Hello Boost Users, <div><br></div><div>I&#39;m now building configuration file parser with Boost.Spirit.</div><div>I have a little trouble understanding how this parser builds attribute:</div><div><br></div><div>It was supposed to parse strings throwing &#39;p&#39; letter away.</div>
<div><br></div><div>*((qi::char_ - &#39;p&#39;) | qi::lit(&#39;p&#39;))</div><div><br></div><div>attribute of qi::lit is Unused.</div><div>attribute of (qi::char_ - &#39;p&#39;) is char.</div><div><br></div><div>so attribute of ((qi::char_ - &#39;p&#39;) | qi::lit(&#39;p&#39;)) should be optional&lt;char&gt; that </div>
<div>is uninitialized optional value when matched against character &#39;p&#39;</div><div><br></div><div>After applying Kleene star it should became vector&lt;optional&lt;char&gt; &gt;.</div><div>It seems to be compatible with string (at least it compiles). But &#39;p&#39; letters</div>
<div>are not thrown away.</div><div><br></div><div>The full example is here: <a href="http://pastebin.com/tCMw22Zy">http://pastebin.com/tCMw22Zy</a></div><div><br></div><div>The output of that example is:</div><div><div>Full parsing</div>
<div>Result: &quot;abcpppdef&quot;</div></div><div><br></div><div>Is it possible to make such a parser without using semantic actions</div><div>like [bind(&amp;string::append, res, _1)] or something like that, which seem</div>
<div>to be less elegant solution.</div><div><br></div><div>Thanks!</div>