.value_ref_hpp" title="Header &lt;boost/log/utility/value_ref.hpp&gt;">boost/log/utility/value_ref.hpp</a>&gt;

</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T1<span class="special">,</span> <span class="keyword">typename</span> TagT1<span class="special">,</span> <span class="keyword">typename</span> T2<span class="special">,</span> <span class="keyword">typename</span> TagT2<span class="special">&gt;</span> 
  <span class="keyword">bool