br>_: @autoclosure (<wbr>) -&gt; Bool, _: @autoclosure (<wbr>) -&gt; String, file:<wbr> StaticString, line: UWord)</a>
        
<div class="comment collapse" id="comment-func-precondition_-autoclosure-bool_-autoclosure-string-file_-staticstring-line_-uword"><div class="p">
    <p>Check a necessary condition for making forward progress.</p>

<p>Use this function to detect conditions that must prevent the
program from proceeding even in shipping code.</p>

<ul><li><p>In playgrounds and -Onone builds (the defa