sub ModName::TIESCALAR {
   my $class = shift;
   my $self;
   return bless(\$self, $class);
}

sub test {
   my $var;
   tie $var, 'ModName';
   return \$var;
}

my $ref = test();
print(tied($$ref) ? 'tied' : 'not tied', "\n");  # tied