title: C++ way of C# Action += function?
body: <p>in C# we can say: </p>
  
  <pre><code>Action act = ()=&gt; {/*stuff*/}; 
  act += ()=&gt; {/*another stuff*/}` 
  </code></pre>
  
  <p>and then call <code>act()</code>. </p>
  
  <p>I wonder how to do such thing in C++ (now  with lambdas it will be quite usefull and if possible not using Boost/Qt signals)?</p>