ol</span> <a class="link" href="basic_environment/const_entry_type.html#idp51453632-bb"><span class="identifier">empty</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="special">}</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Char<span class="special">,</span> <span class="keyword">typename</span> Environment