note: ‘std::optional’ is only available from C++17 onwards

[Ac31415]

Good day, I've tried to compile plankton as instructed but got the following error:

--- stderr: uuv_world_plugins In file included from /usr/include/ignition/math6/ignition/math.hh:30, from /usr/include/sdformat-9.4/sdf/Param.hh:33, from /usr/include/sdformat-9.4/sdf/Element.hh:28, from /usr/include/sdformat-9.4/sdf/Actor.hh:25, from /usr/include/sdformat-9.4/sdf/sdf.hh:2, from /usr/include/gazebo-11/gazebo/common/Battery.hh:25, from /usr/include/gazebo-11/gazebo/common/common.hh:8, from /usr/include/gazebo-11/gazebo/gazebo_core.hh:19, from /usr/include/gazebo-11/gazebo/gazebo.hh:20, from /home/wen-chung/colcon_ws/src/Plankton/uuv_world_plugins/uuv_world_plugins/include/uuv_world_plugins/GaussMarkovProcess.h:28, from /home/wen-chung/colcon_ws/src/Plankton/uuv_world_plugins/uuv_world_plugins/src/GaussMarkovProcess.cpp:24: /usr/include/ignition/math6/ignition/math/Capsule.hh:91:20: error: ‘optional’ in namespace ‘std’ does not name a template type 91 | public: std::optional< MassMatrix3<Precision> > MassMatrix() const; | ^~~~~~~~ /usr/include/ignition/math6/ignition/math/Capsule.hh:91:15: note: ‘std::optional’ is only available from C++17 onwards 91 | public: std::optional< MassMatrix3<Precision> > MassMatrix() const; | ^~~

How do I resolve this? Is there a way to change my c++ version using colcon compiler?

Thanks, Andy Cheng

[jpliquid]

Hi @Ac31415,

Apparently, the recently added Capsule.hh file in Ignition requires C++17.

Could you try opening CMakeLists.txt in uuv_world_plugins folder and replacing the line set(CMAKE_CXX_STANDARD 14) with set(CMAKE_CXX_STANDARD 17) ? Let me know if it fixes the problem.

[Ac31415]

Hi @jpliquid ,

Thanks for your prompt response! The above issues have been resolved. However, another error pops up with uuv_sensor_ros_plugins:

--- stderr: uuv_sensor_ros_plugins /home/wen-chung/colcon_ws/src/Plankton/uuv_sensor_plugins/uuv_sensor_ros_plugins/src/DVLROSPlugin.cpp: In member function ‘virtual void gazebo::DVLROSPlugin::Load(gazebo::physics::ModelPtr, sdf::v9::ElementPtr)’: /home/wen-chung/colcon_ws/src/Plankton/uuv_sensor_plugins/uuv_sensor_ros_plugins/src/DVLROSPlugin.cpp:49:60: error: no matching function for call to ‘tf2_ros::Buffer::Buffer(rclcpp::Clock::SharedPtr)’ 49 | myBuffer.reset(new tf2_ros::Buffer(myRosNode->get_clock())); | ^ In file included from /opt/ros/noetic/include/tf2_ros/transform_listener.h:40, from /home/wen-chung/colcon_ws/src/Plankton/uuv_sensor_plugins/uuv_sensor_ros_plugins/include/uuv_sensor_ros_plugins/ROSBaseModelPlugin.h:37, from /home/wen-chung/colcon_ws/src/Plankton/uuv_sensor_plugins/uuv_sensor_ros_plugins/include/uuv_sensor_ros_plugins/DVLROSPlugin.h:35, from /home/wen-chung/colcon_ws/src/Plankton/uuv_sensor_plugins/uuv_sensor_ros_plugins/src/DVLROSPlugin.cpp:22: /opt/ros/noetic/include/tf2_ros/buffer.h:63:5: note: candidate: ‘tf2_ros::Buffer::Buffer(ros::Duration, bool)’ 63 | Buffer(ros::Duration cache_time = ros::Duration(BufferCore::DEFAULT_CACHE_TIME), bool debug = false); | ^~~~~~ /opt/ros/noetic/include/tf2_ros/buffer.h:63:26: note: no known conversion for argument 1 from ‘rclcpp::Clock::SharedPtr’ {aka ‘std::shared_ptr<rclcpp::Clock>’} to ‘ros::Duration’ 63 | Buffer(ros::Duration cache_time = ros::Duration(BufferCore::DEFAULT_CACHE_TIME), bool debug = false); | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Does this have something to do with the multiple ROS installed in my system?

[Ac31415]

@jpliquid Any updates?

[jpliquid]

@Ac31415 You are fine to have multiple versions of ROS installed on your system, but the error shows that colcon uses Noetic instead of Foxy. Have you correctly sourced your Foxy distribution as indicated here before building Plankton ?

[Ac31415]

Yes I did. And it still recognized Noetic as the current distribution of ROS. So I actually resolved it by uninstalling both distributions of ROS, and then just reinstall ROS2 (Foxy) afterwards.