t
          and output formatting libraries such as <code class="computeroutput"><span class="identifier">scanf</span></code>,
          <code class="computeroutput"><span class="identifier">printf</span></code> or <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">format</span></code> are handling their variable parts.
          In this context you can think about <span class="emphasis"><em>Spirit.Qi</em></span>'s and
          <span cl