PCL point cloud

#include<pcl/visualization/cloud_viewer.h>
#include<iostream>
#include<pcl/io/io.h>
#include<pcl/io/pcd_io.h>
#include<pcl/io/ply_io.h>
#include<pcl/point_types.h> 

int user_data;
using std::cout;



int main()
{
    pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
    char strfilepath[256] = "E:\\Realsense\\librealsense-master\\wrappers\\python\\examples\\out.pcd";
    if (-1 == pcl::io::loadPCDFile(strfilepath, *cloud)) {
        cout << "error   input!" << endl;
        return -1;
    }
    cout << cloud->points.size() << endl;
    pcl::visualization::CloudViewer viewer("Cloud Viewer");  
    viewer.showCloud(cloud);
    

    system("pause");
    return 0;
}