Or, to make things clearer, WinObj_Type->tp_convert would simply point to the current WinObj_Convert function.
So what do you gain with that extension? It seem all that is done is you can replace _Convert by _Type everywhere, with no additional change to the semantics.
ps_GetDrawableSurface = calldll.newcall(psapilib.ps_GetDrawableSurface, Carbon.Qd.GrafPortType)
Not at the moment, but in calldll version 2 there would be. In stead of passing types as "l" or "h" you would pass type objects to newcall(). Newcall() would probably special-case the various ints but for all other types simply call PyArg_Parse(arg, "O@", typeobj, &voidptr).
I still don't understand. In your example, GrafPortType is a return type, not an argument type. So you *have* an anything, and you *want* the GrafPortType. How exactly do you use PyArg_Parse in that scenario?
Also, why would you use this extension inside newcall()? I'd rather expect it in ps_GetDrawableSurface.__call__ instead (i.e. when you deal with a specific call, not when you create the callable instance).