something.pl

{
  package Card;

  sub new {
    my $type = shift;
    my $obj = [];
    my $args = [@_];
    if( ref(\$args->[0]) eq 'SCALAR' ) {
      if( $args->[0] eq 'key' ) {
        $obj = [$args->[1], $args->[3]];
      } else {
        $obj = [\$args];
      }
    } elsif( ref($args) eq 'ARRAY' ) {
      $obj = [\$args];
    } elsif( ref($args) eq 'HASH' ) {
      $obj = [ $args->{key}, $args->{value} ]
    }
    return bless $obj, $type;
  }

  sub key {
    return $_->[0];
  }

  sub value {
    return $_->[1];
  }
}