oost.Fusion</a>
          sequence: a boolean and two double values (the real and the imaginary part
          of the complex number). We want it to match the requirements of our formatting
          grammar, which expects those exact values. The <code class="computeroutput"><span class="identifier">BOOST_FUSION_ADAPT_ADT</span></code>
          macro allows us to specify an arbitrary accessor construct, not necessarily
          limited to just calling a member function of the object instance (represented
