ored
separately from the graph object. The first kind of property is called an <i>internally
stored property</i> while the second kind is called an <i>externally stored
property</i>. BGL uses a uniform mechanism to access both kinds of properties
inside its graph algorithms called the <i>property map</i> interface, described
in Section <a href="property_map.html">Property Map Concepts</a>. In addition,
the <a href="PropertyGraph.html">PropertyGraph</a> concept defines the interface
for obtaining a property 