diff --git a/GUI/Views/SampleDesigner/SampleViewFactory.cpp b/GUI/Views/SampleDesigner/SampleViewFactory.cpp
index e700e398a1a12bd7d6e159b73fac272ddbfef7b8..965abd5ef74aa6b0981a97c124c326299232d792 100644
--- a/GUI/Views/SampleDesigner/SampleViewFactory.cpp
+++ b/GUI/Views/SampleDesigner/SampleViewFactory.cpp
@@ -32,28 +32,23 @@
 #include "GUI/Views/SampleDesigner/ParticleView.h"
 #include "GUI/Views/SampleDesigner/TransformationView.h"
 
-namespace {
-
-const QStringList valid_item_types = {MultiLayerItem::M_TYPE,
-                                      LayerItem::M_TYPE,
-                                      ParticleLayoutItem::M_TYPE,
-                                      ParticleItem::M_TYPE,
-                                      TransformationItem::M_TYPE,
-                                      ParticleCoreShellItem::M_TYPE,
-                                      ParticleCompositionItem::M_TYPE,
-                                      MesoCrystalItem::M_TYPE,
-                                      Interference1DLatticeItem::M_TYPE,
-                                      Interference2DLatticeItem::M_TYPE,
-                                      Interference2DParaCrystalItem::M_TYPE,
-                                      InterferenceFinite2DLatticeItem::M_TYPE,
-                                      InterferenceHardDiskItem::M_TYPE,
-                                      InterferenceRadialParaCrystalItem::M_TYPE};
-
-} // namespace
-
 bool SampleViewFactory::isValidType(const QString& model_type)
 {
-    return model_type.startsWith("FormFactor") || valid_item_types.contains(model_type);
+    return model_type.startsWith("FormFactor")
+        || model_type == MultiLayerItem::M_TYPE
+        || model_type == LayerItem::M_TYPE
+        || model_type == ParticleLayoutItem::M_TYPE
+        || model_type == ParticleItem::M_TYPE
+        || model_type == TransformationItem::M_TYPE
+        || model_type == ParticleCoreShellItem::M_TYPE
+        || model_type == ParticleCompositionItem::M_TYPE
+        || model_type == MesoCrystalItem::M_TYPE
+        || model_type == Interference1DLatticeItem::M_TYPE
+        || model_type == Interference2DLatticeItem::M_TYPE
+        || model_type == Interference2DParaCrystalItem::M_TYPE
+        || model_type == InterferenceFinite2DLatticeItem::M_TYPE
+        || model_type == InterferenceHardDiskItem::M_TYPE
+        || model_type == InterferenceRadialParaCrystalItem::M_TYPE;
 }
 
 IView* SampleViewFactory::createSampleView(const QString& model_type)