 the single <code class="computeroutput"><span class="identifier">create_formatter</span></code>
          method which, when called, will construct a formatter for the particular
          attribute value.
        </p>
<p>
          When the user-defined type supports putting to a stream with <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;&lt;</span></code>
          and this operator behavior is suitable for logging, one can use a simple
          generic forma