问题解决：shared_ptr Assertion px != 0 failed及debug经验分享
问题详细描述：
/usr/include/boost/smart_ptr/shared_ptr.hpp:646: typename boost::detail::sp_dereference::type boost::shared_ptr::operator*() const [with T = pcl::PointCloudpcl::pointxyz; typename boost::detail::sp_dereference::type = pcl::PointCloudpcl::pointxyz&]: Assertion `px != 0’ failed. Aborted (core dumped)
问题原因：
在使用boost::shared_ptr之前未进行初始化或者未正确初始化
错误代码示例：
class Listener
{
public:
pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_passthrough
;
void callback
(const sensor_msgs::PointCloud2ConstPtr& kinect_output
);
};
// end class
void Listener::callback
(const sensor_msgs::PointCloud2ConstPtr& kinect_output
)
{
pcl::PCLPointCloud2::Ptr pc2
(new pcl::PCLPointCloud2
());
pcl_conversions::toPCL
(*kinect_output
, *pc2
);
pcl::PCLPointCloud2::Ptr cloud_filtered
(new pcl::PCLPointCloud2
());
pcl::VoxelGrid<pcl::PCLPointCloud2> sor
;
sor
.setInputCloud
(pc2
);
sor
.setLeafSize
(0
.01f
,0
.01f
,0
.01f
);
sor
.filter(*cloud_filtered
);// filter the point cloud
pcl::PointCloud<pcl::PointXYZ>::Ptr cloudXYZ
(new pcl::PointCloud<pcl::PointXYZ>
);//object cloud
for point cloud
type XYZ
pcl::fromPCLPointCloud2
(*cloud_filtered
,*cloudXYZ
);
//create passthrough
filter object
pcl::PassThrough<pcl::PointXYZ> pass
;
pass
.setInputCloud
(cloudXYZ
);
pass
.setFilterFieldName
("z");
pass
.setFilterLimits
(0
.5
, 1
.5
);
pass
.filter(*cloud_passthrough
);
}
int main
(int argc
, char
**argv
)
{
ros::init
(argc
, argv
, "PointCloud2_to_pointCloudXYZ");
ros::NodeHandle nh
;
Listener listener
;
ros::Publisher pub = nh
.advertise<pcl::PointCloud<pcl::PointXYZ> >
("/filtered", 1000
);
pcl::PointCloud<pcl::PointXYZ>::Ptr cloud
(new pcl::PointCloud<pcl::PointXYZ>
);
cloud
-> points = listener
.cloud_passthrough
->points
;
ros::Rate loop_rate
(10
);
ros::Subscriber sub = nh
.subscribe <sensor_msgs::PointCloud2>
("/camera/depth/points",1000
,&Listener::callback
, &listener
);
while (ros::ok
())
{
pub
.publish
(cloud
);
ros::spinOnce
();
loop_rate
.sleep();
}//end while loop
return 0
;
}//end main
正确初始化示例：
pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_passthrough（new pcl::PointCloud<pcl::PointXYZ>）
;
boost::shared_ptr<Obj> obj
;
obj
->Something
(); // assertion failed
boost::shared_ptr<Obj> obj
(new Obj
);
obj
->Something
(); // ok
最后分享一个debug的经验，能够使用科学上网的童鞋，可以Google搜索stack overflow网站，针对自己遇到的问题进行搜索，一般情况下均可以搜到对应的解决方法（ps:回答前带有绿色对号的基本为经过人们验证的正确解决方案）。
