How do I capture the return value of av_store?

[Kort, Eric]

Can someone help me understand how to capture the return value of av_store?
Here is a short snippet illustrating what I am trying to do (in the context
of a larger procedure wherein the use of av_store actually makes sense):

void update(SV* svArray)
{
  AV* avArray;
  SV* svNewVal;
  int iNewVal;

  avArray = (AV*)SvRV(svArray);
  iNewVal = 3;
  svNewVal = newSViv(iNewVal);
  av_store(avArray, 2, svNewVal);
}

This works, but want I want to do is check the return value of av_store, an
SV**, to make sure it suceeded, and then increment the reference count of
svNewVal if it did.  I tried something like:

  SV* *svReturnVal

and then

  svReturnVal = av_store(avArray, 2, svNewVal);

but that produces the error "assignment from incompatible pointer type".
What is the proper way to capture the return and ensure it is not NULL?

Thanks,
Eric



> -----Original Message-----
> From: Brian Ingerson [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, January 03, 2001 11:28 AM
> To: Jeff Walker
> Cc: '[EMAIL PROTECTED]'; [EMAIL PROTECTED]
> Subject: Re: make a hash from .xs file
> 
> 
> Jeff Walker wrote:
> > 
> > I am trying to build a hash from an .xs file, then return a 
> ref to that hash
> > to the perl code.  I figured out how pass the hash back 
> using a reference,
> > but when I get the hash back, all the keys exist, but all 
> the values are
> > undefined.  Here is some stripped down code that illustrates this:
> > 
> > SV *
> > Blah()
> >         PREINIT:
> 
> 8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<8<
> 
> > 
> > The perl program (which of course uses the module) get the 
> ref returned by
> > Blah.  I then print the keys of this hash and everything is 
> okay.  Then I
> > try to see the values (foreach $thing ( keys( %$hash ) ) ) 
> but they are all
> > not defined (via ! defined($hash{$thing} ))
> 
> Jeff,
> Here is script using Inline.pm that does what you want. 
> 
> --------------------------8<----------------------------
> use Inline C => DATA;
> 
> $hash_ref = my_new_hash(100);
> foreach $key (keys %$hash_ref) {
>     print "$key => $hash_ref->{$key}\n";
> }
> 
> __END__
> 
> __C__
> 
> SV* my_new_hash(int size) {
>     int i;
>     HV* hash = newHV();
>     for (i = 0; i < size; i++) {
>         hv_store_ent(hash, newSVpvf("string #%d", i), 
>                      newSViv(i), 0);
>     }
>     return newRV_noinc((SV*) hash);
> }
> --------------------------8<----------------------------
> 
> You'll need Inline.pm version 0.30. Just run the script. No compiling
> needed.
> 
> If you have any Inline related questions/problems, please post them to
> [EMAIL PROTECTED]
> 
> Brian
> 
> -- 
> perl -le 'use Inline C=>q{SV*JAxH(char*x){return newSVpvf
> ("Just Another %s Hacker",x);}};print JAxH+Perl'
>