I have a question about Boost syslog.

I"m beginner Boost user.

I created attached code and can't understand why it doesn't work.

I execute my code on linux Kubuntu 3.13.0 

After execution I"m looking for test strings in syslog file:

grep "Test" /var/log/syslog

But I don't see any line.

I tried to execute commands from shell

logger "Test from shell"

logger -n 127.0.0.1 -t myapp -p user.notice "Test from shell"

I see these lines after executing grep on /var/log/syslog

I tried to initialize syslog_backend with 

boost::log::keywords::use_impl = boost::log::sinks::syslog::native

instead of

boost::log::keywords::use_impl = boost::log::sinks::syslog::udp_socket_based

but then I get compile message, native not defined.

I found BOOST_LOG_USE_NATIVE_SYSLOG macro which should be defined during Boost build, but I don't understand how to activate this macro in boost build.