use overload;

my %_const_handlers = (
    q => sub {
        if ($_[0] =~ m/^\{.*\}$/) {
            my $str = substr $_[0], 1, length ($_[0]) - 2;
            my @elems = split /\s+/, $str;
            if (defined $elems[1] and $elems[1] eq "..") {
                @elems = $elems[0] .. $elems[2];
            }
            return __PACKAGE__->new (@elems) || $_[1];
        } else {
            return $_[1];
        }
    },
);

sub import { overload::constant %_const_handlers; }

##</code><code>##

kabel@linux:~> perl -w -MSet::Scalar
my $some_ints = '{1 .. 4}';
my $other_ints = '{3 .. 8}';
my $all_ints = $some_ints + $other_ints;

print '[', join( ', ', sort $all_ints->members ), "]\n";
print $Set::Scalar::VERSION, " ", $], $/;

[1, 2, 3, 4, 5, 6, 7, 8]
1.17 5.008
kabel@linux:~>