title: concise syntax for c++ namespace
body: <p>I wonder if it is possible to write the following lengthy namespace usage in a more succinct way:</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;iomanip&gt;
  
  using std::ostream;
  using std::cout;
  using std::endl;
  using std::ios;
  using std::setw;
  using std::setfill;
  using std::hex;
  </code></pre>
  
  <p>say:</p>
  
  <pre><code>using std::{ostream,cout,endl,ios,setw,setfill,hex}; // hypothetically, of course
  </code></pre>