title: It it possible to update specific directory to old revision in Mercurial?
body: <p>I tried to update some files to old revision in many ways, but I haven't found yet.
  (not permanently, just temporarily updating for testing)</p>
  
  <p>For example, the following is OK in SVN.</p>
  
  <pre><code>svn up -r 100 foo.cpp
  U    foo.cpp
  </code></pre>
  
  <p>But in Mercurial, 'up' command doesn't permit file name argument.</p>
  
  <p>Only is it possible to update entire source tree in Mercurial?</p>