of the other cases must be satisfied. To protect code from invalid
usage in Release builds, see <code>preconditionFailure(_:file:line:)</code>.</p>

<ul><li><p>In playgrounds and -Onone builds (the default for Xcode&#39;s Debug
configuration), stop program execution in a debuggable state after
printing <code>message</code>.</p></li><li><p>In -O builds, has no effect.</p></li><li><p>In -Ounchecked builds, the optimizer may assume that this function is
never called. Failure to satisfy that assumption is a ser