he inner constructor call does not have the marker. The constructor
      template propagates the <code class="computeroutput"><span class="keyword">noexcept</span></code>
      status of the inner constructor call. (The constructor template has a trailing
      parameter with a default value that disables the template when its signature
      is too close to the signatures of the automatically-defined non-template copy-
      and/or move-constructors of <code class="computeroutput"><span class="identifier"