to print with <code>message</code> if the precondition fails.
    The default is the file where <code>precondition(_:_:file:line:)</code> is
    called.
  <strong>line:</strong> The line number to print along with <code>message</code> if the assertion
    fails. The default is the line number where
    <code>precondition(_:_:file:line:)</code> is called.</p>

    <h4>Declaration</h4>    
    <code class="language-swift">func precondition(_ condition: @autoclosure () -&gt; Bool, _ message: @autoclosure () -&