Fixed warning

Author: robertosfield

examples/state/vsgclip/vsgclip.cpp

@@ -74,7 +74,7 @@ class IntersectionHandler : public vsg::Inherit<vsg::Visitor, IntersectionHandle
         if (intersector->intersections.empty()) return;
 
         // sort the intersections front to back
-        std::sort(intersector->intersections.begin(), intersector->intersections.end(), [](auto lhs, auto rhs) { return lhs->ratio < rhs->ratio; });
+        std::sort(intersector->intersections.begin(), intersector->intersections.end(), [](auto& lhs, auto& rhs) { return lhs->ratio < rhs->ratio; });
 
         auto& intersection = *intersector->intersections.front();
         world_clipSettings->at(0) = vsg::vec4(static_cast<float>(intersection.worldIntersection.x),