diff -r cef43609a374 -r 0133e565e072 src/main.h
--- a/src/main.h	Sat Dec 14 23:00:01 2019 +0200
+++ b/src/main.h	Wed Jan 01 17:45:56 2020 +0200
@@ -12,3 +12,12 @@
 	// List of setting groups
 	constexpr char mainwindow[] = "mainwindow";
 }
+
+namespace linetypes
+{
+	// Uniquely identifies a model body object
+	struct Id
+	{
+		unsigned int value;
+	};
+}