关于“ROS2 Topic-Statistics-Tutorial编译出错”的思考2

zhangrelay
发布于 2022-05-01 09:53:51
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代码可运行
关于“ROS2 Topic-Statistics-Tutorial编译出错”的思考
复现了一下其中报错信息：
如果选foxy会有如上错误，如果选galactic则不会报错，顺利编译完成。
无需修改：set(CMAKE_CXX_STANDARD 17) windows环境： if(MSVC) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /std:c++17") endif(MSVC)
详细记录：
Hello, ROS 1.0 or ROS 2.0? 1=noetic 2=foxy 3=galactic
2
foxy
ros@ros:~/RobCode/exam_ros2$ colcon build
Starting >>> examples_rclcpp_minimal_publisher
Starting >>> examples_rclcpp_minimal_subscriber
Starting >>> launch_testing_examples
Finished <<< launch_testing_examples [0.72s]
Finished <<< examples_rclcpp_minimal_publisher [11.4s]
--- stderr: examples_rclcpp_minimal_subscriber                               
In file included from /usr/include/c++/9/ext/alloc_traits.h:36,
                 from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/stdexcept:39,
                 from /usr/include/c++/9/array:39,
                 from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:15:
/usr/include/c++/9/bits/alloc_traits.h: In instantiation of ‘struct std::allocator_traits<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:47:9:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/usr/include/c++/9/bits/alloc_traits.h:400:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  400 |       using pointer = _Tp*;
      |             ^~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:403:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  403 |       using const_pointer = const _Tp*;
      |             ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/memory:80,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of ‘struct std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:119:18:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/usr/include/c++/9/bits/unique_ptr.h:71:9: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   71 |         default_delete(const default_delete<_Up>&) noexcept { }
      |         ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:75:7: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   75 |       operator()(_Tp* __ptr) const
      |       ^~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:18:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp: In instantiation of ‘class rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’:
/opt/ros/foxy/include/rclcpp/subscription.hpp:327:57:   required from ‘class rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >’
/usr/include/c++/9/type_traits:1320:45:   required by substitution of ‘template<class _From1, class _To1, class> static std::true_type std::__is_convertible_helper<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*, false>::__test<_From1, _To1, <template-parameter-1-3> >(int) [with _From1 = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*; _To1 = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*; <template-parameter-1-3> = <missing>]’
/usr/include/c++/9/type_traits:1329:42:   required from ‘struct std::__is_convertible_helper<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*, false>’
/usr/include/c++/9/type_traits:1335:12:   required from ‘struct std::is_convertible<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*>’
/usr/include/c++/9/bits/shared_ptr_base.h:927:12:   [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr_base.h:1099:8:   required by substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp> using _Assignable = std::__shared_ptr<_Tp, _Lp>::_Compatible<_Yp, std::__shared_ptr<_Tp, _Lp>&> [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr_base.h:1271:2:   required by substitution of ‘template<class _Yp> std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>::_Assignable<_Yp> std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>::operator=<_Yp>(std::__shared_ptr<_Tp>&&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/usr/include/c++/9/type_traits:1017:12:   required from ‘struct std::is_assignable<std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>&, std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > > >’
/usr/include/c++/9/bits/shared_ptr.h:111:8:   required by substitution of ‘template<class _Tp> template<class _Arg> using _Assignable = typename std::enable_if<std::is_assignable<std::__shared_ptr<_Tp>&, _Arg>::value, std::shared_ptr<_Tp>&>::type [with _Arg = std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
/usr/include/c++/9/bits/shared_ptr.h:341:2:   required by substitution of ‘template<class _Yp> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::_Assignable<std::shared_ptr<_Tp> > std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::operator=<_Yp>(std::shared_ptr<_Tp>&&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:111:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  111 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:125:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  125 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp: In constructor ‘MinimalSubscriber::MinimalSubscriber()’:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75: error: no match for ‘operator=’ (operand types are ‘rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >::SharedPtr’ {aka ‘std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >’} and ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’)
   30 |       "topic", 10, std::bind(&MinimalSubscriber::topic_callback, this, _1));
      |                                                                           ^
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h:309:19: note: candidate: ‘std::shared_ptr<_Tp>& std::shared_ptr<_Tp>::operator=(const std::shared_ptr<_Tp>&) [with _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  309 |       shared_ptr& operator=(const shared_ptr&) noexcept = default;
      |                   ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:309:29: note:   no known conversion for argument 1 from ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ to ‘const std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&’
  309 |       shared_ptr& operator=(const shared_ptr&) noexcept = default;
      |                             ^~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:313:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<const std::shared_ptr<_Yp>&> std::shared_ptr<_Tp>::operator=(const std::shared_ptr<_Yp>&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  313 |  operator=(const shared_ptr<_Yp>& __r) noexcept
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:313:2: note:   template argument deduction/substitution failed:
/usr/include/c++/9/bits/shared_ptr.h: In substitution of ‘template<class _Tp> template<class _Arg> using _Assignable = typename std::enable_if<std::is_assignable<std::__shared_ptr<_Tp>&, _Arg>::value, std::shared_ptr<_Tp>&>::type [with _Arg = const std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >&; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’:
/usr/include/c++/9/bits/shared_ptr.h:313:2:   required by substitution of ‘template<class _Yp> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::_Assignable<const std::shared_ptr<_Tp>&> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::operator=<_Yp>(const std::shared_ptr<_Tp>&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/usr/include/c++/9/bits/shared_ptr.h:111:8: error: no type named ‘type’ in ‘struct std::enable_if<false, std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&>’
  111 |  using _Assignable = typename enable_if<
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:324:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<std::auto_ptr<_Up> > std::shared_ptr<_Tp>::operator=(std::auto_ptr<_Up>&&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  324 |  operator=(auto_ptr<_Yp>&& __r)
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:324:2: note:   template argument deduction/substitution failed:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75: note:   ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ is not derived from ‘std::auto_ptr<_Up>’
   30 |       "topic", 10, std::bind(&MinimalSubscriber::topic_callback, this, _1));
      |                                                                           ^
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h:333:7: note: candidate: ‘std::shared_ptr<_Tp>& std::shared_ptr<_Tp>::operator=(std::shared_ptr<_Tp>&&) [with _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  333 |       operator=(shared_ptr&& __r) noexcept
      |       ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:333:30: note:   no known conversion for argument 1 from ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ to ‘std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&&’
  333 |       operator=(shared_ptr&& __r) noexcept
      |                 ~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/shared_ptr.h:341:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<std::shared_ptr<_Yp> > std::shared_ptr<_Tp>::operator=(std::shared_ptr<_Yp>&&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  341 |  operator=(shared_ptr<_Yp>&& __r) noexcept
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:341:2: note:   substitution of deduced template arguments resulted in errors seen above
/usr/include/c++/9/bits/shared_ptr.h:349:2: note: candidate: ‘template<class _Yp, class _Del> std::shared_ptr<_Tp>::_Assignable<std::unique_ptr<_Up, _Ep> > std::shared_ptr<_Tp>::operator=(std::unique_ptr<_Up, _Ep>&&) [with _Yp = _Yp; _Del = _Del; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  349 |  operator=(unique_ptr<_Yp, _Del>&& __r)
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:349:2: note:   template argument deduction/substitution failed:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75: note:   ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ is not derived from ‘std::unique_ptr<_Tp, _Dp>’
   30 |       "topic", 10, std::bind(&MinimalSubscriber::topic_callback, this, _1));
      |                                                                           ^
In file included from /usr/include/c++/9/ext/alloc_traits.h:36,
                 from /usr/include/c++/9/bits/stl_construct.h:61,
                 from /usr/include/c++/9/memory:64,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/alloc_traits.h: In instantiation of ‘struct std::allocator_traits<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:47:9:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:35:83:   required from here
/usr/include/c++/9/bits/alloc_traits.h:400:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  400 |       using pointer = _Tp*;
      |             ^~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:403:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  403 |       using const_pointer = const _Tp*;
      |             ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/memory:80,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of ‘struct std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:119:18:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:35:83:   required from here
/usr/include/c++/9/bits/unique_ptr.h:71:9: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   71 |         default_delete(const default_delete<_Up>&) noexcept { }
      |         ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:75:7: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   75 |       operator()(_Tp* __ptr) const
      |       ^~~~~~~~
In file included from /usr/include/c++/9/ext/alloc_traits.h:36,
                 from /usr/include/c++/9/bits/stl_construct.h:61,
                 from /usr/include/c++/9/memory:64,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/alloc_traits.h: In instantiation of ‘struct std::allocator_traits<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:47:9:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/usr/include/c++/9/bits/alloc_traits.h:400:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  400 |       using pointer = _Tp*;
      |             ^~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:403:13: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  403 |       using const_pointer = const _Tp*;
      |             ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/memory:80,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of ‘struct std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:119:18:   required from ‘class rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:91:1:   required by substitution of ‘template<class MessageT, class CallbackT, class AllocatorT, class CallbackMessageT, class SubscriptionT, class MessageMemoryStrategyT> std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/usr/include/c++/9/bits/unique_ptr.h:71:9: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   71 |         default_delete(const default_delete<_Up>&) noexcept { }
      |         ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:75:7: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   75 |       operator()(_Tp* __ptr) const
      |       ^~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:18:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp: In instantiation of ‘class rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’:
/opt/ros/foxy/include/rclcpp/subscription.hpp:327:57:   required from ‘class rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >’
/usr/include/c++/9/type_traits:1320:45:   required by substitution of ‘template<class _From1, class _To1, class> static std::true_type std::__is_convertible_helper<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*, false>::__test<_From1, _To1, <template-parameter-1-3> >(int) [with _From1 = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*; _To1 = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*; <template-parameter-1-3> = <missing>]’
/usr/include/c++/9/type_traits:1329:42:   required from ‘struct std::__is_convertible_helper<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*, false>’
/usr/include/c++/9/type_traits:1335:12:   required from ‘struct std::is_convertible<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >*, rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >*>’
/usr/include/c++/9/bits/shared_ptr_base.h:927:12:   [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr_base.h:1099:8:   required by substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp> using _Assignable = std::__shared_ptr<_Tp, _Lp>::_Compatible<_Yp, std::__shared_ptr<_Tp, _Lp>&> [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr_base.h:1271:2:   required by substitution of ‘template<class _Yp> std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>::_Assignable<_Yp> std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>::operator=<_Yp>(std::__shared_ptr<_Tp>&&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/usr/include/c++/9/type_traits:1017:12:   required from ‘struct std::is_assignable<std::__shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >, __gnu_cxx::_S_atomic>&, std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > > >’
/usr/include/c++/9/bits/shared_ptr.h:111:8:   required by substitution of ‘template<class _Tp> template<class _Arg> using _Assignable = typename std::enable_if<std::is_assignable<std::__shared_ptr<_Tp>&, _Arg>::value, std::shared_ptr<_Tp>&>::type [with _Arg = std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
/usr/include/c++/9/bits/shared_ptr.h:341:2:   required by substitution of ‘template<class _Yp> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::_Assignable<std::shared_ptr<_Tp> > std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::operator=<_Yp>(std::shared_ptr<_Tp>&&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:111:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  111 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:125:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  125 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp: In constructor ‘MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()’:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37: error: no match for ‘operator=’ (operand types are ‘rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >::SharedPtr’ {aka ‘std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >’} and ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’)
   44 |       "topic", 10, callback, options);
      |                                     ^
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h:309:19: note: candidate: ‘std::shared_ptr<_Tp>& std::shared_ptr<_Tp>::operator=(const std::shared_ptr<_Tp>&) [with _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  309 |       shared_ptr& operator=(const shared_ptr&) noexcept = default;
      |                   ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:309:29: note:   no known conversion for argument 1 from ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ to ‘const std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&’
  309 |       shared_ptr& operator=(const shared_ptr&) noexcept = default;
      |                             ^~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:313:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<const std::shared_ptr<_Yp>&> std::shared_ptr<_Tp>::operator=(const std::shared_ptr<_Yp>&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  313 |  operator=(const shared_ptr<_Yp>& __r) noexcept
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:313:2: note:   template argument deduction/substitution failed:
/usr/include/c++/9/bits/shared_ptr.h: In substitution of ‘template<class _Tp> template<class _Arg> using _Assignable = typename std::enable_if<std::is_assignable<std::__shared_ptr<_Tp>&, _Arg>::value, std::shared_ptr<_Tp>&>::type [with _Arg = const std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >&; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’:
/usr/include/c++/9/bits/shared_ptr.h:313:2:   required by substitution of ‘template<class _Yp> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::_Assignable<const std::shared_ptr<_Tp>&> std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >::operator=<_Yp>(const std::shared_ptr<_Tp>&) [with _Yp = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/usr/include/c++/9/bits/shared_ptr.h:111:8: error: no type named ‘type’ in ‘struct std::enable_if<false, std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&>’
  111 |  using _Assignable = typename enable_if<
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:324:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<std::auto_ptr<_Up> > std::shared_ptr<_Tp>::operator=(std::auto_ptr<_Up>&&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  324 |  operator=(auto_ptr<_Yp>&& __r)
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:324:2: note:   template argument deduction/substitution failed:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37: note:   ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ is not derived from ‘std::auto_ptr<_Up>’
   44 |       "topic", 10, callback, options);
      |                                     ^
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h:333:7: note: candidate: ‘std::shared_ptr<_Tp>& std::shared_ptr<_Tp>::operator=(std::shared_ptr<_Tp>&&) [with _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  333 |       operator=(shared_ptr&& __r) noexcept
      |       ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:333:30: note:   no known conversion for argument 1 from ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ to ‘std::shared_ptr<rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > > >&&’
  333 |       operator=(shared_ptr&& __r) noexcept
      |                 ~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/shared_ptr.h:341:2: note: candidate: ‘template<class _Yp> std::shared_ptr<_Tp>::_Assignable<std::shared_ptr<_Yp> > std::shared_ptr<_Tp>::operator=(std::shared_ptr<_Yp>&&) [with _Yp = _Yp; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  341 |  operator=(shared_ptr<_Yp>&& __r) noexcept
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:341:2: note:   substitution of deduced template arguments resulted in errors seen above
/usr/include/c++/9/bits/shared_ptr.h:349:2: note: candidate: ‘template<class _Yp, class _Del> std::shared_ptr<_Tp>::_Assignable<std::unique_ptr<_Up, _Ep> > std::shared_ptr<_Tp>::operator=(std::unique_ptr<_Up, _Ep>&&) [with _Yp = _Yp; _Del = _Del; _Tp = rclcpp::Subscription<std_msgs::msg::String_<std::allocator<void> > >]’
  349 |  operator=(unique_ptr<_Yp, _Del>&& __r)
      |  ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:349:2: note:   template argument deduction/substitution failed:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37: note:   ‘std::shared_ptr<rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > > >’ is not derived from ‘std::unique_ptr<_Tp, _Dp>’
   44 |       "topic", 10, callback, options);
      |                                     ^
In file included from /opt/ros/foxy/include/rclcpp/node_interfaces/node_topics_interface.hpp:32,
                 from /opt/ros/foxy/include/rclcpp/node.hpp:55,
                 from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:18:
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp: In instantiation of ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’:
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:97:3: error: no matching function for call to ‘rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >::set(std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>)’
   97 |   any_subscription_callback.set(std::forward<CallbackT>(callback));
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:18:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:81:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   81 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:95:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   95 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  139 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:137:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  137 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  153 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:151:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  151 |     >::type * = nullptr
      |                 ^~~~~~~
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/wait_set_subscriber.cpp: In constructor ‘WaitSetSubscriber::WaitSetSubscriber(rclcpp::NodeOptions)’:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/wait_set_subscriber.cpp:31:58: error: no matching function for call to ‘WaitSetSubscriber::create_callback_group(rclcpp::CallbackGroupType, bool)’
   31 |       rclcpp::CallbackGroupType::MutuallyExclusive, false);
      |                                                          ^
In file included from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/wait_set_subscriber.cpp:18:
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note: candidate: ‘rclcpp::CallbackGroup::SharedPtr rclcpp::Node::create_callback_group(rclcpp::CallbackGroupType)’
  144 |   create_callback_group(rclcpp::CallbackGroupType group_type);
      |   ^~~~~~~~~~~~~~~~~~~~~
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/c++allocator.h:33,
                 from /usr/include/c++/9/bits/allocator.h:46,
                 from /usr/include/c++/9/string:41,
                 from /usr/include/c++/9/stdexcept:39,
                 from /usr/include/c++/9/array:39,
                 from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:15:
/usr/include/c++/9/ext/new_allocator.h: In instantiation of ‘class __gnu_cxx::new_allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/allocator.h:112:11:   required from ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Args = {std::allocator<void>&}]’
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:68:56:   required from ‘rclcpp::AnySubscriptionCallback<MessageT, Alloc>::AnySubscriptionCallback(std::shared_ptr<_Tp>) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:96:57:   required from ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/usr/include/c++/9/ext/new_allocator.h:63:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   63 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/ext/new_allocator.h:64:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   64 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/string:41,
                 from /usr/include/c++/9/stdexcept:39,
                 from /usr/include/c++/9/array:39,
                 from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:15:
/usr/include/c++/9/bits/allocator.h: In instantiation of ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from ‘std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}]’
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Args = {std::allocator<void>&}]’
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:68:56:   required from ‘rclcpp::AnySubscriptionCallback<MessageT, Alloc>::AnySubscriptionCallback(std::shared_ptr<_Tp>) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:96:57:   required from ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:30:75:   required from here
/usr/include/c++/9/bits/allocator.h:117:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  117 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/bits/allocator.h:118:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  118 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp: In instantiation of ‘class rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >’:
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:96:57:   required from ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:35:83:   required from here
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:111:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  111 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:125:8: error: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const _Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’ cannot be overloaded with ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  125 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: previous declaration ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
In file included from /opt/ros/foxy/include/rclcpp/node_interfaces/node_topics_interface.hpp:32,
                 from /opt/ros/foxy/include/rclcpp/node.hpp:55,
                 from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp: In instantiation of ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’:
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = void (&)(const std_msgs::msg::String_<std::allocator<void> >&); AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:35:83:   required from here
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:97:3: error: no matching function for call to ‘rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >::set(void (&)(const std_msgs::msg::String_<std::allocator<void> >&))’
   97 |   any_subscription_callback.set(std::forward<CallbackT>(callback));
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:81:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   81 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:95:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   95 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  139 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:137:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  137 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  153 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:151:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  151 |     >::type * = nullptr
      |                 ^~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/node_interfaces/node_topics_interface.hpp:32,
                 from /opt/ros/foxy/include/rclcpp/node.hpp:55,
                 from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:18:
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp: In instantiation of ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’:
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:97:3: error: no matching function for call to ‘rclcpp::AnySubscriptionCallback<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >::set(MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&)’
   97 |   any_subscription_callback.set(std::forward<CallbackT>(callback));
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /opt/ros/foxy/include/rclcpp/subscription_base.hpp:29,
                 from /opt/ros/foxy/include/rclcpp/callback_group.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/any_executable.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/memory_strategy.hpp:24,
                 from /opt/ros/foxy/include/rclcpp/memory_strategies.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/executor_options.hpp:20,
                 from /opt/ros/foxy/include/rclcpp/executor.hpp:33,
                 from /opt/ros/foxy/include/rclcpp/executors/multi_threaded_executor.hpp:26,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:21,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:18:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   83 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:83:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:81:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   81 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::shared_ptr<_Tp>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
   97 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:97:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:95:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
   95 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  139 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:139:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:137:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  137 |     >::type * = nullptr
      |                 ^~~~~~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note: candidate: ‘template<class CallbackT, typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<const std_msgs::msg::String_<std::allocator<void> >&, std::default_delete<const std_msgs::msg::String_<std::allocator<void> >&> >, const rclcpp::MessageInfo&)> >::value, void>::type* <anonymous> > void rclcpp::AnySubscriptionCallback<MessageT, Alloc>::set(CallbackT) [with CallbackT = CallbackT; typename std::enable_if<rclcpp::function_traits::same_arguments<CallbackT, std::function<void(std::unique_ptr<MessageT, typename std::conditional<std::is_same<typename std::allocator_traits<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type>::rebind_alloc<MessageT>, typename std::allocator<void>::rebind<_Tp1>::other>::value, std::default_delete<_Tp>, rclcpp::allocator::AllocatorDeleter<typename std::allocator_traits<_Alloc>::rebind_traits<MessageT>::allocator_type> >::type>, const rclcpp::MessageInfo&)> >::value>::type* <anonymous> = <enumerator>; MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
  153 |   void set(CallbackT callback)
      |        ^~~
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:153:8: note:   template argument deduction/substitution failed:
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:151:17: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
  151 |     >::type * = nullptr
      |                 ^~~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/c++allocator.h:33,
                 from /usr/include/c++/9/bits/allocator.h:46,
                 from /usr/include/c++/9/memory:63,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/ext/new_allocator.h: In instantiation of ‘class __gnu_cxx::new_allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/allocator.h:112:11:   required from ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Args = {std::allocator<void>&}]’
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:68:56:   required from ‘rclcpp::AnySubscriptionCallback<MessageT, Alloc>::AnySubscriptionCallback(std::shared_ptr<_Tp>) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:96:57:   required from ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/usr/include/c++/9/ext/new_allocator.h:63:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   63 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/ext/new_allocator.h:64:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   64 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/memory:63,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/allocator.h: In instantiation of ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from ‘std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}]’
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Args = {std::allocator<void>&}]’
/opt/ros/foxy/include/rclcpp/any_subscription_callback.hpp:68:56:   required from ‘rclcpp::AnySubscriptionCallback<MessageT, Alloc>::AnySubscriptionCallback(std::shared_ptr<_Tp>) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/subscription_factory.hpp:96:57:   required from ‘rclcpp::SubscriptionFactory rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/create_subscription.hpp:144:63:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::create_subscription(NodeT&&, const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; NodeT = rclcpp::Node&; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node_impl.hpp:98:47:   required from ‘std::shared_ptr<SubscriptionT> rclcpp::Node::create_subscription(const string&, const rclcpp::QoS&, CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; std::string = std::__cxx11::basic_string<char>; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:44:37:   required from here
/usr/include/c++/9/bits/allocator.h:117:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  117 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/bits/allocator.h:118:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  118 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/c++allocator.h:33,
                 from /usr/include/c++/9/bits/allocator.h:46,
                 from /usr/include/c++/9/memory:63,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/ext/new_allocator.h: In instantiation of ‘class __gnu_cxx::new_allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/allocator.h:112:11:   required from ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   [ skipping 7 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr_base.h:1344:71:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}; _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}; _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from ‘std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}]’
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; _Args = {std::shared_ptr<std::allocator<void> >}]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:80:68:   required from ‘static rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::SharedPtr rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::create_default() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>; rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node.hpp:220:45:   required from here
/usr/include/c++/9/ext/new_allocator.h:63:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   63 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/ext/new_allocator.h:64:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
   64 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/memory:63,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/allocator.h: In instantiation of ‘class std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1365:63:   required by substitution of ‘template<class _Yp> struct std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp, std::__void_t<decltype (__enable_shared_from_this_base(declval<const std::__shared_count<__gnu_cxx::_S_atomic>&>(), declval<_Yp*>()))> > [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1387:21:   required by substitution of ‘template<class _Yp, class _Yp2> typename std::enable_if<(! std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::__has_esft_base<_Yp2, void>::value), void>::type std::__shared_ptr<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>, __gnu_cxx::_S_atomic>::_M_enable_shared_from_this_with<_Yp, _Yp2>(_Yp*) [with _Yp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Yp2 = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr_base.h:1345:4:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}; _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from ‘std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = std::allocator<const std_msgs::msg::String_<std::allocator<void> >&>; _Alloc = std::allocator<std::allocator<const std_msgs::msg::String_<std::allocator<void> >&> >; _Args = {std::allocator<void>&}]’
/usr/include/c++/9/bits/shared_ptr.h:717:39:   [ skipping 6 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/9/bits/shared_ptr_base.h:1344:71:   required from ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}; _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from ‘std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}; _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >]’
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from ‘std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; _Alloc = std::allocator<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; _Args = {std::shared_ptr<std::allocator<void> >}]’
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from ‘std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; _Args = {std::shared_ptr<std::allocator<void> >}]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:80:68:   required from ‘static rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::SharedPtr rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::create_default() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>; rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]’
/opt/ros/foxy/include/rclcpp/node.hpp:220:45:   required from here
/usr/include/c++/9/bits/allocator.h:117:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  117 |       typedef _Tp*       pointer;
      |                          ^~~~~~~
/usr/include/c++/9/bits/allocator.h:118:26: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
  118 |       typedef const _Tp* const_pointer;
      |                          ^~~~~~~~~~~~~
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1080:11:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1012:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1012 |       operator->() const noexcept
      |       ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1020:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1020 |       _M_get() const noexcept
      |       ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1162:2: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1162 |  __shared_ptr(const __shared_ptr<_Yp, _Lp>& __r,
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Res> using _Compatible = typename std::enable_if<std::__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type [with _Yp = _Yp; _Res = void; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1172:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Del, class _Res, class _Ptr> using _UniqCompatible = typename std::enable_if<std::__and_<std::__sp_compatible_with<_Yp*, _Tp*>, std::is_convertible<_Ptr, typename std::remove_extent<_Up>::type*> >::value, _Res>::type [with _Yp = _Yp; _Del = _Del; _Res = void; _Ptr = typename std::unique_ptr<_Tp, _Dp>::pointer; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1203:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1219:2: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1219 |  __shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete)
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1309:7: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1309 |       get() const noexcept
      |       ^~~
/usr/include/c++/9/bits/shared_ptr_base.h:1404:24: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1404 |       element_type*    _M_ptr;         // Contained pointer.
      |                        ^~~~~~
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h: In instantiation of ‘class std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr.h:234:2: error: forming pointer to reference type ‘std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
  234 |  shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) noexcept
      |  ^~~~~~~~~~
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:16:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘constexpr std::__shared_ptr<_Tp, _Lp>::__shared_ptr() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:9:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1119:32: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1119 |       : _M_ptr(0), _M_refcount()
      |                                ^
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘void std::__shared_ptr<_Tp, _Lp>::swap(std::__shared_ptr<_Tp, _Lp>&) [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:24:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1326:12: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |            ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1326:28: error: ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’ has no member named ‘_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |                    ~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/functional:59,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function.cpp:15:
/usr/include/c++/9/bits/std_function.h: At global scope:
/usr/include/c++/9/bits/std_function.h:667:7: error: ‘std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]::<lambda(rclcpp::node_interfaces::NodeBaseInterface*, const string&, const rclcpp::QoS&)>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::shared_ptr<rclcpp::SubscriptionBase>; _ArgTypes = {rclcpp::node_interfaces::NodeBaseInterface*, const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, const rclcpp::QoS&}]’, declared using local type ‘rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = std::_Bind<void (MinimalSubscriber::*(MinimalSubscriber*, std::_Placeholder<1>))(const std_msgs::msg::String_<std::allocator<void> >&) const>; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]::<lambda(rclcpp::node_interfaces::NodeBaseInterface*, const string&, const rclcpp::QoS&)>’, is used but never defined [-fpermissive]
  667 |       function<_Res(_ArgTypes...)>::
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
make[2]: *** [CMakeFiles/subscriber_member_function.dir/build.make:63：CMakeFiles/subscriber_member_function.dir/member_function.cpp.o] 错误 1
make[1]: *** [CMakeFiles/Makefile2:146：CMakeFiles/subscriber_member_function.dir/all] 错误 2
make[1]: *** 正在等待未完成的任务....
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1080:11:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1012:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1012 |       operator->() const noexcept
      |       ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1020:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1020 |       _M_get() const noexcept
      |       ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1162:2: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1162 |  __shared_ptr(const __shared_ptr<_Yp, _Lp>& __r,
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Res> using _Compatible = typename std::enable_if<std::__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type [with _Yp = _Yp; _Res = void; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1172:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Del, class _Res, class _Ptr> using _UniqCompatible = typename std::enable_if<std::__and_<std::__sp_compatible_with<_Yp*, _Tp*>, std::is_convertible<_Ptr, typename std::remove_extent<_Up>::type*> >::value, _Res>::type [with _Yp = _Yp; _Del = _Del; _Res = void; _Ptr = typename std::unique_ptr<_Tp, _Dp>::pointer; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1203:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1219:2: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1219 |  __shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete)
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1309:7: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1309 |       get() const noexcept
      |       ^~~
/usr/include/c++/9/bits/shared_ptr_base.h:1404:24: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1404 |       element_type*    _M_ptr;         // Contained pointer.
      |                        ^~~~~~
In file included from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/shared_ptr.h: In instantiation of ‘class std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr.h:234:2: error: forming pointer to reference type ‘std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
  234 |  shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) noexcept
      |  ^~~~~~~~~~
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:16:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘constexpr std::__shared_ptr<_Tp, _Lp>::__shared_ptr() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:9:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1119:32: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1119 |       : _M_ptr(0), _M_refcount()
      |                                ^
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘void std::__shared_ptr<_Tp, _Lp>::swap(std::__shared_ptr<_Tp, _Lp>&) [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:24:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1326:12: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |            ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1326:28: error: ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’ has no member named ‘_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |                    ~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/future:48,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:18,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/member_function_with_topic_statistics.cpp:18:
/usr/include/c++/9/bits/std_function.h: At global scope:
/usr/include/c++/9/bits/std_function.h:667:7: error: ‘std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]::<lambda(rclcpp::node_interfaces::NodeBaseInterface*, const string&, const rclcpp::QoS&)>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::shared_ptr<rclcpp::SubscriptionBase>; _ArgTypes = {rclcpp::node_interfaces::NodeBaseInterface*, const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, const rclcpp::QoS&}]’, declared using local type ‘rclcpp::create_subscription_factory(CallbackT&&, const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>&, typename MessageMemoryStrategyT::SharedPtr, std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT> >) [with MessageT = std_msgs::msg::String_<std::allocator<void> >; CallbackT = MinimalSubscriberWithTopicStatistics::MinimalSubscriberWithTopicStatistics()::<lambda(const String&)>&; AllocatorT = std::allocator<void>; CallbackMessageT = const std_msgs::msg::String_<std::allocator<void> >&; SubscriptionT = rclcpp::Subscription<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void>, rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >; MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> >; typename MessageMemoryStrategyT::SharedPtr = std::shared_ptr<rclcpp::message_memory_strategy::MessageMemoryStrategy<const std_msgs::msg::String_<std::allocator<void> >&, std::allocator<void> > >]::<lambda(rclcpp::node_interfaces::NodeBaseInterface*, const string&, const rclcpp::QoS&)>’, is used but never defined [-fpermissive]
  667 |       function<_Res(_ArgTypes...)>::
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>’:
/usr/include/c++/9/bits/shared_ptr_base.h:1080:11:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1012:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1012 |       operator->() const noexcept
      |       ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1020:7: error: forming pointer to reference type ‘std::__shared_ptr_access<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic, false, false>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1020 |       _M_get() const noexcept
      |       ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1162:2: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1162 |  __shared_ptr(const __shared_ptr<_Yp, _Lp>& __r,
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Res> using _Compatible = typename std::enable_if<std::__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type [with _Yp = _Yp; _Res = void; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1172:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1094:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1094 |  using _Compatible = typename
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In substitution of ‘template<class _Tp, __gnu_cxx::_Lock_policy _Lp> template<class _Yp, class _Del, class _Res, class _Ptr> using _UniqCompatible = typename std::enable_if<std::__and_<std::__sp_compatible_with<_Yp*, _Tp*>, std::is_convertible<_Ptr, typename std::remove_extent<_Up>::type*> >::value, _Res>::type [with _Yp = _Yp; _Del = _Del; _Res = void; _Ptr = typename std::unique_ptr<_Tp, _Dp>::pointer; _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1203:2:   required from ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1104:8: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1104 |  using _UniqCompatible = typename enable_if<__and_<
      |        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1219:2: error: forming pointer to reference type ‘const std_msgs::msg::String_<std::allocator<void> >&’
 1219 |  __shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete)
      |  ^~~~~~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1309:7: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1309 |       get() const noexcept
      |       ^~~
/usr/include/c++/9/bits/shared_ptr_base.h:1404:24: error: forming pointer to reference type ‘std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
 1404 |       element_type*    _M_ptr;         // Contained pointer.
      |                        ^~~~~~
In file included from /usr/include/c++/9/memory:81,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/shared_ptr.h: In instantiation of ‘class std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>’:
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   recursively required from ‘std::shared_ptr<_Tp> rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::borrow_message() [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:85:37:   required from here
/usr/include/c++/9/bits/shared_ptr.h:234:2: error: forming pointer to reference type ‘std::shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&>::element_type’ {aka ‘const std_msgs::msg::String_<std::allocator<void> >&’}
  234 |  shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) noexcept
      |  ^~~~~~~~~~
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:144,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/not_composable.cpp:15:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘constexpr std::__shared_ptr<_Tp, _Lp>::__shared_ptr() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:9:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1119:32: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1119 |       : _M_ptr(0), _M_refcount()
      |                                ^
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of ‘void std::__shared_ptr<_Tp, _Lp>::swap(std::__shared_ptr<_Tp, _Lp>&) [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’:
/usr/include/c++/9/bits/shared_ptr_base.h:1287:24:   required from ‘void std::__shared_ptr<_Tp, _Lp>::reset() [with _Tp = const std_msgs::msg::String_<std::allocator<void> >&; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:109:5:   required from ‘void rclcpp::message_memory_strategy::MessageMemoryStrategy<MessageT, Alloc>::return_message(std::shared_ptr<_Tp>&) [with MessageT = const std_msgs::msg::String_<std::allocator<void> >&; Alloc = std::allocator<void>]’
/opt/ros/foxy/include/rclcpp/message_memory_strategy.hpp:107:16:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:1326:12: error: using invalid field ‘std::__shared_ptr<_Tp, _Lp>::_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |            ^~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1326:28: error: ‘class std::__shared_ptr<const std_msgs::msg::String_<std::allocator<void> >&, __gnu_cxx::_S_atomic>’ has no member named ‘_M_ptr’
 1326 |  std::swap(_M_ptr, __other._M_ptr);
      |                    ~~~~~~~~^~~~~~
make[2]: *** [CMakeFiles/subscriber_member_function_with_topic_statistics.dir/build.make:63：CMakeFiles/subscriber_member_function_with_topic_statistics.dir/member_function_with_topic_statistics.cpp.o] 错误 1
make[1]: *** [CMakeFiles/Makefile2:173：CMakeFiles/subscriber_member_function_with_topic_statistics.dir/all] 错误 2

master/rclcpp/topics/minimal_subscriber/time_triggered_wait_set_subscriber.cpp: In constructor ‘TimeTriggeredWaitSetSubscriber::TimeTriggeredWaitSetSubscriber(rclcpp::NodeOptions)’:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/time_triggered_wait_set_subscriber.cpp:33:58: error: no matching function for call to ‘TimeTriggeredWaitSetSubscriber::create_callback_group(rclcpp::CallbackGroupType, bool)’
   33 |       rclcpp::CallbackGroupType::MutuallyExclusive, false);
      |                                                          ^
In file included from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/time_triggered_wait_set_subscriber.cpp:18:
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note: candidate: ‘rclcpp::CallbackGroup::SharedPtr rclcpp::Node::create_callback_group(rclcpp::CallbackGroupType)’
  144 |   create_callback_group(rclcpp::CallbackGroupType group_type);
      |   ^~~~~~~~~~~~~~~~~~~~~
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note:   candidate expects 1 argument, 2 provided
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/static_wait_set_subscriber.cpp: In lambda function:
/home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/static_wait_set_subscriber.cpp:36:62: error: no matching function for call to ‘StaticWaitSetSubscriber::create_callback_group(rclcpp::CallbackGroupType, bool)’
   36 |           rclcpp::CallbackGroupType::MutuallyExclusive, false);
      |                                                              ^
In file included from /opt/ros/foxy/include/rclcpp/executors/single_threaded_executor.hpp:28,
                 from /opt/ros/foxy/include/rclcpp/executors.hpp:22,
                 from /opt/ros/foxy/include/rclcpp/rclcpp.hpp:146,
                 from /home/ros/RobCode/exam_ros2/src/examples-master/rclcpp/topics/minimal_subscriber/static_wait_set_subscriber.cpp:18:
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note: candidate: ‘rclcpp::CallbackGroup::SharedPtr rclcpp::Node::create_callback_group(rclcpp::CallbackGroupType)’
  144 |   create_callback_group(rclcpp::CallbackGroupType group_type);
      |   ^~~~~~~~~~~~~~~~~~~~~
/opt/ros/foxy/include/rclcpp/node.hpp:144:3: note:   candidate expects 1 argument, 2 provided
make[2]: *** [CMakeFiles/wait_set_subscriber_library.dir/build.make:89：CMakeFiles/wait_set_subscriber_library.dir/time_triggered_wait_set_subscriber.cpp.o] 错误 1
make[2]: *** [CMakeFiles/wait_set_subscriber_library.dir/build.make:76：CMakeFiles/wait_set_subscriber_library.dir/static_wait_set_subscriber.cpp.o] 错误 1
make[1]: *** [CMakeFiles/Makefile2:254：CMakeFiles/wait_set_subscriber_library.dir/all] 错误 2
make: *** [Makefile:141：all] 错误 2
---
Failed   <<< examples_rclcpp_minimal_subscriber [14.4s, exited with code 2]
                                 
Summary: 2 packages finished [14.6s]
  1 package failed: examples_rclcpp_minimal_subscriber
  1 package had stderr output: examples_rclcpp_minimal_subscriber
ros@ros:~/RobCode/exam_ros2$
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原始发表：2022-03-05，如有侵权请联系 cloudcommunity@tencent.com 删除
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