title: Boost.Signals deprecated
body: <blockquote>
    <p>Boost.Signals is no longer being actively maintained, so it has been deprecated. Do not use Boost.Signals for new development (use Boost.Signals2 instead). If you have existing Boost.Signals-based code, it will continue to work, but consider moving to Boost.Signals2.</p>
  </blockquote>
  
  <p><a href="http://www.boost.org/users/history/version_1_54_0.html" rel="nofollow">http://www.boost.org/users/history/version_1_54_0.html</a></p>
  
  <p>So, Signals are deprecated. I'm confused about this. As far as I know, Signals2 is multi-threaded version of Signals. But what if I don't need multi-threading usage of Signals? Will I get some overhead? Can I use boost::signals2::trackable? Will I get any disadvantages using Signals2 in single-thread application?</p>