any</a> <span class="special">&amp;</span> <a class="link" href="any_Conc_1_3_41_13_1_1_1_3.html#id-1_3_41_13_1_1_1_3_14-bb"><span class="keyword">operator</span><span class="special">=</span></a><span class="special">(</span><span class="identifier">U</span> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> U<span class="special">&gt;</span> <a class="li