ass="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">ElemType</span><span class="special">,</span><span class="identifier">Traits</span><span class="special">&gt;</span> <span class="special">&amp;</span> 
  <span class="keyword">operator</span><span class="special">&lt;&lt;</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">b