le">Synopsis</h2>
<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv">parameter ::= 
  (<a class="link" href="paramtype.html" title="BoostBook element paramtype">paramtype</a>, <a class="link" href="default.html" title="BoostBook element default">default</a>?, <a class="link" href="description.html" title="BoostBook element description">description</a>?)
</div>
<div class="refsection">
<a name="idp209958208"></a><h2>Attributes</h2>
<div class="informaltable"><table