_payload_blob_func</td><td>Function to execute at most once, when it is first indicated by the system that data might be available on the connection. It is executed as if via <code>post(peer_socket-&gt;get_executor())</code>, but any executor bound to it (via <code>bind_executor()</code> is ignored). It takes no args and shall return <code><a class="el" href="namespaceipc_1_1util.html#a6cb62ae434900f3a8915b33ec5d61a96" title="Short-hand for an mutable blob somewhere in memory, stored as exactly a void* and 