c++ - 在 C++(和 MoveIt API)上将成员函数的 std::bind 作为参数传递时出现问题

Question

你好，

注意:尽管这是一个与 ROS 相关的问题，但我将其张贴在这里是因为我很确定我的问题出在 C++ 而不是 ROS API。

我正在尝试使用函数 setFromIK定义于 moveit::core::RobotState .

此函数接受一个名为 GroupStateValidityCallbackFn 的可调用参数带有类型(函数签名):

typedef boost::function<bool(RobotState* robot_state, const JointModelGroup* joint_group, const double* joint_group_variable_values)>

问题的出现是因为我试图将一个成员类函数传递给这个参数(因为我需要在处理中来类实例成员字段)，然后绑定(bind)过程就陷入困境。

我的类(class)是这样的:

class CSDA10F{
    public:
       bool validateIKSolution( robot_state::RobotState* robot_state, 
                                        const robot_state::JointModelGroup* joint_group, 
                                        const double* joint_group_variable_value){
              [...]
              // some code here
              [...]
          }

       bool planCartesianMotionTask(MoveGroupInterface* move_group, 
                                                    geometry_msgs::Pose initial_pose, 
                                                    geometry_msgs::Pose final_pose,
                                                    std::vector<MoveGroupInterface::Plan> motion_plans,
                                                    uint max_configurations = 10) {
         [...] // Here I make the call!!!.
            auto ik_check_callback = std::bind(&CSDA10F::validateIKSolution, this, _1, _2, _3);
            ik_solution_found = start_state.setFromIK( joint_model_group, initial_pose, 10, 0.01, ik_check_callback);
         [...]
         }

我为函数的 3 个参数使用了 3 个占位符，但随后编译器就失败了，出现了一个我根本不理解的错误。

In file included from /usr/include/boost/function/detail/maybe_include.hpp:28:0,
                 from /usr/include/boost/function/detail/function_iterate.hpp:14,
                 from /usr/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:62,
                 from /usr/include/boost/function.hpp:64,
                 from /opt/ros/kinetic/include/ros/forwards.h:40,
                 from /opt/ros/kinetic/include/ros/common.h:37,
                 from /opt/ros/kinetic/include/ros/ros.h:43,
                 from /home/invite/catkin_ws/src/invite-robotics/drum_automation/src/bag_handling.cpp:1:
/usr/include/boost/function/function_template.hpp: In instantiation of ‘static R boost::detail::function::function_obj_invoker3<FunctionObj, R, T0, T1, T2>::invoke(boost::detail::function::function_buffer&, T0, T1, T2) [with FunctionObj = std::_Bind<std::_Mem_fn<bool (invite_utils::CSDA10F::*)(moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)>(invite_utils::CSDA10F, boost::arg<1>, boost::arg<2>, boost::arg<3>)>; R = bool; T0 = moveit::core::RobotState*; T1 = const moveit::core::JointModelGroup*; T2 = const double*]’:
/usr/include/boost/function/function_template.hpp:940:38:   required from ‘void boost::function3<R, T1, T2, T3>::assign_to(Functor) [with Functor = std::_Bind<std::_Mem_fn<bool (invite_utils::CSDA10F::*)(moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)>(invite_utils::CSDA10F, boost::arg<1>, boost::arg<2>, boost::arg<3>)>; R = bool; T0 = moveit::core::RobotState*; T1 = const moveit::core::JointModelGroup*; T2 = const double*]’
/usr/include/boost/function/function_template.hpp:728:7:   required from ‘boost::function3<R, T1, T2, T3>::function3(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = std::_Bind<std::_Mem_fn<bool (invite_utils::CSDA10F::*)(moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)>(invite_utils::CSDA10F, boost::arg<1>, boost::arg<2>, boost::arg<3>)>; R = bool; T0 = moveit::core::RobotState*; T1 = const moveit::core::JointModelGroup*; T2 = const double*; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’
/usr/include/boost/function/function_template.hpp:1077:16:   required from ‘boost::function<R(T0, T1, T2)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = std::_Bind<std::_Mem_fn<bool (invite_utils::CSDA10F::*)(moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)>(invite_utils::CSDA10F, boost::arg<1>, boost::arg<2>, boost::arg<3>)>; R = bool; T0 = moveit::core::RobotState*; T1 = const moveit::core::JointModelGroup*; T2 = const double*; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’
/home/invite/catkin_ws/src/invite-robotics/invite_utils/include/invite_utils/csda10f_interface.h:202:116:   required from here
/usr/include/boost/function/function_template.hpp:138:22: error: no match for call to ‘(std::_Bind<std::_Mem_fn<bool (invite_utils::CSDA10F::*)(moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)>(invite_utils::CSDA10F, boost::arg<1>, boost::arg<2>, boost::arg<3>)>) (moveit::core::RobotState*, const moveit::core::JointModelGroup*, const double*)’
           return (*f)(BOOST_FUNCTION_ARGS);

是否在RobotState上声明不允许成员函数？，我相信我在使用 std::bind 时犯了一个错误，但我似乎无法找到它是什么的答案。

我知道什么:

• 我在要绑定(bind)的函数中使用了正确的参数类型
• 我有正确数量的参数 (3)

有什么想法吗？

Answer 1

看起来您正在将 Boost _1、_2、_3 占位符与 std::bind 混合使用.尝试以下操作之一:

• 切换到 boost::bind，
• 在调用之前添加 using std::placeholders;，
• 使用捕获 this 的 lambda 表达式。