Function dds_qset_userdata 

pub unsafe extern "C" fn dds_qset_userdata(
    qos: *mut dds_qos_t,
    value: *const c_void,
    sz: usize,
)

@ingroup qos_setters @component qos_obj @brief Set the userdata of a qos structure.

@param[in,out] qos - Pointer to a dds_qos_t structure that will store the userdata @param[in] value - Pointer to the userdata @param[in] sz - Size of userdata stored in value