</a> Ctypes_static.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t</code></dt><dd><p><code>outbound_group_session_id_length sess</code></p><p>Get the number of bytes returned by olm_outbound_group_session_id()</p></dd></dl><dl><dt class="spec value" id="val-outbound_group_session_id"><a href="#val-outbound_group_session_id" class="anchor"></a><code><span class="keyword">val</span> outbound_group_session_id : <span><a href="../Types/OutboundGroupSession/index.html#type-t">Types.OutboundGroupSession.t</a> C