er x to SHM-stored space for the Widget_list_vec in question.</span></div>
<div class="line">{</div>
<div class="line">  Shm_classic_arena_activator arena_ctx(&amp;a);</div>
<div class="line">  <span class="comment">// call x-&gt; ctors, dtor, methods, operators....</span></div>
<div class="line">} <span class="comment">// Return the active arena to previous value.</span></div>
<div class="ttc" id="aclassipc_1_1shm_1_1classic_1_1Pool__arena_html"><div class="ttname"><a href="classipc_1_1shm_1_1classic_1_1Po