use B qw( svref_2object SVf_IOK SVf_NOK SVf_POK );

sub is_zero {
   my $sv = svref_2object(my $ref = \$_[0]);
   my $flags = $sv->FLAGS;
   return $sv->IVX == 0  if $flags & SVf_IOK;
   return $sv->NVX == 0  if $flags & SVf_NOK;
   return $sv->PV eq "0" if $flags & SVf_POK;
   return 0;
}

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In reply to Re: Determining whether a value is zero. by ikegami
in thread Determining whether a value is zero. by JavaFan

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