Add const and std::as_const

src/playlist/playlistbackend.cpp

@@ -21,6 +21,7 @@
 
 #include "config.h"
 
+#include <utility>
 #include <memory>
 
 #include <QObject>
@@ -307,7 +308,7 @@ PlaylistItemPtr PlaylistBackend::RestoreCueData(PlaylistItemPtr item, SharedPtr<
     }
   }
 
-  for (const Song &from_list : song_list) {
+  for (const Song &from_list : std::as_const(song_list)) {
     if (from_list.url().toEncoded() == song.url().toEncoded() && from_list.beginning_nanosec() == song.beginning_nanosec()) {
       // We found a matching section; replace the input item with a new one containing CUE metadata
       return make_shared<SongPlaylistItem>(from_list);

src/playlist/playlistlistcontainer.cpp

@@ -141,7 +141,8 @@ void PlaylistListContainer::SetApplication(Application *app) {
   QObject::connect(player, &Player::Stopped, this, &PlaylistListContainer::ActiveStopped);
 
   // Get all playlists, even ones that are hidden in the UI.
-  for (const PlaylistBackend::Playlist &p : app->playlist_backend()->GetAllFavoritePlaylists()) {
+  const QList<PlaylistBackend::Playlist> playlists = app->playlist_backend()->GetAllFavoritePlaylists();
+  for (const PlaylistBackend::Playlist &p : playlists) {
     QStandardItem *playlist_item = model_->NewPlaylist(p.name, p.id);
     QStandardItem *parent_folder = model_->FolderByPath(p.ui_path);
     parent_folder->appendRow(playlist_item);
@@ -407,7 +408,8 @@ void PlaylistListContainer::Delete() {
   QSet<int> ids;
   QList<QPersistentModelIndex> folders_to_delete;
 
-  for (const QModelIndex &proxy_index : ui_->tree->selectionModel()->selectedRows()) {
+  const QModelIndexList proxy_indexes = ui_->tree->selectionModel()->selectedRows();
+  for (const QModelIndex &proxy_index : proxy_indexes) {
     const QModelIndex idx = proxy_->mapToSource(proxy_index);
 
     // Is it a playlist?
@@ -439,7 +441,7 @@ void PlaylistListContainer::Delete() {
   }
 
   // Delete the top-level folders.
-  for (const QPersistentModelIndex &idx : folders_to_delete) {
+  for (const QPersistentModelIndex &idx : std::as_const(folders_to_delete)) {
     if (idx.isValid()) {
       model_->removeRow(idx.row(), idx.parent());
     }

src/playlist/playlistundocommands.cpp

@@ -20,6 +20,8 @@
 
 #include "config.h"
 
+#include <utility>
+
 #include <QtGlobal>
 #include <QList>
 #include <QUndoStack>
@@ -92,7 +94,7 @@ bool RemoveItems::mergeWith(const QUndoCommand *other) {
   ranges_.append(remove_command->ranges_);
 
   int sum = 0;
-  for (const Range &range : ranges_) sum += range.count_;
+  for (const Range &range : std::as_const(ranges_)) sum += range.count_;
   setText(tr("remove %n songs", "", sum));
 
   return true;

src/playlist/playlistview.cpp

@@ -865,7 +865,8 @@ void PlaylistView::mousePressEvent(QMouseEvent *event) {
           if (selectedIndexes().contains(idx)) {
             // Update all the selected item ratings
             QModelIndexList src_index_list;
-            for (const QModelIndex &i : selectedIndexes()) {
+            const QModelIndexList indexes = selectedIndexes();
+            for (const QModelIndex &i : indexes) {
               if (i.data(Playlist::Role_CanSetRating).toBool()) {
                 src_index_list << playlist_->filter()->mapToSource(i);
               }
@@ -1548,7 +1549,8 @@ void PlaylistView::RatingHoverIn(const QModelIndex &idx, const QPoint pos) {
 
   update(idx);
   update(old_index);
-  for (const QModelIndex &i : selectedIndexes()) {
+  const QModelIndexList indexes = selectedIndexes();
+  for (const QModelIndex &i : indexes) {
     if (i.column() == Playlist::Column_Rating) update(i);
   }
 
@@ -1569,7 +1571,8 @@ void PlaylistView::RatingHoverOut() {
   setCursor(QCursor());
 
   update(old_index);
-  for (const QModelIndex &i : selectedIndexes()) {
+  const QModelIndexList indexes = selectedIndexes();
+  for (const QModelIndex &i : indexes) {
     if (i.column() == Playlist::Column_Rating) {
       update(i);
     }