 class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;::</span><span class="identifier">infinity</span><span class="special">();</span>
<span class="identifier">ss</span> <span class="special">&lt;&lt;</span> <span class="identifier">inf</span><span class="special">;</span> <span class="comment">// Write out.</span>
<span class="identifier">assert</span><span class="special">(</span><span class="identifier">ss</span><span class="special">.</span><span class="identifier">st