tail --</span></div>
<div class="line"><a name="l00020"></a><span class="lineno">   20</span>&#160; </div>
<div class="line"><a name="l00021"></a><span class="lineno">   21</span>&#160;                <span class="keyword">typedef</span> T value_type;</div>
<div class="line"><a name="l00022"></a><span class="lineno">   22</span>&#160;                <span class="keyword">typedef</span> vec&lt;2, T, Q&gt; type;</div>
<div class="line"><a name="l00023"></a><span class="lineno">   23</span>&#160;              