ds (the default for Xcode&#39;s Debug
configuration): If <code>condition</code> evaluates to <code>false</code>, stop program
execution in a debuggable state after printing <code>message</code>.</p></li><li><p>In <code>-O</code> builds (the default for Xcode&#39;s Release configuration): If
<code>condition</code> evaluates to <code>false</code>, stop program execution.</p></li><li><p>In <code>-Ounchecked</code> builds, <code>condition</code> is not evaluated, but the optimizer
may assume that it <em>always<