title: Forward declare HINSTANCE and friends
body: <p>Is there a way to forward-declare the <code>HINSTANCE</code> type from the WinAPI without including the full (and big) <code>windows.h</code> header?</p>
  
  <p>For example, if I have a class <code>RenderWindow</code> which owns an <code>HINSTANCE mInstance</code>, i will have to include <code>windows.h</code> in <code>RenderWindow.h</code>. So everything that needs <code>RenderWindow</code> also has to include <code>windows.h</code>.</p>
  
  <p>I tried including <code>windef.h</code> but this seems to need some things from <code>windows.h</code>. :-( If I can't forward declare it, is there at least a portable way to use something like <code>long mInstance</code> in <code>RenderWindow</code> instead of <code>HINSTANCE</code>?</p>