On Sun, 19 Jun 2005, Will Lowe wrote:
> I've got some XS code that needs to return a hash reference. The hash
> keys are integers, and the values will all be "undef". The relevant
> chunk of code looks something like this:
>
> RETVAL = (HV*) sv_2mortal( (SV*) newHV );
> /* call some code in an external library */
> num_results = find_results( data, &results );
> if( num_results ) {
> SV* value;
> for( x = 0; x < num_results; x++ ) {
> value = &PL_sv_undef;
> fprintf(stderr, "XS: returning %u => undef\n", results[x]);
> }
> hv_store_ent(RETVAL, sv_2mortal(newSViv(results[x])), value, 0);
> }
> }
> OUTPUT:
> RETVAL
>
> ... but Data::Dumper is confused. Here's the output of the fprintf()s
> above, and what Data::Dumper thinks of the returned hashref, when
> results = [3,4,5]:
>
> XS: returning 3 => undef
> XS: returning 4 => undef
> XS: returning 5 => undef
> $VAR1 = {
> '3' => undef,
> '4' => ${\$VAR1->{'3'}},
> '5' => ${\$VAR1->{'3'}}
> };
>
What happens if you try to return 'n' distinct values?
