On Fri, 05 Sep 2008, Jeffrey Ratcliffe wrote:
>
> void
> sane_open(class, name)
> SANE_String_Const name
> INIT:
> SANE_Status status;
> SANE_Handle h;
> PPCODE:
> status = sane_open(name, &h);
> XPUSHs(sv_2mortal(newSViv(status)));
> 126-> XPUSHs(sv_2mortal(newSVpv(h, 0)));
>
> SANE_Handle is a void pointer:
You probably want to use
XPUSHs(sv_2mortal(newSViv(PTR2IV(h))));
[...]
> So in the typemap I have:
>
> SANE_Handle T_OPAQUEPTR
I think you want just T_PTR instead. Or you can explicitly
restore the pointer from the IV as e.g.:
h = INT2PTR(SANE_Handle, ST(0));
The T_OPAQUEPTR type would pack your pointer into a string, which is
less efficient than just converting it to an IV and back.
It is somewhat confusing that you are using the typemap for your INPUT
parameter but then try to encode the OUTPUT parameter yourself. You
should consistently do one or the other and not mix things (just for the
sake of maintaining the code later).
Cheers,
-Jan
