ass="identifier">a</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="identifier">RealType</span> <a class="link" href="param_type.html#idp74786128-bb"><span class="identifier">b</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="param_type.html#idp74788848-bb">friend function