title: Objective-C, .m / .mm performance difference?
body: <p>I tend to use the .mm extension by default when creating new classes so that I can use ObjC++ later on if I require it.</p>
  
  <p>Is there any disadvantage to doing this? When would you prefer <code>.m</code>?  Does <code>.m</code> compile to a faster executable (since C is generally faster than C++)?</p>