title: how to print ProcessID and ThreadID in dec-format with boost.log
body: <p>I use boost.log in my program, and the default formatter outputs the ProcessID and ThreadID in hex-format, anyone knows how to print them in dec-format, thanks.</p>
  
  <p>this is the github of my code : <a href="https://github.com/owenliang/boost_asio" rel="noreferrer">https://github.com/owenliang/boost_asio</a>, thanks.</p>
  
  <pre><code>  boost::log::formatter scope_formatter = boost::log::expressions::stream &lt;&lt; "[" &lt;&lt;
        boost::log::expressions::format_date_time&lt;boost::posix_time::ptime&gt;("TimeStamp", "%Y-%m-%d %H:%M:%S") &lt;&lt;
        "] [" &lt;&lt; boost::log::expressions::attr&lt;boost::log::attributes::current_process_id::value_type&gt;("ProcessID") &lt;&lt; 
        "-" &lt;&lt; boost::log::expressions::attr&lt;boost::log::attributes::current_thread_id::value_type&gt;("ThreadID") &lt;&lt; "] [" &lt;&lt;
        boost::log::expressions::attr&lt;boost::log::trivial::severity_level&gt;("Severity") &lt;&lt;
        "] " &lt;&lt; boost::log::expressions::format_named_scope("Scope", boost::log::keywords::format = "%c[%F:%l] ", 
          boost::log::keywords::depth = 1) &lt;&lt; boost::log::expressions::smessage;
  </code></pre>