  from typecasts</a>
    </h4>
<p>
      Many special functions evaluate their results at a higher precision than their
      arguments in order to ensure full machine precision in the result: for example,
      a function passed a float argument may evaluate its result using double precision
      internally. Many of the errors listed above may therefore occur not during
      evaluation, but when converting the result to the narrower result type. The
      function:
    </p>
<pre class="programlisting"><s