 their code after the <code><a class="el" href="classipc_1_1session_1_1Session.html" title="A documentation-only concept defining the local side of an IPC conversation (session) with another en...">Session</a></code> data member, so they get deinitialized in the reverse order, in the user's hypothetical recommended <code>App_session</code> class.) Isn't there a problem in B, though? No: the B user shall drop <em>its</em> <code>shared_ptr</code> handles, before invoking B dtor; this will drop their internal 