t accoplishes this by storing values
in a vector, which is resized on demand. 

<p>
Note that <tt>vector_property_map</tt> does not provide reference/pointer 
stability for stored values.

<h3>Example</h3>

<a href="./example3.cpp">example3.cpp</a>:

<p>
<pre>
#include &lt;boost/vector_property_map.hpp&gt;
#include &lt;string&gt;
#include &lt;iostream&gt;

int main()
{
    boost::vector_property_map&lt;std::string&gt; m;
    
    // Assign string to '4'. 
    m[4] = &quot;e&quot;;
    std::cout &lt;&lt; &qu