r">string</span><span class="special">&gt;</span> <span class="identifier">out</span><span class="special">(</span><span class="identifier">str</span><span class="special">);</span>
<span class="identifier">generate</span><span class="special">(</span><span class="identifier">out</span><span class="special">,</span>
    <span class="char">'('</span> <span class="special">&lt;&lt;</span> <span class="identifier">karma</span><span class="special">::</span><span class="identifier">double_</span> <span class="s