title: boost spirit semantic action parameters
body: <p>in this <a href="http://boost-spirit.com/home/2010/03/03/the-anatomy-of-semantic-actions-in-qi/" rel="noreferrer">article about boost spirit semantic actions</a> it is mentioned that </p>
  
  <blockquote>
    <p>There are actually 2 more arguments
    being passed: the parser context and a
    reference to a boolean ‘hit’
    parameter. The parser context is
    meaningful only if the semantic action
    is attached somewhere to the right
    hand side of a rule. We will see more
    information about this shortly. The
    boolean value can be set to false
    inside the semantic action invalidates
    the match in retrospective, making the
    parser fail.</p>
  </blockquote>
  
  <p>All fine, but i've been trying to find an example passing a function object as semantic action that uses the other parameters (parser context and hit boolean) but i haven't found any. I would love to see an example using regular functions or function objects, as i barely can grok the phoenix voodoo</p>