title: Why can in-class initializers only use = or {}?
body: <p><a href="http://www.stroustrup.com/C++11FAQ.html#member-init">In-class initializers</a> (C++11 feature) must be enclosed in curly braces or follow a = sign. They may not be specified inside parenthesis.</p>
  
  <p>What is the reason for this?</p>