xcv_depth CvDEPTH(bstate->bs_sv) long
xcv_padlist *(SV**)&CvPADLIST(bstate->bs_sv) svindex
xcv_outside *(SV**)&CvOUTSIDE(bstate->bs_sv) svindex
+xcv_outside_seq CvOUTSIDE_SEQ(bstate->bs_sv) U32
xcv_flags CvFLAGS(bstate->bs_sv) U16
av_extend bstate->bs_sv SSize_t x
av_push bstate->bs_sv svindex x