&lt;&lt; "edge [style=dashed]" &lt;&lt; std::endl;
    }
  };
}
</pre>

<p>
There exists a class <tt>default_writer</tt>, which can be used as both
vertex/edge and graph property writer, and does nothing. It is useful when
only edge properties must be written, but the function interface also requires a
vertex property writer.

<h3>Parameters</h3>
 OUT: <tt>std::ostream&amp; out</tt>
<blockquote>
  A standard <tt>std::ostream</tt> object.
</blockquote>

 IN: <tt>VertexAndEdgeListGraph&amp; g</tt>
<blockquote