_type</a> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="param_type.html#idp82988880-bb"><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="param_type.html" title="Class param_type">param_type</a> <span class="special">&amp;</span><span class="special">,</span> 