title: How to assign value to LESS variable using selector
body: <p>Since LESS is a pre-compile stylesheet language, this may not achieve what I'm after, but the idea is:</p>
  
  <pre><code>#sidebar {
       width: 40%;
   }
  
  @sidebar_width : @('#sidebar:width');
  
  .some_other_elements {
        width: @sidebar_width;
   }
  </code></pre>
  
  <p>So there are three questions I have:</p>
  
  <ol>
  <li><p>Is something like the above possible? I just discovered LESS and the documentation is making me carsick.</p></li>
  <li><p>If the above is possible, will it produce CSS with the <code>.some_other_elements</code> set to 40% or the actual width of the sidebar? Is it possible to get the actual width using LESS?</p></li>
  <li><p>If you can give me your opinion of the library in general along with the answer or comment, I'd like to hear it. It seems a bit much but maybe it's the next jquery and I need to adopt it sooner than later (or conversely, maybe it's the next YUI and I should forget I ever saw it).</p></li>
  </ol>