ent">// number of characters used</span>
<span class="identifier">n</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">write_some</span><span class="special">(</span> <span class="string">"[1,2"</span> <span class="special">);</span>                     <span class="comment">// parse the first part of the JSON</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">n</span> <span class="sp