(const key_type&amp; v) const
</pre>
The operator bracket for property access.

<hr>

<pre>
std::vector&lt;T&gt;::iterator storage_begin()
std::vector&lt;T&gt;::iterator storage_end()
std::vector&lt;T&gt;::const_iterator storage_begin()
std::vector&lt;T&gt;::const_iterator storage_end()
</pre>

<p>This group of methods gives access to begin and end iterators of the
underlying vector.</p>

<p><b>Rationale:</b> The methods are handy, for example, when it's needed to
specify a single value for all elements in 