TYPEMAP

// https://perldoc.perl.org/perlxs#Returning-SVs,-AVs-and-HVs-through-RETVAL
AV    * T_AVREF_REFCOUNT_FIXED

DLLib * T_DLL

INPUT

T_DLL
  // $Package | $type | $ntype
  if (sv_derived_from($arg, \"Affix::DLLib\")){
    IV tmp = SvIV((SV*)SvRV($arg));
    $var = INT2PTR($type, tmp);
  }
  else
    croak(\"$var is not of type Affix::DLLib\");

OUTPUT

T_DLL
  // $Package | $type | $ntype
  sv_setref_pv($arg, \"Affix::DLLib\", (void*)$var);