build problem

[Thanh-Binh]

by building using CMake I has problema as follows.
error: ‘any_io_executor’
‘class mqtt::socket’} has no member named ‘get_executor’ etc. (see below)
Could you please help me? Thanks
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[ 0%] Building CXX object test/system/CMakeFiles/st_connect.dir/st_connect.cpp.o
In file included from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/tcp_endpoint.hpp:14,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/server.hpp:16,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/common_type.hpp:13,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/session_state.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/broker.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/combi_test.hpp:14,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/st_connect.cpp:8:
/home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/type_erased_socket.hpp:40:17: error: ‘any_io_executor’ in namespace ‘mqtt::as’ does not name a type; did you mean ‘is_executor’?
40 | virtual as::any_io_executor get_executor() = 0;
| ^~~~~~~~~~~~~~~
| is_executor
In file included from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/server.hpp:16,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/common_type.hpp:13,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/session_state.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/broker.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/combi_test.hpp:14,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/st_connect.cpp:8:
/home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/tcp_endpoint.hpp:123:28: error: ‘any_io_executor’ in namespace ‘mqtt::as’ does not name a type; did you mean ‘is_executor’?
123 | MQTT_ALWAYS_INLINE as::any_io_executor get_executor() override final {
| ^~~~~~~~~~~~~~~
| is_executor
In file included from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/server.hpp:18,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/common_type.hpp:13,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/session_state.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/broker/broker.hpp:21,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/combi_test.hpp:14,
from /home/binh/experiments/MQTT/mqtt_cpp/test/system/st_connect.cpp:8:
/home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/endpoint.hpp: In member function ‘auto mqtt::endpoint<Mutex, LockGuard, PacketIdBytes>::get_executor()’:
/home/binh/experiments/MQTT/mqtt_cpp/include/mqtt/endpoint.hpp:4971:25: error: ‘using element_type = class mqtt::socket’ {aka ‘class mqtt::socket’} has no member named ‘get_executor’
4971 | return socket_->get_executor();
| ^~~~~~~~~~~~
make[2]: *** [test/system/CMakeFiles/st_connect.dir/build.make:76: test/system/CMakeFiles/st_connect.dir/st_connect.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:307: test/system/CMakeFiles/st_connect.dir/all] Error 2
make: *** [Makefile:146: all] Error 2