   is permitted to evaluate the static assertion at the point it is first seen,
        irrespective of whether the template is ever instantiated, for example:
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">must_not_be_instantiated</span>
<span class="special">{</span>
   <span class="