title: C++ calling all update() functions in a program
body: <p>I know this is possible but my inexperience with C++ limits me. What I want to do is have some system were I can add <code>update()</code> methods to certain classes and have all the update methods in the program be called every frame. </p>
  
  <p>Unity3D users may be familiar with this. But how does the program know to call every <code>Update()</code> method when there are an undetermined amount of them in undetermined classes.</p>
  
  <p>I suppose it is a system to dynamically call functions throughout the program.</p>