Adapting C++ Types in ROS Melodic

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I'm trying to adapt a lot of code that already has data structures defined to ROS, so I decided to try using roscpp message adaptation since it seems like it could help make the transition easier. But I cant get even the demo code to run.

I've been following this tutorial: " http://wiki.ros.org/roscpp/Overview/MessagesSerializationAndAdaptingTypes#Example:_Adapting_a_custom_Vector3 " in Ubuntu 18.04 with ROS Melodic but it doesn't compile. I copied and pasted the tutorial code, and the things added are:

The include ros/static_assert.h and include geometry_msgs/Vector3.h, to fix dependency issues of the original code

The include ros/ros.h and the main function to test the code

This is the code:

#include <ros/message_traits.h>
#include <ros/serialization.h>
#include "ros/static_assert.h"
#include <ros/ros.h>
#include <geometry_msgs/Vector3.h>

struct MyVector3
{
    double x;
    double y;
    double z;
};
// compile-time assert that sizeof(MyVector3) == serializationLength(x) + serializationLength(y) + serializationLength(z)
ROS_STATIC_ASSERT(sizeof(MyVector3) == 24);

namespace ros
{
    namespace message_traits
    {
// This type is fixed-size (24-bytes)
        template<> struct IsFixedSize<MyVector3> : public TrueType {};
// This type is memcpyable
        template<> struct IsSimple<MyVector3> : public TrueType {};

        template<>
        struct MD5Sum<MyVector3>
        {
            static const char* value()
            {
                // Ensure that if the definition of geometry_msgs/Vector3 changes we have a compile error here.
                ROS_STATIC_ASSERT(MD5Sum<geometry_msgs::Vector3>::static_value1 == 0x4a842b65f413084dULL);
                ROS_STATIC_ASSERT(MD5Sum<geometry_msgs::Vector3>::static_value2 == 0xc2b10fb484ea7f17ULL);
                return MD5Sum<geometry_msgs::Vector3>::value();
            }

            static const char* value(const MyVector3& m)
            {
                return MD5Sum<geometry_msgs::Vector3>::value(m);
            }
        };

        template<>
        struct DataType<MyVector3>
        {
            static const char* value()
            {
                return DataType<geometry_msgs::Vector3>::value();
            }

            static const char* value(const MyVector3& m)
            {
                return DataType<geometry_msgs::Vector3>::value(m);
            }
        };

        template<>
        struct Definition<MyVector3>
        {
            static const char* value()
            {
                return Definition<geometry_msgs::Vector3>::value();
            }

            static const char* value(const MyVector3& m)
            {
                return Definition<geometry_msgs::Vector3>::value(m);
            }
        };
    } // namespace message_traits

    namespace serialization
    {
        template<>
        struct Serializer<MyVector3>
        {
            template<typename Stream, typename T>
            inline static void allInOne(Stream& stream, T t)
            {
                stream.next(t.x);
                stream.next(t.y);
                stream.next(t.z);
            }

            ROS_DECLARE_ALLINONE_SERIALIZER;
        };
    } // namespace serialization
} // namespace ros

int main(int argc, char **argv)
{
    ros::init(argc, argv, "talker");
    ros::NodeHandle n;
    ros::Publisher chatter_pub = n.advertise<geometry_msgs::Vector3>("chatter", 1000);

    ros::Rate loop_rate(10);

    MyVector3 Variance;
    Variance.x = 1.0;
    Variance.y = 2.0;

    int count = 0;
    while (ros::ok())
    {
        chatter_pub.publish(Variance);

        ros::spinOnce();

        loop_rate.sleep();
        ++count;
    }


    return 0;
}

It gives the following error:

/home/user/catkin_ws/src/message_tests/src/message_tests2.cpp: In static member function ‘static const char* ros::message_traits::MD5Sum<MyVector3>::value(const MyVector3&)’:
/home/user/catkin_ws/src/message_tests/src/message_tests2.cpp:37:63: error: no matching function for call to ‘ros::message_traits::MD5Sum<geometry_msgs::Vector3_<std::allocator<void> > >::value(const MyVector3&)’
                 return MD5Sum<geometry_msgs::Vector3>::value(m);
                                                               ^
In file included from /home/user/catkin_ws/src/message_tests/src/message_tests2.cpp:4:0:
/opt/ros/melodic/include/geometry_msgs/Vector3.h:125:22: note: candidate: static const char* ros::message_traits::MD5Sum<geometry_msgs::Vector3_<ContainerAllocator> >::value() [with ContainerAllocator = std::allocator<void>]
   static const char* value()
                      ^~~~~
/opt/ros/melodic/include/geometry_msgs/Vector3.h:125:22: note:   candidate expects 0 arguments, 1 provided
/opt/ros/melodic/include/geometry_msgs/Vector3.h:130:22: note: candidate: static const char* ros ...