4e4b983d535c" title="Short-hand for the Arena type this uses for allocation/deallocation/pointer semantics.">Arena_obj</a> <code>A</code>. In order to perform any work on the <code>*t</code> &ndash; including construction, destruction, and any other operations that require internal alloc/dealloc/ptr-deref also inside <code>A</code> &ndash; activate <code>&amp;A</code> in the relevant thread using an <a class="el" href="classipc_1_1shm_1_1stl_1_1Arena__activator.html" title="RAII-style class operating a stac