                  <p>
                      The return value has to be either <code class="computeroutput"><span class="identifier">fmtflags</span><span class="special">::</span><span class="identifier">scientific</span></code>
                      (generate real number values in scientific notation) or <code class="computeroutput"><span class="identifier">fmtflags</span><span class="special">::</span><span class="identifier">fixed</span></code> (generate real number
                      values in fixed-p