使用 boost::bind 进行订阅回调时出错

Question

我们收到此编译错误，随后出现更多错误，显示当使用 boost：：bind 作为订阅回调时，尝试将订阅参数与所有可能的候选函数匹配。

error: no matching function for call to ‘ros::NodeHandle::subscribe(const char [18], int, boost::_bi::bind_t<void, void (*)(const geometry_msgs::WrenchStamped_<std::allocator<void> >&, moveit::planning_interface::MoveGroup&), boost::_bi::list2<boost::arg<1>, boost::_bi::value<moveit::planning_interface::MoveGroup*> > >)’

我们的代码如下。注释行显示了在未传递 MoveGroup 上下文(对象指针(时有效的代码。

#include <stdio.h>
#include <boost/bind.hpp>
#include <geometry_msgs/WrenchStamped.h>
#include <moveit/move_group_interface/move_group.h>
using namespace Eigen;
using namespace std;
//void contact_callback(const geometry_msgs::WrenchStamped& msg) {
void contact_callback(const geometry_msgs::WrenchStamped& msg, moveit::planning_interface::MoveGroup &group){
//if(msg.wrench.force.z > 5) group.stop();
}
int main(int argc, char **argv) {
ros::init(argc, argv, "get_stiffness");
ros::NodeHandle node_handle; 
ros::AsyncSpinner spinner(1);
spinner.start();
moveit::planning_interface::MoveGroup group("manipulator");
ros::Subscriber contact_sub;
//contact_sub = node_handle.subscribe("/finger1/nano17ft",1,contact_callback);
contact_sub = node_handle.subscribe("/finger1/nano17ft",100,boost::bind(contact_callback,_1,&group));
ros::waitForShutdown();
return 0;
}

Answer 1

处理程序采用MoveGroup，但您将其传递group地址。

而是使用ref(group)：

boost::bind(contact_callback,_1,boost::ref(group))

或者，确实如此

std::bind(contact_callback,std::placeholders::_1,std::ref(group))

更新：

您的回调不符合所需的签名：

void contact_callback(const geometry_msgs::WrenchStamped&, moveit::planning_interface::MoveGroup & group) {

必须是

void contact_callback(const boost::shared_ptr<geometry_msgs::WrenchStamped const>, moveit::planning_interface::MoveGroup & group) {

---

在调用站点，您必须使消息类型显式(在不可推断的上下文中(：

contact_sub = node_handle.subscribe<geometry_msgs::WrenchStamped>("/finger1/nano17ft", 100,
boost::bind(contact_callback, _1, boost::ref(group)));

或者，您可以先显式包装function<>：

boost::function<void(const boost::shared_ptr<geometry_msgs::WrenchStamped const>&)> callback =
boost::bind(contact_callback, _1, boost::ref(group));
contact_sub = node_handle.subscribe("/finger1/nano17ft", 100, callback);

现场演示

所有 roscpp/Eigen 的东西都被存根了：

住在科里鲁

#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/function.hpp>
#include <iostream>
////////////////// STUBS STUBS STUBS //////
//#include <geometry_msgs/WrenchStamped.h>
namespace Eigen {}
namespace geometry_msgs {
struct WrenchStamped {}; }
namespace moveit { namespace planning_interface { struct MoveGroup { std::string name; MoveGroup(std::string s):name(s){} }; } }
namespace ros {
void init(...) {}
void waitForShutdown(...) {}
struct Subscriber {};
struct NodeHandle {
using VoidConstPtr = void const *;
enum class TransportHints {};
template <typename M>
Subscriber subscribe(const std::string &topic, uint32_t queue_size,
const boost::function<void(const boost::shared_ptr<M const> &)> &callback,
const VoidConstPtr &tracked_object = VoidConstPtr(),
const TransportHints &transport_hints = TransportHints())
{ 
(void)topic, (void)queue_size, void(tracked_object), void(transport_hints);
callback({});
return {};
}
};
struct AsyncSpinner {
AsyncSpinner(int) {}
void start() {}
};
};
//#include <moveit/move_group_interface/move_group.h>
////////////////// END STUBS END STUBS END STUBS //////
using namespace Eigen;
void contact_callback(const boost::shared_ptr<geometry_msgs::WrenchStamped const>, moveit::planning_interface::MoveGroup & group) {
// if(msg.wrench.force.z > 5) group.stop();
std::cout << "Invoked! " << group.name << "n";
}
int main(int argc, char **argv) {
ros::init(argc, argv, "get_stiffness");
ros::NodeHandle node_handle;
ros::AsyncSpinner spinner(1);
spinner.start();
moveit::planning_interface::MoveGroup group("manipulator");
ros::Subscriber contact_sub;
contact_sub = node_handle.subscribe<geometry_msgs::WrenchStamped>("/finger1/nano17ft", 100,
boost::bind(contact_callback, _1, boost::ref(group)));
{
boost::function<void(const boost::shared_ptr<geometry_msgs::WrenchStamped const>&)> callback =
boost::bind(contact_callback, _1, boost::ref(group));
contact_sub = node_handle.subscribe("/finger1/nano17ft", 100, callback);
}
ros::waitForShutdown();
}

指纹

Invoked! manipulator
Invoked! manipulator