><span class="special">--</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">gregorian</span><span class="special">::</span><span class="identifier">date_duration</span> <span class="special">&amp;</span> x<span class="special">)</span><span class="special">;</span>
  <span class="special">}</span>
<span class="special">}</span></pre>
</div>
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