C++ 引用作为类成员的函数_C++_Pointers_Lambda_Types_Pass By Reference

C++ 引用作为类成员的函数

c++ pointers lambda types

C++ 引用作为类成员的函数,c++,pointers,lambda,types,pass-by-reference,C++,Pointers,Lambda,Types,Pass By Reference,所以我有一个意大利面代码项目，我正试图使其面向对象。值得一提的是，我遇到了一些我不太理解的错误，所以我尝试创建了一些简单的代码，这些代码确实会抛出相同的错误，但事实并非如此下面是一些编译的简约代码：（文件名为“ims.cpp”）这当然会导致错误，因为参数不再符合我们的期望我的请求如下：这个诊断正确吗如果是：是否可以采取变通办法？如何解决否则：实际问题是什么感谢所有阅读这篇长文章的人，并提前感谢你们的回答解决方案（根据“einpoklum”的建议）最适合我概念的解决方案是

所以我有一个意大利面代码项目，我正试图使其面向对象。值得一提的是，我遇到了一些我不太理解的错误，所以我尝试创建了一些简单的代码，这些代码确实会抛出相同的错误，但事实并非如此

下面是一些编译的简约代码：

（文件名为“ims.cpp”）

这当然会导致错误，因为参数不再符合我们的期望

我的请求如下：

这个诊断正确吗

如果是：是否可以采取变通办法？如何解决

否则：实际问题是什么

感谢所有阅读这篇长文章的人，并提前感谢你们的回答

解决方案（根据“einpoklum”的建议）

最适合我概念的解决方案是lambda，它创建了一个函数来包装恶意的“this”参数

std：：函数无= [this]（const InteractiveMarkerFeedbackConstPtr&feedback）{this->doNothing（feedback）；}

服务器->插入（中间标记，无）

非常感谢您和所有费心阅读全文的人，很抱歉我很难理解地提出这个问题。

试图穿过堆积如山的文本并大胆回答：我认为（但不确定）问题在于您试图通过a（非静态）成员功能，就好像它是一个独立的功能。

这不应该起作用，因为不能“像那样”调用成员函数——它必须有一个关联的对象。在实现级别上，需要使用类实例的地址调用该代码段，以用作

此

对象

在这些情况下，您可以做的是：

使用包装您的成员函数以获得适当的函数，并使用额外的第一个参数作为实例，或
使用lambda以某种方式实例化对象（或仅将实例作为引用）并调用该实例的方法。lambda本身将退化为一个独立函数，您可以传递该函数的指针
如果方法实际上没有使用任何特定于实例的数据，则将其设置为静态

doNothing

应该是

static

，（

static void doNothing（const InteractiveMarkerFeedbackConstPtr&feedback）；

在类定义中）<代码>静态函数没有这个，@Kelvin Sherlock然后会出现一个问题，就是（真实的）函数（真实项目的，一个做某事的函数）实际上使用了类属性，而它当时不能，不是吗？还有别的办法吗？@GDawg请看你是我的英雄<代码>标准：：函数nothing=[this]（const InteractiveMarkerFeedbackConstPtr&feedback）{this->doNothing（feedback）；}

server->insert（inter_标记和IMS:：doNothing）@GDawg:1。如果你发现解决方案有帮助，请考虑投票。2.没有“e”的“英雄”：-）3。要通读你的问题是非常困难的，你应该更加努力地提供最少的例子，我们可以自己编译，看看会发生什么。4.这里列出的两个语句是不相关的，即第二个语句没有使用您定义的lambda；也许你复制错了？sry，upvote暂停，新的堆栈溢出。关于最小代码：抱歉，我没有找到任何与StART C++方法相同的问题^ ^，来测试你需要在我的特定版本中安装ROS的代码等等，只是希望有人能理解这个理论概念，你做到了！服务器->插入（中间标记，无）*英雄
#include <cstdio>

#include <ros/ros.h>

#include <visualization_msgs/Marker.h>
#include <visualization_msgs/InteractiveMarker.h>
#include <interactive_markers/interactive_marker_server.h>
#include <interactive_markers/menu_handler.h>

#include <rosbag/bag.h>
#include <rosbag/view.h>
#include <ros/param.h>

#include <fstream>
#include <cmath>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string.hpp>

using namespace visualization_msgs;
using namespace geometry_msgs;
using namespace std;
using namespace boost;

boost::shared_ptr<interactive_markers::InteractiveMarkerServer> server;

void doNothing(const InteractiveMarkerFeedbackConstPtr &feedback){
}

void testServer(){

  InteractiveMarker inter_marker;
  inter_marker.header.frame_id = 1;
  Point pos;
  pos.x = 3;
  pos.y = 3;
  inter_marker.pose.position = pos;
  inter_marker.scale = 2;
  inter_marker.name = "testServer";

  server->insert(inter_marker, &doNothing);
}

int main(){}

#include <as above>

using namespace visualization_msgs;
using namespace geometry_msgs;
using namespace std;
using namespace boost;

boost::shared_ptr<interactive_markers::InteractiveMarkerServer> server;

void doNothing(){
}

void testServer(){

  InteractiveMarker inter_marker;
  inter_marker.header.frame_id = 1;
  Point pos;
  pos.x = 3;
  pos.y = 3;
  inter_marker.pose.position = pos;
  inter_marker.scale = 2;
  inter_marker.name = "testServer";

  server->insert(inter_marker, &doNothing);
}

int main(){}

    In file included from /usr/include/boost/function/detail/maybe_include.hpp:18:0,
                 from /usr/include/boost/function/detail/function_iterate.hpp:14,
                 from /usr/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:52,
                 from /usr/include/boost/function.hpp:64,
                 from /opt/ros/indigo/include/ros/forwards.h:40,
                 from /opt/ros/indigo/include/ros/common.h:37,
                 from /opt/ros/indigo/include/ros/ros.h:43,
                 from /home/ros/ros/src/robotrainer_editor/heika_beta/ims/src/ims.cpp:3:
/usr/include/boost/function/function_template.hpp: In instantiation of ‘static void boost::detail::function::void_function_invoker1<FunctionPtr, R, T0>::invoke(boost::detail::function::function_buffer&, T0) [with FunctionPtr = void (*)(); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&]’:
/usr/include/boost/function/function_template.hpp:934:38:   required from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = void (*)(); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&]’
/usr/include/boost/function/function_template.hpp:722:7:   required from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (*)(); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&; 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:1069:16:   required from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (*)(); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’
/home/ros/ros/src/robotrainer_editor/heika_beta/ims/src/ims.cpp:40:42:   required from here
/usr/include/boost/function/function_template.hpp:112:11: error: too many arguments to function
           BOOST_FUNCTION_RETURN(f(BOOST_FUNCTION_ARGS));

#include <cstdio>

#include <ros/ros.h>

#include <visualization_msgs/Marker.h>
#include <visualization_msgs/InteractiveMarker.h>
#include <interactive_markers/interactive_marker_server.h>
#include <interactive_markers/menu_handler.h>

#include <rosbag/bag.h>
#include <rosbag/view.h>
#include <ros/param.h>

#include <fstream>
#include <cmath>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string.hpp>

using namespace visualization_msgs;
using namespace geometry_msgs;
using namespace std;
using namespace boost;

class IMS{

  boost::shared_ptr<interactive_markers::InteractiveMarkerServer> server;

  IMS();

  void doNothing(const InteractiveMarkerFeedbackConstPtr &feedback);

  void testServer();

  int main();

};

#include <ims.h>

IMS::IMS(){}

void IMS::doNothing(const InteractiveMarkerFeedbackConstPtr &feedback){
}

void IMS::testServer(){

  InteractiveMarker inter_marker;
  inter_marker.header.frame_id = 1;
  Point pos;
  pos.x = 3;
  pos.y = 3;
  inter_marker.pose.position = pos;
  inter_marker.scale = 2;
  inter_marker.name = "testServer";

  server->insert(inter_marker, &IMS::doNothing); //other options that didn't work either: doNothing);//*this->doNothing(const InteractiveMarkerFeedbackConstPtr &feedback));//*this->doNothing());//this->doNothing);//&this->doNothing);//&IMS::doNothing);//&doNothing);
}

int IMS::main(){}

In file included from /usr/include/boost/function/detail/maybe_include.hpp:18:0,
                 from /usr/include/boost/function/detail/function_iterate.hpp:14,
                 from /usr/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:52,
                 from /usr/include/boost/function.hpp:64,
                 from /opt/ros/indigo/include/ros/forwards.h:40,
                 from /opt/ros/indigo/include/ros/common.h:37,
                 from /opt/ros/indigo/include/ros/ros.h:43,
                 from /home/ros/ros/src/robotrainer_editor/heika_beta/ims/include/ims.h:3,
                 from /home/ros/ros/src/robotrainer_editor/heika_beta/ims/src/ims.cpp:1:
/usr/include/boost/function/function_template.hpp: In instantiation of ‘static void boost::detail::function::function_void_mem_invoker1<MemberPtr, R, T0>::invoke(boost::detail::function::function_buffer&, T0) [with MemberPtr = void (IMS::*)(const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&]’:
/usr/include/boost/function/function_template.hpp:934:38:   required from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = void (IMS::*)(const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&]’
/usr/include/boost/function/function_template.hpp:722:7:   required from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (IMS::*)(const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&; 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:1069:16:   required from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (IMS::*)(const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&); R = void; T0 = const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’
/home/ros/ros/src/robotrainer_editor/heika_beta/ims/src/ims.cpp:19:47:   required from here
/usr/include/boost/function/function_template.hpp:225:11: error: no match for call to ‘(boost::_mfi::mf1<void, IMS, const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&>) (const boost::shared_ptr<const visualization_msgs::InteractiveMarkerFeedback_<std::allocator<void> > >&)’
           BOOST_FUNCTION_RETURN(boost::mem_fn(*f)(BOOST_FUNCTION_ARGS));

void IMS::doNothing(IMS this, const InteractiveMarkerFeedbackConstPtr &feedback){