rd">nullptr</span><span class="special">;</span>
    <span class="keyword">return</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">release</span><span class="special">();</span>
<span class="special">}</span>

<span class="keyword">void</span>
<span class="identifier">pretty_print</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span c