Error using "addpointcloud" in pcl

Here is my code to represent point cloud data.

 pcl::PointCloud<pcl::PointXYZRGBA>::Ptr cloud (new pcl::PointCloud <pcl::PointXYZRGBA>);
if (pcl::io::loadPCDFile ("arg[1]", *cloud) == -1)
return (-1);
boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
viewer->setBackgroundColor (0, 0, 0);
viewer->addPointCloud<pcl::PointXYZRGBA> (cloud, "sample cloud");

      

        
        
        
      

    

Does anyone know why I cannot see my cloud cloud data in the output. Although, when I use the code below to display the cloud above the clouds, I can see it in full:

pcl::visualization::CloudViewer viewer1 ("Simple Cloud Viewer");
viewer1.showCloud (cloud);