package World;
use strict;
use warnings;

use overload '""' => sub { "world" };

sub new { bless {}, __PACKAGE__ }

package main;
use strict;
use warnings;

use Inline C => <<'END_C';

void
magical_concat(SV *a, SV *b) {
    sv_catsv(a, b);
}

END_C

my $greeting = "Hello, ";
my $world = World->new;
magical_concat($greeting, $world);
$greeting .= ".\n";

print $greeting;