader *loader) {
 
   songs_ = loader->songs();
   if (songs_.isEmpty()) {
-    for (const QString &error : loader->errors()) {
+    const QStringList errors = loader->errors();
+    for (const QString &error : errors) {
       emit Error(error);
     }
   }
@@ -177,7 +182,8 @@ void SongLoaderInserter::AsyncLoad() {
     task_manager_->SetTaskProgress(async_load_id, ++async_progress);
 
     if (res == SongLoader::Result::Error) {
-      for (const QString &error : loader->errors()) {
+      const QStringList errors = loader->errors();
+      for (const QString &error : errors) {
         emit Error(error);
       }
       continue;
diff --git a/src/qobuz/qobuzbaserequest.cpp b/src/qobuz/qobuzbaserequest.cpp
index 5c6d34523..d4e95189c 100644
--- a/src/qobuz/qobuzbaserequest.cpp
+++ b/src/qobuz/qobuzbaserequest.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QByteArray>
@@ -57,7 +58,7 @@ QNetworkReply *QobuzBaseRequest::CreateRequest(const QString &ressource_name, co
   std::sort(params.begin(), params.end());
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
diff --git a/src/qobuz/qobuzfavoriterequest.cpp b/src/qobuz/qobuzfavoriterequest.cpp
index fc3d02bc2..418bfb2fa 100644
--- a/src/qobuz/qobuzfavoriterequest.cpp
+++ b/src/qobuz/qobuzfavoriterequest.cpp
@@ -132,9 +132,9 @@ void QobuzFavoriteRequest::AddFavorites(const FavoriteType type, const SongList
 
 void QobuzFavoriteRequest::AddFavoritesRequest(const FavoriteType type, const QStringList &ids_list, const SongList &songs) {
 
-  ParamList params = ParamList() << Param(QStringLiteral("app_id"), app_id())
-                                 << Param(QStringLiteral("user_auth_token"), user_auth_token())
-                                 << Param(FavoriteMethod(type), ids_list.join(QLatin1Char(',')));
+  const ParamList params = ParamList() << Param(QStringLiteral("app_id"), app_id())
+                                       << Param(QStringLiteral("user_auth_token"), user_auth_token())
+                                       << Param(FavoriteMethod(type), ids_list.join(QLatin1Char(',')));
 
   QUrlQuery url_query;
   for (const Param &param : params) {
@@ -227,9 +227,9 @@ void QobuzFavoriteRequest::RemoveFavorites(const FavoriteType type, const SongLi
 
 void QobuzFavoriteRequest::RemoveFavoritesRequest(const FavoriteType type, const QStringList &ids_list, const SongList &songs) {
 
-  ParamList params = ParamList() << Param(QStringLiteral("app_id"), app_id())
-                                 << Param(QStringLiteral("user_auth_token"), user_auth_token())
-                                 << Param(FavoriteMethod(type), ids_list.join(QLatin1Char(',')));
+  const ParamList params = ParamList() << Param(QStringLiteral("app_id"), app_id())
+                                       << Param(QStringLiteral("user_auth_token"), user_auth_token())
+                                       << Param(FavoriteMethod(type), ids_list.join(QLatin1Char(',')));
 
   QUrlQuery url_query;
   for (const Param &param : params) {
diff --git a/src/qobuz/qobuzrequest.cpp b/src/qobuz/qobuzrequest.cpp
index 04ec326c2..be96db970 100644
--- a/src/qobuz/qobuzrequest.cpp
+++ b/src/qobuz/qobuzrequest.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QObject>
 #include <QList>
 #include <QByteArray>
@@ -471,7 +473,7 @@ void QobuzRequest::ArtistsReplyReceived(QNetworkReply *reply, const int limit_re
     return;
   }
 
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {  // Empty array means no results
     if (offset_requested == 0) no_results_ = true;
     ArtistsFinishCheck();
@@ -479,7 +481,7 @@ void QobuzRequest::ArtistsReplyReceived(QNetworkReply *reply, const int limit_re
   }
 
   int artists_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++artists_received;
 
@@ -542,7 +544,7 @@ void QobuzRequest::ArtistsFinishCheck(const int limit, const int offset, const i
   if (artists_requests_queue_.isEmpty() && artists_requests_active_ <= 0) {  // Artist query is finished, get all albums for all artists.
 
     // Get artist albums
-    QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
+    const QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
     for (const ArtistAlbumsRequest &request : requests) {
       AddArtistAlbumsRequest(request.artist);
     }
@@ -687,7 +689,7 @@ void QobuzRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_req
     AlbumsFinishCheck(artist_requested);
     return;
   }
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {
     if ((query_type_ == Type::FavouriteAlbums || query_type_ == Type::SearchAlbums) && offset_requested == 0) {
       no_results_ = true;
@@ -697,7 +699,7 @@ void QobuzRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_req
   }
 
   int albums_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++albums_received;
 
@@ -982,7 +984,7 @@ void QobuzRequest::SongsReceived(QNetworkReply *reply, const Artist &artist_requ
     return;
   }
 
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {
     if ((query_type_ == Type::FavouriteSongs || query_type_ == Type::SearchSongs) && offset_requested == 0) {
       no_results_ = true;
@@ -995,7 +997,7 @@ void QobuzRequest::SongsReceived(QNetworkReply *reply, const Artist &artist_requ
   bool multidisc = false;
   SongList songs;
   int songs_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     if (!value_item.isObject()) {
       Error(QStringLiteral("Invalid Json reply, track is not a object."));
@@ -1012,7 +1014,7 @@ void QobuzRequest::SongsReceived(QNetworkReply *reply, const Artist &artist_requ
     songs << song;
   }
 
-  for (Song song : songs) {
+  for (Song song : std::as_const(songs)) {
     if (compilation) song.set_compilation_detected(true);
     if (!multidisc) song.set_disc(0);
     songs_.insert(song.song_id(), song);
diff --git a/src/qobuz/qobuzservice.cpp b/src/qobuz/qobuzservice.cpp
index 58b6cf7c9..b3290838d 100644
--- a/src/qobuz/qobuzservice.cpp
+++ b/src/qobuz/qobuzservice.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QObject>
@@ -763,7 +764,7 @@ void QobuzService::LoginError(const QString &error, const QVariant &debug) {
   if (!error.isEmpty()) login_errors_ << error;
 
   QString error_html;
-  for (const QString &e : login_errors_) {
+  for (const QString &e : std::as_const(login_errors_)) {
     qLog(Error) << "Qobuz:" << e;
     error_html += e + QStringLiteral("<br />");
   }
diff --git a/src/qobuz/qobuzstreamurlrequest.cpp b/src/qobuz/qobuzstreamurlrequest.cpp
index 7965a76a1..286b38b38 100644
--- a/src/qobuz/qobuzstreamurlrequest.cpp
+++ b/src/qobuz/qobuzstreamurlrequest.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QObject>
 #include <QMimeDatabase>
@@ -122,7 +123,7 @@ void QobuzStreamURLRequest::GetStreamURL() {
 
   QString data_to_sign;
   data_to_sign += QLatin1String("trackgetFileUrl");
-  for (const Param &param : params_to_sign) {
+  for (const Param &param : std::as_const(params_to_sign)) {
     data_to_sign += param.first + param.second;
   }
   data_to_sign += QString::number(timestamp);
@@ -192,7 +193,7 @@ void QobuzStreamURLRequest::StreamURLReceived() {
 
   Song::FileType filetype(Song::FileType::Unknown);
   QMimeDatabase mimedb;
-  QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
+  const QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
   for (const QString &suffix : suffixes) {
     filetype = Song::FiletypeByExtension(suffix);
     if (filetype != Song::FileType::Unknown) break;
diff --git a/src/radios/radioparadiseservice.cpp b/src/radios/radioparadiseservice.cpp
index 49a239f87..d0dcca6aa 100644
--- a/src/radios/radioparadiseservice.cpp
+++ b/src/radios/radioparadiseservice.cpp
@@ -86,10 +86,10 @@ void RadioParadiseService::GetChannelsReply(QNetworkReply *reply, const int task
     emit NewChannels();
     return;
   }
-  QJsonArray array_channels = object[QLatin1String("channels")].toArray();
+  const QJsonArray array_channels = object[QLatin1String("channels")].toArray();
 
   RadioChannelList channels;
-  for (const QJsonValueRef value_channel : array_channels) {
+  for (const QJsonValue &value_channel : array_channels) {
     if (!value_channel.isObject()) continue;
     QJsonObject obj_channel = value_channel.toObject();
     if (!obj_channel.contains(QLatin1String("chan_name")) || !obj_channel.contains(QLatin1String("streams"))) {
@@ -100,8 +100,8 @@ void RadioParadiseService::GetChannelsReply(QNetworkReply *reply, const int task
     if (!value_streams.isArray()) {
       continue;
     }
-    QJsonArray array_streams = obj_channel[QLatin1String("streams")].toArray();
-    for (const QJsonValueRef value_stream : array_streams) {
+    const QJsonArray array_streams = obj_channel[QLatin1String("streams")].toArray();
+    for (const QJsonValue &value_stream : array_streams) {
       if (!value_stream.isObject()) continue;
       QJsonObject obj_stream = value_stream.toObject();
       if (!obj_stream.contains(QLatin1String("label")) || !obj_stream.contains(QLatin1String("url"))) {
diff --git a/src/radios/radioservices.cpp b/src/radios/radioservices.cpp
index 7b0e7fbb8..03b21a028 100644
--- a/src/radios/radioservices.cpp
+++ b/src/radios/radioservices.cpp
@@ -96,7 +96,7 @@ RadioService *RadioServices::ServiceBySource(const Song::Source source) const {
 
 void RadioServices::ReloadSettings() {
 
-  QList<RadioService*> services = services_.values();
+  const QList<RadioService*> services = services_.values();
   for (RadioService *service : services) {
     service->ReloadSettings();
   }
@@ -116,7 +116,7 @@ void RadioServices::RefreshChannels() {
   model_->Reset();
   backend_->DeleteChannelsAsync();
 
-  QList<RadioService*> services = services_.values();
+  const QList<RadioService*> services = services_.values();
   for (RadioService *service : services) {
     service->GetChannels();
   }
diff --git a/src/radios/radioview.cpp b/src/radios/radioview.cpp
index 1d8d86ae4..1e35f7e57 100644
--- a/src/radios/radioview.cpp
+++ b/src/radios/radioview.cpp
@@ -17,6 +17,8 @@
  *
  */
 
+#include <utility>
+
 #include <QWidget>
 #include <QMimeData>
 #include <QDesktopServices>
@@ -154,7 +156,7 @@ void RadioView::Homepage() {
     }
   }
 
-  for (const QUrl &url : urls) {
+  for (const QUrl &url : std::as_const(urls)) {
     QDesktopServices::openUrl(url);
   }
 
@@ -173,7 +175,7 @@ void RadioView::Donate() {
     }
   }
 
-  for (const QUrl &url : urls) {
+  for (const QUrl &url : std::as_const(urls)) {
     QDesktopServices::openUrl(url);
   }
 
diff --git a/src/radios/somafmservice.cpp b/src/radios/somafmservice.cpp
index b62439a24..166acdd9d 100644
--- a/src/radios/somafmservice.cpp
+++ b/src/radios/somafmservice.cpp
@@ -17,6 +17,8 @@
  *
  */
 
+#include <utility>
+
 #include <QObject>
 #include <QString>
 #include <QUrl>
@@ -92,10 +94,10 @@ void SomaFMService::GetChannelsReply(QNetworkReply *reply, const int task_id) {
     emit NewChannels();
     return;
   }
-  QJsonArray array_channels = object[QLatin1String("channels")].toArray();
+  const QJsonArray array_channels = object[QLatin1String("channels")].toArray();
 
   RadioChannelList channels;
-  for (const QJsonValueRef value_channel : array_channels) {
+  for (const QJsonValue &value_channel : array_channels) {
     if (!value_channel.isObject()) continue;
     QJsonObject obj_channel = value_channel.toObject();
     if (!obj_channel.contains(QLatin1String("title")) || !obj_channel.contains(QLatin1String("image"))) {
@@ -103,8 +105,8 @@ void SomaFMService::GetChannelsReply(QNetworkReply *reply, const int task_id) {
     }
     QString name = obj_channel[QLatin1String("title")].toString();
     QString image = obj_channel[QLatin1String("image")].toString();
-    QJsonArray playlists = obj_channel[QLatin1String("playlists")].toArray();
-    for (const QJsonValueRef playlist : playlists) {
+    const QJsonArray playlists = obj_channel[QLatin1String("playlists")].toArray();
+    for (const QJsonValue &playlist : playlists) {
       if (!playlist.isObject()) continue;
       QJsonObject obj_playlist = playlist.toObject();
       if (!obj_playlist.contains(QLatin1String("url")) || !obj_playlist.contains(QLatin1String("quality"))) {
@@ -129,7 +131,7 @@ void SomaFMService::GetChannelsReply(QNetworkReply *reply, const int task_id) {
     emit NewChannels();
   }
   else {
-    for (const RadioChannel &channel : channels) {
+    for (const RadioChannel &channel : std::as_const(channels)) {
       GetStreamUrl(task_id, channel);
     }
   }
diff --git a/src/scrobbler/audioscrobbler.cpp b/src/scrobbler/audioscrobbler.cpp
index 9f2dd1cfd..85f311b4f 100644
--- a/src/scrobbler/audioscrobbler.cpp
+++ b/src/scrobbler/audioscrobbler.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QList>
@@ -98,8 +99,8 @@ void AudioScrobbler::ReloadSettings() {
 
   settings_->ReloadSettings();
 
-  QList<ScrobblerServicePtr> services = services_.values();
-  for (ScrobblerServicePtr service : services) {
+  const QList<ScrobblerServicePtr> services = services_.values();
+  for (ScrobblerServicePtr service : std::as_const(services)) {
     service->ReloadSettings();
   }
 
@@ -131,7 +132,7 @@ void AudioScrobbler::UpdateNowPlaying(const Song &song) {
 
   qLog(Debug) << "Sending now playing for song" << song.artist() << song.album() << song.title();
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled()) continue;
     service->UpdateNowPlaying(song);
@@ -141,7 +142,7 @@ void AudioScrobbler::UpdateNowPlaying(const Song &song) {
 
 void AudioScrobbler::ClearPlaying() {
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled()) continue;
     service->ClearPlaying();
@@ -155,7 +156,7 @@ void AudioScrobbler::Scrobble(const Song &song, const qint64 scrobble_point) {
 
   qLog(Debug) << "Scrobbling song" << song.artist() << song.album() << song.title() << "at" << scrobble_point;
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled()) continue;
     service->Scrobble(song);
@@ -165,7 +166,7 @@ void AudioScrobbler::Scrobble(const Song &song, const qint64 scrobble_point) {
 
 void AudioScrobbler::Love() {
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled() || !service->authenticated()) continue;
     service->Love();
@@ -175,7 +176,7 @@ void AudioScrobbler::Love() {
 
 void AudioScrobbler::Submit() {
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled() || !service->authenticated() || service->submitted()) continue;
     service->StartSubmit();
@@ -185,7 +186,7 @@ void AudioScrobbler::Submit() {
 
 void AudioScrobbler::WriteCache() {
 
-  QList<ScrobblerServicePtr> services = GetAll();
+  const QList<ScrobblerServicePtr> services = GetAll();
   for (ScrobblerServicePtr service : services) {
     if (!service->enabled()) continue;
     service->WriteCache();
diff --git a/src/scrobbler/lastfmimport.cpp b/src/scrobbler/lastfmimport.cpp
index 906d3ec0a..62d4244c7 100644
--- a/src/scrobbler/lastfmimport.cpp
+++ b/src/scrobbler/lastfmimport.cpp
@@ -116,7 +116,7 @@ QNetworkReply *LastFMImport::CreateRequest(const ParamList &request_params) {
   std::sort(params.begin(), params.end());
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -351,9 +351,9 @@ void LastFMImport::GetRecentTracksRequestFinished(QNetworkReply *reply, const in
   }
   else {
 
-    QJsonArray array_track = json_obj[QLatin1String("track")].toArray();
+    const QJsonArray array_track = json_obj[QLatin1String("track")].toArray();
 
-    for (const QJsonValueRef value_track : array_track) {
+    for (const QJsonValue &value_track : array_track) {
 
       ++lastplayed_received_;
 
diff --git a/src/scrobbler/listenbrainzscrobbler.cpp b/src/scrobbler/listenbrainzscrobbler.cpp
index ed209ac22..f8a136c72 100644
--- a/src/scrobbler/listenbrainzscrobbler.cpp
+++ b/src/scrobbler/listenbrainzscrobbler.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QCoreApplication>
 #include <QtGlobal>
@@ -289,7 +290,7 @@ void ListenBrainzScrobbler::RequestAccessToken(const QUrl &redirect_url, const Q
   }
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -412,7 +413,7 @@ QJsonObject ListenBrainzScrobbler::JsonTrackMetadata(const ScrobbleMetadata &met
   }
   if (!artist_mbids_list.isEmpty()) {
     QJsonArray artist_mbids_array;
-    for (const QString &musicbrainz_artist_id : artist_mbids_list) {
+    for (const QString &musicbrainz_artist_id : std::as_const(artist_mbids_list)) {
       if (!musicbrainz_artist_id.isEmpty() && !artist_mbids_array.contains(musicbrainz_artist_id)) {
         artist_mbids_array.append(musicbrainz_artist_id);
       }
@@ -545,7 +546,7 @@ void ListenBrainzScrobbler::Submit() {
 
   QJsonArray array;
   ScrobblerCacheItemPtrList cache_items_sent;
-  ScrobblerCacheItemPtrList all_cache_items = cache_->List();
+  const ScrobblerCacheItemPtrList all_cache_items = cache_->List();
   for (ScrobblerCacheItemPtr cache_item : all_cache_items) {
     if (cache_item->sent) continue;
     if (cache_item->error && cache_items_sent.count() > 0) break;
diff --git a/src/scrobbler/scrobblercache.cpp b/src/scrobbler/scrobblercache.cpp
index bd8538477..1d8228a06 100644
--- a/src/scrobbler/scrobblercache.cpp
+++ b/src/scrobbler/scrobblercache.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <functional>
 #include <chrono>
 #include <memory>
@@ -108,12 +109,12 @@ void ScrobblerCache::ReadCache() {
     qLog(Error) << "Scrobbler cache JSON tracks is not an array.";
     return;
   }
-  QJsonArray json_array = json_tracks.toArray();
+  const QJsonArray json_array = json_tracks.toArray();
   if (json_array.isEmpty()) {
     return;
   }
 
-  for (const QJsonValueRef value : json_array) {
+  for (const QJsonValue &value : json_array) {
     if (!value.isObject()) {
       qLog(Error) << "Scrobbler cache JSON tracks array value is not an object.";
       qLog(Debug) << value;
@@ -203,7 +204,7 @@ void ScrobblerCache::WriteCache() {
   }
 
   QJsonArray array;
-  for (ScrobblerCacheItemPtr cache_item : scrobbler_cache_) {
+  for (ScrobblerCacheItemPtr cache_item : std::as_const(scrobbler_cache_)) {
     QJsonObject object;
     object.insert(QLatin1String("timestamp"), QJsonValue::fromVariant(cache_item->timestamp));
     object.insert(QLatin1String("artist"), QJsonValue::fromVariant(cache_item->metadata.artist));
diff --git a/src/scrobbler/scrobblingapi20.cpp b/src/scrobbler/scrobblingapi20.cpp
index 76d27ba8a..9e46e8b5d 100644
--- a/src/scrobbler/scrobblingapi20.cpp
+++ b/src/scrobbler/scrobblingapi20.cpp
@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QApplication>
 #include <QDesktopServices>
@@ -279,7 +280,8 @@ void ScrobblingAPI20::RequestSession(const QString &token) {
   session_url_query.addQueryItem(QStringLiteral("method"), QStringLiteral("auth.getSession"));
   session_url_query.addQueryItem(QStringLiteral("token"), token);
   QString data_to_sign;
-  for (const Param &param : session_url_query.queryItems()) {
+  const ParamList params = session_url_query.queryItems();
+  for (const Param &param : params) {
     data_to_sign += param.first + param.second;
   }
   data_to_sign += QLatin1String(kSecret);
@@ -360,7 +362,7 @@ QNetworkReply *ScrobblingAPI20::CreateRequest(const ParamList &request_params) {
 
   QUrlQuery url_query;
   QString data_to_sign;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     EncodedParam encoded_param(QUrl::toPercentEncoding(param.first), QUrl::toPercentEncoding(param.second));
     url_query.addQueryItem(QString::fromLatin1(encoded_param.first), QString::fromLatin1(encoded_param.second));
     data_to_sign += param.first + param.second;
@@ -493,7 +495,7 @@ void ScrobblingAPI20::Submit() {
   ParamList params = ParamList() << Param(QStringLiteral("method"), QStringLiteral("track.scrobble"));
 
   int i = 0;
-  ScrobblerCacheItemPtrList all_cache_items = cache_->List();
+  const ScrobblerCacheItemPtrList all_cache_items = cache_->List();
   ScrobblerCacheItemPtrList cache_items_sent;
   for (ScrobblerCacheItemPtr cache_item : all_cache_items) {
     if (cache_item->sent) continue;
@@ -623,7 +625,7 @@ void ScrobblingAPI20::ScrobbleRequestFinished(QNetworkReply *reply, ScrobblerCac
     return;
   }
 
-  for (const QJsonValueRef value : array_scrobble) {
+  for (const QJsonValue &value : std::as_const(array_scrobble)) {
 
     if (!value.isObject()) {
       Error(QStringLiteral("Json scrobbles scrobble array value is not an object."));
diff --git a/src/settings/appearancesettingspage.cpp b/src/settings/appearancesettingspage.cpp
index 156645b84..a3e7793fd 100644
--- a/src/settings/appearancesettingspage.cpp
+++ b/src/settings/appearancesettingspage.cpp
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QApplication>
 #include <QWidget>
 #include <QStyleFactory>
@@ -91,7 +93,8 @@ AppearanceSettingsPage::AppearanceSettingsPage(SettingsDialog *dialog, QWidget *
   setWindowIcon(IconLoader::Load(QStringLiteral("view-media-visualization"), true, 0, 32));
 
   ui_->combobox_style->addItem(QStringLiteral("default"), QStringLiteral("default"));
-  for (const QString &style : QStyleFactory::keys()) {
+  const QStringList styles = QStyleFactory::keys();
+  for (const QString &style : styles) {
     ui_->combobox_style->addItem(style, style);
   }
 
diff --git a/src/settings/backendsettingspage.cpp b/src/settings/backendsettingspage.cpp
index e60cd92a9..e86a6c417 100644
--- a/src/settings/backendsettingspage.cpp
+++ b/src/settings/backendsettingspage.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QWidget>
 #include <QSettings>
@@ -308,7 +310,8 @@ void BackendSettingsPage::Load_Output(QString output, QVariant device) {
   if (output.isEmpty()) output = engine()->DefaultOutput();
 
   ui_->combobox_output->clear();
-  for (const EngineBase::OutputDetails &o : engine()->GetOutputsList()) {
+  const EngineBase::OutputDetailsList outputs = engine()->GetOutputsList();
+  for (const EngineBase::OutputDetails &o : outputs) {
     ui_->combobox_output->addItem(IconLoader::Load(o.iconname), o.description, QVariant::fromValue(o));
   }
   if (ui_->combobox_output->count() > 1) ui_->combobox_output->setEnabled(true);
@@ -370,9 +373,11 @@ void BackendSettingsPage::Load_Device(const QString &output, const QVariant &dev
 #endif
     ui_->combobox_device->addItem(IconLoader::Load(QStringLiteral("soundcard")), QLatin1String(kOutputAutomaticallySelect), QVariant());
 
-  for (DeviceFinder *f : dialog()->app()->device_finders()->ListFinders()) {
+  const QList<DeviceFinder*> device_finders = dialog()->app()->device_finders()->ListFinders();
+  for (DeviceFinder *f : device_finders) {
     if (!f->outputs().contains(output)) continue;
-    for (const EngineDevice &d : f->ListDevices()) {
+    const EngineDeviceList engine_devices = f->ListDevices();
+    for (const EngineDevice &d : engine_devices) {
       devices++;
       ui_->combobox_device->addItem(IconLoader::Load(d.iconname), d.description, d.value);
       if (d.value == device) { df_device = d; }
diff --git a/src/settings/behavioursettingspage.cpp b/src/settings/behavioursettingspage.cpp
index f12602c25..cdc104665 100644
--- a/src/settings/behavioursettingspage.cpp
+++ b/src/settings/behavioursettingspage.cpp
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 
 #include <QVariant>
 #include <QString>
@@ -80,12 +81,12 @@ BehaviourSettingsPage::BehaviourSettingsPage(SettingsDialog *dialog, QWidget *pa
   // Populate the language combo box.  We do this by looking at all the compiled in translations.
   QDir dir1(QStringLiteral(":/translations/"));
   QDir dir2(QStringLiteral(TRANSLATIONS_DIR));
-  QStringList codes(dir1.entryList(QStringList() << QStringLiteral("*.qm")));
+  QStringList codes = dir1.entryList(QStringList() << QStringLiteral("*.qm"));
   if (dir2.exists()) {
     codes << dir2.entryList(QStringList() << QStringLiteral("*.qm"));
   }
   QRegularExpression lang_re(QStringLiteral("^strawberry_(.*).qm$"));
-  for (const QString &filename : codes) {
+  for (const QString &filename : std::as_const(codes)) {
 
     QRegularExpressionMatch re_match = lang_re.match(filename);
 
diff --git a/src/settings/collectionsettingspage.cpp b/src/settings/collectionsettingspage.cpp
index 2c6edc9fb..516f70598 100644
--- a/src/settings/collectionsettingspage.cpp
+++ b/src/settings/collectionsettingspage.cpp
@@ -21,6 +21,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <limits>
 
 #include <QStandardPaths>
@@ -136,7 +137,8 @@ void CollectionSettingsPage::Load() {
   }
 
   ui_->list->model()->removeRows(0, ui_->list->model()->rowCount());
-  for (const QString &path : collection_directory_model_->paths()) {
+  const QStringList paths = collection_directory_model_->paths();
+  for (const QString &path : paths) {
     collectionsettings_directory_model_->AddDirectory(path);
   }
 
@@ -229,13 +231,15 @@ void CollectionSettingsPage::Save() {
 
   s.endGroup();
 
-  for (const CollectionDirectory &dir : collection_directory_model_->directories()) {
+  const QMap<int, CollectionDirectory> dirs = collection_directory_model_->directories();
+  for (const CollectionDirectory &dir : dirs) {
     if (!collectionsettings_directory_model_->paths().contains(dir.path)) {
       collection_backend_->RemoveDirectoryAsync(dir);
     }
   }
 
-  for (const QString &path : collectionsettings_directory_model_->paths()) {
+  const QStringList paths = collectionsettings_directory_model_->paths();
+  for (const QString &path : paths) {
     if (!collection_directory_model_->paths().contains(path)) {
       collection_backend_->AddDirectoryAsync(path);
     }
diff --git a/src/settings/settingspage.cpp b/src/settings/settingspage.cpp
index 69b463d71..266be30f5 100644
--- a/src/settings/settingspage.cpp
+++ b/src/settings/settingspage.cpp
@@ -56,7 +56,7 @@ void SettingsPage::Init(QWidget *ui_widget) {
   sliders_.clear();
   lineedits_.clear();
 
-  QList<QWidget*> list = ui_widget_->findChildren<QWidget*>(QString(), Qt::FindChildrenRecursively);
+  const QList<QWidget*> list = ui_widget_->findChildren<QWidget*>(QString(), Qt::FindChildrenRecursively);
   for (QWidget *w : list) {
     if (QCheckBox *checkbox = qobject_cast<QCheckBox*>(w)) {
       checkboxes_ << qMakePair(checkbox, checkbox->checkState());
diff --git a/src/smartplaylists/smartplaylistquerywizardplugin.cpp b/src/smartplaylists/smartplaylistquerywizardplugin.cpp
index b4337d7c4..6022af332 100644
--- a/src/smartplaylists/smartplaylistquerywizardplugin.cpp
+++ b/src/smartplaylists/smartplaylistquerywizardplugin.cpp
@@ -21,6 +21,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <utility>
 #include <memory>
 
 #include <QWizardPage>
@@ -183,7 +184,7 @@ void SmartPlaylistQueryWizardPlugin::SetGenerator(PlaylistGeneratorPtr g) {
   qDeleteAll(search_page_->terms_);
   search_page_->terms_.clear();
 
-  for (const SmartPlaylistSearchTerm &term : search.terms_) {
+  for (const SmartPlaylistSearchTerm &term : std::as_const(search.terms_)) {
     AddSearchTerm();
     search_page_->terms_.last()->SetTerm(term);
   }
@@ -290,7 +291,7 @@ SmartPlaylistSearch SmartPlaylistQueryWizardPlugin::MakeSearch() const {
   ret.search_type_ = static_cast<SmartPlaylistSearch::SearchType>(search_page_->ui_->type->currentIndex());
 
   // Search terms
-  for (SmartPlaylistSearchTermWidget *widget : search_page_->terms_) {
+  for (SmartPlaylistSearchTermWidget *widget : std::as_const(search_page_->terms_)) {
     SmartPlaylistSearchTerm term = widget->Term();
     if (term.is_valid()) ret.terms_ << term;
   }
diff --git a/src/smartplaylists/smartplaylistsearchtermwidget.cpp b/src/smartplaylists/smartplaylistsearchtermwidget.cpp
index 564e00c0f..c0f1bf6ba 100644
--- a/src/smartplaylists/smartplaylistsearchtermwidget.cpp
+++ b/src/smartplaylists/smartplaylistsearchtermwidget.cpp
@@ -149,7 +149,8 @@ void SmartPlaylistSearchTermWidget::FieldChanged(int index) {
   // Populate the operator combo box
   if (type != current_field_type_) {
     ui_->op->clear();
-    for (const SmartPlaylistSearchTerm::Operator op : SmartPlaylistSearchTerm::OperatorsForType(type)) {
+    const SmartPlaylistSearchTerm::OperatorList operators = SmartPlaylistSearchTerm::OperatorsForType(type);
+    for (const SmartPlaylistSearchTerm::Operator op : operators) {
       const int i = ui_->op->count();
       ui_->op->addItem(SmartPlaylistSearchTerm::OperatorText(type, op));
       ui_->op->setItemData(i, QVariant::fromValue(op));
diff --git a/src/spotify/spotifybaserequest.cpp b/src/spotify/spotifybaserequest.cpp
index d06831269..b28861861 100644
--- a/src/spotify/spotifybaserequest.cpp
+++ b/src/spotify/spotifybaserequest.cpp
@@ -46,10 +46,8 @@ SpotifyBaseRequest::SpotifyBaseRequest(SpotifyService *service, NetworkAccessMan
 
 QNetworkReply *SpotifyBaseRequest::CreateRequest(const QString &ressource_name, const ParamList &params_provided) {
 
-  ParamList params = ParamList() << params_provided;
-
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : params_provided) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
diff --git a/src/spotify/spotifyrequest.cpp b/src/spotify/spotifyrequest.cpp
index 460ae7488..a4093f298 100644
--- a/src/spotify/spotifyrequest.cpp
+++ b/src/spotify/spotifyrequest.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QObject>
 #include <QByteArray>
 #include <QString>
@@ -481,7 +483,7 @@ void SpotifyRequest::ArtistsReplyReceived(QNetworkReply *reply, const int limit_
     return;
   }
 
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {  // Empty array means no results
     if (offset_requested == 0) no_results_ = true;
     ArtistsFinishCheck();
@@ -489,7 +491,7 @@ void SpotifyRequest::ArtistsReplyReceived(QNetworkReply *reply, const int limit_
   }
 
   int artists_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++artists_received;
 
@@ -547,7 +549,7 @@ void SpotifyRequest::ArtistsFinishCheck(const int limit, const int offset, const
   if (artists_requests_queue_.isEmpty() && artists_requests_active_ <= 0) {  // Artist query is finished, get all albums for all artists.
 
     // Get artist albums
-    QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
+    const QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
     for (const ArtistAlbumsRequest &request : requests) {
       AddArtistAlbumsRequest(request.artist);
     }
@@ -670,7 +672,7 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
     AlbumsFinishCheck(artist_artist);
     return;
   }
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {
     if ((type_ == Type::FavouriteAlbums || type_ == Type::SearchAlbums || (type_ == Type::SearchSongs && fetchalbums_)) && offset_requested == 0) {
       no_results_ = true;
@@ -680,7 +682,7 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
   }
 
   int albums_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++albums_received;
 
@@ -727,9 +729,9 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
     album.album = obj_item[QLatin1String("name")].toString();
 
     if (obj_item.contains(QLatin1String("artists")) && obj_item[QLatin1String("artists")].isArray()) {
-      QJsonArray array_artists = obj_item[QLatin1String("artists")].toArray();
+      const QJsonArray array_artists = obj_item[QLatin1String("artists")].toArray();
       bool artist_matches = false;
-      for (const QJsonValueRef value : array_artists) {
+      for (const QJsonValue &value : array_artists) {
         if (!value.isObject()) {
           continue;
         }
@@ -755,8 +757,8 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
     }
 
     if (obj_item.contains(QLatin1String("images")) && obj_item[QLatin1String("images")].isArray()) {
-      QJsonArray array_images = obj_item[QLatin1String("images")].toArray();
-      for (const QJsonValueRef value : array_images) {
+      const QJsonArray array_images = obj_item[QLatin1String("images")].toArray();
+      for (const QJsonValue &value : array_images) {
         if (!value.isObject()) {
           continue;
         }
@@ -774,11 +776,11 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
     if (obj_item.contains(QLatin1String("tracks")) && obj_item[QLatin1String("tracks")].isObject()) {
       QJsonObject obj_tracks = obj_item[QLatin1String("tracks")].toObject();
       if (obj_tracks.contains(QLatin1String("items")) && obj_tracks[QLatin1String("items")].isArray()) {
-        QJsonArray array_tracks = obj_tracks[QLatin1String("items")].toArray();
+        const QJsonArray array_tracks = obj_tracks[QLatin1String("items")].toArray();
         bool compilation = false;
         bool multidisc = false;
         SongList songs;
-        for (const QJsonValueRef value : array_tracks) {
+        for (const QJsonValue &value : array_tracks) {
           if (!value.isObject()) {
             continue;
           }
@@ -793,7 +795,7 @@ void SpotifyRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_a
           if (song.is_compilation()) compilation = true;
           songs << song;
         }
-        for (Song song : songs) {
+        for (Song song : std::as_const(songs)) {
           if (compilation) song.set_compilation_detected(true);
           if (!multidisc) song.set_disc(0);
           songs_.insert(song.song_id(), song);
@@ -980,7 +982,7 @@ void SpotifyRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, c
     return;
   }
 
-  QJsonArray array_items = json_value.toArray();
+  const QJsonArray array_items = json_value.toArray();
   if (array_items.isEmpty()) {
     if ((type_ == Type::FavouriteSongs || type_ == Type::SearchSongs) && offset_requested == 0) {
       no_results_ = true;
@@ -993,7 +995,7 @@ void SpotifyRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, c
   bool multidisc = false;
   SongList songs;
   int songs_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     if (!value_item.isObject()) {
       Error(QStringLiteral("Invalid Json reply, track is not a object."));
@@ -1018,7 +1020,7 @@ void SpotifyRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, c
     songs << song;
   }
 
-  for (Song song : songs) {
+  for (Song song : std::as_const(songs)) {
     if (compilation) song.set_compilation_detected(true);
     if (!multidisc) song.set_disc(0);
     songs_.insert(song.song_id(), song);
@@ -1087,8 +1089,8 @@ void SpotifyRequest::ParseSong(Song &song, const QJsonObject &json_obj, const Ar
   QString artist_id;
   QString artist_title;
   if (json_obj.contains(QLatin1String("artists")) && json_obj[QLatin1String("artists")].isArray()) {
-    QJsonArray array_artists = json_obj[QLatin1String("artists")].toArray();
-    for (const QJsonValueRef value_artist : array_artists) {
+    const QJsonArray array_artists = json_obj[QLatin1String("artists")].toArray();
+    for (const QJsonValue &value_artist : array_artists) {
       if (!value_artist.isObject()) continue;
        QJsonObject obj_artist = value_artist.toObject();
        if (!obj_artist.contains(QLatin1String("type")) || !obj_artist.contains(QLatin1String("id")) || !obj_artist.contains(QLatin1String("name"))) {
@@ -1109,8 +1111,8 @@ void SpotifyRequest::ParseSong(Song &song, const QJsonObject &json_obj, const Ar
       album_id = obj_album[QLatin1String("id")].toString();
       album_title = obj_album[QLatin1String("name")].toString();
       if (obj_album.contains(QLatin1String("images")) && obj_album[QLatin1String("images")].isArray()) {
-        QJsonArray array_images = obj_album[QLatin1String("images")].toArray();
-        for (const QJsonValueRef value : array_images) {
+        const QJsonArray array_images = obj_album[QLatin1String("images")].toArray();
+        for (const QJsonValue &value : array_images) {
           if (!value.isObject()) {
             continue;
           }
diff --git a/src/spotify/spotifyservice.cpp b/src/spotify/spotifyservice.cpp
index c8e4d8865..0e0758b1f 100644
--- a/src/spotify/spotifyservice.cpp
+++ b/src/spotify/spotifyservice.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 #include <chrono>
 
@@ -375,7 +376,7 @@ void SpotifyService::RequestAccessToken(const QString &code, const QUrl &redirec
   }
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -735,7 +736,7 @@ void SpotifyService::LoginError(const QString &error, const QVariant &debug) {
   if (!error.isEmpty()) login_errors_ << error;
 
   QString error_html;
-  for (const QString &e : login_errors_) {
+  for (const QString &e : std::as_const(login_errors_)) {
     qLog(Error) << "Spotify:" << e;
     error_html += e + QLatin1String("<br />");
   }
diff --git a/src/subsonic/subsonicbaserequest.cpp b/src/subsonic/subsonicbaserequest.cpp
index 4be08ff73..f48d4ecf4 100644
--- a/src/subsonic/subsonicbaserequest.cpp
+++ b/src/subsonic/subsonicbaserequest.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QObject>
 #include <QByteArray>
@@ -73,7 +75,7 @@ QUrl SubsonicBaseRequest::CreateUrl(const QUrl &server_url, const SubsonicSettin
   }
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
diff --git a/src/subsonic/subsonicrequest.cpp b/src/subsonic/subsonicrequest.cpp
index 01b75525c..ef938af04 100644
--- a/src/subsonic/subsonicrequest.cpp
+++ b/src/subsonic/subsonicrequest.cpp
@@ -239,7 +239,7 @@ void SubsonicRequest::AlbumsReplyReceived(QNetworkReply *reply, const int offset
     Error(QStringLiteral("Json album is not an array."), json_album);
     AlbumsFinishCheck(offset_requested, size_requested);
   }
-  QJsonArray array_albums = json_album.toArray();
+  const QJsonArray array_albums = json_album.toArray();
 
   if (array_albums.isEmpty()) {
     if (offset_requested == 0) no_results_ = true;
@@ -248,7 +248,7 @@ void SubsonicRequest::AlbumsReplyReceived(QNetworkReply *reply, const int offset
   }
 
   int albums_received = 0;
-  for (const QJsonValueRef value_album : array_albums) {
+  for (const QJsonValue &value_album : array_albums) {
 
     ++albums_received;
 
@@ -425,7 +425,7 @@ void SubsonicRequest::AlbumSongsReplyReceived(QNetworkReply *reply, const QStrin
     SongsFinishCheck();
     return;
   }
-  QJsonArray array_songs = json_song.toArray();
+  const QJsonArray array_songs = json_song.toArray();
 
   qint64 created = 0;
   if (obj_album.contains(QLatin1String("created"))) {
@@ -435,7 +435,7 @@ void SubsonicRequest::AlbumSongsReplyReceived(QNetworkReply *reply, const QStrin
   bool compilation = false;
   bool multidisc = false;
   SongList songs;
-  for (const QJsonValueRef value_song : array_songs) {
+  for (const QJsonValue &value_song : array_songs) {
 
     if (!value_song.isObject()) {
       Error(QStringLiteral("Invalid Json reply, track is not a object."));
@@ -451,7 +451,7 @@ void SubsonicRequest::AlbumSongsReplyReceived(QNetworkReply *reply, const QStrin
     songs << song;
   }
 
-  for (Song song : songs) {
+  for (Song song : std::as_const(songs)) {
     if (compilation) song.set_compilation_detected(true);
     if (!multidisc) {
       song.set_disc(0);
@@ -641,7 +641,7 @@ QString SubsonicRequest::ParseSong(Song &song, const QJsonObject &json_obj, cons
   Song::FileType filetype(Song::FileType::Stream);
   if (!mimetype.isEmpty()) {
     QMimeDatabase mimedb;
-    QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
+    const QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
     for (const QString &suffix : suffixes) {
       filetype = Song::FiletypeByExtension(suffix);
       if (filetype != Song::FileType::Unknown) break;
diff --git a/src/subsonic/subsonicservice.cpp b/src/subsonic/subsonicservice.cpp
index ea656b9eb..990c8315c 100644
--- a/src/subsonic/subsonicservice.cpp
+++ b/src/subsonic/subsonicservice.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QtGlobal>
@@ -169,7 +170,7 @@ void SubsonicService::SendPingWithCredentials(QUrl url, const QString &username,
   }
 
   QUrlQuery url_query(url.query());
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -449,7 +450,7 @@ void SubsonicService::PingError(const QString &error, const QVariant &debug) {
   if (!error.isEmpty()) errors_ << error;
 
   QString error_html;
-  for (const QString &e : errors_) {
+  for (const QString &e : std::as_const(errors_)) {
     qLog(Error) << "Subsonic:" << e;
     error_html += e + QLatin1String("<br />");
   }
diff --git a/src/tidal/tidalbaserequest.cpp b/src/tidal/tidalbaserequest.cpp
index 2ca60b3ed..da8ac02ca 100644
--- a/src/tidal/tidalbaserequest.cpp
+++ b/src/tidal/tidalbaserequest.cpp
@@ -47,8 +47,8 @@ TidalBaseRequest::TidalBaseRequest(TidalService *service, SharedPtr<NetworkAcces
 
 QNetworkReply *TidalBaseRequest::CreateRequest(const QString &ressource_name, const ParamList &params_provided) {
 
-  ParamList params = ParamList() << params_provided
-                                 << Param(QStringLiteral("countryCode"), country_code());
+  const ParamList params = ParamList() << params_provided
+                                       << Param(QStringLiteral("countryCode"), country_code());
 
   QUrlQuery url_query;
   for (const Param &param : params) {
diff --git a/src/tidal/tidalfavoriterequest.cpp b/src/tidal/tidalfavoriterequest.cpp
index 0d315ff3f..2c1334a54 100644
--- a/src/tidal/tidalfavoriterequest.cpp
+++ b/src/tidal/tidalfavoriterequest.cpp
@@ -134,8 +134,8 @@ void TidalFavoriteRequest::AddFavorites(const FavoriteType type, const SongList
 
 void TidalFavoriteRequest::AddFavoritesRequest(const FavoriteType type, const QStringList &id_list, const SongList &songs) {
 
-  ParamList params = ParamList() << Param(QStringLiteral("countryCode"), country_code())
-                                 << Param(FavoriteMethod(type), id_list.join(QLatin1Char(',')));
+  const ParamList params = ParamList() << Param(QStringLiteral("countryCode"), country_code())
+                                       << Param(FavoriteMethod(type), id_list.join(QLatin1Char(',')));
 
   QUrlQuery url_query;
   for (const Param &param : params) {
@@ -204,7 +204,7 @@ void TidalFavoriteRequest::RemoveSongs(const SongList &songs) {
 
 void TidalFavoriteRequest::RemoveSongs(const SongMap &songs) {
 
-  SongList songs_list = songs.values();
+  const SongList songs_list = songs.values();
   for (const Song &song : songs_list) {
     RemoveFavoritesRequest(FavoriteType::Songs, song.song_id(), SongList() << song);
   }
@@ -235,7 +235,7 @@ void TidalFavoriteRequest::RemoveFavorites(const FavoriteType type, const SongLi
     }
   }
 
-  QStringList ids = songs_map.uniqueKeys();
+  const QStringList ids = songs_map.uniqueKeys();
   for (const QString &id : ids) {
     RemoveFavoritesRequest(type, id, songs_map.values(id));
   }
@@ -244,7 +244,7 @@ void TidalFavoriteRequest::RemoveFavorites(const FavoriteType type, const SongLi
 
 void TidalFavoriteRequest::RemoveFavoritesRequest(const FavoriteType type, const QString &id, const SongList &songs) {
 
-  ParamList params = ParamList() << Param(QStringLiteral("countryCode"), country_code());
+  const ParamList params = ParamList() << Param(QStringLiteral("countryCode"), country_code());
 
   QUrlQuery url_query;
   for (const Param &param : params) {
diff --git a/src/tidal/tidalrequest.cpp b/src/tidal/tidalrequest.cpp
index a7230c38d..33f2913df 100644
--- a/src/tidal/tidalrequest.cpp
+++ b/src/tidal/tidalrequest.cpp
@@ -19,6 +19,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QObject>
 #include <QList>
 #include <QByteArray>
@@ -470,14 +472,14 @@ void TidalRequest::ArtistsReplyReceived(QNetworkReply *reply, const int limit_re
     return;
   }
 
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {  // Empty array means no results
     ArtistsFinishCheck();
     return;
   }
 
   int artists_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++artists_received;
 
@@ -540,7 +542,7 @@ void TidalRequest::ArtistsFinishCheck(const int limit, const int offset, const i
   if (artists_requests_queue_.isEmpty() && artists_requests_active_ <= 0) {  // Artist query is finished, get all albums for all artists.
 
     // Get artist albums
-    QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
+    const QList<ArtistAlbumsRequest> requests = artist_albums_requests_pending_.values();
     for (const ArtistAlbumsRequest &request : requests) {
       AddArtistAlbumsRequest(request.artist);
     }
@@ -652,14 +654,14 @@ void TidalRequest::AlbumsReceived(QNetworkReply *reply, const Artist &artist_req
     AlbumsFinishCheck(artist_requested);
     return;
   }
-  QJsonArray array_items = value_items.toArray();
+  const QJsonArray array_items = value_items.toArray();
   if (array_items.isEmpty()) {
     AlbumsFinishCheck(artist_requested);
     return;
   }
 
   int albums_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     ++albums_received;
 
@@ -930,7 +932,7 @@ void TidalRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, con
     return;
   }
 
-  QJsonArray array_items = json_value.toArray();
+  const QJsonArray array_items = json_value.toArray();
   if (array_items.isEmpty()) {
     SongsFinishCheck(artist, album, limit_requested, offset_requested, songs_total, 0);
     return;
@@ -940,7 +942,7 @@ void TidalRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, con
   bool multidisc = false;
   SongList songs;
   int songs_received = 0;
-  for (const QJsonValueRef value_item : array_items) {
+  for (const QJsonValue &value_item : array_items) {
 
     if (!value_item.isObject()) {
       Error(QStringLiteral("Invalid Json reply, track is not a object."));
@@ -966,7 +968,7 @@ void TidalRequest::SongsReceived(QNetworkReply *reply, const Artist &artist, con
     songs << song;
   }
 
-  for (Song song : songs) {
+  for (Song song : std::as_const(songs)) {
     if (compilation) song.set_compilation_detected(true);
     if (!multidisc) song.set_disc(0);
     songs_.insert(song.song_id(), song);
diff --git a/src/tidal/tidalservice.cpp b/src/tidal/tidalservice.cpp
index 053376397..798b3b38b 100644
--- a/src/tidal/tidalservice.cpp
+++ b/src/tidal/tidalservice.cpp
@@ -19,6 +19,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <chrono>
 #include <memory>
 
@@ -379,7 +380,7 @@ void TidalService::RequestAccessToken(const QString &code) {
   }
 
   QUrlQuery url_query;
-  for (const Param &param : params) {
+  for (const Param &param : std::as_const(params)) {
     url_query.addQueryItem(QString::fromLatin1(QUrl::toPercentEncoding(param.first)), QString::fromLatin1(QUrl::toPercentEncoding(param.second)));
   }
 
@@ -1006,7 +1007,7 @@ void TidalService::LoginError(const QString &error, const QVariant &debug) {
   if (!error.isEmpty()) login_errors_ << error;
 
   QString error_html;
-  for (const QString &e : login_errors_) {
+  for (const QString &e : std::as_const(login_errors_)) {
     qLog(Error) << "Tidal:" << e;
     error_html += e + QLatin1String("<br />");
   }
diff --git a/src/tidal/tidalstreamurlrequest.cpp b/src/tidal/tidalstreamurlrequest.cpp
index 39bb34411..1894165b1 100644
--- a/src/tidal/tidalstreamurlrequest.cpp
+++ b/src/tidal/tidalstreamurlrequest.cpp
@@ -233,7 +233,7 @@ void TidalStreamURLRequest::StreamURLReceived() {
 
       QString mimetype = json_obj[QLatin1String("mimeType")].toString();
       QMimeDatabase mimedb;
-      QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
+      const QStringList suffixes = mimedb.mimeTypeForName(mimetype).suffixes();
       for (const QString &suffix : suffixes) {
         filetype = Song::FiletypeByExtension(suffix);
         if (filetype != Song::FileType::Unknown) break;
@@ -253,9 +253,9 @@ void TidalStreamURLRequest::StreamURLReceived() {
       emit StreamURLFailure(id_, media_url_, errors_.first());
       return;
     }
-    QJsonArray json_array_urls = json_urls.toArray();
+    const QJsonArray json_array_urls = json_urls.toArray();
     urls.reserve(json_array_urls.count());
-    for (const QJsonValueRef value : json_array_urls) {
+    for (const QJsonValue &value : json_array_urls) {
       urls << QUrl(value.toString());
     }
   }
diff --git a/src/utilities/imageutils.cpp b/src/utilities/imageutils.cpp
index c8bfba17f..881933cdd 100644
--- a/src/utilities/imageutils.cpp
+++ b/src/utilities/imageutils.cpp
@@ -17,6 +17,8 @@
  *
  */
 
+#include <utility>
+
 #include <QByteArray>
 #include <QString>
 #include <QStringList>
@@ -37,7 +39,8 @@ QStringList ImageUtils::kSupportedImageFormats;
 QStringList ImageUtils::SupportedImageMimeTypes() {
 
   if (kSupportedImageMimeTypes.isEmpty()) {
-    for (const QByteArray &mimetype : QImageReader::supportedMimeTypes()) {
+    const QList<QByteArray> supported_mimetypes = QImageReader::supportedMimeTypes();
+    for (const QByteArray &mimetype : supported_mimetypes) {
       kSupportedImageMimeTypes << QString::fromUtf8(mimetype);
     }
   }
@@ -49,7 +52,8 @@ QStringList ImageUtils::SupportedImageMimeTypes() {
 QStringList ImageUtils::SupportedImageFormats() {
 
   if (kSupportedImageFormats.isEmpty()) {
-    for (const QByteArray &filetype : QImageReader::supportedImageFormats()) {
+    const QList<QByteArray> image_formats = QImageReader::supportedImageFormats();
+    for (const QByteArray &filetype : image_formats) {
       kSupportedImageFormats << QString::fromUtf8(filetype);
     }
   }