tlm_buffer_advance_out_idx
extern tlm_buffer_t *tlm_buffer_advance_out_idx(tlm_buffers_t *);
(void) tlm_buffer_advance_out_idx(bufs);
(void) tlm_buffer_advance_out_idx(bufs);
(void) tlm_buffer_advance_out_idx(bufs);
buffer = tlm_buffer_advance_out_idx(buffers);