pub type dsubd_ex_ft = Option<unsafe extern "C" fn(diagoffx: doff_t, diagx: diag_t, transx: trans_t, m: dim_t, n: dim_t, x: *const f64, rs_x: inc_t, cs_x: inc_t, y: *mut f64, rs_y: inc_t, cs_y: inc_t, cntx: *const cntx_t, rntm: *mut rntm_t)>;
