diff -r b27b90fb993f -r 27259810da6d src/model.h
--- a/src/model.h	Thu Jun 09 19:11:27 2022 +0300
+++ b/src/model.h	Sat Jun 11 14:30:30 2022 +0300
@@ -226,3 +226,13 @@
 
 void save(const Model& model, QIODevice *device);
 void updateHeaderNameField(Model& model, const QString &name);
+
+template<typename T>
+void iterate(const Model& model, std::function<void(const T&)> fn)
+{
+	for (int i = 0; i < model.size(); ++i) {
+		if (std::holds_alternative<T>(model[i])) {
+			fn(std::get<T>(model[i]));
+		}
+	}
+}