e from the input stream <code class="computeroutput">in</code> and converts that value to a tribool. If that value is 0, <code class="computeroutput">x</code> becomes <code class="computeroutput">false</code>; if it is 1, <code class="computeroutput">x</code> becomes <code class="computeroutput">true</code>; if it is 2, <code class="computeroutput">becomes</code> <code class="computeroutput">indetermine</code>; otherwise, the operation fails (and the fail bit is set on the input stream <code class="computer