Re^4: Passing undef to XSUB

I don't know much about XS, but I wonder if this code is able to distinguish between when it's passed undef and when it's passed 0. That is, can it see the difference between foo( undef, undef ) and foo( 0, 0 )? It seems to me the "uninitialized value" warning is undef getting turned into 0.

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Re^5: Passing undef to XSUB by syphilis (Archbishop) on May 08, 2008 at 07:57 UTC
It seems to me the "uninitialized value" warning is undef getting turned into 0 Yes, I think that's right: `use warnings; use Inline C => Config => BUILD_NOISY => 1; use Inline C => <<'EOC'; void foo(int a) {} void bar(SV * a) {} void baz(SV * a) { int i = (int)SvIV(a); } EOC $u = undef; foo($u); # warning bar($u); # no warning baz($u); # warning` [download] Cheers, Rob	[reply] [d/l]

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Re^5: Passing undef to XSUB
by syphilis (Archbishop) on May 08, 2008 at 07:57 UTC

It seems to me the "uninitialized value" warning is undef getting turned into 0

use warnings;

use Inline C => Config =>
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

void foo(int a) {}

void bar(SV * a) {}

void baz(SV * a) {
     int i = (int)SvIV(a);
}
    
EOC

$u = undef;

foo($u); # warning
bar($u); # no warning
baz($u); # warning
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