Codechange: replace x.size() > 0 with !x.empty()

src/vehicle_gui.cpp

@@ -476,7 +476,7 @@ byte GetBestFittingSubType(Vehicle *v_from, Vehicle *v_for, CargoID dest_cargo_t
 
 	byte ret_refit_cyc = 0;
 	bool success = false;
-	if (subtypes.size() > 0) {
+	if (!subtypes.empty()) {
 		/* Check whether any articulated part is refittable to 'dest_cargo_type' with a subtype listed in 'subtypes' */
 		for (Vehicle *v = v_for; v != nullptr; v = v->HasArticulatedPart() ? v->GetNextArticulatedPart() : nullptr) {
 			const Engine *e = v->GetEngine();