diff -r fe094d0687ad -r c27612f0eac0 src/libraries.h
--- a/src/libraries.h	Wed Jun 22 23:51:06 2022 +0300
+++ b/src/libraries.h	Sun Jun 26 19:44:45 2022 +0300
@@ -45,8 +45,10 @@
 QDataStream &operator<<(QDataStream&, const Library&);
 QDataStream &operator>>(QDataStream&, Library&);
 
-using Libraries = QVector<Library>;
-Q_DECLARE_METATYPE(Libraries)
+using Libraries = QList<Library>;
+//QDataStream &operator<<(QDataStream&, const Libraries&);
+//QDataStream &operator>>(QDataStream&, Libraries&);
+//Q_DECLARE_METATYPE(Libraries)
 
 class Configuration;
 
@@ -55,18 +57,18 @@
 	Q_OBJECT
 public:
 	LibrariesModel(QObject* parent = nullptr);
-	QVector<Library>::const_iterator begin() const;
-	QVector<Library>::const_iterator end() const;
+	auto begin() const { return this->libraries.begin(); }
+	auto end() const { return this->libraries.end(); }
 	QString findFile(QString fileName) const;
 	void addLibrary(const Library& library);
-	void removeLibrary(const int libraryIndex);
-	const Library& library(int libraryIndex) const;
-	void setLibraryPath(int libraryIndex, const QDir& path);
-	void setLibraryRole(int libraryIndex, const Library::Role role);
+	void removeLibrary(const std::size_t libraryIndex);
+	const Library& library(std::size_t libraryIndex) const;
+	void setLibraryPath(std::size_t libraryIndex, const QDir& path);
+	void setLibraryRole(std::size_t libraryIndex, const Library::Role role);
 	void restoreFromSettings();
 	void storeToSettings();
-	int count() const;
-	void moveLibrary(const int libraryFromIndex, const int libraryToIndex);
+	std::size_t count() const;
+	void moveLibrary(const std::size_t libraryFromIndex, const std::size_t libraryToIndex);
 	// Definitions for QAbstractTableModel
 	Qt::ItemFlags flags(const QModelIndex& index) const override;
 	QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
@@ -76,7 +78,7 @@
 		int role = Qt::DisplayRole) const override;
 	int rowCount(const QModelIndex&) const override;
 	int columnCount(const QModelIndex&) const override;
-	bool isValidIndex(const int libraryIndex) const;
+	bool isValidIndex(const std::size_t libraryIndex) const;
 	ColorTable loadColorTable(QTextStream& errors) const;
 private:
 	enum Column
@@ -84,6 +86,6 @@
 		RoleColumn,
 		PathColumn
 	};
-	void signalLibraryChange(int library);
+	void signalLibraryChange(std::size_t library);
 	Libraries libraries;
 };