$var->in(@list)

##</code><code>##

package in {
    sub new { bless \$_[1],$_[0] }
    sub in  { my $t = shift; scalar grep { $$t eq $_ } @_ }
};
my $var = in->new(7);
print "yup\n" if $var->in( 0 .. 8 );
__END__
yup